diff --git a/.github/workflows/abidiff.yaml b/.github/workflows/abidiff.yaml
new file mode 100644
index 0000000..186e4fc
--- /dev/null
+++ b/.github/workflows/abidiff.yaml
@@ -0,0 +1,69 @@
+# SPDX-FileCopyrightText: 2025 Andrea Pappacoda <andrea@pappacoda.it>
+# SPDX-License-Identifier: MIT
+
+name: abidiff
+
+on: [push, pull_request]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
+  cancel-in-progress: true
+
+defaults:
+  run:
+    shell: sh
+
+jobs:
+  abi:
+    runs-on: ubuntu-latest
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
+    container:
+      image: debian:testing
+
+    steps:
+    - name: Install dependencies
+      run: apt -y --update install --no-install-recommends
+        abigail-tools
+        ca-certificates
+        g++
+        git
+        libbrotli-dev
+        libssl-dev
+        meson
+        pkg-config
+        python3
+        zlib1g-dev
+
+    - uses: actions/checkout@v4
+      with:
+        path: current
+
+    - uses: actions/checkout@v4
+      with:
+        path: previous
+        fetch-depth: 0
+
+    - name: Checkout previous
+      working-directory: previous
+      run: |
+        git switch master
+        git describe --tags --abbrev=0 master | xargs git checkout
+
+    - name: Build current
+      working-directory: current
+      run: |
+        meson setup --buildtype=debug -Dcpp-httplib_compile=true build
+        ninja -C build
+
+    - name: Build previous
+      working-directory: previous
+      run: |
+        meson setup --buildtype=debug -Dcpp-httplib_compile=true build
+        ninja -C build
+
+    - name: Run abidiff
+      run: abidiff
+        --headers-dir1 previous/build
+        --headers-dir2 current/build
+        previous/build/libcpp-httplib.so
+        current/build/libcpp-httplib.so
diff --git a/.github/workflows/cifuzz.yaml b/.github/workflows/cifuzz.yaml
index 43e1de3..422b58d 100644
--- a/.github/workflows/cifuzz.yaml
+++ b/.github/workflows/cifuzz.yaml
@@ -1,5 +1,11 @@
 name: CIFuzz
+
 on: [pull_request]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   Fuzzing:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 3d84808..296ad29 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -1,22 +1,85 @@
 name: test
 
-on: [push, pull_request]
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+    inputs:
+      gtest_filter:
+        description: 'Google Test filter'
+      test_linux:
+        description: 'Test on Linux'
+        type: boolean
+        default: true
+      test_macos:
+        description: 'Test on MacOS'
+        type: boolean
+        default: true
+      test_windows:
+        description: 'Test on Windows'
+        type: boolean
+        default: true
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
+  cancel-in-progress: true
+
+env:
+  GTEST_FILTER: ${{ github.event.inputs.gtest_filter || '*' }}
 
 jobs:
+  style-check:
+    runs-on: ubuntu-latest
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
+    continue-on-error: true
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+      - name: run style check
+        run: |
+          clang-format --version
+          cd test && make style_check
+
   ubuntu:
     runs-on: ubuntu-latest
+    if: >
+      (github.event_name == 'push') ||
+      (github.event_name == 'pull_request'  &&
+       github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name) ||
+      (github.event_name == 'workflow_dispatch' && github.event.inputs.test_linux == 'true')
+    strategy:
+      matrix:
+        config:
+        - arch_flags: -m32
+          arch_suffix: :i386
+          name: (32-bit)
+        - arch_flags:
+          arch_suffix:
+          name: (64-bit)
+    name: ubuntu ${{ matrix.config.name }}
     steps:
       - name: checkout
         uses: actions/checkout@v4
       - name: install libraries
-        run: sudo apt-get update && sudo apt-get install -y libbrotli-dev libcurl4-openssl-dev
+        run: |
+          sudo dpkg --add-architecture i386
+          sudo apt-get update
+          sudo apt-get install -y libc6-dev${{ matrix.config.arch_suffix }} libstdc++-13-dev${{ matrix.config.arch_suffix }} \
+            libssl-dev${{ matrix.config.arch_suffix }} libcurl4-openssl-dev${{ matrix.config.arch_suffix }} \
+            zlib1g-dev${{ matrix.config.arch_suffix }} libbrotli-dev${{ matrix.config.arch_suffix }} \
+            libzstd-dev${{ matrix.config.arch_suffix }}
       - name: build and run tests
-        run: cd test && make
+        run: cd test && make EXTRA_CXXFLAGS="${{ matrix.config.arch_flags }}"
       - name: run fuzz test target
-        run: cd test && make fuzz_test
+        run: cd test && make EXTRA_CXXFLAGS="${{ matrix.config.arch_flags }}" fuzz_test
 
   macos:
     runs-on: macos-latest
+    if: >
+      (github.event_name == 'push') ||
+      (github.event_name == 'pull_request'  &&
+       github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name) ||
+      (github.event_name == 'workflow_dispatch' && github.event.inputs.test_macos == 'true')
     steps:
       - name: checkout
         uses: actions/checkout@v4
@@ -27,6 +90,27 @@ jobs:
 
   windows:
     runs-on: windows-latest
+    if: >
+      (github.event_name == 'push') ||
+      (github.event_name == 'pull_request'  &&
+       github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name) ||
+      (github.event_name == 'workflow_dispatch' && github.event.inputs.test_windows == 'true')
+    strategy:
+      matrix:
+        config:
+        - with_ssl: false
+          compiled: false
+          run_tests: true
+          name: without SSL
+        - with_ssl: true
+          compiled: false
+          run_tests: true
+          name: with SSL
+        - with_ssl: false
+          compiled: true
+          run_tests: false
+          name: compiled
+    name: windows ${{ matrix.config.name }}
     steps:
     - name: Prepare Git for Checkout on Windows
       run: |
@@ -42,24 +126,28 @@ jobs:
           core.exportVariable('ACTIONS_RUNTIME_TOKEN', process.env.ACTIONS_RUNTIME_TOKEN || '');
     - name: Setup msbuild on windows
       uses: microsoft/setup-msbuild@v2
-    - name: Install libraries
-      run: |
-        vcpkg install gtest curl zlib brotli
-        choco install openssl
-
-    - name: Configure CMake with SSL
-      run: cmake -B build -S . -DCMAKE_BUILD_TYPE=Release -DCMAKE_TOOLCHAIN_FILE=${{ env.VCPKG_ROOT }}/scripts/buildsystems/vcpkg.cmake -DHTTPLIB_TEST=ON -DHTTPLIB_REQUIRE_OPENSSL=ON -DHTTPLIB_REQUIRE_ZLIB=ON -DHTTPLIB_REQUIRE_BROTLI=ON
-    - name: Build with with SSL
-      run: cmake --build build --config Release
-    - name: Run tests with SSL
+    - name: Install vcpkg dependencies
+      run: vcpkg install gtest curl zlib brotli zstd
+    - name: Install OpenSSL
+      if: ${{ matrix.config.with_ssl }}
+      run: choco install openssl
+    - name: Configure CMake ${{ matrix.config.name }}
+      run: >
+        cmake -B build -S .
+        -DCMAKE_BUILD_TYPE=Release
+        -DCMAKE_TOOLCHAIN_FILE=${{ env.VCPKG_ROOT }}/scripts/buildsystems/vcpkg.cmake
+        -DHTTPLIB_TEST=ON
+        -DHTTPLIB_COMPILE=${{ matrix.config.compiled && 'ON' || 'OFF' }}
+        -DHTTPLIB_REQUIRE_ZLIB=ON
+        -DHTTPLIB_REQUIRE_BROTLI=ON
+        -DHTTPLIB_REQUIRE_ZSTD=ON
+        -DHTTPLIB_REQUIRE_OPENSSL=${{ matrix.config.with_ssl && 'ON' || 'OFF' }}
+    - name: Build ${{ matrix.config.name }}
+      run: cmake --build build --config Release -- /v:m /clp:ShowCommandLine
+    - name: Run tests ${{ matrix.config.name }}
+      if: ${{ matrix.config.run_tests }}
       run: ctest --output-on-failure --test-dir build -C Release
 
-    - name: Configure CMake without SSL
-      run: cmake -B build-no-ssl -S . -DCMAKE_BUILD_TYPE=Release -DCMAKE_TOOLCHAIN_FILE=${{ env.VCPKG_ROOT }}/scripts/buildsystems/vcpkg.cmake -DHTTPLIB_TEST=ON -DHTTPLIB_REQUIRE_OPENSSL=ON -DHTTPLIB_REQUIRE_ZLIB=ON -DHTTPLIB_REQUIRE_BROTLI=ON
-    - name: Build without SSL
-      run: cmake --build build-no-ssl --config Release
-    - name: Run tests without SSL
-      run: ctest --output-on-failure --test-dir build-no-ssl -C Release
     env:
       VCPKG_ROOT: "C:/vcpkg"
       VCPKG_BINARY_SOURCES: "clear;x-gha,readwrite"
diff --git a/.gitignore b/.gitignore
index 95c5887..1ae8acf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,6 +23,7 @@ test/test.xcodeproj/*/xcuser*
 test/*.o
 test/*.pem
 test/*.srl
+test/_build_*
 work/
 benchmark/server*
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 61419c6..b0e0fda 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,9 +4,11 @@
 	* HTTPLIB_USE_OPENSSL_IF_AVAILABLE (default on)
 	* HTTPLIB_USE_ZLIB_IF_AVAILABLE (default on)
 	* HTTPLIB_USE_BROTLI_IF_AVAILABLE (default on)
+	* HTTPLIB_USE_ZSTD_IF_AVAILABLE (default on)
 	* HTTPLIB_REQUIRE_OPENSSL (default off)
 	* HTTPLIB_REQUIRE_ZLIB (default off)
 	* HTTPLIB_REQUIRE_BROTLI (default off)
+	* HTTPLIB_REQUIRE_ZSTD (default off)
 	* HTTPLIB_USE_CERTS_FROM_MACOSX_KEYCHAIN (default on)
 	* HTTPLIB_COMPILE (default off)
 	* HTTPLIB_INSTALL (default on)
@@ -16,7 +18,7 @@
 
 	-------------------------------------------------------------------------------
 
-	After installation with Cmake, a find_package(httplib COMPONENTS OpenSSL ZLIB Brotli) is available.
+	After installation with Cmake, a find_package(httplib COMPONENTS OpenSSL ZLIB Brotli zstd) is available.
 	This creates a httplib::httplib target (if found and if listed components are supported).
 	It can be linked like so:
 
@@ -45,6 +47,7 @@
 	* HTTPLIB_IS_USING_OPENSSL - a bool for if OpenSSL support is enabled.
 	* HTTPLIB_IS_USING_ZLIB - a bool for if ZLIB support is enabled.
 	* HTTPLIB_IS_USING_BROTLI - a bool for if Brotli support is enabled.
+	* HTTPLIB_IS_USING_ZSTD - a bool for if ZSTD support is enabled.
 	* HTTPLIB_IS_USING_CERTS_FROM_MACOSX_KEYCHAIN - a bool for if support of loading system certs from the Apple Keychain is enabled.
 	* HTTPLIB_IS_COMPILED - a bool for if the library is compiled, or otherwise header-only.
 	* HTTPLIB_INCLUDE_DIR - the root path to httplib's header (e.g. /usr/include).
@@ -101,6 +104,8 @@ option(HTTPLIB_TEST "Enables testing and builds tests" OFF)
 option(HTTPLIB_REQUIRE_BROTLI "Requires Brotli to be found & linked, or fails build." OFF)
 option(HTTPLIB_USE_BROTLI_IF_AVAILABLE "Uses Brotli (if available) to enable Brotli decompression support." ON)
 option(HTTPLIB_USE_CERTS_FROM_MACOSX_KEYCHAIN "Enable feature to load system certs from the Apple Keychain." ON)
+option(HTTPLIB_REQUIRE_ZSTD "Requires ZSTD to be found & linked, or fails build." OFF)
+option(HTTPLIB_USE_ZSTD_IF_AVAILABLE "Uses ZSTD (if available) to enable zstd support." ON)
 # Defaults to static library
 option(BUILD_SHARED_LIBS "Build the library as a shared library instead of static. Has no effect if using header-only." OFF)
 if (BUILD_SHARED_LIBS AND WIN32 AND HTTPLIB_COMPILE)
@@ -153,6 +158,30 @@ elseif(HTTPLIB_USE_BROTLI_IF_AVAILABLE)
 	set(HTTPLIB_IS_USING_BROTLI ${Brotli_FOUND})
 endif()
 
+if(HTTPLIB_REQUIRE_ZSTD)
+	find_package(zstd)
+	if(NOT zstd_FOUND)
+		find_package(PkgConfig REQUIRED)
+		pkg_check_modules(zstd REQUIRED IMPORTED_TARGET libzstd)
+		add_library(zstd::libzstd ALIAS PkgConfig::zstd)
+	endif()
+	set(HTTPLIB_IS_USING_ZSTD TRUE)
+elseif(HTTPLIB_USE_ZSTD_IF_AVAILABLE)
+	find_package(zstd QUIET)
+	if(NOT zstd_FOUND)
+		find_package(PkgConfig QUIET)
+		if(PKG_CONFIG_FOUND)
+			pkg_check_modules(zstd QUIET IMPORTED_TARGET libzstd)
+
+			if(TARGET PkgConfig::zstd)
+				add_library(zstd::libzstd ALIAS PkgConfig::zstd)
+			endif()
+		endif()
+	endif()
+	# Both find_package and PkgConf set a XXX_FOUND var
+	set(HTTPLIB_IS_USING_ZSTD ${zstd_FOUND})
+endif()
+
 # Used for default, common dirs that the end-user can change (if needed)
 # like CMAKE_INSTALL_INCLUDEDIR or CMAKE_INSTALL_DATADIR
 include(GNUInstallDirs)
@@ -227,6 +256,7 @@ target_link_libraries(${PROJECT_NAME} ${_INTERFACE_OR_PUBLIC}
 		$<$<BOOL:${HTTPLIB_IS_USING_BROTLI}>:Brotli::encoder>
 		$<$<BOOL:${HTTPLIB_IS_USING_BROTLI}>:Brotli::decoder>
 		$<$<BOOL:${HTTPLIB_IS_USING_ZLIB}>:ZLIB::ZLIB>
+		$<$<BOOL:${HTTPLIB_IS_USING_ZSTD}>:zstd::libzstd>
 		$<$<BOOL:${HTTPLIB_IS_USING_OPENSSL}>:OpenSSL::SSL>
 		$<$<BOOL:${HTTPLIB_IS_USING_OPENSSL}>:OpenSSL::Crypto>
 )
@@ -236,6 +266,7 @@ target_compile_definitions(${PROJECT_NAME} ${_INTERFACE_OR_PUBLIC}
 	$<$<BOOL:${HTTPLIB_NO_EXCEPTIONS}>:CPPHTTPLIB_NO_EXCEPTIONS>
 	$<$<BOOL:${HTTPLIB_IS_USING_BROTLI}>:CPPHTTPLIB_BROTLI_SUPPORT>
 	$<$<BOOL:${HTTPLIB_IS_USING_ZLIB}>:CPPHTTPLIB_ZLIB_SUPPORT>
+	$<$<BOOL:${HTTPLIB_IS_USING_ZSTD}>:CPPHTTPLIB_ZSTD_SUPPORT>
 	$<$<BOOL:${HTTPLIB_IS_USING_OPENSSL}>:CPPHTTPLIB_OPENSSL_SUPPORT>
 	$<$<AND:$<PLATFORM_ID:Darwin>,$<BOOL:${HTTPLIB_IS_USING_OPENSSL}>,$<BOOL:${HTTPLIB_IS_USING_CERTS_FROM_MACOSX_KEYCHAIN}>>:CPPHTTPLIB_USE_CERTS_FROM_MACOSX_KEYCHAIN>
 )
diff --git a/Dockerfile b/Dockerfile
index 654845b..4abae17 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,7 +2,7 @@ FROM yhirose4dockerhub/ubuntu-builder AS builder
 WORKDIR /build
 COPY httplib.h .
 COPY docker/main.cc .
-RUN g++ -std=c++23 -static -o server -O2 -I. -DCPPHTTPLIB_USE_POLL main.cc && strip server
+RUN g++ -std=c++23 -static -o server -O2 -I. main.cc && strip server
 
 FROM scratch
 COPY --from=builder /build/server /server
diff --git a/README.md b/README.md
index 6165702..aed19ca 100644
--- a/README.md
+++ b/README.md
@@ -39,10 +39,10 @@ svr.listen("0.0.0.0", 8080);
 #include "path/to/httplib.h"
 
 // HTTP
-httplib::Client cli("http://cpp-httplib-server.yhirose.repl.co");
+httplib::Client cli("http://yhirose.github.io");
 
 // HTTPS
-httplib::Client cli("https://cpp-httplib-server.yhirose.repl.co");
+httplib::Client cli("https://yhirose.github.io");
 
 auto res = cli.Get("/hi");
 res->status;
@@ -125,6 +125,21 @@ int main(void)
     res.set_content(req.body, "text/plain");
   });
 
+  // If the handler takes time to finish, you can also poll the connection state
+  svr.Get("/task", [&](const Request& req, Response& res) {
+    const char * result = nullptr;
+    process.run(); // for example, starting an external process
+    while (result == nullptr) {
+      sleep(1);
+      if (req.is_connection_closed()) {
+        process.kill(); // kill the process
+        return;
+      }
+      result = process.stdout(); // != nullptr if the process finishes
+    }
+    res.set_content(result, "text/plain");
+  });
+
   svr.Get("/stop", [&](const Request& req, Response& res) {
     svr.stop();
   });
@@ -391,11 +406,11 @@ svr.Get("/chunked", [&](const Request& req, Response& res) {
 
 ```cpp
 svr.Get("/content", [&](const Request &req, Response &res) {
-  res.set_file_content("./path/to/conent.html");
+  res.set_file_content("./path/to/content.html");
 });
 
 svr.Get("/content", [&](const Request &req, Response &res) {
-  res.set_file_content("./path/to/conent", "text/html");
+  res.set_file_content("./path/to/content", "text/html");
 });
 ```
 
@@ -447,7 +462,7 @@ Please see [Server example](https://github.com/yhirose/cpp-httplib/blob/master/e
 
 ### Default thread pool support
 
-`ThreadPool` is used as a **default** task queue, and the default thread count is 8, or `std::thread::hardware_concurrency()`. You can change it with `CPPHTTPLIB_THREAD_POOL_COUNT`.
+`ThreadPool` is used as the **default** task queue, with a default thread count of 8 or `std::thread::hardware_concurrency() - 1`, whichever is greater. You can change it with `CPPHTTPLIB_THREAD_POOL_COUNT`.
 
 If you want to set the thread count at runtime, there is no convenient way... But here is how.
 
@@ -639,6 +654,9 @@ res = cli.Options("/resource/foo");
 cli.set_connection_timeout(0, 300000); // 300 milliseconds
 cli.set_read_timeout(5, 0); // 5 seconds
 cli.set_write_timeout(5, 0); // 5 seconds
+
+// This method works the same as curl's `--max-timeout` option
+svr.set_max_timeout(5000); // 5 seconds
 ```
 
 ### Receive content with a content receiver
@@ -825,7 +843,7 @@ Please see https://github.com/google/brotli for more detail.
 
 ### Default `Accept-Encoding` value
 
-The default `Acdcept-Encoding` value contains all possible compression types. So, the following two examples are same.
+The default `Accept-Encoding` value contains all possible compression types. So, the following two examples are same.
 
 ```c++
 res = cli.Get("/resource/foo");
@@ -854,11 +872,6 @@ res->body; // Compressed data
 
 ```
 
-Use `poll` instead of `select`
-------------------------------
-
-`select` system call is used as default since it's more widely supported. If you want to let cpp-httplib use `poll` instead, you can do so with `CPPHTTPLIB_USE_POLL`.
-
 Unix Domain Socket Support
 --------------------------
 
@@ -866,7 +879,7 @@ Unix Domain Socket support is available on Linux and macOS.
 
 ```c++
 // Server
-httplib::Server svr("./my-socket.sock");
+httplib::Server svr;
 svr.set_address_family(AF_UNIX).listen("./my-socket.sock", 80);
 
 // Client
@@ -916,9 +929,6 @@ From Docker Hub
 
 ```bash
 > docker run --rm -it -p 8080:80 -v ./docker/html:/html yhirose4dockerhub/cpp-httplib-server
-...
-
-> docker run --init --rm -it -p 8080:80 -v ./docker/html:/html cpp-httplib-server
 Serving HTTP on 0.0.0.0 port 80 ...
 192.168.65.1 - - [31/Aug/2024:21:33:56 +0000] "GET / HTTP/1.1" 200 599 "-" "curl/8.7.1"
 192.168.65.1 - - [31/Aug/2024:21:34:26 +0000] "GET / HTTP/1.1" 200 599 "-" "Mozilla/5.0 ..."
@@ -951,12 +961,12 @@ Include `httplib.h` before `Windows.h` or include `Windows.h` by defining `WIN32
 > cpp-httplib officially supports only the latest Visual Studio. It might work with former versions of Visual Studio, but I can no longer verify it. Pull requests are always welcome for the older versions of Visual Studio unless they break the C++11 conformance.
 
 > [!NOTE]
-> Windows 8 or lower, Visual Studio 2013 or lower, and Cygwin and MSYS2 including MinGW are neither supported nor tested.
+> Windows 8 or lower, Visual Studio 2015 or lower, and Cygwin and MSYS2 including MinGW are neither supported nor tested.
 
 License
 -------
 
-MIT license (© 2024 Yuji Hirose)
+MIT license (© 2025 Yuji Hirose)
 
 Special Thanks To
 -----------------
diff --git a/benchmark/Makefile b/benchmark/Makefile
index 5107664..fa4f76c 100644
--- a/benchmark/Makefile
+++ b/benchmark/Makefile
@@ -18,22 +18,37 @@ run : server
 	@./server
 
 server : cpp-httplib/main.cpp ../httplib.h
-	g++ -o $@ $(CXXFLAGS) $(CPPHTTPLIB_FLAGS) cpp-httplib/main.cpp
+	@g++ -o $@ $(CXXFLAGS) $(CPPHTTPLIB_FLAGS) cpp-httplib/main.cpp
 
-# cpp-httplib
-bench-base: server-base
-	@echo "---------------------\n cpp-httplib v0.18.0\n---------------------\n"
-	@./server-base & export PID=$$!; $(BENCH); kill $${PID}
+# cpp-httplib v0.19.0
+bench-v19: server-v19
+	@echo "---------------------\n cpp-httplib v0.19.0\n---------------------\n"
+	@./server-v19 & export PID=$$!; $(BENCH); kill $${PID}
 	@echo ""
 
-monitor-base: server-base
-	@./server-base & export PID=$$!; $(MONITOR); kill $${PID}
+monitor-v19: server-v19
+	@./server-v19 & export PID=$$!; $(MONITOR); kill $${PID}
 
-run-base : server-base
-	@./server-base
+run-v19 : server-v19
+	@./server-v19
 
-server-base : cpp-httplib-base/main.cpp cpp-httplib-base/httplib.h
-	g++ -o $@ $(CXXFLAGS) $(CPPHTTPLIB_FLAGS) cpp-httplib-base/main.cpp
+server-v19 : cpp-httplib-v19/main.cpp cpp-httplib-v19/httplib.h
+	@g++ -o $@ $(CXXFLAGS) $(CPPHTTPLIB_FLAGS) cpp-httplib-v19/main.cpp
+
+# cpp-httplib v0.18.0
+bench-v18: server-v18
+	@echo "---------------------\n cpp-httplib v0.18.0\n---------------------\n"
+	@./server-v18 & export PID=$$!; $(BENCH); kill $${PID}
+	@echo ""
+
+monitor-v18: server-v18
+	@./server-v18 & export PID=$$!; $(MONITOR); kill $${PID}
+
+run-v18 : server-v18
+	@./server-v18
+
+server-v18 : cpp-httplib-v18/main.cpp cpp-httplib-v18/httplib.h
+	@g++ -o $@ $(CXXFLAGS) $(CPPHTTPLIB_FLAGS) cpp-httplib-v18/main.cpp
 
 # crow
 bench-crow: server-crow
@@ -48,12 +63,12 @@ run-crow : server-crow
 	@./server-crow
 
 server-crow : crow/main.cpp
-	g++ -o $@ $(CXXFLAGS) crow/main.cpp
+	@g++ -o $@ $(CXXFLAGS) crow/main.cpp
 
 # misc
-build: server server-base server-crow
+build: server server-v18 server-v19 server-crow
 
-bench-all: bench-crow bench bench-base
+bench-all: bench-crow bench bench-v19 bench-v18
 
 issue:
 	bombardier -c 10 -d 30s localhost:8080
diff --git a/benchmark/cpp-httplib-base/httplib.h b/benchmark/cpp-httplib-v18/httplib.h
similarity index 99%
rename from benchmark/cpp-httplib-base/httplib.h
rename to benchmark/cpp-httplib-v18/httplib.h
index 121ce34..3e28fcf 100644
--- a/benchmark/cpp-httplib-base/httplib.h
+++ b/benchmark/cpp-httplib-v18/httplib.h
@@ -1,7 +1,7 @@
 //
 //  httplib.h
 //
-//  Copyright (c) 2024 Yuji Hirose. All rights reserved.
+//  Copyright (c) 2025 Yuji Hirose. All rights reserved.
 //  MIT License
 //
 
diff --git a/benchmark/cpp-httplib-base/main.cpp b/benchmark/cpp-httplib-v18/main.cpp
similarity index 100%
rename from benchmark/cpp-httplib-base/main.cpp
rename to benchmark/cpp-httplib-v18/main.cpp
diff --git a/benchmark/cpp-httplib-v19/httplib.h b/benchmark/cpp-httplib-v19/httplib.h
new file mode 100644
index 0000000..e4799da
--- /dev/null
+++ b/benchmark/cpp-httplib-v19/httplib.h
@@ -0,0 +1,10475 @@
+//
+//  httplib.h
+//
+//  Copyright (c) 2025 Yuji Hirose. All rights reserved.
+//  MIT License
+//
+
+#ifndef CPPHTTPLIB_HTTPLIB_H
+#define CPPHTTPLIB_HTTPLIB_H
+
+#define CPPHTTPLIB_VERSION "0.19.0"
+
+/*
+ * Configuration
+ */
+
+#ifndef CPPHTTPLIB_KEEPALIVE_TIMEOUT_SECOND
+#define CPPHTTPLIB_KEEPALIVE_TIMEOUT_SECOND 5
+#endif
+
+#ifndef CPPHTTPLIB_KEEPALIVE_TIMEOUT_CHECK_INTERVAL_USECOND
+#define CPPHTTPLIB_KEEPALIVE_TIMEOUT_CHECK_INTERVAL_USECOND 10000
+#endif
+
+#ifndef CPPHTTPLIB_KEEPALIVE_MAX_COUNT
+#define CPPHTTPLIB_KEEPALIVE_MAX_COUNT 100
+#endif
+
+#ifndef CPPHTTPLIB_CONNECTION_TIMEOUT_SECOND
+#define CPPHTTPLIB_CONNECTION_TIMEOUT_SECOND 300
+#endif
+
+#ifndef CPPHTTPLIB_CONNECTION_TIMEOUT_USECOND
+#define CPPHTTPLIB_CONNECTION_TIMEOUT_USECOND 0
+#endif
+
+#ifndef CPPHTTPLIB_SERVER_READ_TIMEOUT_SECOND
+#define CPPHTTPLIB_SERVER_READ_TIMEOUT_SECOND 5
+#endif
+
+#ifndef CPPHTTPLIB_SERVER_READ_TIMEOUT_USECOND
+#define CPPHTTPLIB_SERVER_READ_TIMEOUT_USECOND 0
+#endif
+
+#ifndef CPPHTTPLIB_SERVER_WRITE_TIMEOUT_SECOND
+#define CPPHTTPLIB_SERVER_WRITE_TIMEOUT_SECOND 5
+#endif
+
+#ifndef CPPHTTPLIB_SERVER_WRITE_TIMEOUT_USECOND
+#define CPPHTTPLIB_SERVER_WRITE_TIMEOUT_USECOND 0
+#endif
+
+#ifndef CPPHTTPLIB_CLIENT_READ_TIMEOUT_SECOND
+#define CPPHTTPLIB_CLIENT_READ_TIMEOUT_SECOND 300
+#endif
+
+#ifndef CPPHTTPLIB_CLIENT_READ_TIMEOUT_USECOND
+#define CPPHTTPLIB_CLIENT_READ_TIMEOUT_USECOND 0
+#endif
+
+#ifndef CPPHTTPLIB_CLIENT_WRITE_TIMEOUT_SECOND
+#define CPPHTTPLIB_CLIENT_WRITE_TIMEOUT_SECOND 5
+#endif
+
+#ifndef CPPHTTPLIB_CLIENT_WRITE_TIMEOUT_USECOND
+#define CPPHTTPLIB_CLIENT_WRITE_TIMEOUT_USECOND 0
+#endif
+
+#ifndef CPPHTTPLIB_CLIENT_MAX_TIMEOUT_MSECOND
+#define CPPHTTPLIB_CLIENT_MAX_TIMEOUT_MSECOND 0
+#endif
+
+#ifndef CPPHTTPLIB_IDLE_INTERVAL_SECOND
+#define CPPHTTPLIB_IDLE_INTERVAL_SECOND 0
+#endif
+
+#ifndef CPPHTTPLIB_IDLE_INTERVAL_USECOND
+#ifdef _WIN32
+#define CPPHTTPLIB_IDLE_INTERVAL_USECOND 10000
+#else
+#define CPPHTTPLIB_IDLE_INTERVAL_USECOND 0
+#endif
+#endif
+
+#ifndef CPPHTTPLIB_REQUEST_URI_MAX_LENGTH
+#define CPPHTTPLIB_REQUEST_URI_MAX_LENGTH 8192
+#endif
+
+#ifndef CPPHTTPLIB_HEADER_MAX_LENGTH
+#define CPPHTTPLIB_HEADER_MAX_LENGTH 8192
+#endif
+
+#ifndef CPPHTTPLIB_REDIRECT_MAX_COUNT
+#define CPPHTTPLIB_REDIRECT_MAX_COUNT 20
+#endif
+
+#ifndef CPPHTTPLIB_MULTIPART_FORM_DATA_FILE_MAX_COUNT
+#define CPPHTTPLIB_MULTIPART_FORM_DATA_FILE_MAX_COUNT 1024
+#endif
+
+#ifndef CPPHTTPLIB_PAYLOAD_MAX_LENGTH
+#define CPPHTTPLIB_PAYLOAD_MAX_LENGTH ((std::numeric_limits<size_t>::max)())
+#endif
+
+#ifndef CPPHTTPLIB_FORM_URL_ENCODED_PAYLOAD_MAX_LENGTH
+#define CPPHTTPLIB_FORM_URL_ENCODED_PAYLOAD_MAX_LENGTH 8192
+#endif
+
+#ifndef CPPHTTPLIB_RANGE_MAX_COUNT
+#define CPPHTTPLIB_RANGE_MAX_COUNT 1024
+#endif
+
+#ifndef CPPHTTPLIB_TCP_NODELAY
+#define CPPHTTPLIB_TCP_NODELAY false
+#endif
+
+#ifndef CPPHTTPLIB_IPV6_V6ONLY
+#define CPPHTTPLIB_IPV6_V6ONLY false
+#endif
+
+#ifndef CPPHTTPLIB_RECV_BUFSIZ
+#define CPPHTTPLIB_RECV_BUFSIZ size_t(16384u)
+#endif
+
+#ifndef CPPHTTPLIB_COMPRESSION_BUFSIZ
+#define CPPHTTPLIB_COMPRESSION_BUFSIZ size_t(16384u)
+#endif
+
+#ifndef CPPHTTPLIB_THREAD_POOL_COUNT
+#define CPPHTTPLIB_THREAD_POOL_COUNT                                           \
+  ((std::max)(8u, std::thread::hardware_concurrency() > 0                      \
+                      ? std::thread::hardware_concurrency() - 1                \
+                      : 0))
+#endif
+
+#ifndef CPPHTTPLIB_RECV_FLAGS
+#define CPPHTTPLIB_RECV_FLAGS 0
+#endif
+
+#ifndef CPPHTTPLIB_SEND_FLAGS
+#define CPPHTTPLIB_SEND_FLAGS 0
+#endif
+
+#ifndef CPPHTTPLIB_LISTEN_BACKLOG
+#define CPPHTTPLIB_LISTEN_BACKLOG 5
+#endif
+
+/*
+ * Headers
+ */
+
+#ifdef _WIN32
+#ifndef _CRT_SECURE_NO_WARNINGS
+#define _CRT_SECURE_NO_WARNINGS
+#endif //_CRT_SECURE_NO_WARNINGS
+
+#ifndef _CRT_NONSTDC_NO_DEPRECATE
+#define _CRT_NONSTDC_NO_DEPRECATE
+#endif //_CRT_NONSTDC_NO_DEPRECATE
+
+#if defined(_MSC_VER)
+#if _MSC_VER < 1900
+#error Sorry, Visual Studio versions prior to 2015 are not supported
+#endif
+
+#pragma comment(lib, "ws2_32.lib")
+
+#ifdef _WIN64
+using ssize_t = __int64;
+#else
+using ssize_t = long;
+#endif
+#endif // _MSC_VER
+
+#ifndef S_ISREG
+#define S_ISREG(m) (((m) & S_IFREG) == S_IFREG)
+#endif // S_ISREG
+
+#ifndef S_ISDIR
+#define S_ISDIR(m) (((m) & S_IFDIR) == S_IFDIR)
+#endif // S_ISDIR
+
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif // NOMINMAX
+
+#include <io.h>
+#include <winsock2.h>
+#include <ws2tcpip.h>
+
+#ifndef WSA_FLAG_NO_HANDLE_INHERIT
+#define WSA_FLAG_NO_HANDLE_INHERIT 0x80
+#endif
+
+using socket_t = SOCKET;
+#ifdef CPPHTTPLIB_USE_POLL
+#define poll(fds, nfds, timeout) WSAPoll(fds, nfds, timeout)
+#endif
+
+#else // not _WIN32
+
+#include <arpa/inet.h>
+#if !defined(_AIX) && !defined(__MVS__)
+#include <ifaddrs.h>
+#endif
+#ifdef __MVS__
+#include <strings.h>
+#ifndef NI_MAXHOST
+#define NI_MAXHOST 1025
+#endif
+#endif
+#include <net/if.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#ifdef __linux__
+#include <resolv.h>
+#endif
+#include <netinet/tcp.h>
+#ifdef CPPHTTPLIB_USE_POLL
+#include <poll.h>
+#endif
+#include <csignal>
+#include <pthread.h>
+#include <sys/mman.h>
+#ifndef __VMS
+#include <sys/select.h>
+#endif
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+using socket_t = int;
+#ifndef INVALID_SOCKET
+#define INVALID_SOCKET (-1)
+#endif
+#endif //_WIN32
+
+#include <algorithm>
+#include <array>
+#include <atomic>
+#include <cassert>
+#include <cctype>
+#include <climits>
+#include <condition_variable>
+#include <cstring>
+#include <errno.h>
+#include <exception>
+#include <fcntl.h>
+#include <fstream>
+#include <functional>
+#include <iomanip>
+#include <iostream>
+#include <list>
+#include <map>
+#include <memory>
+#include <mutex>
+#include <random>
+#include <regex>
+#include <set>
+#include <sstream>
+#include <string>
+#include <sys/stat.h>
+#include <thread>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+#ifdef _WIN32
+#include <wincrypt.h>
+
+// these are defined in wincrypt.h and it breaks compilation if BoringSSL is
+// used
+#undef X509_NAME
+#undef X509_CERT_PAIR
+#undef X509_EXTENSIONS
+#undef PKCS7_SIGNER_INFO
+
+#ifdef _MSC_VER
+#pragma comment(lib, "crypt32.lib")
+#endif
+#elif defined(CPPHTTPLIB_USE_CERTS_FROM_MACOSX_KEYCHAIN) && defined(__APPLE__)
+#include <TargetConditionals.h>
+#if TARGET_OS_OSX
+#include <CoreFoundation/CoreFoundation.h>
+#include <Security/Security.h>
+#endif // TARGET_OS_OSX
+#endif // _WIN32
+
+#include <openssl/err.h>
+#include <openssl/evp.h>
+#include <openssl/ssl.h>
+#include <openssl/x509v3.h>
+
+#if defined(_WIN32) && defined(OPENSSL_USE_APPLINK)
+#include <openssl/applink.c>
+#endif
+
+#include <iostream>
+#include <sstream>
+
+#if defined(OPENSSL_IS_BORINGSSL) || defined(LIBRESSL_VERSION_NUMBER)
+#if OPENSSL_VERSION_NUMBER < 0x1010107f
+#error Please use OpenSSL or a current version of BoringSSL
+#endif
+#define SSL_get1_peer_certificate SSL_get_peer_certificate
+#elif OPENSSL_VERSION_NUMBER < 0x30000000L
+#error Sorry, OpenSSL versions prior to 3.0.0 are not supported
+#endif
+
+#endif
+
+#ifdef CPPHTTPLIB_ZLIB_SUPPORT
+#include <zlib.h>
+#endif
+
+#ifdef CPPHTTPLIB_BROTLI_SUPPORT
+#include <brotli/decode.h>
+#include <brotli/encode.h>
+#endif
+
+/*
+ * Declaration
+ */
+namespace httplib {
+
+namespace detail {
+
+/*
+ * Backport std::make_unique from C++14.
+ *
+ * NOTE: This code came up with the following stackoverflow post:
+ * https://stackoverflow.com/questions/10149840/c-arrays-and-make-unique
+ *
+ */
+
+template <class T, class... Args>
+typename std::enable_if<!std::is_array<T>::value, std::unique_ptr<T>>::type
+make_unique(Args &&...args) {
+  return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
+}
+
+template <class T>
+typename std::enable_if<std::is_array<T>::value, std::unique_ptr<T>>::type
+make_unique(std::size_t n) {
+  typedef typename std::remove_extent<T>::type RT;
+  return std::unique_ptr<T>(new RT[n]);
+}
+
+namespace case_ignore {
+
+inline unsigned char to_lower(int c) {
+  const static unsigned char table[256] = {
+      0,   1,   2,   3,   4,   5,   6,   7,   8,   9,   10,  11,  12,  13,  14,
+      15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,  29,
+      30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,
+      45,  46,  47,  48,  49,  50,  51,  52,  53,  54,  55,  56,  57,  58,  59,
+      60,  61,  62,  63,  64,  97,  98,  99,  100, 101, 102, 103, 104, 105, 106,
+      107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121,
+      122, 91,  92,  93,  94,  95,  96,  97,  98,  99,  100, 101, 102, 103, 104,
+      105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119,
+      120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134,
+      135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149,
+      150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164,
+      165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179,
+      180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 224, 225, 226,
+      227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241,
+      242, 243, 244, 245, 246, 215, 248, 249, 250, 251, 252, 253, 254, 223, 224,
+      225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
+      240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254,
+      255,
+  };
+  return table[(unsigned char)(char)c];
+}
+
+inline bool equal(const std::string &a, const std::string &b) {
+  return a.size() == b.size() &&
+         std::equal(a.begin(), a.end(), b.begin(), [](char ca, char cb) {
+           return to_lower(ca) == to_lower(cb);
+         });
+}
+
+struct equal_to {
+  bool operator()(const std::string &a, const std::string &b) const {
+    return equal(a, b);
+  }
+};
+
+struct hash {
+  size_t operator()(const std::string &key) const {
+    return hash_core(key.data(), key.size(), 0);
+  }
+
+  size_t hash_core(const char *s, size_t l, size_t h) const {
+    return (l == 0) ? h
+                    : hash_core(s + 1, l - 1,
+                                // Unsets the 6 high bits of h, therefore no
+                                // overflow happens
+                                (((std::numeric_limits<size_t>::max)() >> 6) &
+                                 h * 33) ^
+                                    static_cast<unsigned char>(to_lower(*s)));
+  }
+};
+
+} // namespace case_ignore
+
+// This is based on
+// "http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4189".
+
+struct scope_exit {
+  explicit scope_exit(std::function<void(void)> &&f)
+      : exit_function(std::move(f)), execute_on_destruction{true} {}
+
+  scope_exit(scope_exit &&rhs) noexcept
+      : exit_function(std::move(rhs.exit_function)),
+        execute_on_destruction{rhs.execute_on_destruction} {
+    rhs.release();
+  }
+
+  ~scope_exit() {
+    if (execute_on_destruction) { this->exit_function(); }
+  }
+
+  void release() { this->execute_on_destruction = false; }
+
+private:
+  scope_exit(const scope_exit &) = delete;
+  void operator=(const scope_exit &) = delete;
+  scope_exit &operator=(scope_exit &&) = delete;
+
+  std::function<void(void)> exit_function;
+  bool execute_on_destruction;
+};
+
+} // namespace detail
+
+enum StatusCode {
+  // Information responses
+  Continue_100 = 100,
+  SwitchingProtocol_101 = 101,
+  Processing_102 = 102,
+  EarlyHints_103 = 103,
+
+  // Successful responses
+  OK_200 = 200,
+  Created_201 = 201,
+  Accepted_202 = 202,
+  NonAuthoritativeInformation_203 = 203,
+  NoContent_204 = 204,
+  ResetContent_205 = 205,
+  PartialContent_206 = 206,
+  MultiStatus_207 = 207,
+  AlreadyReported_208 = 208,
+  IMUsed_226 = 226,
+
+  // Redirection messages
+  MultipleChoices_300 = 300,
+  MovedPermanently_301 = 301,
+  Found_302 = 302,
+  SeeOther_303 = 303,
+  NotModified_304 = 304,
+  UseProxy_305 = 305,
+  unused_306 = 306,
+  TemporaryRedirect_307 = 307,
+  PermanentRedirect_308 = 308,
+
+  // Client error responses
+  BadRequest_400 = 400,
+  Unauthorized_401 = 401,
+  PaymentRequired_402 = 402,
+  Forbidden_403 = 403,
+  NotFound_404 = 404,
+  MethodNotAllowed_405 = 405,
+  NotAcceptable_406 = 406,
+  ProxyAuthenticationRequired_407 = 407,
+  RequestTimeout_408 = 408,
+  Conflict_409 = 409,
+  Gone_410 = 410,
+  LengthRequired_411 = 411,
+  PreconditionFailed_412 = 412,
+  PayloadTooLarge_413 = 413,
+  UriTooLong_414 = 414,
+  UnsupportedMediaType_415 = 415,
+  RangeNotSatisfiable_416 = 416,
+  ExpectationFailed_417 = 417,
+  ImATeapot_418 = 418,
+  MisdirectedRequest_421 = 421,
+  UnprocessableContent_422 = 422,
+  Locked_423 = 423,
+  FailedDependency_424 = 424,
+  TooEarly_425 = 425,
+  UpgradeRequired_426 = 426,
+  PreconditionRequired_428 = 428,
+  TooManyRequests_429 = 429,
+  RequestHeaderFieldsTooLarge_431 = 431,
+  UnavailableForLegalReasons_451 = 451,
+
+  // Server error responses
+  InternalServerError_500 = 500,
+  NotImplemented_501 = 501,
+  BadGateway_502 = 502,
+  ServiceUnavailable_503 = 503,
+  GatewayTimeout_504 = 504,
+  HttpVersionNotSupported_505 = 505,
+  VariantAlsoNegotiates_506 = 506,
+  InsufficientStorage_507 = 507,
+  LoopDetected_508 = 508,
+  NotExtended_510 = 510,
+  NetworkAuthenticationRequired_511 = 511,
+};
+
+using Headers =
+    std::unordered_multimap<std::string, std::string, detail::case_ignore::hash,
+                            detail::case_ignore::equal_to>;
+
+using Params = std::multimap<std::string, std::string>;
+using Match = std::smatch;
+
+using Progress = std::function<bool(uint64_t current, uint64_t total)>;
+
+struct Response;
+using ResponseHandler = std::function<bool(const Response &response)>;
+
+struct MultipartFormData {
+  std::string name;
+  std::string content;
+  std::string filename;
+  std::string content_type;
+};
+using MultipartFormDataItems = std::vector<MultipartFormData>;
+using MultipartFormDataMap = std::multimap<std::string, MultipartFormData>;
+
+class DataSink {
+public:
+  DataSink() : os(&sb_), sb_(*this) {}
+
+  DataSink(const DataSink &) = delete;
+  DataSink &operator=(const DataSink &) = delete;
+  DataSink(DataSink &&) = delete;
+  DataSink &operator=(DataSink &&) = delete;
+
+  std::function<bool(const char *data, size_t data_len)> write;
+  std::function<bool()> is_writable;
+  std::function<void()> done;
+  std::function<void(const Headers &trailer)> done_with_trailer;
+  std::ostream os;
+
+private:
+  class data_sink_streambuf final : public std::streambuf {
+  public:
+    explicit data_sink_streambuf(DataSink &sink) : sink_(sink) {}
+
+  protected:
+    std::streamsize xsputn(const char *s, std::streamsize n) override {
+      sink_.write(s, static_cast<size_t>(n));
+      return n;
+    }
+
+  private:
+    DataSink &sink_;
+  };
+
+  data_sink_streambuf sb_;
+};
+
+using ContentProvider =
+    std::function<bool(size_t offset, size_t length, DataSink &sink)>;
+
+using ContentProviderWithoutLength =
+    std::function<bool(size_t offset, DataSink &sink)>;
+
+using ContentProviderResourceReleaser = std::function<void(bool success)>;
+
+struct MultipartFormDataProvider {
+  std::string name;
+  ContentProviderWithoutLength provider;
+  std::string filename;
+  std::string content_type;
+};
+using MultipartFormDataProviderItems = std::vector<MultipartFormDataProvider>;
+
+using ContentReceiverWithProgress =
+    std::function<bool(const char *data, size_t data_length, uint64_t offset,
+                       uint64_t total_length)>;
+
+using ContentReceiver =
+    std::function<bool(const char *data, size_t data_length)>;
+
+using MultipartContentHeader =
+    std::function<bool(const MultipartFormData &file)>;
+
+class ContentReader {
+public:
+  using Reader = std::function<bool(ContentReceiver receiver)>;
+  using MultipartReader = std::function<bool(MultipartContentHeader header,
+                                             ContentReceiver receiver)>;
+
+  ContentReader(Reader reader, MultipartReader multipart_reader)
+      : reader_(std::move(reader)),
+        multipart_reader_(std::move(multipart_reader)) {}
+
+  bool operator()(MultipartContentHeader header,
+                  ContentReceiver receiver) const {
+    return multipart_reader_(std::move(header), std::move(receiver));
+  }
+
+  bool operator()(ContentReceiver receiver) const {
+    return reader_(std::move(receiver));
+  }
+
+  Reader reader_;
+  MultipartReader multipart_reader_;
+};
+
+using Range = std::pair<ssize_t, ssize_t>;
+using Ranges = std::vector<Range>;
+
+struct Request {
+  std::string method;
+  std::string path;
+  Params params;
+  Headers headers;
+  std::string body;
+
+  std::string remote_addr;
+  int remote_port = -1;
+  std::string local_addr;
+  int local_port = -1;
+
+  // for server
+  std::string version;
+  std::string target;
+  MultipartFormDataMap files;
+  Ranges ranges;
+  Match matches;
+  std::unordered_map<std::string, std::string> path_params;
+  std::function<bool()> is_connection_closed = []() { return true; };
+
+  // for client
+  ResponseHandler response_handler;
+  ContentReceiverWithProgress content_receiver;
+  Progress progress;
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  const SSL *ssl = nullptr;
+#endif
+
+  bool has_header(const std::string &key) const;
+  std::string get_header_value(const std::string &key, const char *def = "",
+                               size_t id = 0) const;
+  uint64_t get_header_value_u64(const std::string &key, uint64_t def = 0,
+                                size_t id = 0) const;
+  size_t get_header_value_count(const std::string &key) const;
+  void set_header(const std::string &key, const std::string &val);
+
+  bool has_param(const std::string &key) const;
+  std::string get_param_value(const std::string &key, size_t id = 0) const;
+  size_t get_param_value_count(const std::string &key) const;
+
+  bool is_multipart_form_data() const;
+
+  bool has_file(const std::string &key) const;
+  MultipartFormData get_file_value(const std::string &key) const;
+  std::vector<MultipartFormData> get_file_values(const std::string &key) const;
+
+  // private members...
+  size_t redirect_count_ = CPPHTTPLIB_REDIRECT_MAX_COUNT;
+  size_t content_length_ = 0;
+  ContentProvider content_provider_;
+  bool is_chunked_content_provider_ = false;
+  size_t authorization_count_ = 0;
+  std::chrono::time_point<std::chrono::steady_clock> start_time_ =
+      std::chrono::steady_clock::time_point::min();
+};
+
+struct Response {
+  std::string version;
+  int status = -1;
+  std::string reason;
+  Headers headers;
+  std::string body;
+  std::string location; // Redirect location
+
+  bool has_header(const std::string &key) const;
+  std::string get_header_value(const std::string &key, const char *def = "",
+                               size_t id = 0) const;
+  uint64_t get_header_value_u64(const std::string &key, uint64_t def = 0,
+                                size_t id = 0) const;
+  size_t get_header_value_count(const std::string &key) const;
+  void set_header(const std::string &key, const std::string &val);
+
+  void set_redirect(const std::string &url, int status = StatusCode::Found_302);
+  void set_content(const char *s, size_t n, const std::string &content_type);
+  void set_content(const std::string &s, const std::string &content_type);
+  void set_content(std::string &&s, const std::string &content_type);
+
+  void set_content_provider(
+      size_t length, const std::string &content_type, ContentProvider provider,
+      ContentProviderResourceReleaser resource_releaser = nullptr);
+
+  void set_content_provider(
+      const std::string &content_type, ContentProviderWithoutLength provider,
+      ContentProviderResourceReleaser resource_releaser = nullptr);
+
+  void set_chunked_content_provider(
+      const std::string &content_type, ContentProviderWithoutLength provider,
+      ContentProviderResourceReleaser resource_releaser = nullptr);
+
+  void set_file_content(const std::string &path,
+                        const std::string &content_type);
+  void set_file_content(const std::string &path);
+
+  Response() = default;
+  Response(const Response &) = default;
+  Response &operator=(const Response &) = default;
+  Response(Response &&) = default;
+  Response &operator=(Response &&) = default;
+  ~Response() {
+    if (content_provider_resource_releaser_) {
+      content_provider_resource_releaser_(content_provider_success_);
+    }
+  }
+
+  // private members...
+  size_t content_length_ = 0;
+  ContentProvider content_provider_;
+  ContentProviderResourceReleaser content_provider_resource_releaser_;
+  bool is_chunked_content_provider_ = false;
+  bool content_provider_success_ = false;
+  std::string file_content_path_;
+  std::string file_content_content_type_;
+};
+
+class Stream {
+public:
+  virtual ~Stream() = default;
+
+  virtual bool is_readable() const = 0;
+  virtual bool is_writable() const = 0;
+
+  virtual ssize_t read(char *ptr, size_t size) = 0;
+  virtual ssize_t write(const char *ptr, size_t size) = 0;
+  virtual void get_remote_ip_and_port(std::string &ip, int &port) const = 0;
+  virtual void get_local_ip_and_port(std::string &ip, int &port) const = 0;
+  virtual socket_t socket() const = 0;
+
+  virtual time_t duration() const = 0;
+
+  ssize_t write(const char *ptr);
+  ssize_t write(const std::string &s);
+};
+
+class TaskQueue {
+public:
+  TaskQueue() = default;
+  virtual ~TaskQueue() = default;
+
+  virtual bool enqueue(std::function<void()> fn) = 0;
+  virtual void shutdown() = 0;
+
+  virtual void on_idle() {}
+};
+
+class ThreadPool final : public TaskQueue {
+public:
+  explicit ThreadPool(size_t n, size_t mqr = 0)
+      : shutdown_(false), max_queued_requests_(mqr) {
+    while (n) {
+      threads_.emplace_back(worker(*this));
+      n--;
+    }
+  }
+
+  ThreadPool(const ThreadPool &) = delete;
+  ~ThreadPool() override = default;
+
+  bool enqueue(std::function<void()> fn) override {
+    {
+      std::unique_lock<std::mutex> lock(mutex_);
+      if (max_queued_requests_ > 0 && jobs_.size() >= max_queued_requests_) {
+        return false;
+      }
+      jobs_.push_back(std::move(fn));
+    }
+
+    cond_.notify_one();
+    return true;
+  }
+
+  void shutdown() override {
+    // Stop all worker threads...
+    {
+      std::unique_lock<std::mutex> lock(mutex_);
+      shutdown_ = true;
+    }
+
+    cond_.notify_all();
+
+    // Join...
+    for (auto &t : threads_) {
+      t.join();
+    }
+  }
+
+private:
+  struct worker {
+    explicit worker(ThreadPool &pool) : pool_(pool) {}
+
+    void operator()() {
+      for (;;) {
+        std::function<void()> fn;
+        {
+          std::unique_lock<std::mutex> lock(pool_.mutex_);
+
+          pool_.cond_.wait(
+              lock, [&] { return !pool_.jobs_.empty() || pool_.shutdown_; });
+
+          if (pool_.shutdown_ && pool_.jobs_.empty()) { break; }
+
+          fn = pool_.jobs_.front();
+          pool_.jobs_.pop_front();
+        }
+
+        assert(true == static_cast<bool>(fn));
+        fn();
+      }
+
+#if defined(CPPHTTPLIB_OPENSSL_SUPPORT) && !defined(OPENSSL_IS_BORINGSSL) &&   \
+    !defined(LIBRESSL_VERSION_NUMBER)
+      OPENSSL_thread_stop();
+#endif
+    }
+
+    ThreadPool &pool_;
+  };
+  friend struct worker;
+
+  std::vector<std::thread> threads_;
+  std::list<std::function<void()>> jobs_;
+
+  bool shutdown_;
+  size_t max_queued_requests_ = 0;
+
+  std::condition_variable cond_;
+  std::mutex mutex_;
+};
+
+using Logger = std::function<void(const Request &, const Response &)>;
+
+using SocketOptions = std::function<void(socket_t sock)>;
+
+void default_socket_options(socket_t sock);
+
+const char *status_message(int status);
+
+std::string get_bearer_token_auth(const Request &req);
+
+namespace detail {
+
+class MatcherBase {
+public:
+  virtual ~MatcherBase() = default;
+
+  // Match request path and populate its matches and
+  virtual bool match(Request &request) const = 0;
+};
+
+/**
+ * Captures parameters in request path and stores them in Request::path_params
+ *
+ * Capture name is a substring of a pattern from : to /.
+ * The rest of the pattern is matched agains the request path directly
+ * Parameters are captured starting from the next character after
+ * the end of the last matched static pattern fragment until the next /.
+ *
+ * Example pattern:
+ * "/path/fragments/:capture/more/fragments/:second_capture"
+ * Static fragments:
+ * "/path/fragments/", "more/fragments/"
+ *
+ * Given the following request path:
+ * "/path/fragments/:1/more/fragments/:2"
+ * the resulting capture will be
+ * {{"capture", "1"}, {"second_capture", "2"}}
+ */
+class PathParamsMatcher final : public MatcherBase {
+public:
+  PathParamsMatcher(const std::string &pattern);
+
+  bool match(Request &request) const override;
+
+private:
+  // Treat segment separators as the end of path parameter capture
+  // Does not need to handle query parameters as they are parsed before path
+  // matching
+  static constexpr char separator = '/';
+
+  // Contains static path fragments to match against, excluding the '/' after
+  // path params
+  // Fragments are separated by path params
+  std::vector<std::string> static_fragments_;
+  // Stores the names of the path parameters to be used as keys in the
+  // Request::path_params map
+  std::vector<std::string> param_names_;
+};
+
+/**
+ * Performs std::regex_match on request path
+ * and stores the result in Request::matches
+ *
+ * Note that regex match is performed directly on the whole request.
+ * This means that wildcard patterns may match multiple path segments with /:
+ * "/begin/(.*)/end" will match both "/begin/middle/end" and "/begin/1/2/end".
+ */
+class RegexMatcher final : public MatcherBase {
+public:
+  RegexMatcher(const std::string &pattern) : regex_(pattern) {}
+
+  bool match(Request &request) const override;
+
+private:
+  std::regex regex_;
+};
+
+ssize_t write_headers(Stream &strm, const Headers &headers);
+
+} // namespace detail
+
+class Server {
+public:
+  using Handler = std::function<void(const Request &, Response &)>;
+
+  using ExceptionHandler =
+      std::function<void(const Request &, Response &, std::exception_ptr ep)>;
+
+  enum class HandlerResponse {
+    Handled,
+    Unhandled,
+  };
+  using HandlerWithResponse =
+      std::function<HandlerResponse(const Request &, Response &)>;
+
+  using HandlerWithContentReader = std::function<void(
+      const Request &, Response &, const ContentReader &content_reader)>;
+
+  using Expect100ContinueHandler =
+      std::function<int(const Request &, Response &)>;
+
+  Server();
+
+  virtual ~Server();
+
+  virtual bool is_valid() const;
+
+  Server &Get(const std::string &pattern, Handler handler);
+  Server &Post(const std::string &pattern, Handler handler);
+  Server &Post(const std::string &pattern, HandlerWithContentReader handler);
+  Server &Put(const std::string &pattern, Handler handler);
+  Server &Put(const std::string &pattern, HandlerWithContentReader handler);
+  Server &Patch(const std::string &pattern, Handler handler);
+  Server &Patch(const std::string &pattern, HandlerWithContentReader handler);
+  Server &Delete(const std::string &pattern, Handler handler);
+  Server &Delete(const std::string &pattern, HandlerWithContentReader handler);
+  Server &Options(const std::string &pattern, Handler handler);
+
+  bool set_base_dir(const std::string &dir,
+                    const std::string &mount_point = std::string());
+  bool set_mount_point(const std::string &mount_point, const std::string &dir,
+                       Headers headers = Headers());
+  bool remove_mount_point(const std::string &mount_point);
+  Server &set_file_extension_and_mimetype_mapping(const std::string &ext,
+                                                  const std::string &mime);
+  Server &set_default_file_mimetype(const std::string &mime);
+  Server &set_file_request_handler(Handler handler);
+
+  template <class ErrorHandlerFunc>
+  Server &set_error_handler(ErrorHandlerFunc &&handler) {
+    return set_error_handler_core(
+        std::forward<ErrorHandlerFunc>(handler),
+        std::is_convertible<ErrorHandlerFunc, HandlerWithResponse>{});
+  }
+
+  Server &set_exception_handler(ExceptionHandler handler);
+  Server &set_pre_routing_handler(HandlerWithResponse handler);
+  Server &set_post_routing_handler(Handler handler);
+
+  Server &set_expect_100_continue_handler(Expect100ContinueHandler handler);
+  Server &set_logger(Logger logger);
+
+  Server &set_address_family(int family);
+  Server &set_tcp_nodelay(bool on);
+  Server &set_ipv6_v6only(bool on);
+  Server &set_socket_options(SocketOptions socket_options);
+
+  Server &set_default_headers(Headers headers);
+  Server &
+  set_header_writer(std::function<ssize_t(Stream &, Headers &)> const &writer);
+
+  Server &set_keep_alive_max_count(size_t count);
+  Server &set_keep_alive_timeout(time_t sec);
+
+  Server &set_read_timeout(time_t sec, time_t usec = 0);
+  template <class Rep, class Period>
+  Server &set_read_timeout(const std::chrono::duration<Rep, Period> &duration);
+
+  Server &set_write_timeout(time_t sec, time_t usec = 0);
+  template <class Rep, class Period>
+  Server &set_write_timeout(const std::chrono::duration<Rep, Period> &duration);
+
+  Server &set_idle_interval(time_t sec, time_t usec = 0);
+  template <class Rep, class Period>
+  Server &set_idle_interval(const std::chrono::duration<Rep, Period> &duration);
+
+  Server &set_payload_max_length(size_t length);
+
+  bool bind_to_port(const std::string &host, int port, int socket_flags = 0);
+  int bind_to_any_port(const std::string &host, int socket_flags = 0);
+  bool listen_after_bind();
+
+  bool listen(const std::string &host, int port, int socket_flags = 0);
+
+  bool is_running() const;
+  void wait_until_ready() const;
+  void stop();
+  void decommission();
+
+  std::function<TaskQueue *(void)> new_task_queue;
+
+protected:
+  bool process_request(Stream &strm, const std::string &remote_addr,
+                       int remote_port, const std::string &local_addr,
+                       int local_port, bool close_connection,
+                       bool &connection_closed,
+                       const std::function<void(Request &)> &setup_request);
+
+  std::atomic<socket_t> svr_sock_{INVALID_SOCKET};
+  size_t keep_alive_max_count_ = CPPHTTPLIB_KEEPALIVE_MAX_COUNT;
+  time_t keep_alive_timeout_sec_ = CPPHTTPLIB_KEEPALIVE_TIMEOUT_SECOND;
+  time_t read_timeout_sec_ = CPPHTTPLIB_SERVER_READ_TIMEOUT_SECOND;
+  time_t read_timeout_usec_ = CPPHTTPLIB_SERVER_READ_TIMEOUT_USECOND;
+  time_t write_timeout_sec_ = CPPHTTPLIB_SERVER_WRITE_TIMEOUT_SECOND;
+  time_t write_timeout_usec_ = CPPHTTPLIB_SERVER_WRITE_TIMEOUT_USECOND;
+  time_t idle_interval_sec_ = CPPHTTPLIB_IDLE_INTERVAL_SECOND;
+  time_t idle_interval_usec_ = CPPHTTPLIB_IDLE_INTERVAL_USECOND;
+  size_t payload_max_length_ = CPPHTTPLIB_PAYLOAD_MAX_LENGTH;
+
+private:
+  using Handlers =
+      std::vector<std::pair<std::unique_ptr<detail::MatcherBase>, Handler>>;
+  using HandlersForContentReader =
+      std::vector<std::pair<std::unique_ptr<detail::MatcherBase>,
+                            HandlerWithContentReader>>;
+
+  static std::unique_ptr<detail::MatcherBase>
+  make_matcher(const std::string &pattern);
+
+  Server &set_error_handler_core(HandlerWithResponse handler, std::true_type);
+  Server &set_error_handler_core(Handler handler, std::false_type);
+
+  socket_t create_server_socket(const std::string &host, int port,
+                                int socket_flags,
+                                SocketOptions socket_options) const;
+  int bind_internal(const std::string &host, int port, int socket_flags);
+  bool listen_internal();
+
+  bool routing(Request &req, Response &res, Stream &strm);
+  bool handle_file_request(const Request &req, Response &res,
+                           bool head = false);
+  bool dispatch_request(Request &req, Response &res,
+                        const Handlers &handlers) const;
+  bool dispatch_request_for_content_reader(
+      Request &req, Response &res, ContentReader content_reader,
+      const HandlersForContentReader &handlers) const;
+
+  bool parse_request_line(const char *s, Request &req) const;
+  void apply_ranges(const Request &req, Response &res,
+                    std::string &content_type, std::string &boundary) const;
+  bool write_response(Stream &strm, bool close_connection, Request &req,
+                      Response &res);
+  bool write_response_with_content(Stream &strm, bool close_connection,
+                                   const Request &req, Response &res);
+  bool write_response_core(Stream &strm, bool close_connection,
+                           const Request &req, Response &res,
+                           bool need_apply_ranges);
+  bool write_content_with_provider(Stream &strm, const Request &req,
+                                   Response &res, const std::string &boundary,
+                                   const std::string &content_type);
+  bool read_content(Stream &strm, Request &req, Response &res);
+  bool
+  read_content_with_content_receiver(Stream &strm, Request &req, Response &res,
+                                     ContentReceiver receiver,
+                                     MultipartContentHeader multipart_header,
+                                     ContentReceiver multipart_receiver);
+  bool read_content_core(Stream &strm, Request &req, Response &res,
+                         ContentReceiver receiver,
+                         MultipartContentHeader multipart_header,
+                         ContentReceiver multipart_receiver) const;
+
+  virtual bool process_and_close_socket(socket_t sock);
+
+  std::atomic<bool> is_running_{false};
+  std::atomic<bool> is_decommisioned{false};
+
+  struct MountPointEntry {
+    std::string mount_point;
+    std::string base_dir;
+    Headers headers;
+  };
+  std::vector<MountPointEntry> base_dirs_;
+  std::map<std::string, std::string> file_extension_and_mimetype_map_;
+  std::string default_file_mimetype_ = "application/octet-stream";
+  Handler file_request_handler_;
+
+  Handlers get_handlers_;
+  Handlers post_handlers_;
+  HandlersForContentReader post_handlers_for_content_reader_;
+  Handlers put_handlers_;
+  HandlersForContentReader put_handlers_for_content_reader_;
+  Handlers patch_handlers_;
+  HandlersForContentReader patch_handlers_for_content_reader_;
+  Handlers delete_handlers_;
+  HandlersForContentReader delete_handlers_for_content_reader_;
+  Handlers options_handlers_;
+
+  HandlerWithResponse error_handler_;
+  ExceptionHandler exception_handler_;
+  HandlerWithResponse pre_routing_handler_;
+  Handler post_routing_handler_;
+  Expect100ContinueHandler expect_100_continue_handler_;
+
+  Logger logger_;
+
+  int address_family_ = AF_UNSPEC;
+  bool tcp_nodelay_ = CPPHTTPLIB_TCP_NODELAY;
+  bool ipv6_v6only_ = CPPHTTPLIB_IPV6_V6ONLY;
+  SocketOptions socket_options_ = default_socket_options;
+
+  Headers default_headers_;
+  std::function<ssize_t(Stream &, Headers &)> header_writer_ =
+      detail::write_headers;
+};
+
+enum class Error {
+  Success = 0,
+  Unknown,
+  Connection,
+  BindIPAddress,
+  Read,
+  Write,
+  ExceedRedirectCount,
+  Canceled,
+  SSLConnection,
+  SSLLoadingCerts,
+  SSLServerVerification,
+  SSLServerHostnameVerification,
+  UnsupportedMultipartBoundaryChars,
+  Compression,
+  ConnectionTimeout,
+  ProxyConnection,
+
+  // For internal use only
+  SSLPeerCouldBeClosed_,
+};
+
+std::string to_string(Error error);
+
+std::ostream &operator<<(std::ostream &os, const Error &obj);
+
+class Result {
+public:
+  Result() = default;
+  Result(std::unique_ptr<Response> &&res, Error err,
+         Headers &&request_headers = Headers{})
+      : res_(std::move(res)), err_(err),
+        request_headers_(std::move(request_headers)) {}
+  // Response
+  operator bool() const { return res_ != nullptr; }
+  bool operator==(std::nullptr_t) const { return res_ == nullptr; }
+  bool operator!=(std::nullptr_t) const { return res_ != nullptr; }
+  const Response &value() const { return *res_; }
+  Response &value() { return *res_; }
+  const Response &operator*() const { return *res_; }
+  Response &operator*() { return *res_; }
+  const Response *operator->() const { return res_.get(); }
+  Response *operator->() { return res_.get(); }
+
+  // Error
+  Error error() const { return err_; }
+
+  // Request Headers
+  bool has_request_header(const std::string &key) const;
+  std::string get_request_header_value(const std::string &key,
+                                       const char *def = "",
+                                       size_t id = 0) const;
+  uint64_t get_request_header_value_u64(const std::string &key,
+                                        uint64_t def = 0, size_t id = 0) const;
+  size_t get_request_header_value_count(const std::string &key) const;
+
+private:
+  std::unique_ptr<Response> res_;
+  Error err_ = Error::Unknown;
+  Headers request_headers_;
+};
+
+class ClientImpl {
+public:
+  explicit ClientImpl(const std::string &host);
+
+  explicit ClientImpl(const std::string &host, int port);
+
+  explicit ClientImpl(const std::string &host, int port,
+                      const std::string &client_cert_path,
+                      const std::string &client_key_path);
+
+  virtual ~ClientImpl();
+
+  virtual bool is_valid() const;
+
+  Result Get(const std::string &path);
+  Result Get(const std::string &path, const Headers &headers);
+  Result Get(const std::string &path, Progress progress);
+  Result Get(const std::string &path, const Headers &headers,
+             Progress progress);
+  Result Get(const std::string &path, ContentReceiver content_receiver);
+  Result Get(const std::string &path, const Headers &headers,
+             ContentReceiver content_receiver);
+  Result Get(const std::string &path, ContentReceiver content_receiver,
+             Progress progress);
+  Result Get(const std::string &path, const Headers &headers,
+             ContentReceiver content_receiver, Progress progress);
+  Result Get(const std::string &path, ResponseHandler response_handler,
+             ContentReceiver content_receiver);
+  Result Get(const std::string &path, const Headers &headers,
+             ResponseHandler response_handler,
+             ContentReceiver content_receiver);
+  Result Get(const std::string &path, ResponseHandler response_handler,
+             ContentReceiver content_receiver, Progress progress);
+  Result Get(const std::string &path, const Headers &headers,
+             ResponseHandler response_handler, ContentReceiver content_receiver,
+             Progress progress);
+
+  Result Get(const std::string &path, const Params &params,
+             const Headers &headers, Progress progress = nullptr);
+  Result Get(const std::string &path, const Params &params,
+             const Headers &headers, ContentReceiver content_receiver,
+             Progress progress = nullptr);
+  Result Get(const std::string &path, const Params &params,
+             const Headers &headers, ResponseHandler response_handler,
+             ContentReceiver content_receiver, Progress progress = nullptr);
+
+  Result Head(const std::string &path);
+  Result Head(const std::string &path, const Headers &headers);
+
+  Result Post(const std::string &path);
+  Result Post(const std::string &path, const Headers &headers);
+  Result Post(const std::string &path, const char *body, size_t content_length,
+              const std::string &content_type);
+  Result Post(const std::string &path, const Headers &headers, const char *body,
+              size_t content_length, const std::string &content_type);
+  Result Post(const std::string &path, const Headers &headers, const char *body,
+              size_t content_length, const std::string &content_type,
+              Progress progress);
+  Result Post(const std::string &path, const std::string &body,
+              const std::string &content_type);
+  Result Post(const std::string &path, const std::string &body,
+              const std::string &content_type, Progress progress);
+  Result Post(const std::string &path, const Headers &headers,
+              const std::string &body, const std::string &content_type);
+  Result Post(const std::string &path, const Headers &headers,
+              const std::string &body, const std::string &content_type,
+              Progress progress);
+  Result Post(const std::string &path, size_t content_length,
+              ContentProvider content_provider,
+              const std::string &content_type);
+  Result Post(const std::string &path,
+              ContentProviderWithoutLength content_provider,
+              const std::string &content_type);
+  Result Post(const std::string &path, const Headers &headers,
+              size_t content_length, ContentProvider content_provider,
+              const std::string &content_type);
+  Result Post(const std::string &path, const Headers &headers,
+              ContentProviderWithoutLength content_provider,
+              const std::string &content_type);
+  Result Post(const std::string &path, const Params &params);
+  Result Post(const std::string &path, const Headers &headers,
+              const Params &params);
+  Result Post(const std::string &path, const Headers &headers,
+              const Params &params, Progress progress);
+  Result Post(const std::string &path, const MultipartFormDataItems &items);
+  Result Post(const std::string &path, const Headers &headers,
+              const MultipartFormDataItems &items);
+  Result Post(const std::string &path, const Headers &headers,
+              const MultipartFormDataItems &items, const std::string &boundary);
+  Result Post(const std::string &path, const Headers &headers,
+              const MultipartFormDataItems &items,
+              const MultipartFormDataProviderItems &provider_items);
+
+  Result Put(const std::string &path);
+  Result Put(const std::string &path, const char *body, size_t content_length,
+             const std::string &content_type);
+  Result Put(const std::string &path, const Headers &headers, const char *body,
+             size_t content_length, const std::string &content_type);
+  Result Put(const std::string &path, const Headers &headers, const char *body,
+             size_t content_length, const std::string &content_type,
+             Progress progress);
+  Result Put(const std::string &path, const std::string &body,
+             const std::string &content_type);
+  Result Put(const std::string &path, const std::string &body,
+             const std::string &content_type, Progress progress);
+  Result Put(const std::string &path, const Headers &headers,
+             const std::string &body, const std::string &content_type);
+  Result Put(const std::string &path, const Headers &headers,
+             const std::string &body, const std::string &content_type,
+             Progress progress);
+  Result Put(const std::string &path, size_t content_length,
+             ContentProvider content_provider, const std::string &content_type);
+  Result Put(const std::string &path,
+             ContentProviderWithoutLength content_provider,
+             const std::string &content_type);
+  Result Put(const std::string &path, const Headers &headers,
+             size_t content_length, ContentProvider content_provider,
+             const std::string &content_type);
+  Result Put(const std::string &path, const Headers &headers,
+             ContentProviderWithoutLength content_provider,
+             const std::string &content_type);
+  Result Put(const std::string &path, const Params &params);
+  Result Put(const std::string &path, const Headers &headers,
+             const Params &params);
+  Result Put(const std::string &path, const Headers &headers,
+             const Params &params, Progress progress);
+  Result Put(const std::string &path, const MultipartFormDataItems &items);
+  Result Put(const std::string &path, const Headers &headers,
+             const MultipartFormDataItems &items);
+  Result Put(const std::string &path, const Headers &headers,
+             const MultipartFormDataItems &items, const std::string &boundary);
+  Result Put(const std::string &path, const Headers &headers,
+             const MultipartFormDataItems &items,
+             const MultipartFormDataProviderItems &provider_items);
+
+  Result Patch(const std::string &path);
+  Result Patch(const std::string &path, const char *body, size_t content_length,
+               const std::string &content_type);
+  Result Patch(const std::string &path, const char *body, size_t content_length,
+               const std::string &content_type, Progress progress);
+  Result Patch(const std::string &path, const Headers &headers,
+               const char *body, size_t content_length,
+               const std::string &content_type);
+  Result Patch(const std::string &path, const Headers &headers,
+               const char *body, size_t content_length,
+               const std::string &content_type, Progress progress);
+  Result Patch(const std::string &path, const std::string &body,
+               const std::string &content_type);
+  Result Patch(const std::string &path, const std::string &body,
+               const std::string &content_type, Progress progress);
+  Result Patch(const std::string &path, const Headers &headers,
+               const std::string &body, const std::string &content_type);
+  Result Patch(const std::string &path, const Headers &headers,
+               const std::string &body, const std::string &content_type,
+               Progress progress);
+  Result Patch(const std::string &path, size_t content_length,
+               ContentProvider content_provider,
+               const std::string &content_type);
+  Result Patch(const std::string &path,
+               ContentProviderWithoutLength content_provider,
+               const std::string &content_type);
+  Result Patch(const std::string &path, const Headers &headers,
+               size_t content_length, ContentProvider content_provider,
+               const std::string &content_type);
+  Result Patch(const std::string &path, const Headers &headers,
+               ContentProviderWithoutLength content_provider,
+               const std::string &content_type);
+
+  Result Delete(const std::string &path);
+  Result Delete(const std::string &path, const Headers &headers);
+  Result Delete(const std::string &path, const char *body,
+                size_t content_length, const std::string &content_type);
+  Result Delete(const std::string &path, const char *body,
+                size_t content_length, const std::string &content_type,
+                Progress progress);
+  Result Delete(const std::string &path, const Headers &headers,
+                const char *body, size_t content_length,
+                const std::string &content_type);
+  Result Delete(const std::string &path, const Headers &headers,
+                const char *body, size_t content_length,
+                const std::string &content_type, Progress progress);
+  Result Delete(const std::string &path, const std::string &body,
+                const std::string &content_type);
+  Result Delete(const std::string &path, const std::string &body,
+                const std::string &content_type, Progress progress);
+  Result Delete(const std::string &path, const Headers &headers,
+                const std::string &body, const std::string &content_type);
+  Result Delete(const std::string &path, const Headers &headers,
+                const std::string &body, const std::string &content_type,
+                Progress progress);
+
+  Result Options(const std::string &path);
+  Result Options(const std::string &path, const Headers &headers);
+
+  bool send(Request &req, Response &res, Error &error);
+  Result send(const Request &req);
+
+  void stop();
+
+  std::string host() const;
+  int port() const;
+
+  size_t is_socket_open() const;
+  socket_t socket() const;
+
+  void set_hostname_addr_map(std::map<std::string, std::string> addr_map);
+
+  void set_default_headers(Headers headers);
+
+  void
+  set_header_writer(std::function<ssize_t(Stream &, Headers &)> const &writer);
+
+  void set_address_family(int family);
+  void set_tcp_nodelay(bool on);
+  void set_ipv6_v6only(bool on);
+  void set_socket_options(SocketOptions socket_options);
+
+  void set_connection_timeout(time_t sec, time_t usec = 0);
+  template <class Rep, class Period>
+  void
+  set_connection_timeout(const std::chrono::duration<Rep, Period> &duration);
+
+  void set_read_timeout(time_t sec, time_t usec = 0);
+  template <class Rep, class Period>
+  void set_read_timeout(const std::chrono::duration<Rep, Period> &duration);
+
+  void set_write_timeout(time_t sec, time_t usec = 0);
+  template <class Rep, class Period>
+  void set_write_timeout(const std::chrono::duration<Rep, Period> &duration);
+
+  void set_max_timeout(time_t msec);
+  template <class Rep, class Period>
+  void set_max_timeout(const std::chrono::duration<Rep, Period> &duration);
+
+  void set_basic_auth(const std::string &username, const std::string &password);
+  void set_bearer_token_auth(const std::string &token);
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  void set_digest_auth(const std::string &username,
+                       const std::string &password);
+#endif
+
+  void set_keep_alive(bool on);
+  void set_follow_location(bool on);
+
+  void set_url_encode(bool on);
+
+  void set_compress(bool on);
+
+  void set_decompress(bool on);
+
+  void set_interface(const std::string &intf);
+
+  void set_proxy(const std::string &host, int port);
+  void set_proxy_basic_auth(const std::string &username,
+                            const std::string &password);
+  void set_proxy_bearer_token_auth(const std::string &token);
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  void set_proxy_digest_auth(const std::string &username,
+                             const std::string &password);
+#endif
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  void set_ca_cert_path(const std::string &ca_cert_file_path,
+                        const std::string &ca_cert_dir_path = std::string());
+  void set_ca_cert_store(X509_STORE *ca_cert_store);
+  X509_STORE *create_ca_cert_store(const char *ca_cert, std::size_t size) const;
+#endif
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  void enable_server_certificate_verification(bool enabled);
+  void enable_server_hostname_verification(bool enabled);
+  void set_server_certificate_verifier(std::function<bool(SSL *ssl)> verifier);
+#endif
+
+  void set_logger(Logger logger);
+
+protected:
+  struct Socket {
+    socket_t sock = INVALID_SOCKET;
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+    SSL *ssl = nullptr;
+#endif
+
+    bool is_open() const { return sock != INVALID_SOCKET; }
+  };
+
+  virtual bool create_and_connect_socket(Socket &socket, Error &error);
+
+  // All of:
+  //   shutdown_ssl
+  //   shutdown_socket
+  //   close_socket
+  // should ONLY be called when socket_mutex_ is locked.
+  // Also, shutdown_ssl and close_socket should also NOT be called concurrently
+  // with a DIFFERENT thread sending requests using that socket.
+  virtual void shutdown_ssl(Socket &socket, bool shutdown_gracefully);
+  void shutdown_socket(Socket &socket) const;
+  void close_socket(Socket &socket);
+
+  bool process_request(Stream &strm, Request &req, Response &res,
+                       bool close_connection, Error &error);
+
+  bool write_content_with_provider(Stream &strm, const Request &req,
+                                   Error &error) const;
+
+  void copy_settings(const ClientImpl &rhs);
+
+  // Socket endpoint information
+  const std::string host_;
+  const int port_;
+  const std::string host_and_port_;
+
+  // Current open socket
+  Socket socket_;
+  mutable std::mutex socket_mutex_;
+  std::recursive_mutex request_mutex_;
+
+  // These are all protected under socket_mutex
+  size_t socket_requests_in_flight_ = 0;
+  std::thread::id socket_requests_are_from_thread_ = std::thread::id();
+  bool socket_should_be_closed_when_request_is_done_ = false;
+
+  // Hostname-IP map
+  std::map<std::string, std::string> addr_map_;
+
+  // Default headers
+  Headers default_headers_;
+
+  // Header writer
+  std::function<ssize_t(Stream &, Headers &)> header_writer_ =
+      detail::write_headers;
+
+  // Settings
+  std::string client_cert_path_;
+  std::string client_key_path_;
+
+  time_t connection_timeout_sec_ = CPPHTTPLIB_CONNECTION_TIMEOUT_SECOND;
+  time_t connection_timeout_usec_ = CPPHTTPLIB_CONNECTION_TIMEOUT_USECOND;
+  time_t read_timeout_sec_ = CPPHTTPLIB_CLIENT_READ_TIMEOUT_SECOND;
+  time_t read_timeout_usec_ = CPPHTTPLIB_CLIENT_READ_TIMEOUT_USECOND;
+  time_t write_timeout_sec_ = CPPHTTPLIB_CLIENT_WRITE_TIMEOUT_SECOND;
+  time_t write_timeout_usec_ = CPPHTTPLIB_CLIENT_WRITE_TIMEOUT_USECOND;
+  time_t max_timeout_msec_ = CPPHTTPLIB_CLIENT_MAX_TIMEOUT_MSECOND;
+
+  std::string basic_auth_username_;
+  std::string basic_auth_password_;
+  std::string bearer_token_auth_token_;
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  std::string digest_auth_username_;
+  std::string digest_auth_password_;
+#endif
+
+  bool keep_alive_ = false;
+  bool follow_location_ = false;
+
+  bool url_encode_ = true;
+
+  int address_family_ = AF_UNSPEC;
+  bool tcp_nodelay_ = CPPHTTPLIB_TCP_NODELAY;
+  bool ipv6_v6only_ = CPPHTTPLIB_IPV6_V6ONLY;
+  SocketOptions socket_options_ = nullptr;
+
+  bool compress_ = false;
+  bool decompress_ = true;
+
+  std::string interface_;
+
+  std::string proxy_host_;
+  int proxy_port_ = -1;
+
+  std::string proxy_basic_auth_username_;
+  std::string proxy_basic_auth_password_;
+  std::string proxy_bearer_token_auth_token_;
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  std::string proxy_digest_auth_username_;
+  std::string proxy_digest_auth_password_;
+#endif
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  std::string ca_cert_file_path_;
+  std::string ca_cert_dir_path_;
+
+  X509_STORE *ca_cert_store_ = nullptr;
+#endif
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  bool server_certificate_verification_ = true;
+  bool server_hostname_verification_ = true;
+  std::function<bool(SSL *ssl)> server_certificate_verifier_;
+#endif
+
+  Logger logger_;
+
+private:
+  bool send_(Request &req, Response &res, Error &error);
+  Result send_(Request &&req);
+
+  socket_t create_client_socket(Error &error) const;
+  bool read_response_line(Stream &strm, const Request &req,
+                          Response &res) const;
+  bool write_request(Stream &strm, Request &req, bool close_connection,
+                     Error &error);
+  bool redirect(Request &req, Response &res, Error &error);
+  bool handle_request(Stream &strm, Request &req, Response &res,
+                      bool close_connection, Error &error);
+  std::unique_ptr<Response> send_with_content_provider(
+      Request &req, const char *body, size_t content_length,
+      ContentProvider content_provider,
+      ContentProviderWithoutLength content_provider_without_length,
+      const std::string &content_type, Error &error);
+  Result send_with_content_provider(
+      const std::string &method, const std::string &path,
+      const Headers &headers, const char *body, size_t content_length,
+      ContentProvider content_provider,
+      ContentProviderWithoutLength content_provider_without_length,
+      const std::string &content_type, Progress progress);
+  ContentProviderWithoutLength get_multipart_content_provider(
+      const std::string &boundary, const MultipartFormDataItems &items,
+      const MultipartFormDataProviderItems &provider_items) const;
+
+  std::string adjust_host_string(const std::string &host) const;
+
+  virtual bool
+  process_socket(const Socket &socket,
+                 std::chrono::time_point<std::chrono::steady_clock> start_time,
+                 std::function<bool(Stream &strm)> callback);
+  virtual bool is_ssl() const;
+};
+
+class Client {
+public:
+  // Universal interface
+  explicit Client(const std::string &scheme_host_port);
+
+  explicit Client(const std::string &scheme_host_port,
+                  const std::string &client_cert_path,
+                  const std::string &client_key_path);
+
+  // HTTP only interface
+  explicit Client(const std::string &host, int port);
+
+  explicit Client(const std::string &host, int port,
+                  const std::string &client_cert_path,
+                  const std::string &client_key_path);
+
+  Client(Client &&) = default;
+  Client &operator=(Client &&) = default;
+
+  ~Client();
+
+  bool is_valid() const;
+
+  Result Get(const std::string &path);
+  Result Get(const std::string &path, const Headers &headers);
+  Result Get(const std::string &path, Progress progress);
+  Result Get(const std::string &path, const Headers &headers,
+             Progress progress);
+  Result Get(const std::string &path, ContentReceiver content_receiver);
+  Result Get(const std::string &path, const Headers &headers,
+             ContentReceiver content_receiver);
+  Result Get(const std::string &path, ContentReceiver content_receiver,
+             Progress progress);
+  Result Get(const std::string &path, const Headers &headers,
+             ContentReceiver content_receiver, Progress progress);
+  Result Get(const std::string &path, ResponseHandler response_handler,
+             ContentReceiver content_receiver);
+  Result Get(const std::string &path, const Headers &headers,
+             ResponseHandler response_handler,
+             ContentReceiver content_receiver);
+  Result Get(const std::string &path, const Headers &headers,
+             ResponseHandler response_handler, ContentReceiver content_receiver,
+             Progress progress);
+  Result Get(const std::string &path, ResponseHandler response_handler,
+             ContentReceiver content_receiver, Progress progress);
+
+  Result Get(const std::string &path, const Params &params,
+             const Headers &headers, Progress progress = nullptr);
+  Result Get(const std::string &path, const Params &params,
+             const Headers &headers, ContentReceiver content_receiver,
+             Progress progress = nullptr);
+  Result Get(const std::string &path, const Params &params,
+             const Headers &headers, ResponseHandler response_handler,
+             ContentReceiver content_receiver, Progress progress = nullptr);
+
+  Result Head(const std::string &path);
+  Result Head(const std::string &path, const Headers &headers);
+
+  Result Post(const std::string &path);
+  Result Post(const std::string &path, const Headers &headers);
+  Result Post(const std::string &path, const char *body, size_t content_length,
+              const std::string &content_type);
+  Result Post(const std::string &path, const Headers &headers, const char *body,
+              size_t content_length, const std::string &content_type);
+  Result Post(const std::string &path, const Headers &headers, const char *body,
+              size_t content_length, const std::string &content_type,
+              Progress progress);
+  Result Post(const std::string &path, const std::string &body,
+              const std::string &content_type);
+  Result Post(const std::string &path, const std::string &body,
+              const std::string &content_type, Progress progress);
+  Result Post(const std::string &path, const Headers &headers,
+              const std::string &body, const std::string &content_type);
+  Result Post(const std::string &path, const Headers &headers,
+              const std::string &body, const std::string &content_type,
+              Progress progress);
+  Result Post(const std::string &path, size_t content_length,
+              ContentProvider content_provider,
+              const std::string &content_type);
+  Result Post(const std::string &path,
+              ContentProviderWithoutLength content_provider,
+              const std::string &content_type);
+  Result Post(const std::string &path, const Headers &headers,
+              size_t content_length, ContentProvider content_provider,
+              const std::string &content_type);
+  Result Post(const std::string &path, const Headers &headers,
+              ContentProviderWithoutLength content_provider,
+              const std::string &content_type);
+  Result Post(const std::string &path, const Params &params);
+  Result Post(const std::string &path, const Headers &headers,
+              const Params &params);
+  Result Post(const std::string &path, const Headers &headers,
+              const Params &params, Progress progress);
+  Result Post(const std::string &path, const MultipartFormDataItems &items);
+  Result Post(const std::string &path, const Headers &headers,
+              const MultipartFormDataItems &items);
+  Result Post(const std::string &path, const Headers &headers,
+              const MultipartFormDataItems &items, const std::string &boundary);
+  Result Post(const std::string &path, const Headers &headers,
+              const MultipartFormDataItems &items,
+              const MultipartFormDataProviderItems &provider_items);
+
+  Result Put(const std::string &path);
+  Result Put(const std::string &path, const char *body, size_t content_length,
+             const std::string &content_type);
+  Result Put(const std::string &path, const Headers &headers, const char *body,
+             size_t content_length, const std::string &content_type);
+  Result Put(const std::string &path, const Headers &headers, const char *body,
+             size_t content_length, const std::string &content_type,
+             Progress progress);
+  Result Put(const std::string &path, const std::string &body,
+             const std::string &content_type);
+  Result Put(const std::string &path, const std::string &body,
+             const std::string &content_type, Progress progress);
+  Result Put(const std::string &path, const Headers &headers,
+             const std::string &body, const std::string &content_type);
+  Result Put(const std::string &path, const Headers &headers,
+             const std::string &body, const std::string &content_type,
+             Progress progress);
+  Result Put(const std::string &path, size_t content_length,
+             ContentProvider content_provider, const std::string &content_type);
+  Result Put(const std::string &path,
+             ContentProviderWithoutLength content_provider,
+             const std::string &content_type);
+  Result Put(const std::string &path, const Headers &headers,
+             size_t content_length, ContentProvider content_provider,
+             const std::string &content_type);
+  Result Put(const std::string &path, const Headers &headers,
+             ContentProviderWithoutLength content_provider,
+             const std::string &content_type);
+  Result Put(const std::string &path, const Params &params);
+  Result Put(const std::string &path, const Headers &headers,
+             const Params &params);
+  Result Put(const std::string &path, const Headers &headers,
+             const Params &params, Progress progress);
+  Result Put(const std::string &path, const MultipartFormDataItems &items);
+  Result Put(const std::string &path, const Headers &headers,
+             const MultipartFormDataItems &items);
+  Result Put(const std::string &path, const Headers &headers,
+             const MultipartFormDataItems &items, const std::string &boundary);
+  Result Put(const std::string &path, const Headers &headers,
+             const MultipartFormDataItems &items,
+             const MultipartFormDataProviderItems &provider_items);
+
+  Result Patch(const std::string &path);
+  Result Patch(const std::string &path, const char *body, size_t content_length,
+               const std::string &content_type);
+  Result Patch(const std::string &path, const char *body, size_t content_length,
+               const std::string &content_type, Progress progress);
+  Result Patch(const std::string &path, const Headers &headers,
+               const char *body, size_t content_length,
+               const std::string &content_type);
+  Result Patch(const std::string &path, const Headers &headers,
+               const char *body, size_t content_length,
+               const std::string &content_type, Progress progress);
+  Result Patch(const std::string &path, const std::string &body,
+               const std::string &content_type);
+  Result Patch(const std::string &path, const std::string &body,
+               const std::string &content_type, Progress progress);
+  Result Patch(const std::string &path, const Headers &headers,
+               const std::string &body, const std::string &content_type);
+  Result Patch(const std::string &path, const Headers &headers,
+               const std::string &body, const std::string &content_type,
+               Progress progress);
+  Result Patch(const std::string &path, size_t content_length,
+               ContentProvider content_provider,
+               const std::string &content_type);
+  Result Patch(const std::string &path,
+               ContentProviderWithoutLength content_provider,
+               const std::string &content_type);
+  Result Patch(const std::string &path, const Headers &headers,
+               size_t content_length, ContentProvider content_provider,
+               const std::string &content_type);
+  Result Patch(const std::string &path, const Headers &headers,
+               ContentProviderWithoutLength content_provider,
+               const std::string &content_type);
+
+  Result Delete(const std::string &path);
+  Result Delete(const std::string &path, const Headers &headers);
+  Result Delete(const std::string &path, const char *body,
+                size_t content_length, const std::string &content_type);
+  Result Delete(const std::string &path, const char *body,
+                size_t content_length, const std::string &content_type,
+                Progress progress);
+  Result Delete(const std::string &path, const Headers &headers,
+                const char *body, size_t content_length,
+                const std::string &content_type);
+  Result Delete(const std::string &path, const Headers &headers,
+                const char *body, size_t content_length,
+                const std::string &content_type, Progress progress);
+  Result Delete(const std::string &path, const std::string &body,
+                const std::string &content_type);
+  Result Delete(const std::string &path, const std::string &body,
+                const std::string &content_type, Progress progress);
+  Result Delete(const std::string &path, const Headers &headers,
+                const std::string &body, const std::string &content_type);
+  Result Delete(const std::string &path, const Headers &headers,
+                const std::string &body, const std::string &content_type,
+                Progress progress);
+
+  Result Options(const std::string &path);
+  Result Options(const std::string &path, const Headers &headers);
+
+  bool send(Request &req, Response &res, Error &error);
+  Result send(const Request &req);
+
+  void stop();
+
+  std::string host() const;
+  int port() const;
+
+  size_t is_socket_open() const;
+  socket_t socket() const;
+
+  void set_hostname_addr_map(std::map<std::string, std::string> addr_map);
+
+  void set_default_headers(Headers headers);
+
+  void
+  set_header_writer(std::function<ssize_t(Stream &, Headers &)> const &writer);
+
+  void set_address_family(int family);
+  void set_tcp_nodelay(bool on);
+  void set_socket_options(SocketOptions socket_options);
+
+  void set_connection_timeout(time_t sec, time_t usec = 0);
+  template <class Rep, class Period>
+  void
+  set_connection_timeout(const std::chrono::duration<Rep, Period> &duration);
+
+  void set_read_timeout(time_t sec, time_t usec = 0);
+  template <class Rep, class Period>
+  void set_read_timeout(const std::chrono::duration<Rep, Period> &duration);
+
+  void set_write_timeout(time_t sec, time_t usec = 0);
+  template <class Rep, class Period>
+  void set_write_timeout(const std::chrono::duration<Rep, Period> &duration);
+
+  void set_max_timeout(time_t msec);
+  template <class Rep, class Period>
+  void set_max_timeout(const std::chrono::duration<Rep, Period> &duration);
+
+  void set_basic_auth(const std::string &username, const std::string &password);
+  void set_bearer_token_auth(const std::string &token);
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  void set_digest_auth(const std::string &username,
+                       const std::string &password);
+#endif
+
+  void set_keep_alive(bool on);
+  void set_follow_location(bool on);
+
+  void set_url_encode(bool on);
+
+  void set_compress(bool on);
+
+  void set_decompress(bool on);
+
+  void set_interface(const std::string &intf);
+
+  void set_proxy(const std::string &host, int port);
+  void set_proxy_basic_auth(const std::string &username,
+                            const std::string &password);
+  void set_proxy_bearer_token_auth(const std::string &token);
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  void set_proxy_digest_auth(const std::string &username,
+                             const std::string &password);
+#endif
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  void enable_server_certificate_verification(bool enabled);
+  void enable_server_hostname_verification(bool enabled);
+  void set_server_certificate_verifier(std::function<bool(SSL *ssl)> verifier);
+#endif
+
+  void set_logger(Logger logger);
+
+  // SSL
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  void set_ca_cert_path(const std::string &ca_cert_file_path,
+                        const std::string &ca_cert_dir_path = std::string());
+
+  void set_ca_cert_store(X509_STORE *ca_cert_store);
+  void load_ca_cert_store(const char *ca_cert, std::size_t size);
+
+  long get_openssl_verify_result() const;
+
+  SSL_CTX *ssl_context() const;
+#endif
+
+private:
+  std::unique_ptr<ClientImpl> cli_;
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  bool is_ssl_ = false;
+#endif
+};
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+class SSLServer : public Server {
+public:
+  SSLServer(const char *cert_path, const char *private_key_path,
+            const char *client_ca_cert_file_path = nullptr,
+            const char *client_ca_cert_dir_path = nullptr,
+            const char *private_key_password = nullptr);
+
+  SSLServer(X509 *cert, EVP_PKEY *private_key,
+            X509_STORE *client_ca_cert_store = nullptr);
+
+  SSLServer(
+      const std::function<bool(SSL_CTX &ssl_ctx)> &setup_ssl_ctx_callback);
+
+  ~SSLServer() override;
+
+  bool is_valid() const override;
+
+  SSL_CTX *ssl_context() const;
+
+  void update_certs(X509 *cert, EVP_PKEY *private_key,
+                    X509_STORE *client_ca_cert_store = nullptr);
+
+private:
+  bool process_and_close_socket(socket_t sock) override;
+
+  SSL_CTX *ctx_;
+  std::mutex ctx_mutex_;
+};
+
+class SSLClient final : public ClientImpl {
+public:
+  explicit SSLClient(const std::string &host);
+
+  explicit SSLClient(const std::string &host, int port);
+
+  explicit SSLClient(const std::string &host, int port,
+                     const std::string &client_cert_path,
+                     const std::string &client_key_path,
+                     const std::string &private_key_password = std::string());
+
+  explicit SSLClient(const std::string &host, int port, X509 *client_cert,
+                     EVP_PKEY *client_key,
+                     const std::string &private_key_password = std::string());
+
+  ~SSLClient() override;
+
+  bool is_valid() const override;
+
+  void set_ca_cert_store(X509_STORE *ca_cert_store);
+  void load_ca_cert_store(const char *ca_cert, std::size_t size);
+
+  long get_openssl_verify_result() const;
+
+  SSL_CTX *ssl_context() const;
+
+private:
+  bool create_and_connect_socket(Socket &socket, Error &error) override;
+  void shutdown_ssl(Socket &socket, bool shutdown_gracefully) override;
+  void shutdown_ssl_impl(Socket &socket, bool shutdown_gracefully);
+
+  bool
+  process_socket(const Socket &socket,
+                 std::chrono::time_point<std::chrono::steady_clock> start_time,
+                 std::function<bool(Stream &strm)> callback) override;
+  bool is_ssl() const override;
+
+  bool connect_with_proxy(
+      Socket &sock,
+      std::chrono::time_point<std::chrono::steady_clock> start_time,
+      Response &res, bool &success, Error &error);
+  bool initialize_ssl(Socket &socket, Error &error);
+
+  bool load_certs();
+
+  bool verify_host(X509 *server_cert) const;
+  bool verify_host_with_subject_alt_name(X509 *server_cert) const;
+  bool verify_host_with_common_name(X509 *server_cert) const;
+  bool check_host_name(const char *pattern, size_t pattern_len) const;
+
+  SSL_CTX *ctx_;
+  std::mutex ctx_mutex_;
+  std::once_flag initialize_cert_;
+
+  std::vector<std::string> host_components_;
+
+  long verify_result_ = 0;
+
+  friend class ClientImpl;
+};
+#endif
+
+/*
+ * Implementation of template methods.
+ */
+
+namespace detail {
+
+template <typename T, typename U>
+inline void duration_to_sec_and_usec(const T &duration, U callback) {
+  auto sec = std::chrono::duration_cast<std::chrono::seconds>(duration).count();
+  auto usec = std::chrono::duration_cast<std::chrono::microseconds>(
+                  duration - std::chrono::seconds(sec))
+                  .count();
+  callback(static_cast<time_t>(sec), static_cast<time_t>(usec));
+}
+
+inline bool is_numeric(const std::string &str) {
+  return !str.empty() && std::all_of(str.begin(), str.end(), ::isdigit);
+}
+
+inline uint64_t get_header_value_u64(const Headers &headers,
+                                     const std::string &key, uint64_t def,
+                                     size_t id, bool &is_invalid_value) {
+  is_invalid_value = false;
+  auto rng = headers.equal_range(key);
+  auto it = rng.first;
+  std::advance(it, static_cast<ssize_t>(id));
+  if (it != rng.second) {
+    if (is_numeric(it->second)) {
+      return std::strtoull(it->second.data(), nullptr, 10);
+    } else {
+      is_invalid_value = true;
+    }
+  }
+  return def;
+}
+
+inline uint64_t get_header_value_u64(const Headers &headers,
+                                     const std::string &key, uint64_t def,
+                                     size_t id) {
+  bool dummy = false;
+  return get_header_value_u64(headers, key, def, id, dummy);
+}
+
+} // namespace detail
+
+inline uint64_t Request::get_header_value_u64(const std::string &key,
+                                              uint64_t def, size_t id) const {
+  return detail::get_header_value_u64(headers, key, def, id);
+}
+
+inline uint64_t Response::get_header_value_u64(const std::string &key,
+                                               uint64_t def, size_t id) const {
+  return detail::get_header_value_u64(headers, key, def, id);
+}
+
+inline void default_socket_options(socket_t sock) {
+  int opt = 1;
+#ifdef _WIN32
+  setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
+             reinterpret_cast<const char *>(&opt), sizeof(opt));
+#else
+#ifdef SO_REUSEPORT
+  setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
+             reinterpret_cast<const void *>(&opt), sizeof(opt));
+#else
+  setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
+             reinterpret_cast<const void *>(&opt), sizeof(opt));
+#endif
+#endif
+}
+
+inline const char *status_message(int status) {
+  switch (status) {
+  case StatusCode::Continue_100: return "Continue";
+  case StatusCode::SwitchingProtocol_101: return "Switching Protocol";
+  case StatusCode::Processing_102: return "Processing";
+  case StatusCode::EarlyHints_103: return "Early Hints";
+  case StatusCode::OK_200: return "OK";
+  case StatusCode::Created_201: return "Created";
+  case StatusCode::Accepted_202: return "Accepted";
+  case StatusCode::NonAuthoritativeInformation_203:
+    return "Non-Authoritative Information";
+  case StatusCode::NoContent_204: return "No Content";
+  case StatusCode::ResetContent_205: return "Reset Content";
+  case StatusCode::PartialContent_206: return "Partial Content";
+  case StatusCode::MultiStatus_207: return "Multi-Status";
+  case StatusCode::AlreadyReported_208: return "Already Reported";
+  case StatusCode::IMUsed_226: return "IM Used";
+  case StatusCode::MultipleChoices_300: return "Multiple Choices";
+  case StatusCode::MovedPermanently_301: return "Moved Permanently";
+  case StatusCode::Found_302: return "Found";
+  case StatusCode::SeeOther_303: return "See Other";
+  case StatusCode::NotModified_304: return "Not Modified";
+  case StatusCode::UseProxy_305: return "Use Proxy";
+  case StatusCode::unused_306: return "unused";
+  case StatusCode::TemporaryRedirect_307: return "Temporary Redirect";
+  case StatusCode::PermanentRedirect_308: return "Permanent Redirect";
+  case StatusCode::BadRequest_400: return "Bad Request";
+  case StatusCode::Unauthorized_401: return "Unauthorized";
+  case StatusCode::PaymentRequired_402: return "Payment Required";
+  case StatusCode::Forbidden_403: return "Forbidden";
+  case StatusCode::NotFound_404: return "Not Found";
+  case StatusCode::MethodNotAllowed_405: return "Method Not Allowed";
+  case StatusCode::NotAcceptable_406: return "Not Acceptable";
+  case StatusCode::ProxyAuthenticationRequired_407:
+    return "Proxy Authentication Required";
+  case StatusCode::RequestTimeout_408: return "Request Timeout";
+  case StatusCode::Conflict_409: return "Conflict";
+  case StatusCode::Gone_410: return "Gone";
+  case StatusCode::LengthRequired_411: return "Length Required";
+  case StatusCode::PreconditionFailed_412: return "Precondition Failed";
+  case StatusCode::PayloadTooLarge_413: return "Payload Too Large";
+  case StatusCode::UriTooLong_414: return "URI Too Long";
+  case StatusCode::UnsupportedMediaType_415: return "Unsupported Media Type";
+  case StatusCode::RangeNotSatisfiable_416: return "Range Not Satisfiable";
+  case StatusCode::ExpectationFailed_417: return "Expectation Failed";
+  case StatusCode::ImATeapot_418: return "I'm a teapot";
+  case StatusCode::MisdirectedRequest_421: return "Misdirected Request";
+  case StatusCode::UnprocessableContent_422: return "Unprocessable Content";
+  case StatusCode::Locked_423: return "Locked";
+  case StatusCode::FailedDependency_424: return "Failed Dependency";
+  case StatusCode::TooEarly_425: return "Too Early";
+  case StatusCode::UpgradeRequired_426: return "Upgrade Required";
+  case StatusCode::PreconditionRequired_428: return "Precondition Required";
+  case StatusCode::TooManyRequests_429: return "Too Many Requests";
+  case StatusCode::RequestHeaderFieldsTooLarge_431:
+    return "Request Header Fields Too Large";
+  case StatusCode::UnavailableForLegalReasons_451:
+    return "Unavailable For Legal Reasons";
+  case StatusCode::NotImplemented_501: return "Not Implemented";
+  case StatusCode::BadGateway_502: return "Bad Gateway";
+  case StatusCode::ServiceUnavailable_503: return "Service Unavailable";
+  case StatusCode::GatewayTimeout_504: return "Gateway Timeout";
+  case StatusCode::HttpVersionNotSupported_505:
+    return "HTTP Version Not Supported";
+  case StatusCode::VariantAlsoNegotiates_506: return "Variant Also Negotiates";
+  case StatusCode::InsufficientStorage_507: return "Insufficient Storage";
+  case StatusCode::LoopDetected_508: return "Loop Detected";
+  case StatusCode::NotExtended_510: return "Not Extended";
+  case StatusCode::NetworkAuthenticationRequired_511:
+    return "Network Authentication Required";
+
+  default:
+  case StatusCode::InternalServerError_500: return "Internal Server Error";
+  }
+}
+
+inline std::string get_bearer_token_auth(const Request &req) {
+  if (req.has_header("Authorization")) {
+    static std::string BearerHeaderPrefix = "Bearer ";
+    return req.get_header_value("Authorization")
+        .substr(BearerHeaderPrefix.length());
+  }
+  return "";
+}
+
+template <class Rep, class Period>
+inline Server &
+Server::set_read_timeout(const std::chrono::duration<Rep, Period> &duration) {
+  detail::duration_to_sec_and_usec(
+      duration, [&](time_t sec, time_t usec) { set_read_timeout(sec, usec); });
+  return *this;
+}
+
+template <class Rep, class Period>
+inline Server &
+Server::set_write_timeout(const std::chrono::duration<Rep, Period> &duration) {
+  detail::duration_to_sec_and_usec(
+      duration, [&](time_t sec, time_t usec) { set_write_timeout(sec, usec); });
+  return *this;
+}
+
+template <class Rep, class Period>
+inline Server &
+Server::set_idle_interval(const std::chrono::duration<Rep, Period> &duration) {
+  detail::duration_to_sec_and_usec(
+      duration, [&](time_t sec, time_t usec) { set_idle_interval(sec, usec); });
+  return *this;
+}
+
+inline std::string to_string(const Error error) {
+  switch (error) {
+  case Error::Success: return "Success (no error)";
+  case Error::Connection: return "Could not establish connection";
+  case Error::BindIPAddress: return "Failed to bind IP address";
+  case Error::Read: return "Failed to read connection";
+  case Error::Write: return "Failed to write connection";
+  case Error::ExceedRedirectCount: return "Maximum redirect count exceeded";
+  case Error::Canceled: return "Connection handling canceled";
+  case Error::SSLConnection: return "SSL connection failed";
+  case Error::SSLLoadingCerts: return "SSL certificate loading failed";
+  case Error::SSLServerVerification: return "SSL server verification failed";
+  case Error::SSLServerHostnameVerification:
+    return "SSL server hostname verification failed";
+  case Error::UnsupportedMultipartBoundaryChars:
+    return "Unsupported HTTP multipart boundary characters";
+  case Error::Compression: return "Compression failed";
+  case Error::ConnectionTimeout: return "Connection timed out";
+  case Error::ProxyConnection: return "Proxy connection failed";
+  case Error::Unknown: return "Unknown";
+  default: break;
+  }
+
+  return "Invalid";
+}
+
+inline std::ostream &operator<<(std::ostream &os, const Error &obj) {
+  os << to_string(obj);
+  os << " (" << static_cast<std::underlying_type<Error>::type>(obj) << ')';
+  return os;
+}
+
+inline uint64_t Result::get_request_header_value_u64(const std::string &key,
+                                                     uint64_t def,
+                                                     size_t id) const {
+  return detail::get_header_value_u64(request_headers_, key, def, id);
+}
+
+template <class Rep, class Period>
+inline void ClientImpl::set_connection_timeout(
+    const std::chrono::duration<Rep, Period> &duration) {
+  detail::duration_to_sec_and_usec(duration, [&](time_t sec, time_t usec) {
+    set_connection_timeout(sec, usec);
+  });
+}
+
+template <class Rep, class Period>
+inline void ClientImpl::set_read_timeout(
+    const std::chrono::duration<Rep, Period> &duration) {
+  detail::duration_to_sec_and_usec(
+      duration, [&](time_t sec, time_t usec) { set_read_timeout(sec, usec); });
+}
+
+template <class Rep, class Period>
+inline void ClientImpl::set_write_timeout(
+    const std::chrono::duration<Rep, Period> &duration) {
+  detail::duration_to_sec_and_usec(
+      duration, [&](time_t sec, time_t usec) { set_write_timeout(sec, usec); });
+}
+
+template <class Rep, class Period>
+inline void ClientImpl::set_max_timeout(
+    const std::chrono::duration<Rep, Period> &duration) {
+  auto msec =
+      std::chrono::duration_cast<std::chrono::milliseconds>(duration).count();
+  set_max_timeout(msec);
+}
+
+template <class Rep, class Period>
+inline void Client::set_connection_timeout(
+    const std::chrono::duration<Rep, Period> &duration) {
+  cli_->set_connection_timeout(duration);
+}
+
+template <class Rep, class Period>
+inline void
+Client::set_read_timeout(const std::chrono::duration<Rep, Period> &duration) {
+  cli_->set_read_timeout(duration);
+}
+
+template <class Rep, class Period>
+inline void
+Client::set_write_timeout(const std::chrono::duration<Rep, Period> &duration) {
+  cli_->set_write_timeout(duration);
+}
+
+template <class Rep, class Period>
+inline void
+Client::set_max_timeout(const std::chrono::duration<Rep, Period> &duration) {
+  cli_->set_max_timeout(duration);
+}
+
+/*
+ * Forward declarations and types that will be part of the .h file if split into
+ * .h + .cc.
+ */
+
+std::string hosted_at(const std::string &hostname);
+
+void hosted_at(const std::string &hostname, std::vector<std::string> &addrs);
+
+std::string append_query_params(const std::string &path, const Params &params);
+
+std::pair<std::string, std::string> make_range_header(const Ranges &ranges);
+
+std::pair<std::string, std::string>
+make_basic_authentication_header(const std::string &username,
+                                 const std::string &password,
+                                 bool is_proxy = false);
+
+namespace detail {
+
+#if defined(_WIN32)
+inline std::wstring u8string_to_wstring(const char *s) {
+  std::wstring ws;
+  auto len = static_cast<int>(strlen(s));
+  auto wlen = ::MultiByteToWideChar(CP_UTF8, 0, s, len, nullptr, 0);
+  if (wlen > 0) {
+    ws.resize(wlen);
+    wlen = ::MultiByteToWideChar(
+        CP_UTF8, 0, s, len,
+        const_cast<LPWSTR>(reinterpret_cast<LPCWSTR>(ws.data())), wlen);
+    if (wlen != static_cast<int>(ws.size())) { ws.clear(); }
+  }
+  return ws;
+}
+#endif
+
+struct FileStat {
+  FileStat(const std::string &path);
+  bool is_file() const;
+  bool is_dir() const;
+
+private:
+#if defined(_WIN32)
+  struct _stat st_;
+#else
+  struct stat st_;
+#endif
+  int ret_ = -1;
+};
+
+std::string encode_query_param(const std::string &value);
+
+std::string decode_url(const std::string &s, bool convert_plus_to_space);
+
+void read_file(const std::string &path, std::string &out);
+
+std::string trim_copy(const std::string &s);
+
+void divide(
+    const char *data, std::size_t size, char d,
+    std::function<void(const char *, std::size_t, const char *, std::size_t)>
+        fn);
+
+void divide(
+    const std::string &str, char d,
+    std::function<void(const char *, std::size_t, const char *, std::size_t)>
+        fn);
+
+void split(const char *b, const char *e, char d,
+           std::function<void(const char *, const char *)> fn);
+
+void split(const char *b, const char *e, char d, size_t m,
+           std::function<void(const char *, const char *)> fn);
+
+bool process_client_socket(
+    socket_t sock, time_t read_timeout_sec, time_t read_timeout_usec,
+    time_t write_timeout_sec, time_t write_timeout_usec,
+    time_t max_timeout_msec,
+    std::chrono::time_point<std::chrono::steady_clock> start_time,
+    std::function<bool(Stream &)> callback);
+
+socket_t create_client_socket(const std::string &host, const std::string &ip,
+                              int port, int address_family, bool tcp_nodelay,
+                              bool ipv6_v6only, SocketOptions socket_options,
+                              time_t connection_timeout_sec,
+                              time_t connection_timeout_usec,
+                              time_t read_timeout_sec, time_t read_timeout_usec,
+                              time_t write_timeout_sec,
+                              time_t write_timeout_usec,
+                              const std::string &intf, Error &error);
+
+const char *get_header_value(const Headers &headers, const std::string &key,
+                             const char *def, size_t id);
+
+std::string params_to_query_str(const Params &params);
+
+void parse_query_text(const char *data, std::size_t size, Params &params);
+
+void parse_query_text(const std::string &s, Params &params);
+
+bool parse_multipart_boundary(const std::string &content_type,
+                              std::string &boundary);
+
+bool parse_range_header(const std::string &s, Ranges &ranges);
+
+int close_socket(socket_t sock);
+
+ssize_t send_socket(socket_t sock, const void *ptr, size_t size, int flags);
+
+ssize_t read_socket(socket_t sock, void *ptr, size_t size, int flags);
+
+enum class EncodingType { None = 0, Gzip, Brotli };
+
+EncodingType encoding_type(const Request &req, const Response &res);
+
+class BufferStream final : public Stream {
+public:
+  BufferStream() = default;
+  ~BufferStream() override = default;
+
+  bool is_readable() const override;
+  bool is_writable() const override;
+  ssize_t read(char *ptr, size_t size) override;
+  ssize_t write(const char *ptr, size_t size) override;
+  void get_remote_ip_and_port(std::string &ip, int &port) const override;
+  void get_local_ip_and_port(std::string &ip, int &port) const override;
+  socket_t socket() const override;
+  time_t duration() const override;
+
+  const std::string &get_buffer() const;
+
+private:
+  std::string buffer;
+  size_t position = 0;
+};
+
+class compressor {
+public:
+  virtual ~compressor() = default;
+
+  typedef std::function<bool(const char *data, size_t data_len)> Callback;
+  virtual bool compress(const char *data, size_t data_length, bool last,
+                        Callback callback) = 0;
+};
+
+class decompressor {
+public:
+  virtual ~decompressor() = default;
+
+  virtual bool is_valid() const = 0;
+
+  typedef std::function<bool(const char *data, size_t data_len)> Callback;
+  virtual bool decompress(const char *data, size_t data_length,
+                          Callback callback) = 0;
+};
+
+class nocompressor final : public compressor {
+public:
+  ~nocompressor() override = default;
+
+  bool compress(const char *data, size_t data_length, bool /*last*/,
+                Callback callback) override;
+};
+
+#ifdef CPPHTTPLIB_ZLIB_SUPPORT
+class gzip_compressor final : public compressor {
+public:
+  gzip_compressor();
+  ~gzip_compressor() override;
+
+  bool compress(const char *data, size_t data_length, bool last,
+                Callback callback) override;
+
+private:
+  bool is_valid_ = false;
+  z_stream strm_;
+};
+
+class gzip_decompressor final : public decompressor {
+public:
+  gzip_decompressor();
+  ~gzip_decompressor() override;
+
+  bool is_valid() const override;
+
+  bool decompress(const char *data, size_t data_length,
+                  Callback callback) override;
+
+private:
+  bool is_valid_ = false;
+  z_stream strm_;
+};
+#endif
+
+#ifdef CPPHTTPLIB_BROTLI_SUPPORT
+class brotli_compressor final : public compressor {
+public:
+  brotli_compressor();
+  ~brotli_compressor();
+
+  bool compress(const char *data, size_t data_length, bool last,
+                Callback callback) override;
+
+private:
+  BrotliEncoderState *state_ = nullptr;
+};
+
+class brotli_decompressor final : public decompressor {
+public:
+  brotli_decompressor();
+  ~brotli_decompressor();
+
+  bool is_valid() const override;
+
+  bool decompress(const char *data, size_t data_length,
+                  Callback callback) override;
+
+private:
+  BrotliDecoderResult decoder_r;
+  BrotliDecoderState *decoder_s = nullptr;
+};
+#endif
+
+// NOTE: until the read size reaches `fixed_buffer_size`, use `fixed_buffer`
+// to store data. The call can set memory on stack for performance.
+class stream_line_reader {
+public:
+  stream_line_reader(Stream &strm, char *fixed_buffer,
+                     size_t fixed_buffer_size);
+  const char *ptr() const;
+  size_t size() const;
+  bool end_with_crlf() const;
+  bool getline();
+
+private:
+  void append(char c);
+
+  Stream &strm_;
+  char *fixed_buffer_;
+  const size_t fixed_buffer_size_;
+  size_t fixed_buffer_used_size_ = 0;
+  std::string glowable_buffer_;
+};
+
+class mmap {
+public:
+  mmap(const char *path);
+  ~mmap();
+
+  bool open(const char *path);
+  void close();
+
+  bool is_open() const;
+  size_t size() const;
+  const char *data() const;
+
+private:
+#if defined(_WIN32)
+  HANDLE hFile_ = NULL;
+  HANDLE hMapping_ = NULL;
+#else
+  int fd_ = -1;
+#endif
+  size_t size_ = 0;
+  void *addr_ = nullptr;
+  bool is_open_empty_file = false;
+};
+
+// NOTE: https://www.rfc-editor.org/rfc/rfc9110#section-5
+namespace fields {
+
+inline bool is_token_char(char c) {
+  return std::isalnum(c) || c == '!' || c == '#' || c == '$' || c == '%' ||
+         c == '&' || c == '\'' || c == '*' || c == '+' || c == '-' ||
+         c == '.' || c == '^' || c == '_' || c == '`' || c == '|' || c == '~';
+}
+
+inline bool is_token(const std::string &s) {
+  if (s.empty()) { return false; }
+  for (auto c : s) {
+    if (!is_token_char(c)) { return false; }
+  }
+  return true;
+}
+
+inline bool is_field_name(const std::string &s) { return is_token(s); }
+
+inline bool is_vchar(char c) { return c >= 33 && c <= 126; }
+
+inline bool is_obs_text(char c) { return 128 <= static_cast<unsigned char>(c); }
+
+inline bool is_field_vchar(char c) { return is_vchar(c) || is_obs_text(c); }
+
+inline bool is_field_content(const std::string &s) {
+  if (s.empty()) { return true; }
+
+  if (s.size() == 1) {
+    return is_field_vchar(s[0]);
+  } else if (s.size() == 2) {
+    return is_field_vchar(s[0]) && is_field_vchar(s[1]);
+  } else {
+    size_t i = 0;
+
+    if (!is_field_vchar(s[i])) { return false; }
+    i++;
+
+    while (i < s.size() - 1) {
+      auto c = s[i++];
+      if (c == ' ' || c == '\t' || is_field_vchar(c)) {
+      } else {
+        return false;
+      }
+    }
+
+    return is_field_vchar(s[i]);
+  }
+}
+
+inline bool is_field_value(const std::string &s) { return is_field_content(s); }
+
+} // namespace fields
+
+} // namespace detail
+
+// ----------------------------------------------------------------------------
+
+/*
+ * Implementation that will be part of the .cc file if split into .h + .cc.
+ */
+
+namespace detail {
+
+inline bool is_hex(char c, int &v) {
+  if (0x20 <= c && isdigit(c)) {
+    v = c - '0';
+    return true;
+  } else if ('A' <= c && c <= 'F') {
+    v = c - 'A' + 10;
+    return true;
+  } else if ('a' <= c && c <= 'f') {
+    v = c - 'a' + 10;
+    return true;
+  }
+  return false;
+}
+
+inline bool from_hex_to_i(const std::string &s, size_t i, size_t cnt,
+                          int &val) {
+  if (i >= s.size()) { return false; }
+
+  val = 0;
+  for (; cnt; i++, cnt--) {
+    if (!s[i]) { return false; }
+    auto v = 0;
+    if (is_hex(s[i], v)) {
+      val = val * 16 + v;
+    } else {
+      return false;
+    }
+  }
+  return true;
+}
+
+inline std::string from_i_to_hex(size_t n) {
+  static const auto charset = "0123456789abcdef";
+  std::string ret;
+  do {
+    ret = charset[n & 15] + ret;
+    n >>= 4;
+  } while (n > 0);
+  return ret;
+}
+
+inline size_t to_utf8(int code, char *buff) {
+  if (code < 0x0080) {
+    buff[0] = static_cast<char>(code & 0x7F);
+    return 1;
+  } else if (code < 0x0800) {
+    buff[0] = static_cast<char>(0xC0 | ((code >> 6) & 0x1F));
+    buff[1] = static_cast<char>(0x80 | (code & 0x3F));
+    return 2;
+  } else if (code < 0xD800) {
+    buff[0] = static_cast<char>(0xE0 | ((code >> 12) & 0xF));
+    buff[1] = static_cast<char>(0x80 | ((code >> 6) & 0x3F));
+    buff[2] = static_cast<char>(0x80 | (code & 0x3F));
+    return 3;
+  } else if (code < 0xE000) { // D800 - DFFF is invalid...
+    return 0;
+  } else if (code < 0x10000) {
+    buff[0] = static_cast<char>(0xE0 | ((code >> 12) & 0xF));
+    buff[1] = static_cast<char>(0x80 | ((code >> 6) & 0x3F));
+    buff[2] = static_cast<char>(0x80 | (code & 0x3F));
+    return 3;
+  } else if (code < 0x110000) {
+    buff[0] = static_cast<char>(0xF0 | ((code >> 18) & 0x7));
+    buff[1] = static_cast<char>(0x80 | ((code >> 12) & 0x3F));
+    buff[2] = static_cast<char>(0x80 | ((code >> 6) & 0x3F));
+    buff[3] = static_cast<char>(0x80 | (code & 0x3F));
+    return 4;
+  }
+
+  // NOTREACHED
+  return 0;
+}
+
+// NOTE: This code came up with the following stackoverflow post:
+// https://stackoverflow.com/questions/180947/base64-decode-snippet-in-c
+inline std::string base64_encode(const std::string &in) {
+  static const auto lookup =
+      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+  std::string out;
+  out.reserve(in.size());
+
+  auto val = 0;
+  auto valb = -6;
+
+  for (auto c : in) {
+    val = (val << 8) + static_cast<uint8_t>(c);
+    valb += 8;
+    while (valb >= 0) {
+      out.push_back(lookup[(val >> valb) & 0x3F]);
+      valb -= 6;
+    }
+  }
+
+  if (valb > -6) { out.push_back(lookup[((val << 8) >> (valb + 8)) & 0x3F]); }
+
+  while (out.size() % 4) {
+    out.push_back('=');
+  }
+
+  return out;
+}
+
+inline bool is_valid_path(const std::string &path) {
+  size_t level = 0;
+  size_t i = 0;
+
+  // Skip slash
+  while (i < path.size() && path[i] == '/') {
+    i++;
+  }
+
+  while (i < path.size()) {
+    // Read component
+    auto beg = i;
+    while (i < path.size() && path[i] != '/') {
+      if (path[i] == '\0') {
+        return false;
+      } else if (path[i] == '\\') {
+        return false;
+      }
+      i++;
+    }
+
+    auto len = i - beg;
+    assert(len > 0);
+
+    if (!path.compare(beg, len, ".")) {
+      ;
+    } else if (!path.compare(beg, len, "..")) {
+      if (level == 0) { return false; }
+      level--;
+    } else {
+      level++;
+    }
+
+    // Skip slash
+    while (i < path.size() && path[i] == '/') {
+      i++;
+    }
+  }
+
+  return true;
+}
+
+inline FileStat::FileStat(const std::string &path) {
+#if defined(_WIN32)
+  auto wpath = u8string_to_wstring(path.c_str());
+  ret_ = _wstat(wpath.c_str(), &st_);
+#else
+  ret_ = stat(path.c_str(), &st_);
+#endif
+}
+inline bool FileStat::is_file() const {
+  return ret_ >= 0 && S_ISREG(st_.st_mode);
+}
+inline bool FileStat::is_dir() const {
+  return ret_ >= 0 && S_ISDIR(st_.st_mode);
+}
+
+inline std::string encode_query_param(const std::string &value) {
+  std::ostringstream escaped;
+  escaped.fill('0');
+  escaped << std::hex;
+
+  for (auto c : value) {
+    if (std::isalnum(static_cast<uint8_t>(c)) || c == '-' || c == '_' ||
+        c == '.' || c == '!' || c == '~' || c == '*' || c == '\'' || c == '(' ||
+        c == ')') {
+      escaped << c;
+    } else {
+      escaped << std::uppercase;
+      escaped << '%' << std::setw(2)
+              << static_cast<int>(static_cast<unsigned char>(c));
+      escaped << std::nouppercase;
+    }
+  }
+
+  return escaped.str();
+}
+
+inline std::string encode_url(const std::string &s) {
+  std::string result;
+  result.reserve(s.size());
+
+  for (size_t i = 0; s[i]; i++) {
+    switch (s[i]) {
+    case ' ': result += "%20"; break;
+    case '+': result += "%2B"; break;
+    case '\r': result += "%0D"; break;
+    case '\n': result += "%0A"; break;
+    case '\'': result += "%27"; break;
+    case ',': result += "%2C"; break;
+    // case ':': result += "%3A"; break; // ok? probably...
+    case ';': result += "%3B"; break;
+    default:
+      auto c = static_cast<uint8_t>(s[i]);
+      if (c >= 0x80) {
+        result += '%';
+        char hex[4];
+        auto len = snprintf(hex, sizeof(hex) - 1, "%02X", c);
+        assert(len == 2);
+        result.append(hex, static_cast<size_t>(len));
+      } else {
+        result += s[i];
+      }
+      break;
+    }
+  }
+
+  return result;
+}
+
+inline std::string decode_url(const std::string &s,
+                              bool convert_plus_to_space) {
+  std::string result;
+
+  for (size_t i = 0; i < s.size(); i++) {
+    if (s[i] == '%' && i + 1 < s.size()) {
+      if (s[i + 1] == 'u') {
+        auto val = 0;
+        if (from_hex_to_i(s, i + 2, 4, val)) {
+          // 4 digits Unicode codes
+          char buff[4];
+          size_t len = to_utf8(val, buff);
+          if (len > 0) { result.append(buff, len); }
+          i += 5; // 'u0000'
+        } else {
+          result += s[i];
+        }
+      } else {
+        auto val = 0;
+        if (from_hex_to_i(s, i + 1, 2, val)) {
+          // 2 digits hex codes
+          result += static_cast<char>(val);
+          i += 2; // '00'
+        } else {
+          result += s[i];
+        }
+      }
+    } else if (convert_plus_to_space && s[i] == '+') {
+      result += ' ';
+    } else {
+      result += s[i];
+    }
+  }
+
+  return result;
+}
+
+inline void read_file(const std::string &path, std::string &out) {
+  std::ifstream fs(path, std::ios_base::binary);
+  fs.seekg(0, std::ios_base::end);
+  auto size = fs.tellg();
+  fs.seekg(0);
+  out.resize(static_cast<size_t>(size));
+  fs.read(&out[0], static_cast<std::streamsize>(size));
+}
+
+inline std::string file_extension(const std::string &path) {
+  std::smatch m;
+  static auto re = std::regex("\\.([a-zA-Z0-9]+)$");
+  if (std::regex_search(path, m, re)) { return m[1].str(); }
+  return std::string();
+}
+
+inline bool is_space_or_tab(char c) { return c == ' ' || c == '\t'; }
+
+inline std::pair<size_t, size_t> trim(const char *b, const char *e, size_t left,
+                                      size_t right) {
+  while (b + left < e && is_space_or_tab(b[left])) {
+    left++;
+  }
+  while (right > 0 && is_space_or_tab(b[right - 1])) {
+    right--;
+  }
+  return std::make_pair(left, right);
+}
+
+inline std::string trim_copy(const std::string &s) {
+  auto r = trim(s.data(), s.data() + s.size(), 0, s.size());
+  return s.substr(r.first, r.second - r.first);
+}
+
+inline std::string trim_double_quotes_copy(const std::string &s) {
+  if (s.length() >= 2 && s.front() == '"' && s.back() == '"') {
+    return s.substr(1, s.size() - 2);
+  }
+  return s;
+}
+
+inline void
+divide(const char *data, std::size_t size, char d,
+       std::function<void(const char *, std::size_t, const char *, std::size_t)>
+           fn) {
+  const auto it = std::find(data, data + size, d);
+  const auto found = static_cast<std::size_t>(it != data + size);
+  const auto lhs_data = data;
+  const auto lhs_size = static_cast<std::size_t>(it - data);
+  const auto rhs_data = it + found;
+  const auto rhs_size = size - lhs_size - found;
+
+  fn(lhs_data, lhs_size, rhs_data, rhs_size);
+}
+
+inline void
+divide(const std::string &str, char d,
+       std::function<void(const char *, std::size_t, const char *, std::size_t)>
+           fn) {
+  divide(str.data(), str.size(), d, std::move(fn));
+}
+
+inline void split(const char *b, const char *e, char d,
+                  std::function<void(const char *, const char *)> fn) {
+  return split(b, e, d, (std::numeric_limits<size_t>::max)(), std::move(fn));
+}
+
+inline void split(const char *b, const char *e, char d, size_t m,
+                  std::function<void(const char *, const char *)> fn) {
+  size_t i = 0;
+  size_t beg = 0;
+  size_t count = 1;
+
+  while (e ? (b + i < e) : (b[i] != '\0')) {
+    if (b[i] == d && count < m) {
+      auto r = trim(b, e, beg, i);
+      if (r.first < r.second) { fn(&b[r.first], &b[r.second]); }
+      beg = i + 1;
+      count++;
+    }
+    i++;
+  }
+
+  if (i) {
+    auto r = trim(b, e, beg, i);
+    if (r.first < r.second) { fn(&b[r.first], &b[r.second]); }
+  }
+}
+
+inline stream_line_reader::stream_line_reader(Stream &strm, char *fixed_buffer,
+                                              size_t fixed_buffer_size)
+    : strm_(strm), fixed_buffer_(fixed_buffer),
+      fixed_buffer_size_(fixed_buffer_size) {}
+
+inline const char *stream_line_reader::ptr() const {
+  if (glowable_buffer_.empty()) {
+    return fixed_buffer_;
+  } else {
+    return glowable_buffer_.data();
+  }
+}
+
+inline size_t stream_line_reader::size() const {
+  if (glowable_buffer_.empty()) {
+    return fixed_buffer_used_size_;
+  } else {
+    return glowable_buffer_.size();
+  }
+}
+
+inline bool stream_line_reader::end_with_crlf() const {
+  auto end = ptr() + size();
+  return size() >= 2 && end[-2] == '\r' && end[-1] == '\n';
+}
+
+inline bool stream_line_reader::getline() {
+  fixed_buffer_used_size_ = 0;
+  glowable_buffer_.clear();
+
+#ifndef CPPHTTPLIB_ALLOW_LF_AS_LINE_TERMINATOR
+  char prev_byte = 0;
+#endif
+
+  for (size_t i = 0;; i++) {
+    char byte;
+    auto n = strm_.read(&byte, 1);
+
+    if (n < 0) {
+      return false;
+    } else if (n == 0) {
+      if (i == 0) {
+        return false;
+      } else {
+        break;
+      }
+    }
+
+    append(byte);
+
+#ifdef CPPHTTPLIB_ALLOW_LF_AS_LINE_TERMINATOR
+    if (byte == '\n') { break; }
+#else
+    if (prev_byte == '\r' && byte == '\n') { break; }
+    prev_byte = byte;
+#endif
+  }
+
+  return true;
+}
+
+inline void stream_line_reader::append(char c) {
+  if (fixed_buffer_used_size_ < fixed_buffer_size_ - 1) {
+    fixed_buffer_[fixed_buffer_used_size_++] = c;
+    fixed_buffer_[fixed_buffer_used_size_] = '\0';
+  } else {
+    if (glowable_buffer_.empty()) {
+      assert(fixed_buffer_[fixed_buffer_used_size_] == '\0');
+      glowable_buffer_.assign(fixed_buffer_, fixed_buffer_used_size_);
+    }
+    glowable_buffer_ += c;
+  }
+}
+
+inline mmap::mmap(const char *path) { open(path); }
+
+inline mmap::~mmap() { close(); }
+
+inline bool mmap::open(const char *path) {
+  close();
+
+#if defined(_WIN32)
+  auto wpath = u8string_to_wstring(path);
+  if (wpath.empty()) { return false; }
+
+#if _WIN32_WINNT >= _WIN32_WINNT_WIN8
+  hFile_ = ::CreateFile2(wpath.c_str(), GENERIC_READ, FILE_SHARE_READ,
+                         OPEN_EXISTING, NULL);
+#else
+  hFile_ = ::CreateFileW(wpath.c_str(), GENERIC_READ, FILE_SHARE_READ, NULL,
+                         OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+#endif
+
+  if (hFile_ == INVALID_HANDLE_VALUE) { return false; }
+
+  LARGE_INTEGER size{};
+  if (!::GetFileSizeEx(hFile_, &size)) { return false; }
+  // If the following line doesn't compile due to QuadPart, update Windows SDK.
+  // See:
+  // https://github.com/yhirose/cpp-httplib/issues/1903#issuecomment-2316520721
+  if (static_cast<ULONGLONG>(size.QuadPart) >
+      (std::numeric_limits<decltype(size_)>::max)()) {
+    // `size_t` might be 32-bits, on 32-bits Windows.
+    return false;
+  }
+  size_ = static_cast<size_t>(size.QuadPart);
+
+#if _WIN32_WINNT >= _WIN32_WINNT_WIN8
+  hMapping_ =
+      ::CreateFileMappingFromApp(hFile_, NULL, PAGE_READONLY, size_, NULL);
+#else
+  hMapping_ = ::CreateFileMappingW(hFile_, NULL, PAGE_READONLY, 0, 0, NULL);
+#endif
+
+  // Special treatment for an empty file...
+  if (hMapping_ == NULL && size_ == 0) {
+    close();
+    is_open_empty_file = true;
+    return true;
+  }
+
+  if (hMapping_ == NULL) {
+    close();
+    return false;
+  }
+
+#if _WIN32_WINNT >= _WIN32_WINNT_WIN8
+  addr_ = ::MapViewOfFileFromApp(hMapping_, FILE_MAP_READ, 0, 0);
+#else
+  addr_ = ::MapViewOfFile(hMapping_, FILE_MAP_READ, 0, 0, 0);
+#endif
+
+  if (addr_ == nullptr) {
+    close();
+    return false;
+  }
+#else
+  fd_ = ::open(path, O_RDONLY);
+  if (fd_ == -1) { return false; }
+
+  struct stat sb;
+  if (fstat(fd_, &sb) == -1) {
+    close();
+    return false;
+  }
+  size_ = static_cast<size_t>(sb.st_size);
+
+  addr_ = ::mmap(NULL, size_, PROT_READ, MAP_PRIVATE, fd_, 0);
+
+  // Special treatment for an empty file...
+  if (addr_ == MAP_FAILED && size_ == 0) {
+    close();
+    is_open_empty_file = true;
+    return false;
+  }
+#endif
+
+  return true;
+}
+
+inline bool mmap::is_open() const {
+  return is_open_empty_file ? true : addr_ != nullptr;
+}
+
+inline size_t mmap::size() const { return size_; }
+
+inline const char *mmap::data() const {
+  return is_open_empty_file ? "" : static_cast<const char *>(addr_);
+}
+
+inline void mmap::close() {
+#if defined(_WIN32)
+  if (addr_) {
+    ::UnmapViewOfFile(addr_);
+    addr_ = nullptr;
+  }
+
+  if (hMapping_) {
+    ::CloseHandle(hMapping_);
+    hMapping_ = NULL;
+  }
+
+  if (hFile_ != INVALID_HANDLE_VALUE) {
+    ::CloseHandle(hFile_);
+    hFile_ = INVALID_HANDLE_VALUE;
+  }
+
+  is_open_empty_file = false;
+#else
+  if (addr_ != nullptr) {
+    munmap(addr_, size_);
+    addr_ = nullptr;
+  }
+
+  if (fd_ != -1) {
+    ::close(fd_);
+    fd_ = -1;
+  }
+#endif
+  size_ = 0;
+}
+inline int close_socket(socket_t sock) {
+#ifdef _WIN32
+  return closesocket(sock);
+#else
+  return close(sock);
+#endif
+}
+
+template <typename T> inline ssize_t handle_EINTR(T fn) {
+  ssize_t res = 0;
+  while (true) {
+    res = fn();
+    if (res < 0 && errno == EINTR) {
+      std::this_thread::sleep_for(std::chrono::microseconds{1});
+      continue;
+    }
+    break;
+  }
+  return res;
+}
+
+inline ssize_t read_socket(socket_t sock, void *ptr, size_t size, int flags) {
+  return handle_EINTR([&]() {
+    return recv(sock,
+#ifdef _WIN32
+                static_cast<char *>(ptr), static_cast<int>(size),
+#else
+                ptr, size,
+#endif
+                flags);
+  });
+}
+
+inline ssize_t send_socket(socket_t sock, const void *ptr, size_t size,
+                           int flags) {
+  return handle_EINTR([&]() {
+    return send(sock,
+#ifdef _WIN32
+                static_cast<const char *>(ptr), static_cast<int>(size),
+#else
+                ptr, size,
+#endif
+                flags);
+  });
+}
+
+template <bool Read>
+inline ssize_t select_impl(socket_t sock, time_t sec, time_t usec) {
+#ifdef CPPHTTPLIB_USE_POLL
+  struct pollfd pfd;
+  pfd.fd = sock;
+  pfd.events = (Read ? POLLIN : POLLOUT);
+
+  auto timeout = static_cast<int>(sec * 1000 + usec / 1000);
+
+  return handle_EINTR([&]() { return poll(&pfd, 1, timeout); });
+#else
+#ifndef _WIN32
+  if (sock >= FD_SETSIZE) { return -1; }
+#endif
+
+  fd_set fds, *rfds, *wfds;
+  FD_ZERO(&fds);
+  FD_SET(sock, &fds);
+  rfds = (Read ? &fds : nullptr);
+  wfds = (Read ? nullptr : &fds);
+
+  timeval tv;
+  tv.tv_sec = static_cast<long>(sec);
+  tv.tv_usec = static_cast<decltype(tv.tv_usec)>(usec);
+
+  return handle_EINTR([&]() {
+    return select(static_cast<int>(sock + 1), rfds, wfds, nullptr, &tv);
+  });
+#endif
+}
+
+inline ssize_t select_read(socket_t sock, time_t sec, time_t usec) {
+  return select_impl<true>(sock, sec, usec);
+}
+
+inline ssize_t select_write(socket_t sock, time_t sec, time_t usec) {
+  return select_impl<false>(sock, sec, usec);
+}
+
+inline Error wait_until_socket_is_ready(socket_t sock, time_t sec,
+                                        time_t usec) {
+#ifdef CPPHTTPLIB_USE_POLL
+  struct pollfd pfd_read;
+  pfd_read.fd = sock;
+  pfd_read.events = POLLIN | POLLOUT;
+
+  auto timeout = static_cast<int>(sec * 1000 + usec / 1000);
+
+  auto poll_res = handle_EINTR([&]() { return poll(&pfd_read, 1, timeout); });
+
+  if (poll_res == 0) { return Error::ConnectionTimeout; }
+
+  if (poll_res > 0 && pfd_read.revents & (POLLIN | POLLOUT)) {
+    auto error = 0;
+    socklen_t len = sizeof(error);
+    auto res = getsockopt(sock, SOL_SOCKET, SO_ERROR,
+                          reinterpret_cast<char *>(&error), &len);
+    auto successful = res >= 0 && !error;
+    return successful ? Error::Success : Error::Connection;
+  }
+
+  return Error::Connection;
+#else
+#ifndef _WIN32
+  if (sock >= FD_SETSIZE) { return Error::Connection; }
+#endif
+
+  fd_set fdsr;
+  FD_ZERO(&fdsr);
+  FD_SET(sock, &fdsr);
+
+  auto fdsw = fdsr;
+  auto fdse = fdsr;
+
+  timeval tv;
+  tv.tv_sec = static_cast<long>(sec);
+  tv.tv_usec = static_cast<decltype(tv.tv_usec)>(usec);
+
+  auto ret = handle_EINTR([&]() {
+    return select(static_cast<int>(sock + 1), &fdsr, &fdsw, &fdse, &tv);
+  });
+
+  if (ret == 0) { return Error::ConnectionTimeout; }
+
+  if (ret > 0 && (FD_ISSET(sock, &fdsr) || FD_ISSET(sock, &fdsw))) {
+    auto error = 0;
+    socklen_t len = sizeof(error);
+    auto res = getsockopt(sock, SOL_SOCKET, SO_ERROR,
+                          reinterpret_cast<char *>(&error), &len);
+    auto successful = res >= 0 && !error;
+    return successful ? Error::Success : Error::Connection;
+  }
+  return Error::Connection;
+#endif
+}
+
+inline bool is_socket_alive(socket_t sock) {
+  const auto val = detail::select_read(sock, 0, 0);
+  if (val == 0) {
+    return true;
+  } else if (val < 0 && errno == EBADF) {
+    return false;
+  }
+  char buf[1];
+  return detail::read_socket(sock, &buf[0], sizeof(buf), MSG_PEEK) > 0;
+}
+
+class SocketStream final : public Stream {
+public:
+  SocketStream(socket_t sock, time_t read_timeout_sec, time_t read_timeout_usec,
+               time_t write_timeout_sec, time_t write_timeout_usec,
+               time_t max_timeout_msec = 0,
+               std::chrono::time_point<std::chrono::steady_clock> start_time =
+                   std::chrono::steady_clock::time_point::min());
+  ~SocketStream() override;
+
+  bool is_readable() const override;
+  bool is_writable() const override;
+  ssize_t read(char *ptr, size_t size) override;
+  ssize_t write(const char *ptr, size_t size) override;
+  void get_remote_ip_and_port(std::string &ip, int &port) const override;
+  void get_local_ip_and_port(std::string &ip, int &port) const override;
+  socket_t socket() const override;
+  time_t duration() const override;
+
+private:
+  socket_t sock_;
+  time_t read_timeout_sec_;
+  time_t read_timeout_usec_;
+  time_t write_timeout_sec_;
+  time_t write_timeout_usec_;
+  time_t max_timeout_msec_;
+  const std::chrono::time_point<std::chrono::steady_clock> start_time;
+
+  std::vector<char> read_buff_;
+  size_t read_buff_off_ = 0;
+  size_t read_buff_content_size_ = 0;
+
+  static const size_t read_buff_size_ = 1024l * 4;
+};
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+class SSLSocketStream final : public Stream {
+public:
+  SSLSocketStream(
+      socket_t sock, SSL *ssl, time_t read_timeout_sec,
+      time_t read_timeout_usec, time_t write_timeout_sec,
+      time_t write_timeout_usec, time_t max_timeout_msec = 0,
+      std::chrono::time_point<std::chrono::steady_clock> start_time =
+          std::chrono::steady_clock::time_point::min());
+  ~SSLSocketStream() override;
+
+  bool is_readable() const override;
+  bool is_writable() const override;
+  ssize_t read(char *ptr, size_t size) override;
+  ssize_t write(const char *ptr, size_t size) override;
+  void get_remote_ip_and_port(std::string &ip, int &port) const override;
+  void get_local_ip_and_port(std::string &ip, int &port) const override;
+  socket_t socket() const override;
+  time_t duration() const override;
+
+private:
+  socket_t sock_;
+  SSL *ssl_;
+  time_t read_timeout_sec_;
+  time_t read_timeout_usec_;
+  time_t write_timeout_sec_;
+  time_t write_timeout_usec_;
+  time_t max_timeout_msec_;
+  const std::chrono::time_point<std::chrono::steady_clock> start_time;
+};
+#endif
+
+inline bool keep_alive(const std::atomic<socket_t> &svr_sock, socket_t sock,
+                       time_t keep_alive_timeout_sec) {
+  using namespace std::chrono;
+
+  const auto interval_usec =
+      CPPHTTPLIB_KEEPALIVE_TIMEOUT_CHECK_INTERVAL_USECOND;
+
+  // Avoid expensive `steady_clock::now()` call for the first time
+  if (select_read(sock, 0, interval_usec) > 0) { return true; }
+
+  const auto start = steady_clock::now() - microseconds{interval_usec};
+  const auto timeout = seconds{keep_alive_timeout_sec};
+
+  while (true) {
+    if (svr_sock == INVALID_SOCKET) {
+      break; // Server socket is closed
+    }
+
+    auto val = select_read(sock, 0, interval_usec);
+    if (val < 0) {
+      break; // Ssocket error
+    } else if (val == 0) {
+      if (steady_clock::now() - start > timeout) {
+        break; // Timeout
+      }
+    } else {
+      return true; // Ready for read
+    }
+  }
+
+  return false;
+}
+
+template <typename T>
+inline bool
+process_server_socket_core(const std::atomic<socket_t> &svr_sock, socket_t sock,
+                           size_t keep_alive_max_count,
+                           time_t keep_alive_timeout_sec, T callback) {
+  assert(keep_alive_max_count > 0);
+  auto ret = false;
+  auto count = keep_alive_max_count;
+  while (count > 0 && keep_alive(svr_sock, sock, keep_alive_timeout_sec)) {
+    auto close_connection = count == 1;
+    auto connection_closed = false;
+    ret = callback(close_connection, connection_closed);
+    if (!ret || connection_closed) { break; }
+    count--;
+  }
+  return ret;
+}
+
+template <typename T>
+inline bool
+process_server_socket(const std::atomic<socket_t> &svr_sock, socket_t sock,
+                      size_t keep_alive_max_count,
+                      time_t keep_alive_timeout_sec, time_t read_timeout_sec,
+                      time_t read_timeout_usec, time_t write_timeout_sec,
+                      time_t write_timeout_usec, T callback) {
+  return process_server_socket_core(
+      svr_sock, sock, keep_alive_max_count, keep_alive_timeout_sec,
+      [&](bool close_connection, bool &connection_closed) {
+        SocketStream strm(sock, read_timeout_sec, read_timeout_usec,
+                          write_timeout_sec, write_timeout_usec);
+        return callback(strm, close_connection, connection_closed);
+      });
+}
+
+inline bool process_client_socket(
+    socket_t sock, time_t read_timeout_sec, time_t read_timeout_usec,
+    time_t write_timeout_sec, time_t write_timeout_usec,
+    time_t max_timeout_msec,
+    std::chrono::time_point<std::chrono::steady_clock> start_time,
+    std::function<bool(Stream &)> callback) {
+  SocketStream strm(sock, read_timeout_sec, read_timeout_usec,
+                    write_timeout_sec, write_timeout_usec, max_timeout_msec,
+                    start_time);
+  return callback(strm);
+}
+
+inline int shutdown_socket(socket_t sock) {
+#ifdef _WIN32
+  return shutdown(sock, SD_BOTH);
+#else
+  return shutdown(sock, SHUT_RDWR);
+#endif
+}
+
+inline std::string escape_abstract_namespace_unix_domain(const std::string &s) {
+  if (s.size() > 1 && s[0] == '\0') {
+    auto ret = s;
+    ret[0] = '@';
+    return ret;
+  }
+  return s;
+}
+
+inline std::string
+unescape_abstract_namespace_unix_domain(const std::string &s) {
+  if (s.size() > 1 && s[0] == '@') {
+    auto ret = s;
+    ret[0] = '\0';
+    return ret;
+  }
+  return s;
+}
+
+template <typename BindOrConnect>
+socket_t create_socket(const std::string &host, const std::string &ip, int port,
+                       int address_family, int socket_flags, bool tcp_nodelay,
+                       bool ipv6_v6only, SocketOptions socket_options,
+                       BindOrConnect bind_or_connect) {
+  // Get address info
+  const char *node = nullptr;
+  struct addrinfo hints;
+  struct addrinfo *result;
+
+  memset(&hints, 0, sizeof(struct addrinfo));
+  hints.ai_socktype = SOCK_STREAM;
+  hints.ai_protocol = IPPROTO_IP;
+
+  if (!ip.empty()) {
+    node = ip.c_str();
+    // Ask getaddrinfo to convert IP in c-string to address
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_flags = AI_NUMERICHOST;
+  } else {
+    if (!host.empty()) { node = host.c_str(); }
+    hints.ai_family = address_family;
+    hints.ai_flags = socket_flags;
+  }
+
+#ifndef _WIN32
+  if (hints.ai_family == AF_UNIX) {
+    const auto addrlen = host.length();
+    if (addrlen > sizeof(sockaddr_un::sun_path)) { return INVALID_SOCKET; }
+
+#ifdef SOCK_CLOEXEC
+    auto sock = socket(hints.ai_family, hints.ai_socktype | SOCK_CLOEXEC,
+                       hints.ai_protocol);
+#else
+    auto sock = socket(hints.ai_family, hints.ai_socktype, hints.ai_protocol);
+#endif
+
+    if (sock != INVALID_SOCKET) {
+      sockaddr_un addr{};
+      addr.sun_family = AF_UNIX;
+
+      auto unescaped_host = unescape_abstract_namespace_unix_domain(host);
+      std::copy(unescaped_host.begin(), unescaped_host.end(), addr.sun_path);
+
+      hints.ai_addr = reinterpret_cast<sockaddr *>(&addr);
+      hints.ai_addrlen = static_cast<socklen_t>(
+          sizeof(addr) - sizeof(addr.sun_path) + addrlen);
+
+#ifndef SOCK_CLOEXEC
+      fcntl(sock, F_SETFD, FD_CLOEXEC);
+#endif
+
+      if (socket_options) { socket_options(sock); }
+
+      bool dummy;
+      if (!bind_or_connect(sock, hints, dummy)) {
+        close_socket(sock);
+        sock = INVALID_SOCKET;
+      }
+    }
+    return sock;
+  }
+#endif
+
+  auto service = std::to_string(port);
+
+  if (getaddrinfo(node, service.c_str(), &hints, &result)) {
+#if defined __linux__ && !defined __ANDROID__
+    res_init();
+#endif
+    return INVALID_SOCKET;
+  }
+  auto se = detail::scope_exit([&] { freeaddrinfo(result); });
+
+  for (auto rp = result; rp; rp = rp->ai_next) {
+    // Create a socket
+#ifdef _WIN32
+    auto sock =
+        WSASocketW(rp->ai_family, rp->ai_socktype, rp->ai_protocol, nullptr, 0,
+                   WSA_FLAG_NO_HANDLE_INHERIT | WSA_FLAG_OVERLAPPED);
+    /**
+     * Since the WSA_FLAG_NO_HANDLE_INHERIT is only supported on Windows 7 SP1
+     * and above the socket creation fails on older Windows Systems.
+     *
+     * Let's try to create a socket the old way in this case.
+     *
+     * Reference:
+     * https://docs.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-wsasocketa
+     *
+     * WSA_FLAG_NO_HANDLE_INHERIT:
+     * This flag is supported on Windows 7 with SP1, Windows Server 2008 R2 with
+     * SP1, and later
+     *
+     */
+    if (sock == INVALID_SOCKET) {
+      sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+    }
+#else
+
+#ifdef SOCK_CLOEXEC
+    auto sock =
+        socket(rp->ai_family, rp->ai_socktype | SOCK_CLOEXEC, rp->ai_protocol);
+#else
+    auto sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+#endif
+
+#endif
+    if (sock == INVALID_SOCKET) { continue; }
+
+#if !defined _WIN32 && !defined SOCK_CLOEXEC
+    if (fcntl(sock, F_SETFD, FD_CLOEXEC) == -1) {
+      close_socket(sock);
+      continue;
+    }
+#endif
+
+    if (tcp_nodelay) {
+      auto opt = 1;
+#ifdef _WIN32
+      setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
+                 reinterpret_cast<const char *>(&opt), sizeof(opt));
+#else
+      setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
+                 reinterpret_cast<const void *>(&opt), sizeof(opt));
+#endif
+    }
+
+    if (rp->ai_family == AF_INET6) {
+      auto opt = ipv6_v6only ? 1 : 0;
+#ifdef _WIN32
+      setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
+                 reinterpret_cast<const char *>(&opt), sizeof(opt));
+#else
+      setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
+                 reinterpret_cast<const void *>(&opt), sizeof(opt));
+#endif
+    }
+
+    if (socket_options) { socket_options(sock); }
+
+    // bind or connect
+    auto quit = false;
+    if (bind_or_connect(sock, *rp, quit)) { return sock; }
+
+    close_socket(sock);
+
+    if (quit) { break; }
+  }
+
+  return INVALID_SOCKET;
+}
+
+inline void set_nonblocking(socket_t sock, bool nonblocking) {
+#ifdef _WIN32
+  auto flags = nonblocking ? 1UL : 0UL;
+  ioctlsocket(sock, FIONBIO, &flags);
+#else
+  auto flags = fcntl(sock, F_GETFL, 0);
+  fcntl(sock, F_SETFL,
+        nonblocking ? (flags | O_NONBLOCK) : (flags & (~O_NONBLOCK)));
+#endif
+}
+
+inline bool is_connection_error() {
+#ifdef _WIN32
+  return WSAGetLastError() != WSAEWOULDBLOCK;
+#else
+  return errno != EINPROGRESS;
+#endif
+}
+
+inline bool bind_ip_address(socket_t sock, const std::string &host) {
+  struct addrinfo hints;
+  struct addrinfo *result;
+
+  memset(&hints, 0, sizeof(struct addrinfo));
+  hints.ai_family = AF_UNSPEC;
+  hints.ai_socktype = SOCK_STREAM;
+  hints.ai_protocol = 0;
+
+  if (getaddrinfo(host.c_str(), "0", &hints, &result)) { return false; }
+  auto se = detail::scope_exit([&] { freeaddrinfo(result); });
+
+  auto ret = false;
+  for (auto rp = result; rp; rp = rp->ai_next) {
+    const auto &ai = *rp;
+    if (!::bind(sock, ai.ai_addr, static_cast<socklen_t>(ai.ai_addrlen))) {
+      ret = true;
+      break;
+    }
+  }
+
+  return ret;
+}
+
+#if !defined _WIN32 && !defined ANDROID && !defined _AIX && !defined __MVS__
+#define USE_IF2IP
+#endif
+
+#ifdef USE_IF2IP
+inline std::string if2ip(int address_family, const std::string &ifn) {
+  struct ifaddrs *ifap;
+  getifaddrs(&ifap);
+  auto se = detail::scope_exit([&] { freeifaddrs(ifap); });
+
+  std::string addr_candidate;
+  for (auto ifa = ifap; ifa; ifa = ifa->ifa_next) {
+    if (ifa->ifa_addr && ifn == ifa->ifa_name &&
+        (AF_UNSPEC == address_family ||
+         ifa->ifa_addr->sa_family == address_family)) {
+      if (ifa->ifa_addr->sa_family == AF_INET) {
+        auto sa = reinterpret_cast<struct sockaddr_in *>(ifa->ifa_addr);
+        char buf[INET_ADDRSTRLEN];
+        if (inet_ntop(AF_INET, &sa->sin_addr, buf, INET_ADDRSTRLEN)) {
+          return std::string(buf, INET_ADDRSTRLEN);
+        }
+      } else if (ifa->ifa_addr->sa_family == AF_INET6) {
+        auto sa = reinterpret_cast<struct sockaddr_in6 *>(ifa->ifa_addr);
+        if (!IN6_IS_ADDR_LINKLOCAL(&sa->sin6_addr)) {
+          char buf[INET6_ADDRSTRLEN] = {};
+          if (inet_ntop(AF_INET6, &sa->sin6_addr, buf, INET6_ADDRSTRLEN)) {
+            // equivalent to mac's IN6_IS_ADDR_UNIQUE_LOCAL
+            auto s6_addr_head = sa->sin6_addr.s6_addr[0];
+            if (s6_addr_head == 0xfc || s6_addr_head == 0xfd) {
+              addr_candidate = std::string(buf, INET6_ADDRSTRLEN);
+            } else {
+              return std::string(buf, INET6_ADDRSTRLEN);
+            }
+          }
+        }
+      }
+    }
+  }
+  return addr_candidate;
+}
+#endif
+
+inline socket_t create_client_socket(
+    const std::string &host, const std::string &ip, int port,
+    int address_family, bool tcp_nodelay, bool ipv6_v6only,
+    SocketOptions socket_options, time_t connection_timeout_sec,
+    time_t connection_timeout_usec, time_t read_timeout_sec,
+    time_t read_timeout_usec, time_t write_timeout_sec,
+    time_t write_timeout_usec, const std::string &intf, Error &error) {
+  auto sock = create_socket(
+      host, ip, port, address_family, 0, tcp_nodelay, ipv6_v6only,
+      std::move(socket_options),
+      [&](socket_t sock2, struct addrinfo &ai, bool &quit) -> bool {
+        if (!intf.empty()) {
+#ifdef USE_IF2IP
+          auto ip_from_if = if2ip(address_family, intf);
+          if (ip_from_if.empty()) { ip_from_if = intf; }
+          if (!bind_ip_address(sock2, ip_from_if)) {
+            error = Error::BindIPAddress;
+            return false;
+          }
+#endif
+        }
+
+        set_nonblocking(sock2, true);
+
+        auto ret =
+            ::connect(sock2, ai.ai_addr, static_cast<socklen_t>(ai.ai_addrlen));
+
+        if (ret < 0) {
+          if (is_connection_error()) {
+            error = Error::Connection;
+            return false;
+          }
+          error = wait_until_socket_is_ready(sock2, connection_timeout_sec,
+                                             connection_timeout_usec);
+          if (error != Error::Success) {
+            if (error == Error::ConnectionTimeout) { quit = true; }
+            return false;
+          }
+        }
+
+        set_nonblocking(sock2, false);
+
+        {
+#ifdef _WIN32
+          auto timeout = static_cast<uint32_t>(read_timeout_sec * 1000 +
+                                               read_timeout_usec / 1000);
+          setsockopt(sock2, SOL_SOCKET, SO_RCVTIMEO,
+                     reinterpret_cast<const char *>(&timeout), sizeof(timeout));
+#else
+          timeval tv;
+          tv.tv_sec = static_cast<long>(read_timeout_sec);
+          tv.tv_usec = static_cast<decltype(tv.tv_usec)>(read_timeout_usec);
+          setsockopt(sock2, SOL_SOCKET, SO_RCVTIMEO,
+                     reinterpret_cast<const void *>(&tv), sizeof(tv));
+#endif
+        }
+        {
+
+#ifdef _WIN32
+          auto timeout = static_cast<uint32_t>(write_timeout_sec * 1000 +
+                                               write_timeout_usec / 1000);
+          setsockopt(sock2, SOL_SOCKET, SO_SNDTIMEO,
+                     reinterpret_cast<const char *>(&timeout), sizeof(timeout));
+#else
+          timeval tv;
+          tv.tv_sec = static_cast<long>(write_timeout_sec);
+          tv.tv_usec = static_cast<decltype(tv.tv_usec)>(write_timeout_usec);
+          setsockopt(sock2, SOL_SOCKET, SO_SNDTIMEO,
+                     reinterpret_cast<const void *>(&tv), sizeof(tv));
+#endif
+        }
+
+        error = Error::Success;
+        return true;
+      });
+
+  if (sock != INVALID_SOCKET) {
+    error = Error::Success;
+  } else {
+    if (error == Error::Success) { error = Error::Connection; }
+  }
+
+  return sock;
+}
+
+inline bool get_ip_and_port(const struct sockaddr_storage &addr,
+                            socklen_t addr_len, std::string &ip, int &port) {
+  if (addr.ss_family == AF_INET) {
+    port = ntohs(reinterpret_cast<const struct sockaddr_in *>(&addr)->sin_port);
+  } else if (addr.ss_family == AF_INET6) {
+    port =
+        ntohs(reinterpret_cast<const struct sockaddr_in6 *>(&addr)->sin6_port);
+  } else {
+    return false;
+  }
+
+  std::array<char, NI_MAXHOST> ipstr{};
+  if (getnameinfo(reinterpret_cast<const struct sockaddr *>(&addr), addr_len,
+                  ipstr.data(), static_cast<socklen_t>(ipstr.size()), nullptr,
+                  0, NI_NUMERICHOST)) {
+    return false;
+  }
+
+  ip = ipstr.data();
+  return true;
+}
+
+inline void get_local_ip_and_port(socket_t sock, std::string &ip, int &port) {
+  struct sockaddr_storage addr;
+  socklen_t addr_len = sizeof(addr);
+  if (!getsockname(sock, reinterpret_cast<struct sockaddr *>(&addr),
+                   &addr_len)) {
+    get_ip_and_port(addr, addr_len, ip, port);
+  }
+}
+
+inline void get_remote_ip_and_port(socket_t sock, std::string &ip, int &port) {
+  struct sockaddr_storage addr;
+  socklen_t addr_len = sizeof(addr);
+
+  if (!getpeername(sock, reinterpret_cast<struct sockaddr *>(&addr),
+                   &addr_len)) {
+#ifndef _WIN32
+    if (addr.ss_family == AF_UNIX) {
+#if defined(__linux__)
+      struct ucred ucred;
+      socklen_t len = sizeof(ucred);
+      if (getsockopt(sock, SOL_SOCKET, SO_PEERCRED, &ucred, &len) == 0) {
+        port = ucred.pid;
+      }
+#elif defined(SOL_LOCAL) && defined(SO_PEERPID) // __APPLE__
+      pid_t pid;
+      socklen_t len = sizeof(pid);
+      if (getsockopt(sock, SOL_LOCAL, SO_PEERPID, &pid, &len) == 0) {
+        port = pid;
+      }
+#endif
+      return;
+    }
+#endif
+    get_ip_and_port(addr, addr_len, ip, port);
+  }
+}
+
+inline constexpr unsigned int str2tag_core(const char *s, size_t l,
+                                           unsigned int h) {
+  return (l == 0)
+             ? h
+             : str2tag_core(
+                   s + 1, l - 1,
+                   // Unsets the 6 high bits of h, therefore no overflow happens
+                   (((std::numeric_limits<unsigned int>::max)() >> 6) &
+                    h * 33) ^
+                       static_cast<unsigned char>(*s));
+}
+
+inline unsigned int str2tag(const std::string &s) {
+  return str2tag_core(s.data(), s.size(), 0);
+}
+
+namespace udl {
+
+inline constexpr unsigned int operator""_t(const char *s, size_t l) {
+  return str2tag_core(s, l, 0);
+}
+
+} // namespace udl
+
+inline std::string
+find_content_type(const std::string &path,
+                  const std::map<std::string, std::string> &user_data,
+                  const std::string &default_content_type) {
+  auto ext = file_extension(path);
+
+  auto it = user_data.find(ext);
+  if (it != user_data.end()) { return it->second; }
+
+  using udl::operator""_t;
+
+  switch (str2tag(ext)) {
+  default: return default_content_type;
+
+  case "css"_t: return "text/css";
+  case "csv"_t: return "text/csv";
+  case "htm"_t:
+  case "html"_t: return "text/html";
+  case "js"_t:
+  case "mjs"_t: return "text/javascript";
+  case "txt"_t: return "text/plain";
+  case "vtt"_t: return "text/vtt";
+
+  case "apng"_t: return "image/apng";
+  case "avif"_t: return "image/avif";
+  case "bmp"_t: return "image/bmp";
+  case "gif"_t: return "image/gif";
+  case "png"_t: return "image/png";
+  case "svg"_t: return "image/svg+xml";
+  case "webp"_t: return "image/webp";
+  case "ico"_t: return "image/x-icon";
+  case "tif"_t: return "image/tiff";
+  case "tiff"_t: return "image/tiff";
+  case "jpg"_t:
+  case "jpeg"_t: return "image/jpeg";
+
+  case "mp4"_t: return "video/mp4";
+  case "mpeg"_t: return "video/mpeg";
+  case "webm"_t: return "video/webm";
+
+  case "mp3"_t: return "audio/mp3";
+  case "mpga"_t: return "audio/mpeg";
+  case "weba"_t: return "audio/webm";
+  case "wav"_t: return "audio/wave";
+
+  case "otf"_t: return "font/otf";
+  case "ttf"_t: return "font/ttf";
+  case "woff"_t: return "font/woff";
+  case "woff2"_t: return "font/woff2";
+
+  case "7z"_t: return "application/x-7z-compressed";
+  case "atom"_t: return "application/atom+xml";
+  case "pdf"_t: return "application/pdf";
+  case "json"_t: return "application/json";
+  case "rss"_t: return "application/rss+xml";
+  case "tar"_t: return "application/x-tar";
+  case "xht"_t:
+  case "xhtml"_t: return "application/xhtml+xml";
+  case "xslt"_t: return "application/xslt+xml";
+  case "xml"_t: return "application/xml";
+  case "gz"_t: return "application/gzip";
+  case "zip"_t: return "application/zip";
+  case "wasm"_t: return "application/wasm";
+  }
+}
+
+inline bool can_compress_content_type(const std::string &content_type) {
+  using udl::operator""_t;
+
+  auto tag = str2tag(content_type);
+
+  switch (tag) {
+  case "image/svg+xml"_t:
+  case "application/javascript"_t:
+  case "application/json"_t:
+  case "application/xml"_t:
+  case "application/protobuf"_t:
+  case "application/xhtml+xml"_t: return true;
+
+  case "text/event-stream"_t: return false;
+
+  default: return !content_type.rfind("text/", 0);
+  }
+}
+
+inline EncodingType encoding_type(const Request &req, const Response &res) {
+  auto ret =
+      detail::can_compress_content_type(res.get_header_value("Content-Type"));
+  if (!ret) { return EncodingType::None; }
+
+  const auto &s = req.get_header_value("Accept-Encoding");
+  (void)(s);
+
+#ifdef CPPHTTPLIB_BROTLI_SUPPORT
+  // TODO: 'Accept-Encoding' has br, not br;q=0
+  ret = s.find("br") != std::string::npos;
+  if (ret) { return EncodingType::Brotli; }
+#endif
+
+#ifdef CPPHTTPLIB_ZLIB_SUPPORT
+  // TODO: 'Accept-Encoding' has gzip, not gzip;q=0
+  ret = s.find("gzip") != std::string::npos;
+  if (ret) { return EncodingType::Gzip; }
+#endif
+
+  return EncodingType::None;
+}
+
+inline bool nocompressor::compress(const char *data, size_t data_length,
+                                   bool /*last*/, Callback callback) {
+  if (!data_length) { return true; }
+  return callback(data, data_length);
+}
+
+#ifdef CPPHTTPLIB_ZLIB_SUPPORT
+inline gzip_compressor::gzip_compressor() {
+  std::memset(&strm_, 0, sizeof(strm_));
+  strm_.zalloc = Z_NULL;
+  strm_.zfree = Z_NULL;
+  strm_.opaque = Z_NULL;
+
+  is_valid_ = deflateInit2(&strm_, Z_DEFAULT_COMPRESSION, Z_DEFLATED, 31, 8,
+                           Z_DEFAULT_STRATEGY) == Z_OK;
+}
+
+inline gzip_compressor::~gzip_compressor() { deflateEnd(&strm_); }
+
+inline bool gzip_compressor::compress(const char *data, size_t data_length,
+                                      bool last, Callback callback) {
+  assert(is_valid_);
+
+  do {
+    constexpr size_t max_avail_in =
+        (std::numeric_limits<decltype(strm_.avail_in)>::max)();
+
+    strm_.avail_in = static_cast<decltype(strm_.avail_in)>(
+        (std::min)(data_length, max_avail_in));
+    strm_.next_in = const_cast<Bytef *>(reinterpret_cast<const Bytef *>(data));
+
+    data_length -= strm_.avail_in;
+    data += strm_.avail_in;
+
+    auto flush = (last && data_length == 0) ? Z_FINISH : Z_NO_FLUSH;
+    auto ret = Z_OK;
+
+    std::array<char, CPPHTTPLIB_COMPRESSION_BUFSIZ> buff{};
+    do {
+      strm_.avail_out = static_cast<uInt>(buff.size());
+      strm_.next_out = reinterpret_cast<Bytef *>(buff.data());
+
+      ret = deflate(&strm_, flush);
+      if (ret == Z_STREAM_ERROR) { return false; }
+
+      if (!callback(buff.data(), buff.size() - strm_.avail_out)) {
+        return false;
+      }
+    } while (strm_.avail_out == 0);
+
+    assert((flush == Z_FINISH && ret == Z_STREAM_END) ||
+           (flush == Z_NO_FLUSH && ret == Z_OK));
+    assert(strm_.avail_in == 0);
+  } while (data_length > 0);
+
+  return true;
+}
+
+inline gzip_decompressor::gzip_decompressor() {
+  std::memset(&strm_, 0, sizeof(strm_));
+  strm_.zalloc = Z_NULL;
+  strm_.zfree = Z_NULL;
+  strm_.opaque = Z_NULL;
+
+  // 15 is the value of wbits, which should be at the maximum possible value
+  // to ensure that any gzip stream can be decoded. The offset of 32 specifies
+  // that the stream type should be automatically detected either gzip or
+  // deflate.
+  is_valid_ = inflateInit2(&strm_, 32 + 15) == Z_OK;
+}
+
+inline gzip_decompressor::~gzip_decompressor() { inflateEnd(&strm_); }
+
+inline bool gzip_decompressor::is_valid() const { return is_valid_; }
+
+inline bool gzip_decompressor::decompress(const char *data, size_t data_length,
+                                          Callback callback) {
+  assert(is_valid_);
+
+  auto ret = Z_OK;
+
+  do {
+    constexpr size_t max_avail_in =
+        (std::numeric_limits<decltype(strm_.avail_in)>::max)();
+
+    strm_.avail_in = static_cast<decltype(strm_.avail_in)>(
+        (std::min)(data_length, max_avail_in));
+    strm_.next_in = const_cast<Bytef *>(reinterpret_cast<const Bytef *>(data));
+
+    data_length -= strm_.avail_in;
+    data += strm_.avail_in;
+
+    std::array<char, CPPHTTPLIB_COMPRESSION_BUFSIZ> buff{};
+    while (strm_.avail_in > 0 && ret == Z_OK) {
+      strm_.avail_out = static_cast<uInt>(buff.size());
+      strm_.next_out = reinterpret_cast<Bytef *>(buff.data());
+
+      ret = inflate(&strm_, Z_NO_FLUSH);
+
+      assert(ret != Z_STREAM_ERROR);
+      switch (ret) {
+      case Z_NEED_DICT:
+      case Z_DATA_ERROR:
+      case Z_MEM_ERROR: inflateEnd(&strm_); return false;
+      }
+
+      if (!callback(buff.data(), buff.size() - strm_.avail_out)) {
+        return false;
+      }
+    }
+
+    if (ret != Z_OK && ret != Z_STREAM_END) { return false; }
+
+  } while (data_length > 0);
+
+  return true;
+}
+#endif
+
+#ifdef CPPHTTPLIB_BROTLI_SUPPORT
+inline brotli_compressor::brotli_compressor() {
+  state_ = BrotliEncoderCreateInstance(nullptr, nullptr, nullptr);
+}
+
+inline brotli_compressor::~brotli_compressor() {
+  BrotliEncoderDestroyInstance(state_);
+}
+
+inline bool brotli_compressor::compress(const char *data, size_t data_length,
+                                        bool last, Callback callback) {
+  std::array<uint8_t, CPPHTTPLIB_COMPRESSION_BUFSIZ> buff{};
+
+  auto operation = last ? BROTLI_OPERATION_FINISH : BROTLI_OPERATION_PROCESS;
+  auto available_in = data_length;
+  auto next_in = reinterpret_cast<const uint8_t *>(data);
+
+  for (;;) {
+    if (last) {
+      if (BrotliEncoderIsFinished(state_)) { break; }
+    } else {
+      if (!available_in) { break; }
+    }
+
+    auto available_out = buff.size();
+    auto next_out = buff.data();
+
+    if (!BrotliEncoderCompressStream(state_, operation, &available_in, &next_in,
+                                     &available_out, &next_out, nullptr)) {
+      return false;
+    }
+
+    auto output_bytes = buff.size() - available_out;
+    if (output_bytes) {
+      callback(reinterpret_cast<const char *>(buff.data()), output_bytes);
+    }
+  }
+
+  return true;
+}
+
+inline brotli_decompressor::brotli_decompressor() {
+  decoder_s = BrotliDecoderCreateInstance(0, 0, 0);
+  decoder_r = decoder_s ? BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT
+                        : BROTLI_DECODER_RESULT_ERROR;
+}
+
+inline brotli_decompressor::~brotli_decompressor() {
+  if (decoder_s) { BrotliDecoderDestroyInstance(decoder_s); }
+}
+
+inline bool brotli_decompressor::is_valid() const { return decoder_s; }
+
+inline bool brotli_decompressor::decompress(const char *data,
+                                            size_t data_length,
+                                            Callback callback) {
+  if (decoder_r == BROTLI_DECODER_RESULT_SUCCESS ||
+      decoder_r == BROTLI_DECODER_RESULT_ERROR) {
+    return 0;
+  }
+
+  auto next_in = reinterpret_cast<const uint8_t *>(data);
+  size_t avail_in = data_length;
+  size_t total_out;
+
+  decoder_r = BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT;
+
+  std::array<char, CPPHTTPLIB_COMPRESSION_BUFSIZ> buff{};
+  while (decoder_r == BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT) {
+    char *next_out = buff.data();
+    size_t avail_out = buff.size();
+
+    decoder_r = BrotliDecoderDecompressStream(
+        decoder_s, &avail_in, &next_in, &avail_out,
+        reinterpret_cast<uint8_t **>(&next_out), &total_out);
+
+    if (decoder_r == BROTLI_DECODER_RESULT_ERROR) { return false; }
+
+    if (!callback(buff.data(), buff.size() - avail_out)) { return false; }
+  }
+
+  return decoder_r == BROTLI_DECODER_RESULT_SUCCESS ||
+         decoder_r == BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT;
+}
+#endif
+
+inline bool has_header(const Headers &headers, const std::string &key) {
+  return headers.find(key) != headers.end();
+}
+
+inline const char *get_header_value(const Headers &headers,
+                                    const std::string &key, const char *def,
+                                    size_t id) {
+  auto rng = headers.equal_range(key);
+  auto it = rng.first;
+  std::advance(it, static_cast<ssize_t>(id));
+  if (it != rng.second) { return it->second.c_str(); }
+  return def;
+}
+
+template <typename T>
+inline bool parse_header(const char *beg, const char *end, T fn) {
+  // Skip trailing spaces and tabs.
+  while (beg < end && is_space_or_tab(end[-1])) {
+    end--;
+  }
+
+  auto p = beg;
+  while (p < end && *p != ':') {
+    p++;
+  }
+
+  if (p == end) { return false; }
+
+  auto key_end = p;
+
+  if (*p++ != ':') { return false; }
+
+  while (p < end && is_space_or_tab(*p)) {
+    p++;
+  }
+
+  if (p <= end) {
+    auto key_len = key_end - beg;
+    if (!key_len) { return false; }
+
+    auto key = std::string(beg, key_end);
+    // auto val = (case_ignore::equal(key, "Location") ||
+    //             case_ignore::equal(key, "Referer"))
+    //                ? std::string(p, end)
+    //                : decode_url(std::string(p, end), false);
+    auto val = std::string(p, end);
+
+    if (!detail::fields::is_field_value(val)) { return false; }
+
+    if (case_ignore::equal(key, "Location") ||
+        case_ignore::equal(key, "Referer")) {
+      fn(key, val);
+    } else {
+      fn(key, decode_url(val, false));
+    }
+
+    return true;
+  }
+
+  return false;
+}
+
+inline bool read_headers(Stream &strm, Headers &headers) {
+  const auto bufsiz = 2048;
+  char buf[bufsiz];
+  stream_line_reader line_reader(strm, buf, bufsiz);
+
+  for (;;) {
+    if (!line_reader.getline()) { return false; }
+
+    // Check if the line ends with CRLF.
+    auto line_terminator_len = 2;
+    if (line_reader.end_with_crlf()) {
+      // Blank line indicates end of headers.
+      if (line_reader.size() == 2) { break; }
+    } else {
+#ifdef CPPHTTPLIB_ALLOW_LF_AS_LINE_TERMINATOR
+      // Blank line indicates end of headers.
+      if (line_reader.size() == 1) { break; }
+      line_terminator_len = 1;
+#else
+      continue; // Skip invalid line.
+#endif
+    }
+
+    if (line_reader.size() > CPPHTTPLIB_HEADER_MAX_LENGTH) { return false; }
+
+    // Exclude line terminator
+    auto end = line_reader.ptr() + line_reader.size() - line_terminator_len;
+
+    if (!parse_header(line_reader.ptr(), end,
+                      [&](const std::string &key, const std::string &val) {
+                        headers.emplace(key, val);
+                      })) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+inline bool read_content_with_length(Stream &strm, uint64_t len,
+                                     Progress progress,
+                                     ContentReceiverWithProgress out) {
+  char buf[CPPHTTPLIB_RECV_BUFSIZ];
+
+  uint64_t r = 0;
+  while (r < len) {
+    auto read_len = static_cast<size_t>(len - r);
+    auto n = strm.read(buf, (std::min)(read_len, CPPHTTPLIB_RECV_BUFSIZ));
+    if (n <= 0) { return false; }
+
+    if (!out(buf, static_cast<size_t>(n), r, len)) { return false; }
+    r += static_cast<uint64_t>(n);
+
+    if (progress) {
+      if (!progress(r, len)) { return false; }
+    }
+  }
+
+  return true;
+}
+
+inline void skip_content_with_length(Stream &strm, uint64_t len) {
+  char buf[CPPHTTPLIB_RECV_BUFSIZ];
+  uint64_t r = 0;
+  while (r < len) {
+    auto read_len = static_cast<size_t>(len - r);
+    auto n = strm.read(buf, (std::min)(read_len, CPPHTTPLIB_RECV_BUFSIZ));
+    if (n <= 0) { return; }
+    r += static_cast<uint64_t>(n);
+  }
+}
+
+inline bool read_content_without_length(Stream &strm,
+                                        ContentReceiverWithProgress out) {
+  char buf[CPPHTTPLIB_RECV_BUFSIZ];
+  uint64_t r = 0;
+  for (;;) {
+    auto n = strm.read(buf, CPPHTTPLIB_RECV_BUFSIZ);
+    if (n <= 0) { return false; }
+
+    if (!out(buf, static_cast<size_t>(n), r, 0)) { return false; }
+    r += static_cast<uint64_t>(n);
+  }
+
+  return true;
+}
+
+template <typename T>
+inline bool read_content_chunked(Stream &strm, T &x,
+                                 ContentReceiverWithProgress out) {
+  const auto bufsiz = 16;
+  char buf[bufsiz];
+
+  stream_line_reader line_reader(strm, buf, bufsiz);
+
+  if (!line_reader.getline()) { return false; }
+
+  unsigned long chunk_len;
+  while (true) {
+    char *end_ptr;
+
+    chunk_len = std::strtoul(line_reader.ptr(), &end_ptr, 16);
+
+    if (end_ptr == line_reader.ptr()) { return false; }
+    if (chunk_len == ULONG_MAX) { return false; }
+
+    if (chunk_len == 0) { break; }
+
+    if (!read_content_with_length(strm, chunk_len, nullptr, out)) {
+      return false;
+    }
+
+    if (!line_reader.getline()) { return false; }
+
+    if (strcmp(line_reader.ptr(), "\r\n") != 0) { return false; }
+
+    if (!line_reader.getline()) { return false; }
+  }
+
+  assert(chunk_len == 0);
+
+  // NOTE: In RFC 9112, '7.1 Chunked Transfer Coding' mentiones "The chunked
+  // transfer coding is complete when a chunk with a chunk-size of zero is
+  // received, possibly followed by a trailer section, and finally terminated by
+  // an empty line". https://www.rfc-editor.org/rfc/rfc9112.html#section-7.1
+  //
+  // In '7.1.3. Decoding Chunked', however, the pseudo-code in the section
+  // does't care for the existence of the final CRLF. In other words, it seems
+  // to be ok whether the final CRLF exists or not in the chunked data.
+  // https://www.rfc-editor.org/rfc/rfc9112.html#section-7.1.3
+  //
+  // According to the reference code in RFC 9112, cpp-htpplib now allows
+  // chuncked transfer coding data without the final CRLF.
+  if (!line_reader.getline()) { return true; }
+
+  while (strcmp(line_reader.ptr(), "\r\n") != 0) {
+    if (line_reader.size() > CPPHTTPLIB_HEADER_MAX_LENGTH) { return false; }
+
+    // Exclude line terminator
+    constexpr auto line_terminator_len = 2;
+    auto end = line_reader.ptr() + line_reader.size() - line_terminator_len;
+
+    parse_header(line_reader.ptr(), end,
+                 [&](const std::string &key, const std::string &val) {
+                   x.headers.emplace(key, val);
+                 });
+
+    if (!line_reader.getline()) { return false; }
+  }
+
+  return true;
+}
+
+inline bool is_chunked_transfer_encoding(const Headers &headers) {
+  return case_ignore::equal(
+      get_header_value(headers, "Transfer-Encoding", "", 0), "chunked");
+}
+
+template <typename T, typename U>
+bool prepare_content_receiver(T &x, int &status,
+                              ContentReceiverWithProgress receiver,
+                              bool decompress, U callback) {
+  if (decompress) {
+    std::string encoding = x.get_header_value("Content-Encoding");
+    std::unique_ptr<decompressor> decompressor;
+
+    if (encoding == "gzip" || encoding == "deflate") {
+#ifdef CPPHTTPLIB_ZLIB_SUPPORT
+      decompressor = detail::make_unique<gzip_decompressor>();
+#else
+      status = StatusCode::UnsupportedMediaType_415;
+      return false;
+#endif
+    } else if (encoding.find("br") != std::string::npos) {
+#ifdef CPPHTTPLIB_BROTLI_SUPPORT
+      decompressor = detail::make_unique<brotli_decompressor>();
+#else
+      status = StatusCode::UnsupportedMediaType_415;
+      return false;
+#endif
+    }
+
+    if (decompressor) {
+      if (decompressor->is_valid()) {
+        ContentReceiverWithProgress out = [&](const char *buf, size_t n,
+                                              uint64_t off, uint64_t len) {
+          return decompressor->decompress(buf, n,
+                                          [&](const char *buf2, size_t n2) {
+                                            return receiver(buf2, n2, off, len);
+                                          });
+        };
+        return callback(std::move(out));
+      } else {
+        status = StatusCode::InternalServerError_500;
+        return false;
+      }
+    }
+  }
+
+  ContentReceiverWithProgress out = [&](const char *buf, size_t n, uint64_t off,
+                                        uint64_t len) {
+    return receiver(buf, n, off, len);
+  };
+  return callback(std::move(out));
+}
+
+template <typename T>
+bool read_content(Stream &strm, T &x, size_t payload_max_length, int &status,
+                  Progress progress, ContentReceiverWithProgress receiver,
+                  bool decompress) {
+  return prepare_content_receiver(
+      x, status, std::move(receiver), decompress,
+      [&](const ContentReceiverWithProgress &out) {
+        auto ret = true;
+        auto exceed_payload_max_length = false;
+
+        if (is_chunked_transfer_encoding(x.headers)) {
+          ret = read_content_chunked(strm, x, out);
+        } else if (!has_header(x.headers, "Content-Length")) {
+          ret = read_content_without_length(strm, out);
+        } else {
+          auto is_invalid_value = false;
+          auto len = get_header_value_u64(
+              x.headers, "Content-Length",
+              (std::numeric_limits<uint64_t>::max)(), 0, is_invalid_value);
+
+          if (is_invalid_value) {
+            ret = false;
+          } else if (len > payload_max_length) {
+            exceed_payload_max_length = true;
+            skip_content_with_length(strm, len);
+            ret = false;
+          } else if (len > 0) {
+            ret = read_content_with_length(strm, len, std::move(progress), out);
+          }
+        }
+
+        if (!ret) {
+          status = exceed_payload_max_length ? StatusCode::PayloadTooLarge_413
+                                             : StatusCode::BadRequest_400;
+        }
+        return ret;
+      });
+}
+
+inline ssize_t write_request_line(Stream &strm, const std::string &method,
+                                  const std::string &path) {
+  std::string s = method;
+  s += " ";
+  s += path;
+  s += " HTTP/1.1\r\n";
+  return strm.write(s.data(), s.size());
+}
+
+inline ssize_t write_response_line(Stream &strm, int status) {
+  std::string s = "HTTP/1.1 ";
+  s += std::to_string(status);
+  s += " ";
+  s += httplib::status_message(status);
+  s += "\r\n";
+  return strm.write(s.data(), s.size());
+}
+
+inline ssize_t write_headers(Stream &strm, const Headers &headers) {
+  ssize_t write_len = 0;
+  for (const auto &x : headers) {
+    std::string s;
+    s = x.first;
+    s += ": ";
+    s += x.second;
+    s += "\r\n";
+
+    auto len = strm.write(s.data(), s.size());
+    if (len < 0) { return len; }
+    write_len += len;
+  }
+  auto len = strm.write("\r\n");
+  if (len < 0) { return len; }
+  write_len += len;
+  return write_len;
+}
+
+inline bool write_data(Stream &strm, const char *d, size_t l) {
+  size_t offset = 0;
+  while (offset < l) {
+    auto length = strm.write(d + offset, l - offset);
+    if (length < 0) { return false; }
+    offset += static_cast<size_t>(length);
+  }
+  return true;
+}
+
+template <typename T>
+inline bool write_content(Stream &strm, const ContentProvider &content_provider,
+                          size_t offset, size_t length, T is_shutting_down,
+                          Error &error) {
+  size_t end_offset = offset + length;
+  auto ok = true;
+  DataSink data_sink;
+
+  data_sink.write = [&](const char *d, size_t l) -> bool {
+    if (ok) {
+      if (strm.is_writable() && write_data(strm, d, l)) {
+        offset += l;
+      } else {
+        ok = false;
+      }
+    }
+    return ok;
+  };
+
+  data_sink.is_writable = [&]() -> bool { return strm.is_writable(); };
+
+  while (offset < end_offset && !is_shutting_down()) {
+    if (!strm.is_writable()) {
+      error = Error::Write;
+      return false;
+    } else if (!content_provider(offset, end_offset - offset, data_sink)) {
+      error = Error::Canceled;
+      return false;
+    } else if (!ok) {
+      error = Error::Write;
+      return false;
+    }
+  }
+
+  error = Error::Success;
+  return true;
+}
+
+template <typename T>
+inline bool write_content(Stream &strm, const ContentProvider &content_provider,
+                          size_t offset, size_t length,
+                          const T &is_shutting_down) {
+  auto error = Error::Success;
+  return write_content(strm, content_provider, offset, length, is_shutting_down,
+                       error);
+}
+
+template <typename T>
+inline bool
+write_content_without_length(Stream &strm,
+                             const ContentProvider &content_provider,
+                             const T &is_shutting_down) {
+  size_t offset = 0;
+  auto data_available = true;
+  auto ok = true;
+  DataSink data_sink;
+
+  data_sink.write = [&](const char *d, size_t l) -> bool {
+    if (ok) {
+      offset += l;
+      if (!strm.is_writable() || !write_data(strm, d, l)) { ok = false; }
+    }
+    return ok;
+  };
+
+  data_sink.is_writable = [&]() -> bool { return strm.is_writable(); };
+
+  data_sink.done = [&](void) { data_available = false; };
+
+  while (data_available && !is_shutting_down()) {
+    if (!strm.is_writable()) {
+      return false;
+    } else if (!content_provider(offset, 0, data_sink)) {
+      return false;
+    } else if (!ok) {
+      return false;
+    }
+  }
+  return true;
+}
+
+template <typename T, typename U>
+inline bool
+write_content_chunked(Stream &strm, const ContentProvider &content_provider,
+                      const T &is_shutting_down, U &compressor, Error &error) {
+  size_t offset = 0;
+  auto data_available = true;
+  auto ok = true;
+  DataSink data_sink;
+
+  data_sink.write = [&](const char *d, size_t l) -> bool {
+    if (ok) {
+      data_available = l > 0;
+      offset += l;
+
+      std::string payload;
+      if (compressor.compress(d, l, false,
+                              [&](const char *data, size_t data_len) {
+                                payload.append(data, data_len);
+                                return true;
+                              })) {
+        if (!payload.empty()) {
+          // Emit chunked response header and footer for each chunk
+          auto chunk =
+              from_i_to_hex(payload.size()) + "\r\n" + payload + "\r\n";
+          if (!strm.is_writable() ||
+              !write_data(strm, chunk.data(), chunk.size())) {
+            ok = false;
+          }
+        }
+      } else {
+        ok = false;
+      }
+    }
+    return ok;
+  };
+
+  data_sink.is_writable = [&]() -> bool { return strm.is_writable(); };
+
+  auto done_with_trailer = [&](const Headers *trailer) {
+    if (!ok) { return; }
+
+    data_available = false;
+
+    std::string payload;
+    if (!compressor.compress(nullptr, 0, true,
+                             [&](const char *data, size_t data_len) {
+                               payload.append(data, data_len);
+                               return true;
+                             })) {
+      ok = false;
+      return;
+    }
+
+    if (!payload.empty()) {
+      // Emit chunked response header and footer for each chunk
+      auto chunk = from_i_to_hex(payload.size()) + "\r\n" + payload + "\r\n";
+      if (!strm.is_writable() ||
+          !write_data(strm, chunk.data(), chunk.size())) {
+        ok = false;
+        return;
+      }
+    }
+
+    static const std::string done_marker("0\r\n");
+    if (!write_data(strm, done_marker.data(), done_marker.size())) {
+      ok = false;
+    }
+
+    // Trailer
+    if (trailer) {
+      for (const auto &kv : *trailer) {
+        std::string field_line = kv.first + ": " + kv.second + "\r\n";
+        if (!write_data(strm, field_line.data(), field_line.size())) {
+          ok = false;
+        }
+      }
+    }
+
+    static const std::string crlf("\r\n");
+    if (!write_data(strm, crlf.data(), crlf.size())) { ok = false; }
+  };
+
+  data_sink.done = [&](void) { done_with_trailer(nullptr); };
+
+  data_sink.done_with_trailer = [&](const Headers &trailer) {
+    done_with_trailer(&trailer);
+  };
+
+  while (data_available && !is_shutting_down()) {
+    if (!strm.is_writable()) {
+      error = Error::Write;
+      return false;
+    } else if (!content_provider(offset, 0, data_sink)) {
+      error = Error::Canceled;
+      return false;
+    } else if (!ok) {
+      error = Error::Write;
+      return false;
+    }
+  }
+
+  error = Error::Success;
+  return true;
+}
+
+template <typename T, typename U>
+inline bool write_content_chunked(Stream &strm,
+                                  const ContentProvider &content_provider,
+                                  const T &is_shutting_down, U &compressor) {
+  auto error = Error::Success;
+  return write_content_chunked(strm, content_provider, is_shutting_down,
+                               compressor, error);
+}
+
+template <typename T>
+inline bool redirect(T &cli, Request &req, Response &res,
+                     const std::string &path, const std::string &location,
+                     Error &error) {
+  Request new_req = req;
+  new_req.path = path;
+  new_req.redirect_count_ -= 1;
+
+  if (res.status == StatusCode::SeeOther_303 &&
+      (req.method != "GET" && req.method != "HEAD")) {
+    new_req.method = "GET";
+    new_req.body.clear();
+    new_req.headers.clear();
+  }
+
+  Response new_res;
+
+  auto ret = cli.send(new_req, new_res, error);
+  if (ret) {
+    req = new_req;
+    res = new_res;
+
+    if (res.location.empty()) { res.location = location; }
+  }
+  return ret;
+}
+
+inline std::string params_to_query_str(const Params &params) {
+  std::string query;
+
+  for (auto it = params.begin(); it != params.end(); ++it) {
+    if (it != params.begin()) { query += "&"; }
+    query += it->first;
+    query += "=";
+    query += encode_query_param(it->second);
+  }
+  return query;
+}
+
+inline void parse_query_text(const char *data, std::size_t size,
+                             Params &params) {
+  std::set<std::string> cache;
+  split(data, data + size, '&', [&](const char *b, const char *e) {
+    std::string kv(b, e);
+    if (cache.find(kv) != cache.end()) { return; }
+    cache.insert(std::move(kv));
+
+    std::string key;
+    std::string val;
+    divide(b, static_cast<std::size_t>(e - b), '=',
+           [&](const char *lhs_data, std::size_t lhs_size, const char *rhs_data,
+               std::size_t rhs_size) {
+             key.assign(lhs_data, lhs_size);
+             val.assign(rhs_data, rhs_size);
+           });
+
+    if (!key.empty()) {
+      params.emplace(decode_url(key, true), decode_url(val, true));
+    }
+  });
+}
+
+inline void parse_query_text(const std::string &s, Params &params) {
+  parse_query_text(s.data(), s.size(), params);
+}
+
+inline bool parse_multipart_boundary(const std::string &content_type,
+                                     std::string &boundary) {
+  auto boundary_keyword = "boundary=";
+  auto pos = content_type.find(boundary_keyword);
+  if (pos == std::string::npos) { return false; }
+  auto end = content_type.find(';', pos);
+  auto beg = pos + strlen(boundary_keyword);
+  boundary = trim_double_quotes_copy(content_type.substr(beg, end - beg));
+  return !boundary.empty();
+}
+
+inline void parse_disposition_params(const std::string &s, Params &params) {
+  std::set<std::string> cache;
+  split(s.data(), s.data() + s.size(), ';', [&](const char *b, const char *e) {
+    std::string kv(b, e);
+    if (cache.find(kv) != cache.end()) { return; }
+    cache.insert(kv);
+
+    std::string key;
+    std::string val;
+    split(b, e, '=', [&](const char *b2, const char *e2) {
+      if (key.empty()) {
+        key.assign(b2, e2);
+      } else {
+        val.assign(b2, e2);
+      }
+    });
+
+    if (!key.empty()) {
+      params.emplace(trim_double_quotes_copy((key)),
+                     trim_double_quotes_copy((val)));
+    }
+  });
+}
+
+#ifdef CPPHTTPLIB_NO_EXCEPTIONS
+inline bool parse_range_header(const std::string &s, Ranges &ranges) {
+#else
+inline bool parse_range_header(const std::string &s, Ranges &ranges) try {
+#endif
+  auto is_valid = [](const std::string &str) {
+    return std::all_of(str.cbegin(), str.cend(),
+                       [](unsigned char c) { return std::isdigit(c); });
+  };
+
+  if (s.size() > 7 && s.compare(0, 6, "bytes=") == 0) {
+    const auto pos = static_cast<size_t>(6);
+    const auto len = static_cast<size_t>(s.size() - 6);
+    auto all_valid_ranges = true;
+    split(&s[pos], &s[pos + len], ',', [&](const char *b, const char *e) {
+      if (!all_valid_ranges) { return; }
+
+      const auto it = std::find(b, e, '-');
+      if (it == e) {
+        all_valid_ranges = false;
+        return;
+      }
+
+      const auto lhs = std::string(b, it);
+      const auto rhs = std::string(it + 1, e);
+      if (!is_valid(lhs) || !is_valid(rhs)) {
+        all_valid_ranges = false;
+        return;
+      }
+
+      const auto first =
+          static_cast<ssize_t>(lhs.empty() ? -1 : std::stoll(lhs));
+      const auto last =
+          static_cast<ssize_t>(rhs.empty() ? -1 : std::stoll(rhs));
+      if ((first == -1 && last == -1) ||
+          (first != -1 && last != -1 && first > last)) {
+        all_valid_ranges = false;
+        return;
+      }
+
+      ranges.emplace_back(first, last);
+    });
+    return all_valid_ranges && !ranges.empty();
+  }
+  return false;
+#ifdef CPPHTTPLIB_NO_EXCEPTIONS
+}
+#else
+} catch (...) { return false; }
+#endif
+
+class MultipartFormDataParser {
+public:
+  MultipartFormDataParser() = default;
+
+  void set_boundary(std::string &&boundary) {
+    boundary_ = boundary;
+    dash_boundary_crlf_ = dash_ + boundary_ + crlf_;
+    crlf_dash_boundary_ = crlf_ + dash_ + boundary_;
+  }
+
+  bool is_valid() const { return is_valid_; }
+
+  bool parse(const char *buf, size_t n, const ContentReceiver &content_callback,
+             const MultipartContentHeader &header_callback) {
+
+    buf_append(buf, n);
+
+    while (buf_size() > 0) {
+      switch (state_) {
+      case 0: { // Initial boundary
+        buf_erase(buf_find(dash_boundary_crlf_));
+        if (dash_boundary_crlf_.size() > buf_size()) { return true; }
+        if (!buf_start_with(dash_boundary_crlf_)) { return false; }
+        buf_erase(dash_boundary_crlf_.size());
+        state_ = 1;
+        break;
+      }
+      case 1: { // New entry
+        clear_file_info();
+        state_ = 2;
+        break;
+      }
+      case 2: { // Headers
+        auto pos = buf_find(crlf_);
+        if (pos > CPPHTTPLIB_HEADER_MAX_LENGTH) { return false; }
+        while (pos < buf_size()) {
+          // Empty line
+          if (pos == 0) {
+            if (!header_callback(file_)) {
+              is_valid_ = false;
+              return false;
+            }
+            buf_erase(crlf_.size());
+            state_ = 3;
+            break;
+          }
+
+          const auto header = buf_head(pos);
+
+          if (!parse_header(header.data(), header.data() + header.size(),
+                            [&](const std::string &, const std::string &) {})) {
+            is_valid_ = false;
+            return false;
+          }
+
+          static const std::string header_content_type = "Content-Type:";
+
+          if (start_with_case_ignore(header, header_content_type)) {
+            file_.content_type =
+                trim_copy(header.substr(header_content_type.size()));
+          } else {
+            static const std::regex re_content_disposition(
+                R"~(^Content-Disposition:\s*form-data;\s*(.*)$)~",
+                std::regex_constants::icase);
+
+            std::smatch m;
+            if (std::regex_match(header, m, re_content_disposition)) {
+              Params params;
+              parse_disposition_params(m[1], params);
+
+              auto it = params.find("name");
+              if (it != params.end()) {
+                file_.name = it->second;
+              } else {
+                is_valid_ = false;
+                return false;
+              }
+
+              it = params.find("filename");
+              if (it != params.end()) { file_.filename = it->second; }
+
+              it = params.find("filename*");
+              if (it != params.end()) {
+                // Only allow UTF-8 enconnding...
+                static const std::regex re_rfc5987_encoding(
+                    R"~(^UTF-8''(.+?)$)~", std::regex_constants::icase);
+
+                std::smatch m2;
+                if (std::regex_match(it->second, m2, re_rfc5987_encoding)) {
+                  file_.filename = decode_url(m2[1], false); // override...
+                } else {
+                  is_valid_ = false;
+                  return false;
+                }
+              }
+            }
+          }
+          buf_erase(pos + crlf_.size());
+          pos = buf_find(crlf_);
+        }
+        if (state_ != 3) { return true; }
+        break;
+      }
+      case 3: { // Body
+        if (crlf_dash_boundary_.size() > buf_size()) { return true; }
+        auto pos = buf_find(crlf_dash_boundary_);
+        if (pos < buf_size()) {
+          if (!content_callback(buf_data(), pos)) {
+            is_valid_ = false;
+            return false;
+          }
+          buf_erase(pos + crlf_dash_boundary_.size());
+          state_ = 4;
+        } else {
+          auto len = buf_size() - crlf_dash_boundary_.size();
+          if (len > 0) {
+            if (!content_callback(buf_data(), len)) {
+              is_valid_ = false;
+              return false;
+            }
+            buf_erase(len);
+          }
+          return true;
+        }
+        break;
+      }
+      case 4: { // Boundary
+        if (crlf_.size() > buf_size()) { return true; }
+        if (buf_start_with(crlf_)) {
+          buf_erase(crlf_.size());
+          state_ = 1;
+        } else {
+          if (dash_.size() > buf_size()) { return true; }
+          if (buf_start_with(dash_)) {
+            buf_erase(dash_.size());
+            is_valid_ = true;
+            buf_erase(buf_size()); // Remove epilogue
+          } else {
+            return true;
+          }
+        }
+        break;
+      }
+      }
+    }
+
+    return true;
+  }
+
+private:
+  void clear_file_info() {
+    file_.name.clear();
+    file_.filename.clear();
+    file_.content_type.clear();
+  }
+
+  bool start_with_case_ignore(const std::string &a,
+                              const std::string &b) const {
+    if (a.size() < b.size()) { return false; }
+    for (size_t i = 0; i < b.size(); i++) {
+      if (case_ignore::to_lower(a[i]) != case_ignore::to_lower(b[i])) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  const std::string dash_ = "--";
+  const std::string crlf_ = "\r\n";
+  std::string boundary_;
+  std::string dash_boundary_crlf_;
+  std::string crlf_dash_boundary_;
+
+  size_t state_ = 0;
+  bool is_valid_ = false;
+  MultipartFormData file_;
+
+  // Buffer
+  bool start_with(const std::string &a, size_t spos, size_t epos,
+                  const std::string &b) const {
+    if (epos - spos < b.size()) { return false; }
+    for (size_t i = 0; i < b.size(); i++) {
+      if (a[i + spos] != b[i]) { return false; }
+    }
+    return true;
+  }
+
+  size_t buf_size() const { return buf_epos_ - buf_spos_; }
+
+  const char *buf_data() const { return &buf_[buf_spos_]; }
+
+  std::string buf_head(size_t l) const { return buf_.substr(buf_spos_, l); }
+
+  bool buf_start_with(const std::string &s) const {
+    return start_with(buf_, buf_spos_, buf_epos_, s);
+  }
+
+  size_t buf_find(const std::string &s) const {
+    auto c = s.front();
+
+    size_t off = buf_spos_;
+    while (off < buf_epos_) {
+      auto pos = off;
+      while (true) {
+        if (pos == buf_epos_) { return buf_size(); }
+        if (buf_[pos] == c) { break; }
+        pos++;
+      }
+
+      auto remaining_size = buf_epos_ - pos;
+      if (s.size() > remaining_size) { return buf_size(); }
+
+      if (start_with(buf_, pos, buf_epos_, s)) { return pos - buf_spos_; }
+
+      off = pos + 1;
+    }
+
+    return buf_size();
+  }
+
+  void buf_append(const char *data, size_t n) {
+    auto remaining_size = buf_size();
+    if (remaining_size > 0 && buf_spos_ > 0) {
+      for (size_t i = 0; i < remaining_size; i++) {
+        buf_[i] = buf_[buf_spos_ + i];
+      }
+    }
+    buf_spos_ = 0;
+    buf_epos_ = remaining_size;
+
+    if (remaining_size + n > buf_.size()) { buf_.resize(remaining_size + n); }
+
+    for (size_t i = 0; i < n; i++) {
+      buf_[buf_epos_ + i] = data[i];
+    }
+    buf_epos_ += n;
+  }
+
+  void buf_erase(size_t size) { buf_spos_ += size; }
+
+  std::string buf_;
+  size_t buf_spos_ = 0;
+  size_t buf_epos_ = 0;
+};
+
+inline std::string random_string(size_t length) {
+  static const char data[] =
+      "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+  // std::random_device might actually be deterministic on some
+  // platforms, but due to lack of support in the c++ standard library,
+  // doing better requires either some ugly hacks or breaking portability.
+  static std::random_device seed_gen;
+
+  // Request 128 bits of entropy for initialization
+  static std::seed_seq seed_sequence{seed_gen(), seed_gen(), seed_gen(),
+                                     seed_gen()};
+
+  static std::mt19937 engine(seed_sequence);
+
+  std::string result;
+  for (size_t i = 0; i < length; i++) {
+    result += data[engine() % (sizeof(data) - 1)];
+  }
+  return result;
+}
+
+inline std::string make_multipart_data_boundary() {
+  return "--cpp-httplib-multipart-data-" + detail::random_string(16);
+}
+
+inline bool is_multipart_boundary_chars_valid(const std::string &boundary) {
+  auto valid = true;
+  for (size_t i = 0; i < boundary.size(); i++) {
+    auto c = boundary[i];
+    if (!std::isalnum(c) && c != '-' && c != '_') {
+      valid = false;
+      break;
+    }
+  }
+  return valid;
+}
+
+template <typename T>
+inline std::string
+serialize_multipart_formdata_item_begin(const T &item,
+                                        const std::string &boundary) {
+  std::string body = "--" + boundary + "\r\n";
+  body += "Content-Disposition: form-data; name=\"" + item.name + "\"";
+  if (!item.filename.empty()) {
+    body += "; filename=\"" + item.filename + "\"";
+  }
+  body += "\r\n";
+  if (!item.content_type.empty()) {
+    body += "Content-Type: " + item.content_type + "\r\n";
+  }
+  body += "\r\n";
+
+  return body;
+}
+
+inline std::string serialize_multipart_formdata_item_end() { return "\r\n"; }
+
+inline std::string
+serialize_multipart_formdata_finish(const std::string &boundary) {
+  return "--" + boundary + "--\r\n";
+}
+
+inline std::string
+serialize_multipart_formdata_get_content_type(const std::string &boundary) {
+  return "multipart/form-data; boundary=" + boundary;
+}
+
+inline std::string
+serialize_multipart_formdata(const MultipartFormDataItems &items,
+                             const std::string &boundary, bool finish = true) {
+  std::string body;
+
+  for (const auto &item : items) {
+    body += serialize_multipart_formdata_item_begin(item, boundary);
+    body += item.content + serialize_multipart_formdata_item_end();
+  }
+
+  if (finish) { body += serialize_multipart_formdata_finish(boundary); }
+
+  return body;
+}
+
+inline bool range_error(Request &req, Response &res) {
+  if (!req.ranges.empty() && 200 <= res.status && res.status < 300) {
+    ssize_t contant_len = static_cast<ssize_t>(
+        res.content_length_ ? res.content_length_ : res.body.size());
+
+    ssize_t prev_first_pos = -1;
+    ssize_t prev_last_pos = -1;
+    size_t overwrapping_count = 0;
+
+    // NOTE: The following Range check is based on '14.2. Range' in RFC 9110
+    // 'HTTP Semantics' to avoid potential denial-of-service attacks.
+    // https://www.rfc-editor.org/rfc/rfc9110#section-14.2
+
+    // Too many ranges
+    if (req.ranges.size() > CPPHTTPLIB_RANGE_MAX_COUNT) { return true; }
+
+    for (auto &r : req.ranges) {
+      auto &first_pos = r.first;
+      auto &last_pos = r.second;
+
+      if (first_pos == -1 && last_pos == -1) {
+        first_pos = 0;
+        last_pos = contant_len;
+      }
+
+      if (first_pos == -1) {
+        first_pos = contant_len - last_pos;
+        last_pos = contant_len - 1;
+      }
+
+      // NOTE: RFC-9110 '14.1.2. Byte Ranges':
+      // A client can limit the number of bytes requested without knowing the
+      // size of the selected representation. If the last-pos value is absent,
+      // or if the value is greater than or equal to the current length of the
+      // representation data, the byte range is interpreted as the remainder of
+      // the representation (i.e., the server replaces the value of last-pos
+      // with a value that is one less than the current length of the selected
+      // representation).
+      // https://www.rfc-editor.org/rfc/rfc9110.html#section-14.1.2-6
+      if (last_pos == -1 || last_pos >= contant_len) {
+        last_pos = contant_len - 1;
+      }
+
+      // Range must be within content length
+      if (!(0 <= first_pos && first_pos <= last_pos &&
+            last_pos <= contant_len - 1)) {
+        return true;
+      }
+
+      // Ranges must be in ascending order
+      if (first_pos <= prev_first_pos) { return true; }
+
+      // Request must not have more than two overlapping ranges
+      if (first_pos <= prev_last_pos) {
+        overwrapping_count++;
+        if (overwrapping_count > 2) { return true; }
+      }
+
+      prev_first_pos = (std::max)(prev_first_pos, first_pos);
+      prev_last_pos = (std::max)(prev_last_pos, last_pos);
+    }
+  }
+
+  return false;
+}
+
+inline std::pair<size_t, size_t>
+get_range_offset_and_length(Range r, size_t content_length) {
+  assert(r.first != -1 && r.second != -1);
+  assert(0 <= r.first && r.first < static_cast<ssize_t>(content_length));
+  assert(r.first <= r.second &&
+         r.second < static_cast<ssize_t>(content_length));
+  (void)(content_length);
+  return std::make_pair(r.first, static_cast<size_t>(r.second - r.first) + 1);
+}
+
+inline std::string make_content_range_header_field(
+    const std::pair<size_t, size_t> &offset_and_length, size_t content_length) {
+  auto st = offset_and_length.first;
+  auto ed = st + offset_and_length.second - 1;
+
+  std::string field = "bytes ";
+  field += std::to_string(st);
+  field += "-";
+  field += std::to_string(ed);
+  field += "/";
+  field += std::to_string(content_length);
+  return field;
+}
+
+template <typename SToken, typename CToken, typename Content>
+bool process_multipart_ranges_data(const Request &req,
+                                   const std::string &boundary,
+                                   const std::string &content_type,
+                                   size_t content_length, SToken stoken,
+                                   CToken ctoken, Content content) {
+  for (size_t i = 0; i < req.ranges.size(); i++) {
+    ctoken("--");
+    stoken(boundary);
+    ctoken("\r\n");
+    if (!content_type.empty()) {
+      ctoken("Content-Type: ");
+      stoken(content_type);
+      ctoken("\r\n");
+    }
+
+    auto offset_and_length =
+        get_range_offset_and_length(req.ranges[i], content_length);
+
+    ctoken("Content-Range: ");
+    stoken(make_content_range_header_field(offset_and_length, content_length));
+    ctoken("\r\n");
+    ctoken("\r\n");
+
+    if (!content(offset_and_length.first, offset_and_length.second)) {
+      return false;
+    }
+    ctoken("\r\n");
+  }
+
+  ctoken("--");
+  stoken(boundary);
+  ctoken("--");
+
+  return true;
+}
+
+inline void make_multipart_ranges_data(const Request &req, Response &res,
+                                       const std::string &boundary,
+                                       const std::string &content_type,
+                                       size_t content_length,
+                                       std::string &data) {
+  process_multipart_ranges_data(
+      req, boundary, content_type, content_length,
+      [&](const std::string &token) { data += token; },
+      [&](const std::string &token) { data += token; },
+      [&](size_t offset, size_t length) {
+        assert(offset + length <= content_length);
+        data += res.body.substr(offset, length);
+        return true;
+      });
+}
+
+inline size_t get_multipart_ranges_data_length(const Request &req,
+                                               const std::string &boundary,
+                                               const std::string &content_type,
+                                               size_t content_length) {
+  size_t data_length = 0;
+
+  process_multipart_ranges_data(
+      req, boundary, content_type, content_length,
+      [&](const std::string &token) { data_length += token.size(); },
+      [&](const std::string &token) { data_length += token.size(); },
+      [&](size_t /*offset*/, size_t length) {
+        data_length += length;
+        return true;
+      });
+
+  return data_length;
+}
+
+template <typename T>
+inline bool
+write_multipart_ranges_data(Stream &strm, const Request &req, Response &res,
+                            const std::string &boundary,
+                            const std::string &content_type,
+                            size_t content_length, const T &is_shutting_down) {
+  return process_multipart_ranges_data(
+      req, boundary, content_type, content_length,
+      [&](const std::string &token) { strm.write(token); },
+      [&](const std::string &token) { strm.write(token); },
+      [&](size_t offset, size_t length) {
+        return write_content(strm, res.content_provider_, offset, length,
+                             is_shutting_down);
+      });
+}
+
+inline bool expect_content(const Request &req) {
+  if (req.method == "POST" || req.method == "PUT" || req.method == "PATCH" ||
+      req.method == "DELETE") {
+    return true;
+  }
+  if (req.has_header("Content-Length") &&
+      req.get_header_value_u64("Content-Length") > 0) {
+    return true;
+  }
+  if (is_chunked_transfer_encoding(req.headers)) { return true; }
+  return false;
+}
+
+inline bool has_crlf(const std::string &s) {
+  auto p = s.c_str();
+  while (*p) {
+    if (*p == '\r' || *p == '\n') { return true; }
+    p++;
+  }
+  return false;
+}
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+inline std::string message_digest(const std::string &s, const EVP_MD *algo) {
+  auto context = std::unique_ptr<EVP_MD_CTX, decltype(&EVP_MD_CTX_free)>(
+      EVP_MD_CTX_new(), EVP_MD_CTX_free);
+
+  unsigned int hash_length = 0;
+  unsigned char hash[EVP_MAX_MD_SIZE];
+
+  EVP_DigestInit_ex(context.get(), algo, nullptr);
+  EVP_DigestUpdate(context.get(), s.c_str(), s.size());
+  EVP_DigestFinal_ex(context.get(), hash, &hash_length);
+
+  std::stringstream ss;
+  for (auto i = 0u; i < hash_length; ++i) {
+    ss << std::hex << std::setw(2) << std::setfill('0')
+       << static_cast<unsigned int>(hash[i]);
+  }
+
+  return ss.str();
+}
+
+inline std::string MD5(const std::string &s) {
+  return message_digest(s, EVP_md5());
+}
+
+inline std::string SHA_256(const std::string &s) {
+  return message_digest(s, EVP_sha256());
+}
+
+inline std::string SHA_512(const std::string &s) {
+  return message_digest(s, EVP_sha512());
+}
+
+inline std::pair<std::string, std::string> make_digest_authentication_header(
+    const Request &req, const std::map<std::string, std::string> &auth,
+    size_t cnonce_count, const std::string &cnonce, const std::string &username,
+    const std::string &password, bool is_proxy = false) {
+  std::string nc;
+  {
+    std::stringstream ss;
+    ss << std::setfill('0') << std::setw(8) << std::hex << cnonce_count;
+    nc = ss.str();
+  }
+
+  std::string qop;
+  if (auth.find("qop") != auth.end()) {
+    qop = auth.at("qop");
+    if (qop.find("auth-int") != std::string::npos) {
+      qop = "auth-int";
+    } else if (qop.find("auth") != std::string::npos) {
+      qop = "auth";
+    } else {
+      qop.clear();
+    }
+  }
+
+  std::string algo = "MD5";
+  if (auth.find("algorithm") != auth.end()) { algo = auth.at("algorithm"); }
+
+  std::string response;
+  {
+    auto H = algo == "SHA-256"   ? detail::SHA_256
+             : algo == "SHA-512" ? detail::SHA_512
+                                 : detail::MD5;
+
+    auto A1 = username + ":" + auth.at("realm") + ":" + password;
+
+    auto A2 = req.method + ":" + req.path;
+    if (qop == "auth-int") { A2 += ":" + H(req.body); }
+
+    if (qop.empty()) {
+      response = H(H(A1) + ":" + auth.at("nonce") + ":" + H(A2));
+    } else {
+      response = H(H(A1) + ":" + auth.at("nonce") + ":" + nc + ":" + cnonce +
+                   ":" + qop + ":" + H(A2));
+    }
+  }
+
+  auto opaque = (auth.find("opaque") != auth.end()) ? auth.at("opaque") : "";
+
+  auto field = "Digest username=\"" + username + "\", realm=\"" +
+               auth.at("realm") + "\", nonce=\"" + auth.at("nonce") +
+               "\", uri=\"" + req.path + "\", algorithm=" + algo +
+               (qop.empty() ? ", response=\""
+                            : ", qop=" + qop + ", nc=" + nc + ", cnonce=\"" +
+                                  cnonce + "\", response=\"") +
+               response + "\"" +
+               (opaque.empty() ? "" : ", opaque=\"" + opaque + "\"");
+
+  auto key = is_proxy ? "Proxy-Authorization" : "Authorization";
+  return std::make_pair(key, field);
+}
+
+inline bool is_ssl_peer_could_be_closed(SSL *ssl, socket_t sock) {
+  detail::set_nonblocking(sock, true);
+  auto se = detail::scope_exit([&]() { detail::set_nonblocking(sock, false); });
+
+  char buf[1];
+  return !SSL_peek(ssl, buf, 1) &&
+         SSL_get_error(ssl, 0) == SSL_ERROR_ZERO_RETURN;
+}
+
+#ifdef _WIN32
+// NOTE: This code came up with the following stackoverflow post:
+// https://stackoverflow.com/questions/9507184/can-openssl-on-windows-use-the-system-certificate-store
+inline bool load_system_certs_on_windows(X509_STORE *store) {
+  auto hStore = CertOpenSystemStoreW((HCRYPTPROV_LEGACY)NULL, L"ROOT");
+  if (!hStore) { return false; }
+
+  auto result = false;
+  PCCERT_CONTEXT pContext = NULL;
+  while ((pContext = CertEnumCertificatesInStore(hStore, pContext)) !=
+         nullptr) {
+    auto encoded_cert =
+        static_cast<const unsigned char *>(pContext->pbCertEncoded);
+
+    auto x509 = d2i_X509(NULL, &encoded_cert, pContext->cbCertEncoded);
+    if (x509) {
+      X509_STORE_add_cert(store, x509);
+      X509_free(x509);
+      result = true;
+    }
+  }
+
+  CertFreeCertificateContext(pContext);
+  CertCloseStore(hStore, 0);
+
+  return result;
+}
+#elif defined(CPPHTTPLIB_USE_CERTS_FROM_MACOSX_KEYCHAIN) && defined(__APPLE__)
+#if TARGET_OS_OSX
+template <typename T>
+using CFObjectPtr =
+    std::unique_ptr<typename std::remove_pointer<T>::type, void (*)(CFTypeRef)>;
+
+inline void cf_object_ptr_deleter(CFTypeRef obj) {
+  if (obj) { CFRelease(obj); }
+}
+
+inline bool retrieve_certs_from_keychain(CFObjectPtr<CFArrayRef> &certs) {
+  CFStringRef keys[] = {kSecClass, kSecMatchLimit, kSecReturnRef};
+  CFTypeRef values[] = {kSecClassCertificate, kSecMatchLimitAll,
+                        kCFBooleanTrue};
+
+  CFObjectPtr<CFDictionaryRef> query(
+      CFDictionaryCreate(nullptr, reinterpret_cast<const void **>(keys), values,
+                         sizeof(keys) / sizeof(keys[0]),
+                         &kCFTypeDictionaryKeyCallBacks,
+                         &kCFTypeDictionaryValueCallBacks),
+      cf_object_ptr_deleter);
+
+  if (!query) { return false; }
+
+  CFTypeRef security_items = nullptr;
+  if (SecItemCopyMatching(query.get(), &security_items) != errSecSuccess ||
+      CFArrayGetTypeID() != CFGetTypeID(security_items)) {
+    return false;
+  }
+
+  certs.reset(reinterpret_cast<CFArrayRef>(security_items));
+  return true;
+}
+
+inline bool retrieve_root_certs_from_keychain(CFObjectPtr<CFArrayRef> &certs) {
+  CFArrayRef root_security_items = nullptr;
+  if (SecTrustCopyAnchorCertificates(&root_security_items) != errSecSuccess) {
+    return false;
+  }
+
+  certs.reset(root_security_items);
+  return true;
+}
+
+inline bool add_certs_to_x509_store(CFArrayRef certs, X509_STORE *store) {
+  auto result = false;
+  for (auto i = 0; i < CFArrayGetCount(certs); ++i) {
+    const auto cert = reinterpret_cast<const __SecCertificate *>(
+        CFArrayGetValueAtIndex(certs, i));
+
+    if (SecCertificateGetTypeID() != CFGetTypeID(cert)) { continue; }
+
+    CFDataRef cert_data = nullptr;
+    if (SecItemExport(cert, kSecFormatX509Cert, 0, nullptr, &cert_data) !=
+        errSecSuccess) {
+      continue;
+    }
+
+    CFObjectPtr<CFDataRef> cert_data_ptr(cert_data, cf_object_ptr_deleter);
+
+    auto encoded_cert = static_cast<const unsigned char *>(
+        CFDataGetBytePtr(cert_data_ptr.get()));
+
+    auto x509 =
+        d2i_X509(NULL, &encoded_cert, CFDataGetLength(cert_data_ptr.get()));
+
+    if (x509) {
+      X509_STORE_add_cert(store, x509);
+      X509_free(x509);
+      result = true;
+    }
+  }
+
+  return result;
+}
+
+inline bool load_system_certs_on_macos(X509_STORE *store) {
+  auto result = false;
+  CFObjectPtr<CFArrayRef> certs(nullptr, cf_object_ptr_deleter);
+  if (retrieve_certs_from_keychain(certs) && certs) {
+    result = add_certs_to_x509_store(certs.get(), store);
+  }
+
+  if (retrieve_root_certs_from_keychain(certs) && certs) {
+    result = add_certs_to_x509_store(certs.get(), store) || result;
+  }
+
+  return result;
+}
+#endif // TARGET_OS_OSX
+#endif // _WIN32
+#endif // CPPHTTPLIB_OPENSSL_SUPPORT
+
+#ifdef _WIN32
+class WSInit {
+public:
+  WSInit() {
+    WSADATA wsaData;
+    if (WSAStartup(0x0002, &wsaData) == 0) is_valid_ = true;
+  }
+
+  ~WSInit() {
+    if (is_valid_) WSACleanup();
+  }
+
+  bool is_valid_ = false;
+};
+
+static WSInit wsinit_;
+#endif
+
+inline bool parse_www_authenticate(const Response &res,
+                                   std::map<std::string, std::string> &auth,
+                                   bool is_proxy) {
+  auto auth_key = is_proxy ? "Proxy-Authenticate" : "WWW-Authenticate";
+  if (res.has_header(auth_key)) {
+    static auto re = std::regex(R"~((?:(?:,\s*)?(.+?)=(?:"(.*?)"|([^,]*))))~");
+    auto s = res.get_header_value(auth_key);
+    auto pos = s.find(' ');
+    if (pos != std::string::npos) {
+      auto type = s.substr(0, pos);
+      if (type == "Basic") {
+        return false;
+      } else if (type == "Digest") {
+        s = s.substr(pos + 1);
+        auto beg = std::sregex_iterator(s.begin(), s.end(), re);
+        for (auto i = beg; i != std::sregex_iterator(); ++i) {
+          const auto &m = *i;
+          auto key = s.substr(static_cast<size_t>(m.position(1)),
+                              static_cast<size_t>(m.length(1)));
+          auto val = m.length(2) > 0
+                         ? s.substr(static_cast<size_t>(m.position(2)),
+                                    static_cast<size_t>(m.length(2)))
+                         : s.substr(static_cast<size_t>(m.position(3)),
+                                    static_cast<size_t>(m.length(3)));
+          auth[key] = val;
+        }
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
+class ContentProviderAdapter {
+public:
+  explicit ContentProviderAdapter(
+      ContentProviderWithoutLength &&content_provider)
+      : content_provider_(content_provider) {}
+
+  bool operator()(size_t offset, size_t, DataSink &sink) {
+    return content_provider_(offset, sink);
+  }
+
+private:
+  ContentProviderWithoutLength content_provider_;
+};
+
+} // namespace detail
+
+inline std::string hosted_at(const std::string &hostname) {
+  std::vector<std::string> addrs;
+  hosted_at(hostname, addrs);
+  if (addrs.empty()) { return std::string(); }
+  return addrs[0];
+}
+
+inline void hosted_at(const std::string &hostname,
+                      std::vector<std::string> &addrs) {
+  struct addrinfo hints;
+  struct addrinfo *result;
+
+  memset(&hints, 0, sizeof(struct addrinfo));
+  hints.ai_family = AF_UNSPEC;
+  hints.ai_socktype = SOCK_STREAM;
+  hints.ai_protocol = 0;
+
+  if (getaddrinfo(hostname.c_str(), nullptr, &hints, &result)) {
+#if defined __linux__ && !defined __ANDROID__
+    res_init();
+#endif
+    return;
+  }
+  auto se = detail::scope_exit([&] { freeaddrinfo(result); });
+
+  for (auto rp = result; rp; rp = rp->ai_next) {
+    const auto &addr =
+        *reinterpret_cast<struct sockaddr_storage *>(rp->ai_addr);
+    std::string ip;
+    auto dummy = -1;
+    if (detail::get_ip_and_port(addr, sizeof(struct sockaddr_storage), ip,
+                                dummy)) {
+      addrs.push_back(ip);
+    }
+  }
+}
+
+inline std::string append_query_params(const std::string &path,
+                                       const Params &params) {
+  std::string path_with_query = path;
+  const static std::regex re("[^?]+\\?.*");
+  auto delm = std::regex_match(path, re) ? '&' : '?';
+  path_with_query += delm + detail::params_to_query_str(params);
+  return path_with_query;
+}
+
+// Header utilities
+inline std::pair<std::string, std::string>
+make_range_header(const Ranges &ranges) {
+  std::string field = "bytes=";
+  auto i = 0;
+  for (const auto &r : ranges) {
+    if (i != 0) { field += ", "; }
+    if (r.first != -1) { field += std::to_string(r.first); }
+    field += '-';
+    if (r.second != -1) { field += std::to_string(r.second); }
+    i++;
+  }
+  return std::make_pair("Range", std::move(field));
+}
+
+inline std::pair<std::string, std::string>
+make_basic_authentication_header(const std::string &username,
+                                 const std::string &password, bool is_proxy) {
+  auto field = "Basic " + detail::base64_encode(username + ":" + password);
+  auto key = is_proxy ? "Proxy-Authorization" : "Authorization";
+  return std::make_pair(key, std::move(field));
+}
+
+inline std::pair<std::string, std::string>
+make_bearer_token_authentication_header(const std::string &token,
+                                        bool is_proxy = false) {
+  auto field = "Bearer " + token;
+  auto key = is_proxy ? "Proxy-Authorization" : "Authorization";
+  return std::make_pair(key, std::move(field));
+}
+
+// Request implementation
+inline bool Request::has_header(const std::string &key) const {
+  return detail::has_header(headers, key);
+}
+
+inline std::string Request::get_header_value(const std::string &key,
+                                             const char *def, size_t id) const {
+  return detail::get_header_value(headers, key, def, id);
+}
+
+inline size_t Request::get_header_value_count(const std::string &key) const {
+  auto r = headers.equal_range(key);
+  return static_cast<size_t>(std::distance(r.first, r.second));
+}
+
+inline void Request::set_header(const std::string &key,
+                                const std::string &val) {
+  if (detail::fields::is_field_name(key) &&
+      detail::fields::is_field_value(val)) {
+    headers.emplace(key, val);
+  }
+}
+
+inline bool Request::has_param(const std::string &key) const {
+  return params.find(key) != params.end();
+}
+
+inline std::string Request::get_param_value(const std::string &key,
+                                            size_t id) const {
+  auto rng = params.equal_range(key);
+  auto it = rng.first;
+  std::advance(it, static_cast<ssize_t>(id));
+  if (it != rng.second) { return it->second; }
+  return std::string();
+}
+
+inline size_t Request::get_param_value_count(const std::string &key) const {
+  auto r = params.equal_range(key);
+  return static_cast<size_t>(std::distance(r.first, r.second));
+}
+
+inline bool Request::is_multipart_form_data() const {
+  const auto &content_type = get_header_value("Content-Type");
+  return !content_type.rfind("multipart/form-data", 0);
+}
+
+inline bool Request::has_file(const std::string &key) const {
+  return files.find(key) != files.end();
+}
+
+inline MultipartFormData Request::get_file_value(const std::string &key) const {
+  auto it = files.find(key);
+  if (it != files.end()) { return it->second; }
+  return MultipartFormData();
+}
+
+inline std::vector<MultipartFormData>
+Request::get_file_values(const std::string &key) const {
+  std::vector<MultipartFormData> values;
+  auto rng = files.equal_range(key);
+  for (auto it = rng.first; it != rng.second; it++) {
+    values.push_back(it->second);
+  }
+  return values;
+}
+
+// Response implementation
+inline bool Response::has_header(const std::string &key) const {
+  return headers.find(key) != headers.end();
+}
+
+inline std::string Response::get_header_value(const std::string &key,
+                                              const char *def,
+                                              size_t id) const {
+  return detail::get_header_value(headers, key, def, id);
+}
+
+inline size_t Response::get_header_value_count(const std::string &key) const {
+  auto r = headers.equal_range(key);
+  return static_cast<size_t>(std::distance(r.first, r.second));
+}
+
+inline void Response::set_header(const std::string &key,
+                                 const std::string &val) {
+  if (detail::fields::is_field_name(key) &&
+      detail::fields::is_field_value(val)) {
+    headers.emplace(key, val);
+  }
+}
+
+inline void Response::set_redirect(const std::string &url, int stat) {
+  if (detail::fields::is_field_value(url)) {
+    set_header("Location", url);
+    if (300 <= stat && stat < 400) {
+      this->status = stat;
+    } else {
+      this->status = StatusCode::Found_302;
+    }
+  }
+}
+
+inline void Response::set_content(const char *s, size_t n,
+                                  const std::string &content_type) {
+  body.assign(s, n);
+
+  auto rng = headers.equal_range("Content-Type");
+  headers.erase(rng.first, rng.second);
+  set_header("Content-Type", content_type);
+}
+
+inline void Response::set_content(const std::string &s,
+                                  const std::string &content_type) {
+  set_content(s.data(), s.size(), content_type);
+}
+
+inline void Response::set_content(std::string &&s,
+                                  const std::string &content_type) {
+  body = std::move(s);
+
+  auto rng = headers.equal_range("Content-Type");
+  headers.erase(rng.first, rng.second);
+  set_header("Content-Type", content_type);
+}
+
+inline void Response::set_content_provider(
+    size_t in_length, const std::string &content_type, ContentProvider provider,
+    ContentProviderResourceReleaser resource_releaser) {
+  set_header("Content-Type", content_type);
+  content_length_ = in_length;
+  if (in_length > 0) { content_provider_ = std::move(provider); }
+  content_provider_resource_releaser_ = std::move(resource_releaser);
+  is_chunked_content_provider_ = false;
+}
+
+inline void Response::set_content_provider(
+    const std::string &content_type, ContentProviderWithoutLength provider,
+    ContentProviderResourceReleaser resource_releaser) {
+  set_header("Content-Type", content_type);
+  content_length_ = 0;
+  content_provider_ = detail::ContentProviderAdapter(std::move(provider));
+  content_provider_resource_releaser_ = std::move(resource_releaser);
+  is_chunked_content_provider_ = false;
+}
+
+inline void Response::set_chunked_content_provider(
+    const std::string &content_type, ContentProviderWithoutLength provider,
+    ContentProviderResourceReleaser resource_releaser) {
+  set_header("Content-Type", content_type);
+  content_length_ = 0;
+  content_provider_ = detail::ContentProviderAdapter(std::move(provider));
+  content_provider_resource_releaser_ = std::move(resource_releaser);
+  is_chunked_content_provider_ = true;
+}
+
+inline void Response::set_file_content(const std::string &path,
+                                       const std::string &content_type) {
+  file_content_path_ = path;
+  file_content_content_type_ = content_type;
+}
+
+inline void Response::set_file_content(const std::string &path) {
+  file_content_path_ = path;
+}
+
+// Result implementation
+inline bool Result::has_request_header(const std::string &key) const {
+  return request_headers_.find(key) != request_headers_.end();
+}
+
+inline std::string Result::get_request_header_value(const std::string &key,
+                                                    const char *def,
+                                                    size_t id) const {
+  return detail::get_header_value(request_headers_, key, def, id);
+}
+
+inline size_t
+Result::get_request_header_value_count(const std::string &key) const {
+  auto r = request_headers_.equal_range(key);
+  return static_cast<size_t>(std::distance(r.first, r.second));
+}
+
+// Stream implementation
+inline ssize_t Stream::write(const char *ptr) {
+  return write(ptr, strlen(ptr));
+}
+
+inline ssize_t Stream::write(const std::string &s) {
+  return write(s.data(), s.size());
+}
+
+namespace detail {
+
+inline void calc_actual_timeout(time_t max_timeout_msec,
+                                time_t duration_msec, time_t timeout_sec,
+                                time_t timeout_usec, time_t &actual_timeout_sec,
+                                time_t &actual_timeout_usec) {
+  auto timeout_msec = (timeout_sec * 1000) + (timeout_usec / 1000);
+
+  auto actual_timeout_msec =
+      std::min(max_timeout_msec - duration_msec, timeout_msec);
+
+  actual_timeout_sec = actual_timeout_msec / 1000;
+  actual_timeout_usec = (actual_timeout_msec % 1000) * 1000;
+}
+
+// Socket stream implementation
+inline SocketStream::SocketStream(
+    socket_t sock, time_t read_timeout_sec, time_t read_timeout_usec,
+    time_t write_timeout_sec, time_t write_timeout_usec,
+    time_t max_timeout_msec,
+    std::chrono::time_point<std::chrono::steady_clock> start_time)
+    : sock_(sock), read_timeout_sec_(read_timeout_sec),
+      read_timeout_usec_(read_timeout_usec),
+      write_timeout_sec_(write_timeout_sec),
+      write_timeout_usec_(write_timeout_usec),
+      max_timeout_msec_(max_timeout_msec), start_time(start_time),
+      read_buff_(read_buff_size_, 0) {}
+
+inline SocketStream::~SocketStream() = default;
+
+inline bool SocketStream::is_readable() const {
+  if (max_timeout_msec_ <= 0) {
+    return select_read(sock_, read_timeout_sec_, read_timeout_usec_) > 0;
+  }
+
+  time_t read_timeout_sec;
+  time_t read_timeout_usec;
+  calc_actual_timeout(max_timeout_msec_, duration(), read_timeout_sec_,
+                      read_timeout_usec_, read_timeout_sec, read_timeout_usec);
+
+  return select_read(sock_, read_timeout_sec, read_timeout_usec) > 0;
+}
+
+inline bool SocketStream::is_writable() const {
+  return select_write(sock_, write_timeout_sec_, write_timeout_usec_) > 0 &&
+         is_socket_alive(sock_);
+}
+
+inline ssize_t SocketStream::read(char *ptr, size_t size) {
+#ifdef _WIN32
+  size =
+      (std::min)(size, static_cast<size_t>((std::numeric_limits<int>::max)()));
+#else
+  size = (std::min)(size,
+                    static_cast<size_t>((std::numeric_limits<ssize_t>::max)()));
+#endif
+
+  if (read_buff_off_ < read_buff_content_size_) {
+    auto remaining_size = read_buff_content_size_ - read_buff_off_;
+    if (size <= remaining_size) {
+      memcpy(ptr, read_buff_.data() + read_buff_off_, size);
+      read_buff_off_ += size;
+      return static_cast<ssize_t>(size);
+    } else {
+      memcpy(ptr, read_buff_.data() + read_buff_off_, remaining_size);
+      read_buff_off_ += remaining_size;
+      return static_cast<ssize_t>(remaining_size);
+    }
+  }
+
+  if (!is_readable()) { return -1; }
+
+  read_buff_off_ = 0;
+  read_buff_content_size_ = 0;
+
+  if (size < read_buff_size_) {
+    auto n = read_socket(sock_, read_buff_.data(), read_buff_size_,
+                         CPPHTTPLIB_RECV_FLAGS);
+    if (n <= 0) {
+      return n;
+    } else if (n <= static_cast<ssize_t>(size)) {
+      memcpy(ptr, read_buff_.data(), static_cast<size_t>(n));
+      return n;
+    } else {
+      memcpy(ptr, read_buff_.data(), size);
+      read_buff_off_ = size;
+      read_buff_content_size_ = static_cast<size_t>(n);
+      return static_cast<ssize_t>(size);
+    }
+  } else {
+    return read_socket(sock_, ptr, size, CPPHTTPLIB_RECV_FLAGS);
+  }
+}
+
+inline ssize_t SocketStream::write(const char *ptr, size_t size) {
+  if (!is_writable()) { return -1; }
+
+#if defined(_WIN32) && !defined(_WIN64)
+  size =
+      (std::min)(size, static_cast<size_t>((std::numeric_limits<int>::max)()));
+#endif
+
+  return send_socket(sock_, ptr, size, CPPHTTPLIB_SEND_FLAGS);
+}
+
+inline void SocketStream::get_remote_ip_and_port(std::string &ip,
+                                                 int &port) const {
+  return detail::get_remote_ip_and_port(sock_, ip, port);
+}
+
+inline void SocketStream::get_local_ip_and_port(std::string &ip,
+                                                int &port) const {
+  return detail::get_local_ip_and_port(sock_, ip, port);
+}
+
+inline socket_t SocketStream::socket() const { return sock_; }
+
+inline time_t SocketStream::duration() const {
+  return std::chrono::duration_cast<std::chrono::milliseconds>(
+             std::chrono::steady_clock::now() - start_time)
+      .count();
+}
+
+// Buffer stream implementation
+inline bool BufferStream::is_readable() const { return true; }
+
+inline bool BufferStream::is_writable() const { return true; }
+
+inline ssize_t BufferStream::read(char *ptr, size_t size) {
+#if defined(_MSC_VER) && _MSC_VER < 1910
+  auto len_read = buffer._Copy_s(ptr, size, size, position);
+#else
+  auto len_read = buffer.copy(ptr, size, position);
+#endif
+  position += static_cast<size_t>(len_read);
+  return static_cast<ssize_t>(len_read);
+}
+
+inline ssize_t BufferStream::write(const char *ptr, size_t size) {
+  buffer.append(ptr, size);
+  return static_cast<ssize_t>(size);
+}
+
+inline void BufferStream::get_remote_ip_and_port(std::string & /*ip*/,
+                                                 int & /*port*/) const {}
+
+inline void BufferStream::get_local_ip_and_port(std::string & /*ip*/,
+                                                int & /*port*/) const {}
+
+inline socket_t BufferStream::socket() const { return 0; }
+
+inline time_t BufferStream::duration() const { return 0; }
+
+inline const std::string &BufferStream::get_buffer() const { return buffer; }
+
+inline PathParamsMatcher::PathParamsMatcher(const std::string &pattern) {
+  static constexpr char marker[] = "/:";
+
+  // One past the last ending position of a path param substring
+  std::size_t last_param_end = 0;
+
+#ifndef CPPHTTPLIB_NO_EXCEPTIONS
+  // Needed to ensure that parameter names are unique during matcher
+  // construction
+  // If exceptions are disabled, only last duplicate path
+  // parameter will be set
+  std::unordered_set<std::string> param_name_set;
+#endif
+
+  while (true) {
+    const auto marker_pos = pattern.find(
+        marker, last_param_end == 0 ? last_param_end : last_param_end - 1);
+    if (marker_pos == std::string::npos) { break; }
+
+    static_fragments_.push_back(
+        pattern.substr(last_param_end, marker_pos - last_param_end + 1));
+
+    const auto param_name_start = marker_pos + 2;
+
+    auto sep_pos = pattern.find(separator, param_name_start);
+    if (sep_pos == std::string::npos) { sep_pos = pattern.length(); }
+
+    auto param_name =
+        pattern.substr(param_name_start, sep_pos - param_name_start);
+
+#ifndef CPPHTTPLIB_NO_EXCEPTIONS
+    if (param_name_set.find(param_name) != param_name_set.cend()) {
+      std::string msg = "Encountered path parameter '" + param_name +
+                        "' multiple times in route pattern '" + pattern + "'.";
+      throw std::invalid_argument(msg);
+    }
+#endif
+
+    param_names_.push_back(std::move(param_name));
+
+    last_param_end = sep_pos + 1;
+  }
+
+  if (last_param_end < pattern.length()) {
+    static_fragments_.push_back(pattern.substr(last_param_end));
+  }
+}
+
+inline bool PathParamsMatcher::match(Request &request) const {
+  request.matches = std::smatch();
+  request.path_params.clear();
+  request.path_params.reserve(param_names_.size());
+
+  // One past the position at which the path matched the pattern last time
+  std::size_t starting_pos = 0;
+  for (size_t i = 0; i < static_fragments_.size(); ++i) {
+    const auto &fragment = static_fragments_[i];
+
+    if (starting_pos + fragment.length() > request.path.length()) {
+      return false;
+    }
+
+    // Avoid unnecessary allocation by using strncmp instead of substr +
+    // comparison
+    if (std::strncmp(request.path.c_str() + starting_pos, fragment.c_str(),
+                     fragment.length()) != 0) {
+      return false;
+    }
+
+    starting_pos += fragment.length();
+
+    // Should only happen when we have a static fragment after a param
+    // Example: '/users/:id/subscriptions'
+    // The 'subscriptions' fragment here does not have a corresponding param
+    if (i >= param_names_.size()) { continue; }
+
+    auto sep_pos = request.path.find(separator, starting_pos);
+    if (sep_pos == std::string::npos) { sep_pos = request.path.length(); }
+
+    const auto &param_name = param_names_[i];
+
+    request.path_params.emplace(
+        param_name, request.path.substr(starting_pos, sep_pos - starting_pos));
+
+    // Mark everything up to '/' as matched
+    starting_pos = sep_pos + 1;
+  }
+  // Returns false if the path is longer than the pattern
+  return starting_pos >= request.path.length();
+}
+
+inline bool RegexMatcher::match(Request &request) const {
+  request.path_params.clear();
+  return std::regex_match(request.path, request.matches, regex_);
+}
+
+} // namespace detail
+
+// HTTP server implementation
+inline Server::Server()
+    : new_task_queue(
+          [] { return new ThreadPool(CPPHTTPLIB_THREAD_POOL_COUNT); }) {
+#ifndef _WIN32
+  signal(SIGPIPE, SIG_IGN);
+#endif
+}
+
+inline Server::~Server() = default;
+
+inline std::unique_ptr<detail::MatcherBase>
+Server::make_matcher(const std::string &pattern) {
+  if (pattern.find("/:") != std::string::npos) {
+    return detail::make_unique<detail::PathParamsMatcher>(pattern);
+  } else {
+    return detail::make_unique<detail::RegexMatcher>(pattern);
+  }
+}
+
+inline Server &Server::Get(const std::string &pattern, Handler handler) {
+  get_handlers_.emplace_back(make_matcher(pattern), std::move(handler));
+  return *this;
+}
+
+inline Server &Server::Post(const std::string &pattern, Handler handler) {
+  post_handlers_.emplace_back(make_matcher(pattern), std::move(handler));
+  return *this;
+}
+
+inline Server &Server::Post(const std::string &pattern,
+                            HandlerWithContentReader handler) {
+  post_handlers_for_content_reader_.emplace_back(make_matcher(pattern),
+                                                 std::move(handler));
+  return *this;
+}
+
+inline Server &Server::Put(const std::string &pattern, Handler handler) {
+  put_handlers_.emplace_back(make_matcher(pattern), std::move(handler));
+  return *this;
+}
+
+inline Server &Server::Put(const std::string &pattern,
+                           HandlerWithContentReader handler) {
+  put_handlers_for_content_reader_.emplace_back(make_matcher(pattern),
+                                                std::move(handler));
+  return *this;
+}
+
+inline Server &Server::Patch(const std::string &pattern, Handler handler) {
+  patch_handlers_.emplace_back(make_matcher(pattern), std::move(handler));
+  return *this;
+}
+
+inline Server &Server::Patch(const std::string &pattern,
+                             HandlerWithContentReader handler) {
+  patch_handlers_for_content_reader_.emplace_back(make_matcher(pattern),
+                                                  std::move(handler));
+  return *this;
+}
+
+inline Server &Server::Delete(const std::string &pattern, Handler handler) {
+  delete_handlers_.emplace_back(make_matcher(pattern), std::move(handler));
+  return *this;
+}
+
+inline Server &Server::Delete(const std::string &pattern,
+                              HandlerWithContentReader handler) {
+  delete_handlers_for_content_reader_.emplace_back(make_matcher(pattern),
+                                                   std::move(handler));
+  return *this;
+}
+
+inline Server &Server::Options(const std::string &pattern, Handler handler) {
+  options_handlers_.emplace_back(make_matcher(pattern), std::move(handler));
+  return *this;
+}
+
+inline bool Server::set_base_dir(const std::string &dir,
+                                 const std::string &mount_point) {
+  return set_mount_point(mount_point, dir);
+}
+
+inline bool Server::set_mount_point(const std::string &mount_point,
+                                    const std::string &dir, Headers headers) {
+  detail::FileStat stat(dir);
+  if (stat.is_dir()) {
+    std::string mnt = !mount_point.empty() ? mount_point : "/";
+    if (!mnt.empty() && mnt[0] == '/') {
+      base_dirs_.push_back({mnt, dir, std::move(headers)});
+      return true;
+    }
+  }
+  return false;
+}
+
+inline bool Server::remove_mount_point(const std::string &mount_point) {
+  for (auto it = base_dirs_.begin(); it != base_dirs_.end(); ++it) {
+    if (it->mount_point == mount_point) {
+      base_dirs_.erase(it);
+      return true;
+    }
+  }
+  return false;
+}
+
+inline Server &
+Server::set_file_extension_and_mimetype_mapping(const std::string &ext,
+                                                const std::string &mime) {
+  file_extension_and_mimetype_map_[ext] = mime;
+  return *this;
+}
+
+inline Server &Server::set_default_file_mimetype(const std::string &mime) {
+  default_file_mimetype_ = mime;
+  return *this;
+}
+
+inline Server &Server::set_file_request_handler(Handler handler) {
+  file_request_handler_ = std::move(handler);
+  return *this;
+}
+
+inline Server &Server::set_error_handler_core(HandlerWithResponse handler,
+                                              std::true_type) {
+  error_handler_ = std::move(handler);
+  return *this;
+}
+
+inline Server &Server::set_error_handler_core(Handler handler,
+                                              std::false_type) {
+  error_handler_ = [handler](const Request &req, Response &res) {
+    handler(req, res);
+    return HandlerResponse::Handled;
+  };
+  return *this;
+}
+
+inline Server &Server::set_exception_handler(ExceptionHandler handler) {
+  exception_handler_ = std::move(handler);
+  return *this;
+}
+
+inline Server &Server::set_pre_routing_handler(HandlerWithResponse handler) {
+  pre_routing_handler_ = std::move(handler);
+  return *this;
+}
+
+inline Server &Server::set_post_routing_handler(Handler handler) {
+  post_routing_handler_ = std::move(handler);
+  return *this;
+}
+
+inline Server &Server::set_logger(Logger logger) {
+  logger_ = std::move(logger);
+  return *this;
+}
+
+inline Server &
+Server::set_expect_100_continue_handler(Expect100ContinueHandler handler) {
+  expect_100_continue_handler_ = std::move(handler);
+  return *this;
+}
+
+inline Server &Server::set_address_family(int family) {
+  address_family_ = family;
+  return *this;
+}
+
+inline Server &Server::set_tcp_nodelay(bool on) {
+  tcp_nodelay_ = on;
+  return *this;
+}
+
+inline Server &Server::set_ipv6_v6only(bool on) {
+  ipv6_v6only_ = on;
+  return *this;
+}
+
+inline Server &Server::set_socket_options(SocketOptions socket_options) {
+  socket_options_ = std::move(socket_options);
+  return *this;
+}
+
+inline Server &Server::set_default_headers(Headers headers) {
+  default_headers_ = std::move(headers);
+  return *this;
+}
+
+inline Server &Server::set_header_writer(
+    std::function<ssize_t(Stream &, Headers &)> const &writer) {
+  header_writer_ = writer;
+  return *this;
+}
+
+inline Server &Server::set_keep_alive_max_count(size_t count) {
+  keep_alive_max_count_ = count;
+  return *this;
+}
+
+inline Server &Server::set_keep_alive_timeout(time_t sec) {
+  keep_alive_timeout_sec_ = sec;
+  return *this;
+}
+
+inline Server &Server::set_read_timeout(time_t sec, time_t usec) {
+  read_timeout_sec_ = sec;
+  read_timeout_usec_ = usec;
+  return *this;
+}
+
+inline Server &Server::set_write_timeout(time_t sec, time_t usec) {
+  write_timeout_sec_ = sec;
+  write_timeout_usec_ = usec;
+  return *this;
+}
+
+inline Server &Server::set_idle_interval(time_t sec, time_t usec) {
+  idle_interval_sec_ = sec;
+  idle_interval_usec_ = usec;
+  return *this;
+}
+
+inline Server &Server::set_payload_max_length(size_t length) {
+  payload_max_length_ = length;
+  return *this;
+}
+
+inline bool Server::bind_to_port(const std::string &host, int port,
+                                 int socket_flags) {
+  auto ret = bind_internal(host, port, socket_flags);
+  if (ret == -1) { is_decommisioned = true; }
+  return ret >= 0;
+}
+inline int Server::bind_to_any_port(const std::string &host, int socket_flags) {
+  auto ret = bind_internal(host, 0, socket_flags);
+  if (ret == -1) { is_decommisioned = true; }
+  return ret;
+}
+
+inline bool Server::listen_after_bind() { return listen_internal(); }
+
+inline bool Server::listen(const std::string &host, int port,
+                           int socket_flags) {
+  return bind_to_port(host, port, socket_flags) && listen_internal();
+}
+
+inline bool Server::is_running() const { return is_running_; }
+
+inline void Server::wait_until_ready() const {
+  while (!is_running_ && !is_decommisioned) {
+    std::this_thread::sleep_for(std::chrono::milliseconds{1});
+  }
+}
+
+inline void Server::stop() {
+  if (is_running_) {
+    assert(svr_sock_ != INVALID_SOCKET);
+    std::atomic<socket_t> sock(svr_sock_.exchange(INVALID_SOCKET));
+    detail::shutdown_socket(sock);
+    detail::close_socket(sock);
+  }
+  is_decommisioned = false;
+}
+
+inline void Server::decommission() { is_decommisioned = true; }
+
+inline bool Server::parse_request_line(const char *s, Request &req) const {
+  auto len = strlen(s);
+  if (len < 2 || s[len - 2] != '\r' || s[len - 1] != '\n') { return false; }
+  len -= 2;
+
+  {
+    size_t count = 0;
+
+    detail::split(s, s + len, ' ', [&](const char *b, const char *e) {
+      switch (count) {
+      case 0: req.method = std::string(b, e); break;
+      case 1: req.target = std::string(b, e); break;
+      case 2: req.version = std::string(b, e); break;
+      default: break;
+      }
+      count++;
+    });
+
+    if (count != 3) { return false; }
+  }
+
+  static const std::set<std::string> methods{
+      "GET",     "HEAD",    "POST",  "PUT",   "DELETE",
+      "CONNECT", "OPTIONS", "TRACE", "PATCH", "PRI"};
+
+  if (methods.find(req.method) == methods.end()) { return false; }
+
+  if (req.version != "HTTP/1.1" && req.version != "HTTP/1.0") { return false; }
+
+  {
+    // Skip URL fragment
+    for (size_t i = 0; i < req.target.size(); i++) {
+      if (req.target[i] == '#') {
+        req.target.erase(i);
+        break;
+      }
+    }
+
+    detail::divide(req.target, '?',
+                   [&](const char *lhs_data, std::size_t lhs_size,
+                       const char *rhs_data, std::size_t rhs_size) {
+                     req.path = detail::decode_url(
+                         std::string(lhs_data, lhs_size), false);
+                     detail::parse_query_text(rhs_data, rhs_size, req.params);
+                   });
+  }
+
+  return true;
+}
+
+inline bool Server::write_response(Stream &strm, bool close_connection,
+                                   Request &req, Response &res) {
+  // NOTE: `req.ranges` should be empty, otherwise it will be applied
+  // incorrectly to the error content.
+  req.ranges.clear();
+  return write_response_core(strm, close_connection, req, res, false);
+}
+
+inline bool Server::write_response_with_content(Stream &strm,
+                                                bool close_connection,
+                                                const Request &req,
+                                                Response &res) {
+  return write_response_core(strm, close_connection, req, res, true);
+}
+
+inline bool Server::write_response_core(Stream &strm, bool close_connection,
+                                        const Request &req, Response &res,
+                                        bool need_apply_ranges) {
+  assert(res.status != -1);
+
+  if (400 <= res.status && error_handler_ &&
+      error_handler_(req, res) == HandlerResponse::Handled) {
+    need_apply_ranges = true;
+  }
+
+  std::string content_type;
+  std::string boundary;
+  if (need_apply_ranges) { apply_ranges(req, res, content_type, boundary); }
+
+  // Prepare additional headers
+  if (close_connection || req.get_header_value("Connection") == "close") {
+    res.set_header("Connection", "close");
+  } else {
+    std::string s = "timeout=";
+    s += std::to_string(keep_alive_timeout_sec_);
+    s += ", max=";
+    s += std::to_string(keep_alive_max_count_);
+    res.set_header("Keep-Alive", s);
+  }
+
+  if ((!res.body.empty() || res.content_length_ > 0 || res.content_provider_) &&
+      !res.has_header("Content-Type")) {
+    res.set_header("Content-Type", "text/plain");
+  }
+
+  if (res.body.empty() && !res.content_length_ && !res.content_provider_ &&
+      !res.has_header("Content-Length")) {
+    res.set_header("Content-Length", "0");
+  }
+
+  if (req.method == "HEAD" && !res.has_header("Accept-Ranges")) {
+    res.set_header("Accept-Ranges", "bytes");
+  }
+
+  if (post_routing_handler_) { post_routing_handler_(req, res); }
+
+  // Response line and headers
+  {
+    detail::BufferStream bstrm;
+    if (!detail::write_response_line(bstrm, res.status)) { return false; }
+    if (!header_writer_(bstrm, res.headers)) { return false; }
+
+    // Flush buffer
+    auto &data = bstrm.get_buffer();
+    detail::write_data(strm, data.data(), data.size());
+  }
+
+  // Body
+  auto ret = true;
+  if (req.method != "HEAD") {
+    if (!res.body.empty()) {
+      if (!detail::write_data(strm, res.body.data(), res.body.size())) {
+        ret = false;
+      }
+    } else if (res.content_provider_) {
+      if (write_content_with_provider(strm, req, res, boundary, content_type)) {
+        res.content_provider_success_ = true;
+      } else {
+        ret = false;
+      }
+    }
+  }
+
+  // Log
+  if (logger_) { logger_(req, res); }
+
+  return ret;
+}
+
+inline bool
+Server::write_content_with_provider(Stream &strm, const Request &req,
+                                    Response &res, const std::string &boundary,
+                                    const std::string &content_type) {
+  auto is_shutting_down = [this]() {
+    return this->svr_sock_ == INVALID_SOCKET;
+  };
+
+  if (res.content_length_ > 0) {
+    if (req.ranges.empty()) {
+      return detail::write_content(strm, res.content_provider_, 0,
+                                   res.content_length_, is_shutting_down);
+    } else if (req.ranges.size() == 1) {
+      auto offset_and_length = detail::get_range_offset_and_length(
+          req.ranges[0], res.content_length_);
+
+      return detail::write_content(strm, res.content_provider_,
+                                   offset_and_length.first,
+                                   offset_and_length.second, is_shutting_down);
+    } else {
+      return detail::write_multipart_ranges_data(
+          strm, req, res, boundary, content_type, res.content_length_,
+          is_shutting_down);
+    }
+  } else {
+    if (res.is_chunked_content_provider_) {
+      auto type = detail::encoding_type(req, res);
+
+      std::unique_ptr<detail::compressor> compressor;
+      if (type == detail::EncodingType::Gzip) {
+#ifdef CPPHTTPLIB_ZLIB_SUPPORT
+        compressor = detail::make_unique<detail::gzip_compressor>();
+#endif
+      } else if (type == detail::EncodingType::Brotli) {
+#ifdef CPPHTTPLIB_BROTLI_SUPPORT
+        compressor = detail::make_unique<detail::brotli_compressor>();
+#endif
+      } else {
+        compressor = detail::make_unique<detail::nocompressor>();
+      }
+      assert(compressor != nullptr);
+
+      return detail::write_content_chunked(strm, res.content_provider_,
+                                           is_shutting_down, *compressor);
+    } else {
+      return detail::write_content_without_length(strm, res.content_provider_,
+                                                  is_shutting_down);
+    }
+  }
+}
+
+inline bool Server::read_content(Stream &strm, Request &req, Response &res) {
+  MultipartFormDataMap::iterator cur;
+  auto file_count = 0;
+  if (read_content_core(
+          strm, req, res,
+          // Regular
+          [&](const char *buf, size_t n) {
+            if (req.body.size() + n > req.body.max_size()) { return false; }
+            req.body.append(buf, n);
+            return true;
+          },
+          // Multipart
+          [&](const MultipartFormData &file) {
+            if (file_count++ == CPPHTTPLIB_MULTIPART_FORM_DATA_FILE_MAX_COUNT) {
+              return false;
+            }
+            cur = req.files.emplace(file.name, file);
+            return true;
+          },
+          [&](const char *buf, size_t n) {
+            auto &content = cur->second.content;
+            if (content.size() + n > content.max_size()) { return false; }
+            content.append(buf, n);
+            return true;
+          })) {
+    const auto &content_type = req.get_header_value("Content-Type");
+    if (!content_type.find("application/x-www-form-urlencoded")) {
+      if (req.body.size() > CPPHTTPLIB_FORM_URL_ENCODED_PAYLOAD_MAX_LENGTH) {
+        res.status = StatusCode::PayloadTooLarge_413; // NOTE: should be 414?
+        return false;
+      }
+      detail::parse_query_text(req.body, req.params);
+    }
+    return true;
+  }
+  return false;
+}
+
+inline bool Server::read_content_with_content_receiver(
+    Stream &strm, Request &req, Response &res, ContentReceiver receiver,
+    MultipartContentHeader multipart_header,
+    ContentReceiver multipart_receiver) {
+  return read_content_core(strm, req, res, std::move(receiver),
+                           std::move(multipart_header),
+                           std::move(multipart_receiver));
+}
+
+inline bool
+Server::read_content_core(Stream &strm, Request &req, Response &res,
+                          ContentReceiver receiver,
+                          MultipartContentHeader multipart_header,
+                          ContentReceiver multipart_receiver) const {
+  detail::MultipartFormDataParser multipart_form_data_parser;
+  ContentReceiverWithProgress out;
+
+  if (req.is_multipart_form_data()) {
+    const auto &content_type = req.get_header_value("Content-Type");
+    std::string boundary;
+    if (!detail::parse_multipart_boundary(content_type, boundary)) {
+      res.status = StatusCode::BadRequest_400;
+      return false;
+    }
+
+    multipart_form_data_parser.set_boundary(std::move(boundary));
+    out = [&](const char *buf, size_t n, uint64_t /*off*/, uint64_t /*len*/) {
+      /* For debug
+      size_t pos = 0;
+      while (pos < n) {
+        auto read_size = (std::min)<size_t>(1, n - pos);
+        auto ret = multipart_form_data_parser.parse(
+            buf + pos, read_size, multipart_receiver, multipart_header);
+        if (!ret) { return false; }
+        pos += read_size;
+      }
+      return true;
+      */
+      return multipart_form_data_parser.parse(buf, n, multipart_receiver,
+                                              multipart_header);
+    };
+  } else {
+    out = [receiver](const char *buf, size_t n, uint64_t /*off*/,
+                     uint64_t /*len*/) { return receiver(buf, n); };
+  }
+
+  if (req.method == "DELETE" && !req.has_header("Content-Length")) {
+    return true;
+  }
+
+  if (!detail::read_content(strm, req, payload_max_length_, res.status, nullptr,
+                            out, true)) {
+    return false;
+  }
+
+  if (req.is_multipart_form_data()) {
+    if (!multipart_form_data_parser.is_valid()) {
+      res.status = StatusCode::BadRequest_400;
+      return false;
+    }
+  }
+
+  return true;
+}
+
+inline bool Server::handle_file_request(const Request &req, Response &res,
+                                        bool head) {
+  for (const auto &entry : base_dirs_) {
+    // Prefix match
+    if (!req.path.compare(0, entry.mount_point.size(), entry.mount_point)) {
+      std::string sub_path = "/" + req.path.substr(entry.mount_point.size());
+      if (detail::is_valid_path(sub_path)) {
+        auto path = entry.base_dir + sub_path;
+        if (path.back() == '/') { path += "index.html"; }
+
+        detail::FileStat stat(path);
+
+        if (stat.is_dir()) {
+          res.set_redirect(sub_path + "/", StatusCode::MovedPermanently_301);
+          return true;
+        }
+
+        if (stat.is_file()) {
+          for (const auto &kv : entry.headers) {
+            res.set_header(kv.first, kv.second);
+          }
+
+          auto mm = std::make_shared<detail::mmap>(path.c_str());
+          if (!mm->is_open()) { return false; }
+
+          res.set_content_provider(
+              mm->size(),
+              detail::find_content_type(path, file_extension_and_mimetype_map_,
+                                        default_file_mimetype_),
+              [mm](size_t offset, size_t length, DataSink &sink) -> bool {
+                sink.write(mm->data() + offset, length);
+                return true;
+              });
+
+          if (!head && file_request_handler_) {
+            file_request_handler_(req, res);
+          }
+
+          return true;
+        }
+      }
+    }
+  }
+  return false;
+}
+
+inline socket_t
+Server::create_server_socket(const std::string &host, int port,
+                             int socket_flags,
+                             SocketOptions socket_options) const {
+  return detail::create_socket(
+      host, std::string(), port, address_family_, socket_flags, tcp_nodelay_,
+      ipv6_v6only_, std::move(socket_options),
+      [](socket_t sock, struct addrinfo &ai, bool & /*quit*/) -> bool {
+        if (::bind(sock, ai.ai_addr, static_cast<socklen_t>(ai.ai_addrlen))) {
+          return false;
+        }
+        if (::listen(sock, CPPHTTPLIB_LISTEN_BACKLOG)) { return false; }
+        return true;
+      });
+}
+
+inline int Server::bind_internal(const std::string &host, int port,
+                                 int socket_flags) {
+  if (is_decommisioned) { return -1; }
+
+  if (!is_valid()) { return -1; }
+
+  svr_sock_ = create_server_socket(host, port, socket_flags, socket_options_);
+  if (svr_sock_ == INVALID_SOCKET) { return -1; }
+
+  if (port == 0) {
+    struct sockaddr_storage addr;
+    socklen_t addr_len = sizeof(addr);
+    if (getsockname(svr_sock_, reinterpret_cast<struct sockaddr *>(&addr),
+                    &addr_len) == -1) {
+      return -1;
+    }
+    if (addr.ss_family == AF_INET) {
+      return ntohs(reinterpret_cast<struct sockaddr_in *>(&addr)->sin_port);
+    } else if (addr.ss_family == AF_INET6) {
+      return ntohs(reinterpret_cast<struct sockaddr_in6 *>(&addr)->sin6_port);
+    } else {
+      return -1;
+    }
+  } else {
+    return port;
+  }
+}
+
+inline bool Server::listen_internal() {
+  if (is_decommisioned) { return false; }
+
+  auto ret = true;
+  is_running_ = true;
+  auto se = detail::scope_exit([&]() { is_running_ = false; });
+
+  {
+    std::unique_ptr<TaskQueue> task_queue(new_task_queue());
+
+    while (svr_sock_ != INVALID_SOCKET) {
+#ifndef _WIN32
+      if (idle_interval_sec_ > 0 || idle_interval_usec_ > 0) {
+#endif
+        auto val = detail::select_read(svr_sock_, idle_interval_sec_,
+                                       idle_interval_usec_);
+        if (val == 0) { // Timeout
+          task_queue->on_idle();
+          continue;
+        }
+#ifndef _WIN32
+      }
+#endif
+
+#if defined _WIN32
+      // sockets conneced via WASAccept inherit flags NO_HANDLE_INHERIT,
+      // OVERLAPPED
+      socket_t sock = WSAAccept(svr_sock_, nullptr, nullptr, nullptr, 0);
+#elif defined SOCK_CLOEXEC
+      socket_t sock = accept4(svr_sock_, nullptr, nullptr, SOCK_CLOEXEC);
+#else
+      socket_t sock = accept(svr_sock_, nullptr, nullptr);
+#endif
+
+      if (sock == INVALID_SOCKET) {
+        if (errno == EMFILE) {
+          // The per-process limit of open file descriptors has been reached.
+          // Try to accept new connections after a short sleep.
+          std::this_thread::sleep_for(std::chrono::microseconds{1});
+          continue;
+        } else if (errno == EINTR || errno == EAGAIN) {
+          continue;
+        }
+        if (svr_sock_ != INVALID_SOCKET) {
+          detail::close_socket(svr_sock_);
+          ret = false;
+        } else {
+          ; // The server socket was closed by user.
+        }
+        break;
+      }
+
+      {
+#ifdef _WIN32
+        auto timeout = static_cast<uint32_t>(read_timeout_sec_ * 1000 +
+                                             read_timeout_usec_ / 1000);
+        setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
+                   reinterpret_cast<const char *>(&timeout), sizeof(timeout));
+#else
+        timeval tv;
+        tv.tv_sec = static_cast<long>(read_timeout_sec_);
+        tv.tv_usec = static_cast<decltype(tv.tv_usec)>(read_timeout_usec_);
+        setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
+                   reinterpret_cast<const void *>(&tv), sizeof(tv));
+#endif
+      }
+      {
+
+#ifdef _WIN32
+        auto timeout = static_cast<uint32_t>(write_timeout_sec_ * 1000 +
+                                             write_timeout_usec_ / 1000);
+        setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO,
+                   reinterpret_cast<const char *>(&timeout), sizeof(timeout));
+#else
+        timeval tv;
+        tv.tv_sec = static_cast<long>(write_timeout_sec_);
+        tv.tv_usec = static_cast<decltype(tv.tv_usec)>(write_timeout_usec_);
+        setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO,
+                   reinterpret_cast<const void *>(&tv), sizeof(tv));
+#endif
+      }
+
+      if (!task_queue->enqueue(
+              [this, sock]() { process_and_close_socket(sock); })) {
+        detail::shutdown_socket(sock);
+        detail::close_socket(sock);
+      }
+    }
+
+    task_queue->shutdown();
+  }
+
+  is_decommisioned = !ret;
+  return ret;
+}
+
+inline bool Server::routing(Request &req, Response &res, Stream &strm) {
+  if (pre_routing_handler_ &&
+      pre_routing_handler_(req, res) == HandlerResponse::Handled) {
+    return true;
+  }
+
+  // File handler
+  auto is_head_request = req.method == "HEAD";
+  if ((req.method == "GET" || is_head_request) &&
+      handle_file_request(req, res, is_head_request)) {
+    return true;
+  }
+
+  if (detail::expect_content(req)) {
+    // Content reader handler
+    {
+      ContentReader reader(
+          [&](ContentReceiver receiver) {
+            return read_content_with_content_receiver(
+                strm, req, res, std::move(receiver), nullptr, nullptr);
+          },
+          [&](MultipartContentHeader header, ContentReceiver receiver) {
+            return read_content_with_content_receiver(strm, req, res, nullptr,
+                                                      std::move(header),
+                                                      std::move(receiver));
+          });
+
+      if (req.method == "POST") {
+        if (dispatch_request_for_content_reader(
+                req, res, std::move(reader),
+                post_handlers_for_content_reader_)) {
+          return true;
+        }
+      } else if (req.method == "PUT") {
+        if (dispatch_request_for_content_reader(
+                req, res, std::move(reader),
+                put_handlers_for_content_reader_)) {
+          return true;
+        }
+      } else if (req.method == "PATCH") {
+        if (dispatch_request_for_content_reader(
+                req, res, std::move(reader),
+                patch_handlers_for_content_reader_)) {
+          return true;
+        }
+      } else if (req.method == "DELETE") {
+        if (dispatch_request_for_content_reader(
+                req, res, std::move(reader),
+                delete_handlers_for_content_reader_)) {
+          return true;
+        }
+      }
+    }
+
+    // Read content into `req.body`
+    if (!read_content(strm, req, res)) { return false; }
+  }
+
+  // Regular handler
+  if (req.method == "GET" || req.method == "HEAD") {
+    return dispatch_request(req, res, get_handlers_);
+  } else if (req.method == "POST") {
+    return dispatch_request(req, res, post_handlers_);
+  } else if (req.method == "PUT") {
+    return dispatch_request(req, res, put_handlers_);
+  } else if (req.method == "DELETE") {
+    return dispatch_request(req, res, delete_handlers_);
+  } else if (req.method == "OPTIONS") {
+    return dispatch_request(req, res, options_handlers_);
+  } else if (req.method == "PATCH") {
+    return dispatch_request(req, res, patch_handlers_);
+  }
+
+  res.status = StatusCode::BadRequest_400;
+  return false;
+}
+
+inline bool Server::dispatch_request(Request &req, Response &res,
+                                     const Handlers &handlers) const {
+  for (const auto &x : handlers) {
+    const auto &matcher = x.first;
+    const auto &handler = x.second;
+
+    if (matcher->match(req)) {
+      handler(req, res);
+      return true;
+    }
+  }
+  return false;
+}
+
+inline void Server::apply_ranges(const Request &req, Response &res,
+                                 std::string &content_type,
+                                 std::string &boundary) const {
+  if (req.ranges.size() > 1 && res.status == StatusCode::PartialContent_206) {
+    auto it = res.headers.find("Content-Type");
+    if (it != res.headers.end()) {
+      content_type = it->second;
+      res.headers.erase(it);
+    }
+
+    boundary = detail::make_multipart_data_boundary();
+
+    res.set_header("Content-Type",
+                   "multipart/byteranges; boundary=" + boundary);
+  }
+
+  auto type = detail::encoding_type(req, res);
+
+  if (res.body.empty()) {
+    if (res.content_length_ > 0) {
+      size_t length = 0;
+      if (req.ranges.empty() || res.status != StatusCode::PartialContent_206) {
+        length = res.content_length_;
+      } else if (req.ranges.size() == 1) {
+        auto offset_and_length = detail::get_range_offset_and_length(
+            req.ranges[0], res.content_length_);
+
+        length = offset_and_length.second;
+
+        auto content_range = detail::make_content_range_header_field(
+            offset_and_length, res.content_length_);
+        res.set_header("Content-Range", content_range);
+      } else {
+        length = detail::get_multipart_ranges_data_length(
+            req, boundary, content_type, res.content_length_);
+      }
+      res.set_header("Content-Length", std::to_string(length));
+    } else {
+      if (res.content_provider_) {
+        if (res.is_chunked_content_provider_) {
+          res.set_header("Transfer-Encoding", "chunked");
+          if (type == detail::EncodingType::Gzip) {
+            res.set_header("Content-Encoding", "gzip");
+          } else if (type == detail::EncodingType::Brotli) {
+            res.set_header("Content-Encoding", "br");
+          }
+        }
+      }
+    }
+  } else {
+    if (req.ranges.empty() || res.status != StatusCode::PartialContent_206) {
+      ;
+    } else if (req.ranges.size() == 1) {
+      auto offset_and_length =
+          detail::get_range_offset_and_length(req.ranges[0], res.body.size());
+      auto offset = offset_and_length.first;
+      auto length = offset_and_length.second;
+
+      auto content_range = detail::make_content_range_header_field(
+          offset_and_length, res.body.size());
+      res.set_header("Content-Range", content_range);
+
+      assert(offset + length <= res.body.size());
+      res.body = res.body.substr(offset, length);
+    } else {
+      std::string data;
+      detail::make_multipart_ranges_data(req, res, boundary, content_type,
+                                         res.body.size(), data);
+      res.body.swap(data);
+    }
+
+    if (type != detail::EncodingType::None) {
+      std::unique_ptr<detail::compressor> compressor;
+      std::string content_encoding;
+
+      if (type == detail::EncodingType::Gzip) {
+#ifdef CPPHTTPLIB_ZLIB_SUPPORT
+        compressor = detail::make_unique<detail::gzip_compressor>();
+        content_encoding = "gzip";
+#endif
+      } else if (type == detail::EncodingType::Brotli) {
+#ifdef CPPHTTPLIB_BROTLI_SUPPORT
+        compressor = detail::make_unique<detail::brotli_compressor>();
+        content_encoding = "br";
+#endif
+      }
+
+      if (compressor) {
+        std::string compressed;
+        if (compressor->compress(res.body.data(), res.body.size(), true,
+                                 [&](const char *data, size_t data_len) {
+                                   compressed.append(data, data_len);
+                                   return true;
+                                 })) {
+          res.body.swap(compressed);
+          res.set_header("Content-Encoding", content_encoding);
+        }
+      }
+    }
+
+    auto length = std::to_string(res.body.size());
+    res.set_header("Content-Length", length);
+  }
+}
+
+inline bool Server::dispatch_request_for_content_reader(
+    Request &req, Response &res, ContentReader content_reader,
+    const HandlersForContentReader &handlers) const {
+  for (const auto &x : handlers) {
+    const auto &matcher = x.first;
+    const auto &handler = x.second;
+
+    if (matcher->match(req)) {
+      handler(req, res, content_reader);
+      return true;
+    }
+  }
+  return false;
+}
+
+inline bool
+Server::process_request(Stream &strm, const std::string &remote_addr,
+                        int remote_port, const std::string &local_addr,
+                        int local_port, bool close_connection,
+                        bool &connection_closed,
+                        const std::function<void(Request &)> &setup_request) {
+  std::array<char, 2048> buf{};
+
+  detail::stream_line_reader line_reader(strm, buf.data(), buf.size());
+
+  // Connection has been closed on client
+  if (!line_reader.getline()) { return false; }
+
+  Request req;
+
+  Response res;
+  res.version = "HTTP/1.1";
+  res.headers = default_headers_;
+
+#ifdef _WIN32
+  // TODO: Increase FD_SETSIZE statically (libzmq), dynamically (MySQL).
+#else
+#ifndef CPPHTTPLIB_USE_POLL
+  // Socket file descriptor exceeded FD_SETSIZE...
+  if (strm.socket() >= FD_SETSIZE) {
+    Headers dummy;
+    detail::read_headers(strm, dummy);
+    res.status = StatusCode::InternalServerError_500;
+    return write_response(strm, close_connection, req, res);
+  }
+#endif
+#endif
+
+  // Request line and headers
+  if (!parse_request_line(line_reader.ptr(), req) ||
+      !detail::read_headers(strm, req.headers)) {
+    res.status = StatusCode::BadRequest_400;
+    return write_response(strm, close_connection, req, res);
+  }
+
+  // Check if the request URI doesn't exceed the limit
+  if (req.target.size() > CPPHTTPLIB_REQUEST_URI_MAX_LENGTH) {
+    Headers dummy;
+    detail::read_headers(strm, dummy);
+    res.status = StatusCode::UriTooLong_414;
+    return write_response(strm, close_connection, req, res);
+  }
+
+  if (req.get_header_value("Connection") == "close") {
+    connection_closed = true;
+  }
+
+  if (req.version == "HTTP/1.0" &&
+      req.get_header_value("Connection") != "Keep-Alive") {
+    connection_closed = true;
+  }
+
+  req.remote_addr = remote_addr;
+  req.remote_port = remote_port;
+  req.set_header("REMOTE_ADDR", req.remote_addr);
+  req.set_header("REMOTE_PORT", std::to_string(req.remote_port));
+
+  req.local_addr = local_addr;
+  req.local_port = local_port;
+  req.set_header("LOCAL_ADDR", req.local_addr);
+  req.set_header("LOCAL_PORT", std::to_string(req.local_port));
+
+  if (req.has_header("Range")) {
+    const auto &range_header_value = req.get_header_value("Range");
+    if (!detail::parse_range_header(range_header_value, req.ranges)) {
+      res.status = StatusCode::RangeNotSatisfiable_416;
+      return write_response(strm, close_connection, req, res);
+    }
+  }
+
+  if (setup_request) { setup_request(req); }
+
+  if (req.get_header_value("Expect") == "100-continue") {
+    int status = StatusCode::Continue_100;
+    if (expect_100_continue_handler_) {
+      status = expect_100_continue_handler_(req, res);
+    }
+    switch (status) {
+    case StatusCode::Continue_100:
+    case StatusCode::ExpectationFailed_417:
+      detail::write_response_line(strm, status);
+      strm.write("\r\n");
+      break;
+    default:
+      connection_closed = true;
+      return write_response(strm, true, req, res);
+    }
+  }
+
+  // Setup `is_connection_closed` method
+  req.is_connection_closed = [&]() {
+    return !detail::is_socket_alive(strm.socket());
+  };
+
+  // Routing
+  auto routed = false;
+#ifdef CPPHTTPLIB_NO_EXCEPTIONS
+  routed = routing(req, res, strm);
+#else
+  try {
+    routed = routing(req, res, strm);
+  } catch (std::exception &e) {
+    if (exception_handler_) {
+      auto ep = std::current_exception();
+      exception_handler_(req, res, ep);
+      routed = true;
+    } else {
+      res.status = StatusCode::InternalServerError_500;
+      std::string val;
+      auto s = e.what();
+      for (size_t i = 0; s[i]; i++) {
+        switch (s[i]) {
+        case '\r': val += "\\r"; break;
+        case '\n': val += "\\n"; break;
+        default: val += s[i]; break;
+        }
+      }
+      res.set_header("EXCEPTION_WHAT", val);
+    }
+  } catch (...) {
+    if (exception_handler_) {
+      auto ep = std::current_exception();
+      exception_handler_(req, res, ep);
+      routed = true;
+    } else {
+      res.status = StatusCode::InternalServerError_500;
+      res.set_header("EXCEPTION_WHAT", "UNKNOWN");
+    }
+  }
+#endif
+  if (routed) {
+    if (res.status == -1) {
+      res.status = req.ranges.empty() ? StatusCode::OK_200
+                                      : StatusCode::PartialContent_206;
+    }
+
+    // Serve file content by using a content provider
+    if (!res.file_content_path_.empty()) {
+      const auto &path = res.file_content_path_;
+      auto mm = std::make_shared<detail::mmap>(path.c_str());
+      if (!mm->is_open()) {
+        res.body.clear();
+        res.content_length_ = 0;
+        res.content_provider_ = nullptr;
+        res.status = StatusCode::NotFound_404;
+        return write_response(strm, close_connection, req, res);
+      }
+
+      auto content_type = res.file_content_content_type_;
+      if (content_type.empty()) {
+        content_type = detail::find_content_type(
+            path, file_extension_and_mimetype_map_, default_file_mimetype_);
+      }
+
+      res.set_content_provider(
+          mm->size(), content_type,
+          [mm](size_t offset, size_t length, DataSink &sink) -> bool {
+            sink.write(mm->data() + offset, length);
+            return true;
+          });
+    }
+
+    if (detail::range_error(req, res)) {
+      res.body.clear();
+      res.content_length_ = 0;
+      res.content_provider_ = nullptr;
+      res.status = StatusCode::RangeNotSatisfiable_416;
+      return write_response(strm, close_connection, req, res);
+    }
+
+    return write_response_with_content(strm, close_connection, req, res);
+  } else {
+    if (res.status == -1) { res.status = StatusCode::NotFound_404; }
+
+    return write_response(strm, close_connection, req, res);
+  }
+}
+
+inline bool Server::is_valid() const { return true; }
+
+inline bool Server::process_and_close_socket(socket_t sock) {
+  std::string remote_addr;
+  int remote_port = 0;
+  detail::get_remote_ip_and_port(sock, remote_addr, remote_port);
+
+  std::string local_addr;
+  int local_port = 0;
+  detail::get_local_ip_and_port(sock, local_addr, local_port);
+
+  auto ret = detail::process_server_socket(
+      svr_sock_, sock, keep_alive_max_count_, keep_alive_timeout_sec_,
+      read_timeout_sec_, read_timeout_usec_, write_timeout_sec_,
+      write_timeout_usec_,
+      [&](Stream &strm, bool close_connection, bool &connection_closed) {
+        return process_request(strm, remote_addr, remote_port, local_addr,
+                               local_port, close_connection, connection_closed,
+                               nullptr);
+      });
+
+  detail::shutdown_socket(sock);
+  detail::close_socket(sock);
+  return ret;
+}
+
+// HTTP client implementation
+inline ClientImpl::ClientImpl(const std::string &host)
+    : ClientImpl(host, 80, std::string(), std::string()) {}
+
+inline ClientImpl::ClientImpl(const std::string &host, int port)
+    : ClientImpl(host, port, std::string(), std::string()) {}
+
+inline ClientImpl::ClientImpl(const std::string &host, int port,
+                              const std::string &client_cert_path,
+                              const std::string &client_key_path)
+    : host_(detail::escape_abstract_namespace_unix_domain(host)), port_(port),
+      host_and_port_(adjust_host_string(host_) + ":" + std::to_string(port)),
+      client_cert_path_(client_cert_path), client_key_path_(client_key_path) {}
+
+inline ClientImpl::~ClientImpl() {
+  std::lock_guard<std::mutex> guard(socket_mutex_);
+  shutdown_socket(socket_);
+  close_socket(socket_);
+}
+
+inline bool ClientImpl::is_valid() const { return true; }
+
+inline void ClientImpl::copy_settings(const ClientImpl &rhs) {
+  client_cert_path_ = rhs.client_cert_path_;
+  client_key_path_ = rhs.client_key_path_;
+  connection_timeout_sec_ = rhs.connection_timeout_sec_;
+  read_timeout_sec_ = rhs.read_timeout_sec_;
+  read_timeout_usec_ = rhs.read_timeout_usec_;
+  write_timeout_sec_ = rhs.write_timeout_sec_;
+  write_timeout_usec_ = rhs.write_timeout_usec_;
+  max_timeout_msec_ = rhs.max_timeout_msec_;
+  basic_auth_username_ = rhs.basic_auth_username_;
+  basic_auth_password_ = rhs.basic_auth_password_;
+  bearer_token_auth_token_ = rhs.bearer_token_auth_token_;
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  digest_auth_username_ = rhs.digest_auth_username_;
+  digest_auth_password_ = rhs.digest_auth_password_;
+#endif
+  keep_alive_ = rhs.keep_alive_;
+  follow_location_ = rhs.follow_location_;
+  url_encode_ = rhs.url_encode_;
+  address_family_ = rhs.address_family_;
+  tcp_nodelay_ = rhs.tcp_nodelay_;
+  ipv6_v6only_ = rhs.ipv6_v6only_;
+  socket_options_ = rhs.socket_options_;
+  compress_ = rhs.compress_;
+  decompress_ = rhs.decompress_;
+  interface_ = rhs.interface_;
+  proxy_host_ = rhs.proxy_host_;
+  proxy_port_ = rhs.proxy_port_;
+  proxy_basic_auth_username_ = rhs.proxy_basic_auth_username_;
+  proxy_basic_auth_password_ = rhs.proxy_basic_auth_password_;
+  proxy_bearer_token_auth_token_ = rhs.proxy_bearer_token_auth_token_;
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  proxy_digest_auth_username_ = rhs.proxy_digest_auth_username_;
+  proxy_digest_auth_password_ = rhs.proxy_digest_auth_password_;
+#endif
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  ca_cert_file_path_ = rhs.ca_cert_file_path_;
+  ca_cert_dir_path_ = rhs.ca_cert_dir_path_;
+  ca_cert_store_ = rhs.ca_cert_store_;
+#endif
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  server_certificate_verification_ = rhs.server_certificate_verification_;
+  server_hostname_verification_ = rhs.server_hostname_verification_;
+  server_certificate_verifier_ = rhs.server_certificate_verifier_;
+#endif
+  logger_ = rhs.logger_;
+}
+
+inline socket_t ClientImpl::create_client_socket(Error &error) const {
+  if (!proxy_host_.empty() && proxy_port_ != -1) {
+    return detail::create_client_socket(
+        proxy_host_, std::string(), proxy_port_, address_family_, tcp_nodelay_,
+        ipv6_v6only_, socket_options_, connection_timeout_sec_,
+        connection_timeout_usec_, read_timeout_sec_, read_timeout_usec_,
+        write_timeout_sec_, write_timeout_usec_, interface_, error);
+  }
+
+  // Check is custom IP specified for host_
+  std::string ip;
+  auto it = addr_map_.find(host_);
+  if (it != addr_map_.end()) { ip = it->second; }
+
+  return detail::create_client_socket(
+      host_, ip, port_, address_family_, tcp_nodelay_, ipv6_v6only_,
+      socket_options_, connection_timeout_sec_, connection_timeout_usec_,
+      read_timeout_sec_, read_timeout_usec_, write_timeout_sec_,
+      write_timeout_usec_, interface_, error);
+}
+
+inline bool ClientImpl::create_and_connect_socket(Socket &socket,
+                                                  Error &error) {
+  auto sock = create_client_socket(error);
+  if (sock == INVALID_SOCKET) { return false; }
+  socket.sock = sock;
+  return true;
+}
+
+inline void ClientImpl::shutdown_ssl(Socket & /*socket*/,
+                                     bool /*shutdown_gracefully*/) {
+  // If there are any requests in flight from threads other than us, then it's
+  // a thread-unsafe race because individual ssl* objects are not thread-safe.
+  assert(socket_requests_in_flight_ == 0 ||
+         socket_requests_are_from_thread_ == std::this_thread::get_id());
+}
+
+inline void ClientImpl::shutdown_socket(Socket &socket) const {
+  if (socket.sock == INVALID_SOCKET) { return; }
+  detail::shutdown_socket(socket.sock);
+}
+
+inline void ClientImpl::close_socket(Socket &socket) {
+  // If there are requests in flight in another thread, usually closing
+  // the socket will be fine and they will simply receive an error when
+  // using the closed socket, but it is still a bug since rarely the OS
+  // may reassign the socket id to be used for a new socket, and then
+  // suddenly they will be operating on a live socket that is different
+  // than the one they intended!
+  assert(socket_requests_in_flight_ == 0 ||
+         socket_requests_are_from_thread_ == std::this_thread::get_id());
+
+  // It is also a bug if this happens while SSL is still active
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  assert(socket.ssl == nullptr);
+#endif
+  if (socket.sock == INVALID_SOCKET) { return; }
+  detail::close_socket(socket.sock);
+  socket.sock = INVALID_SOCKET;
+}
+
+inline bool ClientImpl::read_response_line(Stream &strm, const Request &req,
+                                           Response &res) const {
+  std::array<char, 2048> buf{};
+
+  detail::stream_line_reader line_reader(strm, buf.data(), buf.size());
+
+  if (!line_reader.getline()) { return false; }
+
+#ifdef CPPHTTPLIB_ALLOW_LF_AS_LINE_TERMINATOR
+  const static std::regex re("(HTTP/1\\.[01]) (\\d{3})(?: (.*?))?\r?\n");
+#else
+  const static std::regex re("(HTTP/1\\.[01]) (\\d{3})(?: (.*?))?\r\n");
+#endif
+
+  std::cmatch m;
+  if (!std::regex_match(line_reader.ptr(), m, re)) {
+    return req.method == "CONNECT";
+  }
+  res.version = std::string(m[1]);
+  res.status = std::stoi(std::string(m[2]));
+  res.reason = std::string(m[3]);
+
+  // Ignore '100 Continue'
+  while (res.status == StatusCode::Continue_100) {
+    if (!line_reader.getline()) { return false; } // CRLF
+    if (!line_reader.getline()) { return false; } // next response line
+
+    if (!std::regex_match(line_reader.ptr(), m, re)) { return false; }
+    res.version = std::string(m[1]);
+    res.status = std::stoi(std::string(m[2]));
+    res.reason = std::string(m[3]);
+  }
+
+  return true;
+}
+
+inline bool ClientImpl::send(Request &req, Response &res, Error &error) {
+  std::lock_guard<std::recursive_mutex> request_mutex_guard(request_mutex_);
+  auto ret = send_(req, res, error);
+  if (error == Error::SSLPeerCouldBeClosed_) {
+    assert(!ret);
+    ret = send_(req, res, error);
+  }
+  return ret;
+}
+
+inline bool ClientImpl::send_(Request &req, Response &res, Error &error) {
+  {
+    std::lock_guard<std::mutex> guard(socket_mutex_);
+
+    // Set this to false immediately - if it ever gets set to true by the end of
+    // the request, we know another thread instructed us to close the socket.
+    socket_should_be_closed_when_request_is_done_ = false;
+
+    auto is_alive = false;
+    if (socket_.is_open()) {
+      is_alive = detail::is_socket_alive(socket_.sock);
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+      if (is_alive && is_ssl()) {
+        if (detail::is_ssl_peer_could_be_closed(socket_.ssl, socket_.sock)) {
+          is_alive = false;
+        }
+      }
+#endif
+
+      if (!is_alive) {
+        // Attempt to avoid sigpipe by shutting down nongracefully if it seems
+        // like the other side has already closed the connection Also, there
+        // cannot be any requests in flight from other threads since we locked
+        // request_mutex_, so safe to close everything immediately
+        const bool shutdown_gracefully = false;
+        shutdown_ssl(socket_, shutdown_gracefully);
+        shutdown_socket(socket_);
+        close_socket(socket_);
+      }
+    }
+
+    if (!is_alive) {
+      if (!create_and_connect_socket(socket_, error)) { return false; }
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+      // TODO: refactoring
+      if (is_ssl()) {
+        auto &scli = static_cast<SSLClient &>(*this);
+        if (!proxy_host_.empty() && proxy_port_ != -1) {
+          auto success = false;
+          if (!scli.connect_with_proxy(socket_, req.start_time_, res, success,
+                                       error)) {
+            return success;
+          }
+        }
+
+        if (!scli.initialize_ssl(socket_, error)) { return false; }
+      }
+#endif
+    }
+
+    // Mark the current socket as being in use so that it cannot be closed by
+    // anyone else while this request is ongoing, even though we will be
+    // releasing the mutex.
+    if (socket_requests_in_flight_ > 1) {
+      assert(socket_requests_are_from_thread_ == std::this_thread::get_id());
+    }
+    socket_requests_in_flight_ += 1;
+    socket_requests_are_from_thread_ = std::this_thread::get_id();
+  }
+
+  for (const auto &header : default_headers_) {
+    if (req.headers.find(header.first) == req.headers.end()) {
+      req.headers.insert(header);
+    }
+  }
+
+  auto ret = false;
+  auto close_connection = !keep_alive_;
+
+  auto se = detail::scope_exit([&]() {
+    // Briefly lock mutex in order to mark that a request is no longer ongoing
+    std::lock_guard<std::mutex> guard(socket_mutex_);
+    socket_requests_in_flight_ -= 1;
+    if (socket_requests_in_flight_ <= 0) {
+      assert(socket_requests_in_flight_ == 0);
+      socket_requests_are_from_thread_ = std::thread::id();
+    }
+
+    if (socket_should_be_closed_when_request_is_done_ || close_connection ||
+        !ret) {
+      shutdown_ssl(socket_, true);
+      shutdown_socket(socket_);
+      close_socket(socket_);
+    }
+  });
+
+  ret = process_socket(socket_, req.start_time_, [&](Stream &strm) {
+    return handle_request(strm, req, res, close_connection, error);
+  });
+
+  if (!ret) {
+    if (error == Error::Success) { error = Error::Unknown; }
+  }
+
+  return ret;
+}
+
+inline Result ClientImpl::send(const Request &req) {
+  auto req2 = req;
+  return send_(std::move(req2));
+}
+
+inline Result ClientImpl::send_(Request &&req) {
+  auto res = detail::make_unique<Response>();
+  auto error = Error::Success;
+  auto ret = send(req, *res, error);
+  return Result{ret ? std::move(res) : nullptr, error, std::move(req.headers)};
+}
+
+inline bool ClientImpl::handle_request(Stream &strm, Request &req,
+                                       Response &res, bool close_connection,
+                                       Error &error) {
+  if (req.path.empty()) {
+    error = Error::Connection;
+    return false;
+  }
+
+  auto req_save = req;
+
+  bool ret;
+
+  if (!is_ssl() && !proxy_host_.empty() && proxy_port_ != -1) {
+    auto req2 = req;
+    req2.path = "http://" + host_and_port_ + req.path;
+    ret = process_request(strm, req2, res, close_connection, error);
+    req = req2;
+    req.path = req_save.path;
+  } else {
+    ret = process_request(strm, req, res, close_connection, error);
+  }
+
+  if (!ret) { return false; }
+
+  if (res.get_header_value("Connection") == "close" ||
+      (res.version == "HTTP/1.0" && res.reason != "Connection established")) {
+    // TODO this requires a not-entirely-obvious chain of calls to be correct
+    // for this to be safe.
+
+    // This is safe to call because handle_request is only called by send_
+    // which locks the request mutex during the process. It would be a bug
+    // to call it from a different thread since it's a thread-safety issue
+    // to do these things to the socket if another thread is using the socket.
+    std::lock_guard<std::mutex> guard(socket_mutex_);
+    shutdown_ssl(socket_, true);
+    shutdown_socket(socket_);
+    close_socket(socket_);
+  }
+
+  if (300 < res.status && res.status < 400 && follow_location_) {
+    req = req_save;
+    ret = redirect(req, res, error);
+  }
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  if ((res.status == StatusCode::Unauthorized_401 ||
+       res.status == StatusCode::ProxyAuthenticationRequired_407) &&
+      req.authorization_count_ < 5) {
+    auto is_proxy = res.status == StatusCode::ProxyAuthenticationRequired_407;
+    const auto &username =
+        is_proxy ? proxy_digest_auth_username_ : digest_auth_username_;
+    const auto &password =
+        is_proxy ? proxy_digest_auth_password_ : digest_auth_password_;
+
+    if (!username.empty() && !password.empty()) {
+      std::map<std::string, std::string> auth;
+      if (detail::parse_www_authenticate(res, auth, is_proxy)) {
+        Request new_req = req;
+        new_req.authorization_count_ += 1;
+        new_req.headers.erase(is_proxy ? "Proxy-Authorization"
+                                       : "Authorization");
+        new_req.headers.insert(detail::make_digest_authentication_header(
+            req, auth, new_req.authorization_count_, detail::random_string(10),
+            username, password, is_proxy));
+
+        Response new_res;
+
+        ret = send(new_req, new_res, error);
+        if (ret) { res = new_res; }
+      }
+    }
+  }
+#endif
+
+  return ret;
+}
+
+inline bool ClientImpl::redirect(Request &req, Response &res, Error &error) {
+  if (req.redirect_count_ == 0) {
+    error = Error::ExceedRedirectCount;
+    return false;
+  }
+
+  auto location = res.get_header_value("location");
+  if (location.empty()) { return false; }
+
+  const static std::regex re(
+      R"((?:(https?):)?(?://(?:\[([a-fA-F\d:]+)\]|([^:/?#]+))(?::(\d+))?)?([^?#]*)(\?[^#]*)?(?:#.*)?)");
+
+  std::smatch m;
+  if (!std::regex_match(location, m, re)) { return false; }
+
+  auto scheme = is_ssl() ? "https" : "http";
+
+  auto next_scheme = m[1].str();
+  auto next_host = m[2].str();
+  if (next_host.empty()) { next_host = m[3].str(); }
+  auto port_str = m[4].str();
+  auto next_path = m[5].str();
+  auto next_query = m[6].str();
+
+  auto next_port = port_;
+  if (!port_str.empty()) {
+    next_port = std::stoi(port_str);
+  } else if (!next_scheme.empty()) {
+    next_port = next_scheme == "https" ? 443 : 80;
+  }
+
+  if (next_scheme.empty()) { next_scheme = scheme; }
+  if (next_host.empty()) { next_host = host_; }
+  if (next_path.empty()) { next_path = "/"; }
+
+  auto path = detail::decode_url(next_path, true) + next_query;
+
+  if (next_scheme == scheme && next_host == host_ && next_port == port_) {
+    return detail::redirect(*this, req, res, path, location, error);
+  } else {
+    if (next_scheme == "https") {
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+      SSLClient cli(next_host, next_port);
+      cli.copy_settings(*this);
+      if (ca_cert_store_) { cli.set_ca_cert_store(ca_cert_store_); }
+      return detail::redirect(cli, req, res, path, location, error);
+#else
+      return false;
+#endif
+    } else {
+      ClientImpl cli(next_host, next_port);
+      cli.copy_settings(*this);
+      return detail::redirect(cli, req, res, path, location, error);
+    }
+  }
+}
+
+inline bool ClientImpl::write_content_with_provider(Stream &strm,
+                                                    const Request &req,
+                                                    Error &error) const {
+  auto is_shutting_down = []() { return false; };
+
+  if (req.is_chunked_content_provider_) {
+    // TODO: Brotli support
+    std::unique_ptr<detail::compressor> compressor;
+#ifdef CPPHTTPLIB_ZLIB_SUPPORT
+    if (compress_) {
+      compressor = detail::make_unique<detail::gzip_compressor>();
+    } else
+#endif
+    {
+      compressor = detail::make_unique<detail::nocompressor>();
+    }
+
+    return detail::write_content_chunked(strm, req.content_provider_,
+                                         is_shutting_down, *compressor, error);
+  } else {
+    return detail::write_content(strm, req.content_provider_, 0,
+                                 req.content_length_, is_shutting_down, error);
+  }
+}
+
+inline bool ClientImpl::write_request(Stream &strm, Request &req,
+                                      bool close_connection, Error &error) {
+  // Prepare additional headers
+  if (close_connection) {
+    if (!req.has_header("Connection")) {
+      req.set_header("Connection", "close");
+    }
+  }
+
+  if (!req.has_header("Host")) {
+    if (is_ssl()) {
+      if (port_ == 443) {
+        req.set_header("Host", host_);
+      } else {
+        req.set_header("Host", host_and_port_);
+      }
+    } else {
+      if (port_ == 80) {
+        req.set_header("Host", host_);
+      } else {
+        req.set_header("Host", host_and_port_);
+      }
+    }
+  }
+
+  if (!req.has_header("Accept")) { req.set_header("Accept", "*/*"); }
+
+  if (!req.content_receiver) {
+    if (!req.has_header("Accept-Encoding")) {
+      std::string accept_encoding;
+#ifdef CPPHTTPLIB_BROTLI_SUPPORT
+      accept_encoding = "br";
+#endif
+#ifdef CPPHTTPLIB_ZLIB_SUPPORT
+      if (!accept_encoding.empty()) { accept_encoding += ", "; }
+      accept_encoding += "gzip, deflate";
+#endif
+      req.set_header("Accept-Encoding", accept_encoding);
+    }
+
+#ifndef CPPHTTPLIB_NO_DEFAULT_USER_AGENT
+    if (!req.has_header("User-Agent")) {
+      auto agent = std::string("cpp-httplib/") + CPPHTTPLIB_VERSION;
+      req.set_header("User-Agent", agent);
+    }
+#endif
+  };
+
+  if (req.body.empty()) {
+    if (req.content_provider_) {
+      if (!req.is_chunked_content_provider_) {
+        if (!req.has_header("Content-Length")) {
+          auto length = std::to_string(req.content_length_);
+          req.set_header("Content-Length", length);
+        }
+      }
+    } else {
+      if (req.method == "POST" || req.method == "PUT" ||
+          req.method == "PATCH") {
+        req.set_header("Content-Length", "0");
+      }
+    }
+  } else {
+    if (!req.has_header("Content-Type")) {
+      req.set_header("Content-Type", "text/plain");
+    }
+
+    if (!req.has_header("Content-Length")) {
+      auto length = std::to_string(req.body.size());
+      req.set_header("Content-Length", length);
+    }
+  }
+
+  if (!basic_auth_password_.empty() || !basic_auth_username_.empty()) {
+    if (!req.has_header("Authorization")) {
+      req.headers.insert(make_basic_authentication_header(
+          basic_auth_username_, basic_auth_password_, false));
+    }
+  }
+
+  if (!proxy_basic_auth_username_.empty() &&
+      !proxy_basic_auth_password_.empty()) {
+    if (!req.has_header("Proxy-Authorization")) {
+      req.headers.insert(make_basic_authentication_header(
+          proxy_basic_auth_username_, proxy_basic_auth_password_, true));
+    }
+  }
+
+  if (!bearer_token_auth_token_.empty()) {
+    if (!req.has_header("Authorization")) {
+      req.headers.insert(make_bearer_token_authentication_header(
+          bearer_token_auth_token_, false));
+    }
+  }
+
+  if (!proxy_bearer_token_auth_token_.empty()) {
+    if (!req.has_header("Proxy-Authorization")) {
+      req.headers.insert(make_bearer_token_authentication_header(
+          proxy_bearer_token_auth_token_, true));
+    }
+  }
+
+  // Request line and headers
+  {
+    detail::BufferStream bstrm;
+
+    const auto &path_with_query =
+        req.params.empty() ? req.path
+                           : append_query_params(req.path, req.params);
+
+    const auto &path =
+        url_encode_ ? detail::encode_url(path_with_query) : path_with_query;
+
+    detail::write_request_line(bstrm, req.method, path);
+
+    header_writer_(bstrm, req.headers);
+
+    // Flush buffer
+    auto &data = bstrm.get_buffer();
+    if (!detail::write_data(strm, data.data(), data.size())) {
+      error = Error::Write;
+      return false;
+    }
+  }
+
+  // Body
+  if (req.body.empty()) {
+    return write_content_with_provider(strm, req, error);
+  }
+
+  if (!detail::write_data(strm, req.body.data(), req.body.size())) {
+    error = Error::Write;
+    return false;
+  }
+
+  return true;
+}
+
+inline std::unique_ptr<Response> ClientImpl::send_with_content_provider(
+    Request &req, const char *body, size_t content_length,
+    ContentProvider content_provider,
+    ContentProviderWithoutLength content_provider_without_length,
+    const std::string &content_type, Error &error) {
+  if (!content_type.empty()) { req.set_header("Content-Type", content_type); }
+
+#ifdef CPPHTTPLIB_ZLIB_SUPPORT
+  if (compress_) { req.set_header("Content-Encoding", "gzip"); }
+#endif
+
+#ifdef CPPHTTPLIB_ZLIB_SUPPORT
+  if (compress_ && !content_provider_without_length) {
+    // TODO: Brotli support
+    detail::gzip_compressor compressor;
+
+    if (content_provider) {
+      auto ok = true;
+      size_t offset = 0;
+      DataSink data_sink;
+
+      data_sink.write = [&](const char *data, size_t data_len) -> bool {
+        if (ok) {
+          auto last = offset + data_len == content_length;
+
+          auto ret = compressor.compress(
+              data, data_len, last,
+              [&](const char *compressed_data, size_t compressed_data_len) {
+                req.body.append(compressed_data, compressed_data_len);
+                return true;
+              });
+
+          if (ret) {
+            offset += data_len;
+          } else {
+            ok = false;
+          }
+        }
+        return ok;
+      };
+
+      while (ok && offset < content_length) {
+        if (!content_provider(offset, content_length - offset, data_sink)) {
+          error = Error::Canceled;
+          return nullptr;
+        }
+      }
+    } else {
+      if (!compressor.compress(body, content_length, true,
+                               [&](const char *data, size_t data_len) {
+                                 req.body.append(data, data_len);
+                                 return true;
+                               })) {
+        error = Error::Compression;
+        return nullptr;
+      }
+    }
+  } else
+#endif
+  {
+    if (content_provider) {
+      req.content_length_ = content_length;
+      req.content_provider_ = std::move(content_provider);
+      req.is_chunked_content_provider_ = false;
+    } else if (content_provider_without_length) {
+      req.content_length_ = 0;
+      req.content_provider_ = detail::ContentProviderAdapter(
+          std::move(content_provider_without_length));
+      req.is_chunked_content_provider_ = true;
+      req.set_header("Transfer-Encoding", "chunked");
+    } else {
+      req.body.assign(body, content_length);
+    }
+  }
+
+  auto res = detail::make_unique<Response>();
+  return send(req, *res, error) ? std::move(res) : nullptr;
+}
+
+inline Result ClientImpl::send_with_content_provider(
+    const std::string &method, const std::string &path, const Headers &headers,
+    const char *body, size_t content_length, ContentProvider content_provider,
+    ContentProviderWithoutLength content_provider_without_length,
+    const std::string &content_type, Progress progress) {
+  Request req;
+  req.method = method;
+  req.headers = headers;
+  req.path = path;
+  req.progress = progress;
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
+
+  auto error = Error::Success;
+
+  auto res = send_with_content_provider(
+      req, body, content_length, std::move(content_provider),
+      std::move(content_provider_without_length), content_type, error);
+
+  return Result{std::move(res), error, std::move(req.headers)};
+}
+
+inline std::string
+ClientImpl::adjust_host_string(const std::string &host) const {
+  if (host.find(':') != std::string::npos) { return "[" + host + "]"; }
+  return host;
+}
+
+inline bool ClientImpl::process_request(Stream &strm, Request &req,
+                                        Response &res, bool close_connection,
+                                        Error &error) {
+  // Send request
+  if (!write_request(strm, req, close_connection, error)) { return false; }
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+  if (is_ssl()) {
+    auto is_proxy_enabled = !proxy_host_.empty() && proxy_port_ != -1;
+    if (!is_proxy_enabled) {
+      if (detail::is_ssl_peer_could_be_closed(socket_.ssl, socket_.sock)) {
+        error = Error::SSLPeerCouldBeClosed_;
+        return false;
+      }
+    }
+  }
+#endif
+
+  // Receive response and headers
+  if (!read_response_line(strm, req, res) ||
+      !detail::read_headers(strm, res.headers)) {
+    error = Error::Read;
+    return false;
+  }
+
+  // Body
+  if ((res.status != StatusCode::NoContent_204) && req.method != "HEAD" &&
+      req.method != "CONNECT") {
+    auto redirect = 300 < res.status && res.status < 400 &&
+                    res.status != StatusCode::NotModified_304 &&
+                    follow_location_;
+
+    if (req.response_handler && !redirect) {
+      if (!req.response_handler(res)) {
+        error = Error::Canceled;
+        return false;
+      }
+    }
+
+    auto out =
+        req.content_receiver
+            ? static_cast<ContentReceiverWithProgress>(
+                  [&](const char *buf, size_t n, uint64_t off, uint64_t len) {
+                    if (redirect) { return true; }
+                    auto ret = req.content_receiver(buf, n, off, len);
+                    if (!ret) { error = Error::Canceled; }
+                    return ret;
+                  })
+            : static_cast<ContentReceiverWithProgress>(
+                  [&](const char *buf, size_t n, uint64_t /*off*/,
+                      uint64_t /*len*/) {
+                    assert(res.body.size() + n <= res.body.max_size());
+                    res.body.append(buf, n);
+                    return true;
+                  });
+
+    auto progress = [&](uint64_t current, uint64_t total) {
+      if (!req.progress || redirect) { return true; }
+      auto ret = req.progress(current, total);
+      if (!ret) { error = Error::Canceled; }
+      return ret;
+    };
+
+    if (res.has_header("Content-Length")) {
+      if (!req.content_receiver) {
+        auto len = res.get_header_value_u64("Content-Length");
+        if (len > res.body.max_size()) {
+          error = Error::Read;
+          return false;
+        }
+        res.body.reserve(static_cast<size_t>(len));
+      }
+    }
+
+    if (res.status != StatusCode::NotModified_304) {
+      int dummy_status;
+      if (!detail::read_content(strm, res, (std::numeric_limits<size_t>::max)(),
+                                dummy_status, std::move(progress),
+                                std::move(out), decompress_)) {
+        if (error != Error::Canceled) { error = Error::Read; }
+        return false;
+      }
+    }
+  }
+
+  // Log
+  if (logger_) { logger_(req, res); }
+
+  return true;
+}
+
+inline ContentProviderWithoutLength ClientImpl::get_multipart_content_provider(
+    const std::string &boundary, const MultipartFormDataItems &items,
+    const MultipartFormDataProviderItems &provider_items) const {
+  size_t cur_item = 0;
+  size_t cur_start = 0;
+  // cur_item and cur_start are copied to within the std::function and maintain
+  // state between successive calls
+  return [&, cur_item, cur_start](size_t offset,
+                                  DataSink &sink) mutable -> bool {
+    if (!offset && !items.empty()) {
+      sink.os << detail::serialize_multipart_formdata(items, boundary, false);
+      return true;
+    } else if (cur_item < provider_items.size()) {
+      if (!cur_start) {
+        const auto &begin = detail::serialize_multipart_formdata_item_begin(
+            provider_items[cur_item], boundary);
+        offset += begin.size();
+        cur_start = offset;
+        sink.os << begin;
+      }
+
+      DataSink cur_sink;
+      auto has_data = true;
+      cur_sink.write = sink.write;
+      cur_sink.done = [&]() { has_data = false; };
+
+      if (!provider_items[cur_item].provider(offset - cur_start, cur_sink)) {
+        return false;
+      }
+
+      if (!has_data) {
+        sink.os << detail::serialize_multipart_formdata_item_end();
+        cur_item++;
+        cur_start = 0;
+      }
+      return true;
+    } else {
+      sink.os << detail::serialize_multipart_formdata_finish(boundary);
+      sink.done();
+      return true;
+    }
+  };
+}
+
+inline bool ClientImpl::process_socket(
+    const Socket &socket,
+    std::chrono::time_point<std::chrono::steady_clock> start_time,
+    std::function<bool(Stream &strm)> callback) {
+  return detail::process_client_socket(
+      socket.sock, read_timeout_sec_, read_timeout_usec_, write_timeout_sec_,
+      write_timeout_usec_, max_timeout_msec_, start_time,
+      std::move(callback));
+}
+
+inline bool ClientImpl::is_ssl() const { return false; }
+
+inline Result ClientImpl::Get(const std::string &path) {
+  return Get(path, Headers(), Progress());
+}
+
+inline Result ClientImpl::Get(const std::string &path, Progress progress) {
+  return Get(path, Headers(), std::move(progress));
+}
+
+inline Result ClientImpl::Get(const std::string &path, const Headers &headers) {
+  return Get(path, headers, Progress());
+}
+
+inline Result ClientImpl::Get(const std::string &path, const Headers &headers,
+                              Progress progress) {
+  Request req;
+  req.method = "GET";
+  req.path = path;
+  req.headers = headers;
+  req.progress = std::move(progress);
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
+
+  return send_(std::move(req));
+}
+
+inline Result ClientImpl::Get(const std::string &path,
+                              ContentReceiver content_receiver) {
+  return Get(path, Headers(), nullptr, std::move(content_receiver), nullptr);
+}
+
+inline Result ClientImpl::Get(const std::string &path,
+                              ContentReceiver content_receiver,
+                              Progress progress) {
+  return Get(path, Headers(), nullptr, std::move(content_receiver),
+             std::move(progress));
+}
+
+inline Result ClientImpl::Get(const std::string &path, const Headers &headers,
+                              ContentReceiver content_receiver) {
+  return Get(path, headers, nullptr, std::move(content_receiver), nullptr);
+}
+
+inline Result ClientImpl::Get(const std::string &path, const Headers &headers,
+                              ContentReceiver content_receiver,
+                              Progress progress) {
+  return Get(path, headers, nullptr, std::move(content_receiver),
+             std::move(progress));
+}
+
+inline Result ClientImpl::Get(const std::string &path,
+                              ResponseHandler response_handler,
+                              ContentReceiver content_receiver) {
+  return Get(path, Headers(), std::move(response_handler),
+             std::move(content_receiver), nullptr);
+}
+
+inline Result ClientImpl::Get(const std::string &path, const Headers &headers,
+                              ResponseHandler response_handler,
+                              ContentReceiver content_receiver) {
+  return Get(path, headers, std::move(response_handler),
+             std::move(content_receiver), nullptr);
+}
+
+inline Result ClientImpl::Get(const std::string &path,
+                              ResponseHandler response_handler,
+                              ContentReceiver content_receiver,
+                              Progress progress) {
+  return Get(path, Headers(), std::move(response_handler),
+             std::move(content_receiver), std::move(progress));
+}
+
+inline Result ClientImpl::Get(const std::string &path, const Headers &headers,
+                              ResponseHandler response_handler,
+                              ContentReceiver content_receiver,
+                              Progress progress) {
+  Request req;
+  req.method = "GET";
+  req.path = path;
+  req.headers = headers;
+  req.response_handler = std::move(response_handler);
+  req.content_receiver =
+      [content_receiver](const char *data, size_t data_length,
+                         uint64_t /*offset*/, uint64_t /*total_length*/) {
+        return content_receiver(data, data_length);
+      };
+  req.progress = std::move(progress);
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
+
+  return send_(std::move(req));
+}
+
+inline Result ClientImpl::Get(const std::string &path, const Params &params,
+                              const Headers &headers, Progress progress) {
+  if (params.empty()) { return Get(path, headers); }
+
+  std::string path_with_query = append_query_params(path, params);
+  return Get(path_with_query, headers, std::move(progress));
+}
+
+inline Result ClientImpl::Get(const std::string &path, const Params &params,
+                              const Headers &headers,
+                              ContentReceiver content_receiver,
+                              Progress progress) {
+  return Get(path, params, headers, nullptr, std::move(content_receiver),
+             std::move(progress));
+}
+
+inline Result ClientImpl::Get(const std::string &path, const Params &params,
+                              const Headers &headers,
+                              ResponseHandler response_handler,
+                              ContentReceiver content_receiver,
+                              Progress progress) {
+  if (params.empty()) {
+    return Get(path, headers, std::move(response_handler),
+               std::move(content_receiver), std::move(progress));
+  }
+
+  std::string path_with_query = append_query_params(path, params);
+  return Get(path_with_query, headers, std::move(response_handler),
+             std::move(content_receiver), std::move(progress));
+}
+
+inline Result ClientImpl::Head(const std::string &path) {
+  return Head(path, Headers());
+}
+
+inline Result ClientImpl::Head(const std::string &path,
+                               const Headers &headers) {
+  Request req;
+  req.method = "HEAD";
+  req.headers = headers;
+  req.path = path;
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
+
+  return send_(std::move(req));
+}
+
+inline Result ClientImpl::Post(const std::string &path) {
+  return Post(path, std::string(), std::string());
+}
+
+inline Result ClientImpl::Post(const std::string &path,
+                               const Headers &headers) {
+  return Post(path, headers, nullptr, 0, std::string());
+}
+
+inline Result ClientImpl::Post(const std::string &path, const char *body,
+                               size_t content_length,
+                               const std::string &content_type) {
+  return Post(path, Headers(), body, content_length, content_type, nullptr);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const Headers &headers,
+                               const char *body, size_t content_length,
+                               const std::string &content_type) {
+  return send_with_content_provider("POST", path, headers, body, content_length,
+                                    nullptr, nullptr, content_type, nullptr);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const Headers &headers,
+                               const char *body, size_t content_length,
+                               const std::string &content_type,
+                               Progress progress) {
+  return send_with_content_provider("POST", path, headers, body, content_length,
+                                    nullptr, nullptr, content_type, progress);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const std::string &body,
+                               const std::string &content_type) {
+  return Post(path, Headers(), body, content_type);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const std::string &body,
+                               const std::string &content_type,
+                               Progress progress) {
+  return Post(path, Headers(), body, content_type, progress);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const Headers &headers,
+                               const std::string &body,
+                               const std::string &content_type) {
+  return send_with_content_provider("POST", path, headers, body.data(),
+                                    body.size(), nullptr, nullptr, content_type,
+                                    nullptr);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const Headers &headers,
+                               const std::string &body,
+                               const std::string &content_type,
+                               Progress progress) {
+  return send_with_content_provider("POST", path, headers, body.data(),
+                                    body.size(), nullptr, nullptr, content_type,
+                                    progress);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const Params &params) {
+  return Post(path, Headers(), params);
+}
+
+inline Result ClientImpl::Post(const std::string &path, size_t content_length,
+                               ContentProvider content_provider,
+                               const std::string &content_type) {
+  return Post(path, Headers(), content_length, std::move(content_provider),
+              content_type);
+}
+
+inline Result ClientImpl::Post(const std::string &path,
+                               ContentProviderWithoutLength content_provider,
+                               const std::string &content_type) {
+  return Post(path, Headers(), std::move(content_provider), content_type);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const Headers &headers,
+                               size_t content_length,
+                               ContentProvider content_provider,
+                               const std::string &content_type) {
+  return send_with_content_provider("POST", path, headers, nullptr,
+                                    content_length, std::move(content_provider),
+                                    nullptr, content_type, nullptr);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const Headers &headers,
+                               ContentProviderWithoutLength content_provider,
+                               const std::string &content_type) {
+  return send_with_content_provider("POST", path, headers, nullptr, 0, nullptr,
+                                    std::move(content_provider), content_type,
+                                    nullptr);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const Headers &headers,
+                               const Params &params) {
+  auto query = detail::params_to_query_str(params);
+  return Post(path, headers, query, "application/x-www-form-urlencoded");
+}
+
+inline Result ClientImpl::Post(const std::string &path, const Headers &headers,
+                               const Params &params, Progress progress) {
+  auto query = detail::params_to_query_str(params);
+  return Post(path, headers, query, "application/x-www-form-urlencoded",
+              progress);
+}
+
+inline Result ClientImpl::Post(const std::string &path,
+                               const MultipartFormDataItems &items) {
+  return Post(path, Headers(), items);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const Headers &headers,
+                               const MultipartFormDataItems &items) {
+  const auto &boundary = detail::make_multipart_data_boundary();
+  const auto &content_type =
+      detail::serialize_multipart_formdata_get_content_type(boundary);
+  const auto &body = detail::serialize_multipart_formdata(items, boundary);
+  return Post(path, headers, body, content_type);
+}
+
+inline Result ClientImpl::Post(const std::string &path, const Headers &headers,
+                               const MultipartFormDataItems &items,
+                               const std::string &boundary) {
+  if (!detail::is_multipart_boundary_chars_valid(boundary)) {
+    return Result{nullptr, Error::UnsupportedMultipartBoundaryChars};
+  }
+
+  const auto &content_type =
+      detail::serialize_multipart_formdata_get_content_type(boundary);
+  const auto &body = detail::serialize_multipart_formdata(items, boundary);
+  return Post(path, headers, body, content_type);
+}
+
+inline Result
+ClientImpl::Post(const std::string &path, const Headers &headers,
+                 const MultipartFormDataItems &items,
+                 const MultipartFormDataProviderItems &provider_items) {
+  const auto &boundary = detail::make_multipart_data_boundary();
+  const auto &content_type =
+      detail::serialize_multipart_formdata_get_content_type(boundary);
+  return send_with_content_provider(
+      "POST", path, headers, nullptr, 0, nullptr,
+      get_multipart_content_provider(boundary, items, provider_items),
+      content_type, nullptr);
+}
+
+inline Result ClientImpl::Put(const std::string &path) {
+  return Put(path, std::string(), std::string());
+}
+
+inline Result ClientImpl::Put(const std::string &path, const char *body,
+                              size_t content_length,
+                              const std::string &content_type) {
+  return Put(path, Headers(), body, content_length, content_type);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const Headers &headers,
+                              const char *body, size_t content_length,
+                              const std::string &content_type) {
+  return send_with_content_provider("PUT", path, headers, body, content_length,
+                                    nullptr, nullptr, content_type, nullptr);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const Headers &headers,
+                              const char *body, size_t content_length,
+                              const std::string &content_type,
+                              Progress progress) {
+  return send_with_content_provider("PUT", path, headers, body, content_length,
+                                    nullptr, nullptr, content_type, progress);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const std::string &body,
+                              const std::string &content_type) {
+  return Put(path, Headers(), body, content_type);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const std::string &body,
+                              const std::string &content_type,
+                              Progress progress) {
+  return Put(path, Headers(), body, content_type, progress);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const Headers &headers,
+                              const std::string &body,
+                              const std::string &content_type) {
+  return send_with_content_provider("PUT", path, headers, body.data(),
+                                    body.size(), nullptr, nullptr, content_type,
+                                    nullptr);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const Headers &headers,
+                              const std::string &body,
+                              const std::string &content_type,
+                              Progress progress) {
+  return send_with_content_provider("PUT", path, headers, body.data(),
+                                    body.size(), nullptr, nullptr, content_type,
+                                    progress);
+}
+
+inline Result ClientImpl::Put(const std::string &path, size_t content_length,
+                              ContentProvider content_provider,
+                              const std::string &content_type) {
+  return Put(path, Headers(), content_length, std::move(content_provider),
+             content_type);
+}
+
+inline Result ClientImpl::Put(const std::string &path,
+                              ContentProviderWithoutLength content_provider,
+                              const std::string &content_type) {
+  return Put(path, Headers(), std::move(content_provider), content_type);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const Headers &headers,
+                              size_t content_length,
+                              ContentProvider content_provider,
+                              const std::string &content_type) {
+  return send_with_content_provider("PUT", path, headers, nullptr,
+                                    content_length, std::move(content_provider),
+                                    nullptr, content_type, nullptr);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const Headers &headers,
+                              ContentProviderWithoutLength content_provider,
+                              const std::string &content_type) {
+  return send_with_content_provider("PUT", path, headers, nullptr, 0, nullptr,
+                                    std::move(content_provider), content_type,
+                                    nullptr);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const Params &params) {
+  return Put(path, Headers(), params);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const Headers &headers,
+                              const Params &params) {
+  auto query = detail::params_to_query_str(params);
+  return Put(path, headers, query, "application/x-www-form-urlencoded");
+}
+
+inline Result ClientImpl::Put(const std::string &path, const Headers &headers,
+                              const Params &params, Progress progress) {
+  auto query = detail::params_to_query_str(params);
+  return Put(path, headers, query, "application/x-www-form-urlencoded",
+             progress);
+}
+
+inline Result ClientImpl::Put(const std::string &path,
+                              const MultipartFormDataItems &items) {
+  return Put(path, Headers(), items);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const Headers &headers,
+                              const MultipartFormDataItems &items) {
+  const auto &boundary = detail::make_multipart_data_boundary();
+  const auto &content_type =
+      detail::serialize_multipart_formdata_get_content_type(boundary);
+  const auto &body = detail::serialize_multipart_formdata(items, boundary);
+  return Put(path, headers, body, content_type);
+}
+
+inline Result ClientImpl::Put(const std::string &path, const Headers &headers,
+                              const MultipartFormDataItems &items,
+                              const std::string &boundary) {
+  if (!detail::is_multipart_boundary_chars_valid(boundary)) {
+    return Result{nullptr, Error::UnsupportedMultipartBoundaryChars};
+  }
+
+  const auto &content_type =
+      detail::serialize_multipart_formdata_get_content_type(boundary);
+  const auto &body = detail::serialize_multipart_formdata(items, boundary);
+  return Put(path, headers, body, content_type);
+}
+
+inline Result
+ClientImpl::Put(const std::string &path, const Headers &headers,
+                const MultipartFormDataItems &items,
+                const MultipartFormDataProviderItems &provider_items) {
+  const auto &boundary = detail::make_multipart_data_boundary();
+  const auto &content_type =
+      detail::serialize_multipart_formdata_get_content_type(boundary);
+  return send_with_content_provider(
+      "PUT", path, headers, nullptr, 0, nullptr,
+      get_multipart_content_provider(boundary, items, provider_items),
+      content_type, nullptr);
+}
+inline Result ClientImpl::Patch(const std::string &path) {
+  return Patch(path, std::string(), std::string());
+}
+
+inline Result ClientImpl::Patch(const std::string &path, const char *body,
+                                size_t content_length,
+                                const std::string &content_type) {
+  return Patch(path, Headers(), body, content_length, content_type);
+}
+
+inline Result ClientImpl::Patch(const std::string &path, const char *body,
+                                size_t content_length,
+                                const std::string &content_type,
+                                Progress progress) {
+  return Patch(path, Headers(), body, content_length, content_type, progress);
+}
+
+inline Result ClientImpl::Patch(const std::string &path, const Headers &headers,
+                                const char *body, size_t content_length,
+                                const std::string &content_type) {
+  return Patch(path, headers, body, content_length, content_type, nullptr);
+}
+
+inline Result ClientImpl::Patch(const std::string &path, const Headers &headers,
+                                const char *body, size_t content_length,
+                                const std::string &content_type,
+                                Progress progress) {
+  return send_with_content_provider("PATCH", path, headers, body,
+                                    content_length, nullptr, nullptr,
+                                    content_type, progress);
+}
+
+inline Result ClientImpl::Patch(const std::string &path,
+                                const std::string &body,
+                                const std::string &content_type) {
+  return Patch(path, Headers(), body, content_type);
+}
+
+inline Result ClientImpl::Patch(const std::string &path,
+                                const std::string &body,
+                                const std::string &content_type,
+                                Progress progress) {
+  return Patch(path, Headers(), body, content_type, progress);
+}
+
+inline Result ClientImpl::Patch(const std::string &path, const Headers &headers,
+                                const std::string &body,
+                                const std::string &content_type) {
+  return Patch(path, headers, body, content_type, nullptr);
+}
+
+inline Result ClientImpl::Patch(const std::string &path, const Headers &headers,
+                                const std::string &body,
+                                const std::string &content_type,
+                                Progress progress) {
+  return send_with_content_provider("PATCH", path, headers, body.data(),
+                                    body.size(), nullptr, nullptr, content_type,
+                                    progress);
+}
+
+inline Result ClientImpl::Patch(const std::string &path, size_t content_length,
+                                ContentProvider content_provider,
+                                const std::string &content_type) {
+  return Patch(path, Headers(), content_length, std::move(content_provider),
+               content_type);
+}
+
+inline Result ClientImpl::Patch(const std::string &path,
+                                ContentProviderWithoutLength content_provider,
+                                const std::string &content_type) {
+  return Patch(path, Headers(), std::move(content_provider), content_type);
+}
+
+inline Result ClientImpl::Patch(const std::string &path, const Headers &headers,
+                                size_t content_length,
+                                ContentProvider content_provider,
+                                const std::string &content_type) {
+  return send_with_content_provider("PATCH", path, headers, nullptr,
+                                    content_length, std::move(content_provider),
+                                    nullptr, content_type, nullptr);
+}
+
+inline Result ClientImpl::Patch(const std::string &path, const Headers &headers,
+                                ContentProviderWithoutLength content_provider,
+                                const std::string &content_type) {
+  return send_with_content_provider("PATCH", path, headers, nullptr, 0, nullptr,
+                                    std::move(content_provider), content_type,
+                                    nullptr);
+}
+
+inline Result ClientImpl::Delete(const std::string &path) {
+  return Delete(path, Headers(), std::string(), std::string());
+}
+
+inline Result ClientImpl::Delete(const std::string &path,
+                                 const Headers &headers) {
+  return Delete(path, headers, std::string(), std::string());
+}
+
+inline Result ClientImpl::Delete(const std::string &path, const char *body,
+                                 size_t content_length,
+                                 const std::string &content_type) {
+  return Delete(path, Headers(), body, content_length, content_type);
+}
+
+inline Result ClientImpl::Delete(const std::string &path, const char *body,
+                                 size_t content_length,
+                                 const std::string &content_type,
+                                 Progress progress) {
+  return Delete(path, Headers(), body, content_length, content_type, progress);
+}
+
+inline Result ClientImpl::Delete(const std::string &path,
+                                 const Headers &headers, const char *body,
+                                 size_t content_length,
+                                 const std::string &content_type) {
+  return Delete(path, headers, body, content_length, content_type, nullptr);
+}
+
+inline Result ClientImpl::Delete(const std::string &path,
+                                 const Headers &headers, const char *body,
+                                 size_t content_length,
+                                 const std::string &content_type,
+                                 Progress progress) {
+  Request req;
+  req.method = "DELETE";
+  req.headers = headers;
+  req.path = path;
+  req.progress = progress;
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
+
+  if (!content_type.empty()) { req.set_header("Content-Type", content_type); }
+  req.body.assign(body, content_length);
+
+  return send_(std::move(req));
+}
+
+inline Result ClientImpl::Delete(const std::string &path,
+                                 const std::string &body,
+                                 const std::string &content_type) {
+  return Delete(path, Headers(), body.data(), body.size(), content_type);
+}
+
+inline Result ClientImpl::Delete(const std::string &path,
+                                 const std::string &body,
+                                 const std::string &content_type,
+                                 Progress progress) {
+  return Delete(path, Headers(), body.data(), body.size(), content_type,
+                progress);
+}
+
+inline Result ClientImpl::Delete(const std::string &path,
+                                 const Headers &headers,
+                                 const std::string &body,
+                                 const std::string &content_type) {
+  return Delete(path, headers, body.data(), body.size(), content_type);
+}
+
+inline Result ClientImpl::Delete(const std::string &path,
+                                 const Headers &headers,
+                                 const std::string &body,
+                                 const std::string &content_type,
+                                 Progress progress) {
+  return Delete(path, headers, body.data(), body.size(), content_type,
+                progress);
+}
+
+inline Result ClientImpl::Options(const std::string &path) {
+  return Options(path, Headers());
+}
+
+inline Result ClientImpl::Options(const std::string &path,
+                                  const Headers &headers) {
+  Request req;
+  req.method = "OPTIONS";
+  req.headers = headers;
+  req.path = path;
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
+
+  return send_(std::move(req));
+}
+
+inline void ClientImpl::stop() {
+  std::lock_guard<std::mutex> guard(socket_mutex_);
+
+  // If there is anything ongoing right now, the ONLY thread-safe thing we can
+  // do is to shutdown_socket, so that threads using this socket suddenly
+  // discover they can't read/write any more and error out. Everything else
+  // (closing the socket, shutting ssl down) is unsafe because these actions are
+  // not thread-safe.
+  if (socket_requests_in_flight_ > 0) {
+    shutdown_socket(socket_);
+
+    // Aside from that, we set a flag for the socket to be closed when we're
+    // done.
+    socket_should_be_closed_when_request_is_done_ = true;
+    return;
+  }
+
+  // Otherwise, still holding the mutex, we can shut everything down ourselves
+  shutdown_ssl(socket_, true);
+  shutdown_socket(socket_);
+  close_socket(socket_);
+}
+
+inline std::string ClientImpl::host() const { return host_; }
+
+inline int ClientImpl::port() const { return port_; }
+
+inline size_t ClientImpl::is_socket_open() const {
+  std::lock_guard<std::mutex> guard(socket_mutex_);
+  return socket_.is_open();
+}
+
+inline socket_t ClientImpl::socket() const { return socket_.sock; }
+
+inline void ClientImpl::set_connection_timeout(time_t sec, time_t usec) {
+  connection_timeout_sec_ = sec;
+  connection_timeout_usec_ = usec;
+}
+
+inline void ClientImpl::set_read_timeout(time_t sec, time_t usec) {
+  read_timeout_sec_ = sec;
+  read_timeout_usec_ = usec;
+}
+
+inline void ClientImpl::set_write_timeout(time_t sec, time_t usec) {
+  write_timeout_sec_ = sec;
+  write_timeout_usec_ = usec;
+}
+
+inline void ClientImpl::set_max_timeout(time_t msec) {
+  max_timeout_msec_ = msec;
+}
+
+inline void ClientImpl::set_basic_auth(const std::string &username,
+                                       const std::string &password) {
+  basic_auth_username_ = username;
+  basic_auth_password_ = password;
+}
+
+inline void ClientImpl::set_bearer_token_auth(const std::string &token) {
+  bearer_token_auth_token_ = token;
+}
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+inline void ClientImpl::set_digest_auth(const std::string &username,
+                                        const std::string &password) {
+  digest_auth_username_ = username;
+  digest_auth_password_ = password;
+}
+#endif
+
+inline void ClientImpl::set_keep_alive(bool on) { keep_alive_ = on; }
+
+inline void ClientImpl::set_follow_location(bool on) { follow_location_ = on; }
+
+inline void ClientImpl::set_url_encode(bool on) { url_encode_ = on; }
+
+inline void
+ClientImpl::set_hostname_addr_map(std::map<std::string, std::string> addr_map) {
+  addr_map_ = std::move(addr_map);
+}
+
+inline void ClientImpl::set_default_headers(Headers headers) {
+  default_headers_ = std::move(headers);
+}
+
+inline void ClientImpl::set_header_writer(
+    std::function<ssize_t(Stream &, Headers &)> const &writer) {
+  header_writer_ = writer;
+}
+
+inline void ClientImpl::set_address_family(int family) {
+  address_family_ = family;
+}
+
+inline void ClientImpl::set_tcp_nodelay(bool on) { tcp_nodelay_ = on; }
+
+inline void ClientImpl::set_ipv6_v6only(bool on) { ipv6_v6only_ = on; }
+
+inline void ClientImpl::set_socket_options(SocketOptions socket_options) {
+  socket_options_ = std::move(socket_options);
+}
+
+inline void ClientImpl::set_compress(bool on) { compress_ = on; }
+
+inline void ClientImpl::set_decompress(bool on) { decompress_ = on; }
+
+inline void ClientImpl::set_interface(const std::string &intf) {
+  interface_ = intf;
+}
+
+inline void ClientImpl::set_proxy(const std::string &host, int port) {
+  proxy_host_ = host;
+  proxy_port_ = port;
+}
+
+inline void ClientImpl::set_proxy_basic_auth(const std::string &username,
+                                             const std::string &password) {
+  proxy_basic_auth_username_ = username;
+  proxy_basic_auth_password_ = password;
+}
+
+inline void ClientImpl::set_proxy_bearer_token_auth(const std::string &token) {
+  proxy_bearer_token_auth_token_ = token;
+}
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+inline void ClientImpl::set_proxy_digest_auth(const std::string &username,
+                                              const std::string &password) {
+  proxy_digest_auth_username_ = username;
+  proxy_digest_auth_password_ = password;
+}
+
+inline void ClientImpl::set_ca_cert_path(const std::string &ca_cert_file_path,
+                                         const std::string &ca_cert_dir_path) {
+  ca_cert_file_path_ = ca_cert_file_path;
+  ca_cert_dir_path_ = ca_cert_dir_path;
+}
+
+inline void ClientImpl::set_ca_cert_store(X509_STORE *ca_cert_store) {
+  if (ca_cert_store && ca_cert_store != ca_cert_store_) {
+    ca_cert_store_ = ca_cert_store;
+  }
+}
+
+inline X509_STORE *ClientImpl::create_ca_cert_store(const char *ca_cert,
+                                                    std::size_t size) const {
+  auto mem = BIO_new_mem_buf(ca_cert, static_cast<int>(size));
+  auto se = detail::scope_exit([&] { BIO_free_all(mem); });
+  if (!mem) { return nullptr; }
+
+  auto inf = PEM_X509_INFO_read_bio(mem, nullptr, nullptr, nullptr);
+  if (!inf) { return nullptr; }
+
+  auto cts = X509_STORE_new();
+  if (cts) {
+    for (auto i = 0; i < static_cast<int>(sk_X509_INFO_num(inf)); i++) {
+      auto itmp = sk_X509_INFO_value(inf, i);
+      if (!itmp) { continue; }
+
+      if (itmp->x509) { X509_STORE_add_cert(cts, itmp->x509); }
+      if (itmp->crl) { X509_STORE_add_crl(cts, itmp->crl); }
+    }
+  }
+
+  sk_X509_INFO_pop_free(inf, X509_INFO_free);
+  return cts;
+}
+
+inline void ClientImpl::enable_server_certificate_verification(bool enabled) {
+  server_certificate_verification_ = enabled;
+}
+
+inline void ClientImpl::enable_server_hostname_verification(bool enabled) {
+  server_hostname_verification_ = enabled;
+}
+
+inline void ClientImpl::set_server_certificate_verifier(
+    std::function<bool(SSL *ssl)> verifier) {
+  server_certificate_verifier_ = verifier;
+}
+#endif
+
+inline void ClientImpl::set_logger(Logger logger) {
+  logger_ = std::move(logger);
+}
+
+/*
+ * SSL Implementation
+ */
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+namespace detail {
+
+template <typename U, typename V>
+inline SSL *ssl_new(socket_t sock, SSL_CTX *ctx, std::mutex &ctx_mutex,
+                    U SSL_connect_or_accept, V setup) {
+  SSL *ssl = nullptr;
+  {
+    std::lock_guard<std::mutex> guard(ctx_mutex);
+    ssl = SSL_new(ctx);
+  }
+
+  if (ssl) {
+    set_nonblocking(sock, true);
+    auto bio = BIO_new_socket(static_cast<int>(sock), BIO_NOCLOSE);
+    BIO_set_nbio(bio, 1);
+    SSL_set_bio(ssl, bio, bio);
+
+    if (!setup(ssl) || SSL_connect_or_accept(ssl) != 1) {
+      SSL_shutdown(ssl);
+      {
+        std::lock_guard<std::mutex> guard(ctx_mutex);
+        SSL_free(ssl);
+      }
+      set_nonblocking(sock, false);
+      return nullptr;
+    }
+    BIO_set_nbio(bio, 0);
+    set_nonblocking(sock, false);
+  }
+
+  return ssl;
+}
+
+inline void ssl_delete(std::mutex &ctx_mutex, SSL *ssl, socket_t sock,
+                       bool shutdown_gracefully) {
+  // sometimes we may want to skip this to try to avoid SIGPIPE if we know
+  // the remote has closed the network connection
+  // Note that it is not always possible to avoid SIGPIPE, this is merely a
+  // best-efforts.
+  if (shutdown_gracefully) {
+#ifdef _WIN32
+    (void)(sock);
+    SSL_shutdown(ssl);
+#else
+    timeval tv;
+    tv.tv_sec = 1;
+    tv.tv_usec = 0;
+    setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
+               reinterpret_cast<const void *>(&tv), sizeof(tv));
+
+    auto ret = SSL_shutdown(ssl);
+    while (ret == 0) {
+      std::this_thread::sleep_for(std::chrono::milliseconds{100});
+      ret = SSL_shutdown(ssl);
+    }
+#endif
+  }
+
+  std::lock_guard<std::mutex> guard(ctx_mutex);
+  SSL_free(ssl);
+}
+
+template <typename U>
+bool ssl_connect_or_accept_nonblocking(socket_t sock, SSL *ssl,
+                                       U ssl_connect_or_accept,
+                                       time_t timeout_sec,
+                                       time_t timeout_usec) {
+  auto res = 0;
+  while ((res = ssl_connect_or_accept(ssl)) != 1) {
+    auto err = SSL_get_error(ssl, res);
+    switch (err) {
+    case SSL_ERROR_WANT_READ:
+      if (select_read(sock, timeout_sec, timeout_usec) > 0) { continue; }
+      break;
+    case SSL_ERROR_WANT_WRITE:
+      if (select_write(sock, timeout_sec, timeout_usec) > 0) { continue; }
+      break;
+    default: break;
+    }
+    return false;
+  }
+  return true;
+}
+
+template <typename T>
+inline bool process_server_socket_ssl(
+    const std::atomic<socket_t> &svr_sock, SSL *ssl, socket_t sock,
+    size_t keep_alive_max_count, time_t keep_alive_timeout_sec,
+    time_t read_timeout_sec, time_t read_timeout_usec, time_t write_timeout_sec,
+    time_t write_timeout_usec, T callback) {
+  return process_server_socket_core(
+      svr_sock, sock, keep_alive_max_count, keep_alive_timeout_sec,
+      [&](bool close_connection, bool &connection_closed) {
+        SSLSocketStream strm(sock, ssl, read_timeout_sec, read_timeout_usec,
+                             write_timeout_sec, write_timeout_usec);
+        return callback(strm, close_connection, connection_closed);
+      });
+}
+
+template <typename T>
+inline bool process_client_socket_ssl(
+    SSL *ssl, socket_t sock, time_t read_timeout_sec, time_t read_timeout_usec,
+    time_t write_timeout_sec, time_t write_timeout_usec,
+    time_t max_timeout_msec,
+    std::chrono::time_point<std::chrono::steady_clock> start_time, T callback) {
+  SSLSocketStream strm(sock, ssl, read_timeout_sec, read_timeout_usec,
+                       write_timeout_sec, write_timeout_usec,
+                       max_timeout_msec, start_time);
+  return callback(strm);
+}
+
+class SSLInit {
+public:
+  SSLInit() {
+    OPENSSL_init_ssl(
+        OPENSSL_INIT_LOAD_SSL_STRINGS | OPENSSL_INIT_LOAD_CRYPTO_STRINGS, NULL);
+  }
+};
+
+// SSL socket stream implementation
+inline SSLSocketStream::SSLSocketStream(
+    socket_t sock, SSL *ssl, time_t read_timeout_sec, time_t read_timeout_usec,
+    time_t write_timeout_sec, time_t write_timeout_usec,
+    time_t max_timeout_msec,
+    std::chrono::time_point<std::chrono::steady_clock> start_time)
+    : sock_(sock), ssl_(ssl), read_timeout_sec_(read_timeout_sec),
+      read_timeout_usec_(read_timeout_usec),
+      write_timeout_sec_(write_timeout_sec),
+      write_timeout_usec_(write_timeout_usec),
+      max_timeout_msec_(max_timeout_msec), start_time(start_time) {
+  SSL_clear_mode(ssl, SSL_MODE_AUTO_RETRY);
+}
+
+inline SSLSocketStream::~SSLSocketStream() = default;
+
+inline bool SSLSocketStream::is_readable() const {
+  if (max_timeout_msec_ <= 0) {
+    return select_read(sock_, read_timeout_sec_, read_timeout_usec_) > 0;
+  }
+
+  time_t read_timeout_sec;
+  time_t read_timeout_usec;
+  calc_actual_timeout(max_timeout_msec_, duration(), read_timeout_sec_,
+                      read_timeout_usec_, read_timeout_sec, read_timeout_usec);
+
+  return select_read(sock_, read_timeout_sec, read_timeout_usec) > 0;
+}
+
+inline bool SSLSocketStream::is_writable() const {
+  return select_write(sock_, write_timeout_sec_, write_timeout_usec_) > 0 &&
+         is_socket_alive(sock_) && !is_ssl_peer_could_be_closed(ssl_, sock_);
+}
+
+inline ssize_t SSLSocketStream::read(char *ptr, size_t size) {
+  if (SSL_pending(ssl_) > 0) {
+    return SSL_read(ssl_, ptr, static_cast<int>(size));
+  } else if (is_readable()) {
+    auto ret = SSL_read(ssl_, ptr, static_cast<int>(size));
+    if (ret < 0) {
+      auto err = SSL_get_error(ssl_, ret);
+      auto n = 1000;
+#ifdef _WIN32
+      while (--n >= 0 && (err == SSL_ERROR_WANT_READ ||
+                          (err == SSL_ERROR_SYSCALL &&
+                           WSAGetLastError() == WSAETIMEDOUT))) {
+#else
+      while (--n >= 0 && err == SSL_ERROR_WANT_READ) {
+#endif
+        if (SSL_pending(ssl_) > 0) {
+          return SSL_read(ssl_, ptr, static_cast<int>(size));
+        } else if (is_readable()) {
+          std::this_thread::sleep_for(std::chrono::microseconds{10});
+          ret = SSL_read(ssl_, ptr, static_cast<int>(size));
+          if (ret >= 0) { return ret; }
+          err = SSL_get_error(ssl_, ret);
+        } else {
+          return -1;
+        }
+      }
+    }
+    return ret;
+  } else {
+    return -1;
+  }
+}
+
+inline ssize_t SSLSocketStream::write(const char *ptr, size_t size) {
+  if (is_writable()) {
+    auto handle_size = static_cast<int>(
+        std::min<size_t>(size, (std::numeric_limits<int>::max)()));
+
+    auto ret = SSL_write(ssl_, ptr, static_cast<int>(handle_size));
+    if (ret < 0) {
+      auto err = SSL_get_error(ssl_, ret);
+      auto n = 1000;
+#ifdef _WIN32
+      while (--n >= 0 && (err == SSL_ERROR_WANT_WRITE ||
+                          (err == SSL_ERROR_SYSCALL &&
+                           WSAGetLastError() == WSAETIMEDOUT))) {
+#else
+      while (--n >= 0 && err == SSL_ERROR_WANT_WRITE) {
+#endif
+        if (is_writable()) {
+          std::this_thread::sleep_for(std::chrono::microseconds{10});
+          ret = SSL_write(ssl_, ptr, static_cast<int>(handle_size));
+          if (ret >= 0) { return ret; }
+          err = SSL_get_error(ssl_, ret);
+        } else {
+          return -1;
+        }
+      }
+    }
+    return ret;
+  }
+  return -1;
+}
+
+inline void SSLSocketStream::get_remote_ip_and_port(std::string &ip,
+                                                    int &port) const {
+  detail::get_remote_ip_and_port(sock_, ip, port);
+}
+
+inline void SSLSocketStream::get_local_ip_and_port(std::string &ip,
+                                                   int &port) const {
+  detail::get_local_ip_and_port(sock_, ip, port);
+}
+
+inline socket_t SSLSocketStream::socket() const { return sock_; }
+
+inline time_t SSLSocketStream::duration() const {
+  return std::chrono::duration_cast<std::chrono::milliseconds>(
+             std::chrono::steady_clock::now() - start_time)
+      .count();
+}
+
+static SSLInit sslinit_;
+
+} // namespace detail
+
+// SSL HTTP server implementation
+inline SSLServer::SSLServer(const char *cert_path, const char *private_key_path,
+                            const char *client_ca_cert_file_path,
+                            const char *client_ca_cert_dir_path,
+                            const char *private_key_password) {
+  ctx_ = SSL_CTX_new(TLS_server_method());
+
+  if (ctx_) {
+    SSL_CTX_set_options(ctx_,
+                        SSL_OP_NO_COMPRESSION |
+                            SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
+
+    SSL_CTX_set_min_proto_version(ctx_, TLS1_2_VERSION);
+
+    if (private_key_password != nullptr && (private_key_password[0] != '\0')) {
+      SSL_CTX_set_default_passwd_cb_userdata(
+          ctx_,
+          reinterpret_cast<void *>(const_cast<char *>(private_key_password)));
+    }
+
+    if (SSL_CTX_use_certificate_chain_file(ctx_, cert_path) != 1 ||
+        SSL_CTX_use_PrivateKey_file(ctx_, private_key_path, SSL_FILETYPE_PEM) !=
+            1 ||
+        SSL_CTX_check_private_key(ctx_) != 1) {
+      SSL_CTX_free(ctx_);
+      ctx_ = nullptr;
+    } else if (client_ca_cert_file_path || client_ca_cert_dir_path) {
+      SSL_CTX_load_verify_locations(ctx_, client_ca_cert_file_path,
+                                    client_ca_cert_dir_path);
+
+      SSL_CTX_set_verify(
+          ctx_, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, nullptr);
+    }
+  }
+}
+
+inline SSLServer::SSLServer(X509 *cert, EVP_PKEY *private_key,
+                            X509_STORE *client_ca_cert_store) {
+  ctx_ = SSL_CTX_new(TLS_server_method());
+
+  if (ctx_) {
+    SSL_CTX_set_options(ctx_,
+                        SSL_OP_NO_COMPRESSION |
+                            SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
+
+    SSL_CTX_set_min_proto_version(ctx_, TLS1_2_VERSION);
+
+    if (SSL_CTX_use_certificate(ctx_, cert) != 1 ||
+        SSL_CTX_use_PrivateKey(ctx_, private_key) != 1) {
+      SSL_CTX_free(ctx_);
+      ctx_ = nullptr;
+    } else if (client_ca_cert_store) {
+      SSL_CTX_set_cert_store(ctx_, client_ca_cert_store);
+
+      SSL_CTX_set_verify(
+          ctx_, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, nullptr);
+    }
+  }
+}
+
+inline SSLServer::SSLServer(
+    const std::function<bool(SSL_CTX &ssl_ctx)> &setup_ssl_ctx_callback) {
+  ctx_ = SSL_CTX_new(TLS_method());
+  if (ctx_) {
+    if (!setup_ssl_ctx_callback(*ctx_)) {
+      SSL_CTX_free(ctx_);
+      ctx_ = nullptr;
+    }
+  }
+}
+
+inline SSLServer::~SSLServer() {
+  if (ctx_) { SSL_CTX_free(ctx_); }
+}
+
+inline bool SSLServer::is_valid() const { return ctx_; }
+
+inline SSL_CTX *SSLServer::ssl_context() const { return ctx_; }
+
+inline void SSLServer::update_certs(X509 *cert, EVP_PKEY *private_key,
+                                    X509_STORE *client_ca_cert_store) {
+
+  std::lock_guard<std::mutex> guard(ctx_mutex_);
+
+  SSL_CTX_use_certificate(ctx_, cert);
+  SSL_CTX_use_PrivateKey(ctx_, private_key);
+
+  if (client_ca_cert_store != nullptr) {
+    SSL_CTX_set_cert_store(ctx_, client_ca_cert_store);
+  }
+}
+
+inline bool SSLServer::process_and_close_socket(socket_t sock) {
+  auto ssl = detail::ssl_new(
+      sock, ctx_, ctx_mutex_,
+      [&](SSL *ssl2) {
+        return detail::ssl_connect_or_accept_nonblocking(
+            sock, ssl2, SSL_accept, read_timeout_sec_, read_timeout_usec_);
+      },
+      [](SSL * /*ssl2*/) { return true; });
+
+  auto ret = false;
+  if (ssl) {
+    std::string remote_addr;
+    int remote_port = 0;
+    detail::get_remote_ip_and_port(sock, remote_addr, remote_port);
+
+    std::string local_addr;
+    int local_port = 0;
+    detail::get_local_ip_and_port(sock, local_addr, local_port);
+
+    ret = detail::process_server_socket_ssl(
+        svr_sock_, ssl, sock, keep_alive_max_count_, keep_alive_timeout_sec_,
+        read_timeout_sec_, read_timeout_usec_, write_timeout_sec_,
+        write_timeout_usec_,
+        [&](Stream &strm, bool close_connection, bool &connection_closed) {
+          return process_request(strm, remote_addr, remote_port, local_addr,
+                                 local_port, close_connection,
+                                 connection_closed,
+                                 [&](Request &req) { req.ssl = ssl; });
+        });
+
+    // Shutdown gracefully if the result seemed successful, non-gracefully if
+    // the connection appeared to be closed.
+    const bool shutdown_gracefully = ret;
+    detail::ssl_delete(ctx_mutex_, ssl, sock, shutdown_gracefully);
+  }
+
+  detail::shutdown_socket(sock);
+  detail::close_socket(sock);
+  return ret;
+}
+
+// SSL HTTP client implementation
+inline SSLClient::SSLClient(const std::string &host)
+    : SSLClient(host, 443, std::string(), std::string()) {}
+
+inline SSLClient::SSLClient(const std::string &host, int port)
+    : SSLClient(host, port, std::string(), std::string()) {}
+
+inline SSLClient::SSLClient(const std::string &host, int port,
+                            const std::string &client_cert_path,
+                            const std::string &client_key_path,
+                            const std::string &private_key_password)
+    : ClientImpl(host, port, client_cert_path, client_key_path) {
+  ctx_ = SSL_CTX_new(TLS_client_method());
+
+  SSL_CTX_set_min_proto_version(ctx_, TLS1_2_VERSION);
+
+  detail::split(&host_[0], &host_[host_.size()], '.',
+                [&](const char *b, const char *e) {
+                  host_components_.emplace_back(b, e);
+                });
+
+  if (!client_cert_path.empty() && !client_key_path.empty()) {
+    if (!private_key_password.empty()) {
+      SSL_CTX_set_default_passwd_cb_userdata(
+          ctx_, reinterpret_cast<void *>(
+                    const_cast<char *>(private_key_password.c_str())));
+    }
+
+    if (SSL_CTX_use_certificate_file(ctx_, client_cert_path.c_str(),
+                                     SSL_FILETYPE_PEM) != 1 ||
+        SSL_CTX_use_PrivateKey_file(ctx_, client_key_path.c_str(),
+                                    SSL_FILETYPE_PEM) != 1) {
+      SSL_CTX_free(ctx_);
+      ctx_ = nullptr;
+    }
+  }
+}
+
+inline SSLClient::SSLClient(const std::string &host, int port,
+                            X509 *client_cert, EVP_PKEY *client_key,
+                            const std::string &private_key_password)
+    : ClientImpl(host, port) {
+  ctx_ = SSL_CTX_new(TLS_client_method());
+
+  detail::split(&host_[0], &host_[host_.size()], '.',
+                [&](const char *b, const char *e) {
+                  host_components_.emplace_back(b, e);
+                });
+
+  if (client_cert != nullptr && client_key != nullptr) {
+    if (!private_key_password.empty()) {
+      SSL_CTX_set_default_passwd_cb_userdata(
+          ctx_, reinterpret_cast<void *>(
+                    const_cast<char *>(private_key_password.c_str())));
+    }
+
+    if (SSL_CTX_use_certificate(ctx_, client_cert) != 1 ||
+        SSL_CTX_use_PrivateKey(ctx_, client_key) != 1) {
+      SSL_CTX_free(ctx_);
+      ctx_ = nullptr;
+    }
+  }
+}
+
+inline SSLClient::~SSLClient() {
+  if (ctx_) { SSL_CTX_free(ctx_); }
+  // Make sure to shut down SSL since shutdown_ssl will resolve to the
+  // base function rather than the derived function once we get to the
+  // base class destructor, and won't free the SSL (causing a leak).
+  shutdown_ssl_impl(socket_, true);
+}
+
+inline bool SSLClient::is_valid() const { return ctx_; }
+
+inline void SSLClient::set_ca_cert_store(X509_STORE *ca_cert_store) {
+  if (ca_cert_store) {
+    if (ctx_) {
+      if (SSL_CTX_get_cert_store(ctx_) != ca_cert_store) {
+        // Free memory allocated for old cert and use new store `ca_cert_store`
+        SSL_CTX_set_cert_store(ctx_, ca_cert_store);
+      }
+    } else {
+      X509_STORE_free(ca_cert_store);
+    }
+  }
+}
+
+inline void SSLClient::load_ca_cert_store(const char *ca_cert,
+                                          std::size_t size) {
+  set_ca_cert_store(ClientImpl::create_ca_cert_store(ca_cert, size));
+}
+
+inline long SSLClient::get_openssl_verify_result() const {
+  return verify_result_;
+}
+
+inline SSL_CTX *SSLClient::ssl_context() const { return ctx_; }
+
+inline bool SSLClient::create_and_connect_socket(Socket &socket, Error &error) {
+  return is_valid() && ClientImpl::create_and_connect_socket(socket, error);
+}
+
+// Assumes that socket_mutex_ is locked and that there are no requests in flight
+inline bool SSLClient::connect_with_proxy(
+    Socket &socket,
+    std::chrono::time_point<std::chrono::steady_clock> start_time,
+    Response &res, bool &success, Error &error) {
+  success = true;
+  Response proxy_res;
+  if (!detail::process_client_socket(
+          socket.sock, read_timeout_sec_, read_timeout_usec_,
+          write_timeout_sec_, write_timeout_usec_, max_timeout_msec_,
+          start_time, [&](Stream &strm) {
+            Request req2;
+            req2.method = "CONNECT";
+            req2.path = host_and_port_;
+            if (max_timeout_msec_ > 0) {
+              req2.start_time_ = std::chrono::steady_clock::now();
+            }
+            return process_request(strm, req2, proxy_res, false, error);
+          })) {
+    // Thread-safe to close everything because we are assuming there are no
+    // requests in flight
+    shutdown_ssl(socket, true);
+    shutdown_socket(socket);
+    close_socket(socket);
+    success = false;
+    return false;
+  }
+
+  if (proxy_res.status == StatusCode::ProxyAuthenticationRequired_407) {
+    if (!proxy_digest_auth_username_.empty() &&
+        !proxy_digest_auth_password_.empty()) {
+      std::map<std::string, std::string> auth;
+      if (detail::parse_www_authenticate(proxy_res, auth, true)) {
+        proxy_res = Response();
+        if (!detail::process_client_socket(
+                socket.sock, read_timeout_sec_, read_timeout_usec_,
+                write_timeout_sec_, write_timeout_usec_, max_timeout_msec_,
+                start_time, [&](Stream &strm) {
+                  Request req3;
+                  req3.method = "CONNECT";
+                  req3.path = host_and_port_;
+                  req3.headers.insert(detail::make_digest_authentication_header(
+                      req3, auth, 1, detail::random_string(10),
+                      proxy_digest_auth_username_, proxy_digest_auth_password_,
+                      true));
+                  if (max_timeout_msec_ > 0) {
+                    req3.start_time_ = std::chrono::steady_clock::now();
+                  }
+                  return process_request(strm, req3, proxy_res, false, error);
+                })) {
+          // Thread-safe to close everything because we are assuming there are
+          // no requests in flight
+          shutdown_ssl(socket, true);
+          shutdown_socket(socket);
+          close_socket(socket);
+          success = false;
+          return false;
+        }
+      }
+    }
+  }
+
+  // If status code is not 200, proxy request is failed.
+  // Set error to ProxyConnection and return proxy response
+  // as the response of the request
+  if (proxy_res.status != StatusCode::OK_200) {
+    error = Error::ProxyConnection;
+    res = std::move(proxy_res);
+    // Thread-safe to close everything because we are assuming there are
+    // no requests in flight
+    shutdown_ssl(socket, true);
+    shutdown_socket(socket);
+    close_socket(socket);
+    return false;
+  }
+
+  return true;
+}
+
+inline bool SSLClient::load_certs() {
+  auto ret = true;
+
+  std::call_once(initialize_cert_, [&]() {
+    std::lock_guard<std::mutex> guard(ctx_mutex_);
+    if (!ca_cert_file_path_.empty()) {
+      if (!SSL_CTX_load_verify_locations(ctx_, ca_cert_file_path_.c_str(),
+                                         nullptr)) {
+        ret = false;
+      }
+    } else if (!ca_cert_dir_path_.empty()) {
+      if (!SSL_CTX_load_verify_locations(ctx_, nullptr,
+                                         ca_cert_dir_path_.c_str())) {
+        ret = false;
+      }
+    } else {
+      auto loaded = false;
+#ifdef _WIN32
+      loaded =
+          detail::load_system_certs_on_windows(SSL_CTX_get_cert_store(ctx_));
+#elif defined(CPPHTTPLIB_USE_CERTS_FROM_MACOSX_KEYCHAIN) && defined(__APPLE__)
+#if TARGET_OS_OSX
+      loaded = detail::load_system_certs_on_macos(SSL_CTX_get_cert_store(ctx_));
+#endif // TARGET_OS_OSX
+#endif // _WIN32
+      if (!loaded) { SSL_CTX_set_default_verify_paths(ctx_); }
+    }
+  });
+
+  return ret;
+}
+
+inline bool SSLClient::initialize_ssl(Socket &socket, Error &error) {
+  auto ssl = detail::ssl_new(
+      socket.sock, ctx_, ctx_mutex_,
+      [&](SSL *ssl2) {
+        if (server_certificate_verification_) {
+          if (!load_certs()) {
+            error = Error::SSLLoadingCerts;
+            return false;
+          }
+          SSL_set_verify(ssl2, SSL_VERIFY_NONE, nullptr);
+        }
+
+        if (!detail::ssl_connect_or_accept_nonblocking(
+                socket.sock, ssl2, SSL_connect, connection_timeout_sec_,
+                connection_timeout_usec_)) {
+          error = Error::SSLConnection;
+          return false;
+        }
+
+        if (server_certificate_verification_) {
+          if (server_certificate_verifier_) {
+            if (!server_certificate_verifier_(ssl2)) {
+              error = Error::SSLServerVerification;
+              return false;
+            }
+          } else {
+            verify_result_ = SSL_get_verify_result(ssl2);
+
+            if (verify_result_ != X509_V_OK) {
+              error = Error::SSLServerVerification;
+              return false;
+            }
+
+            auto server_cert = SSL_get1_peer_certificate(ssl2);
+            auto se = detail::scope_exit([&] { X509_free(server_cert); });
+
+            if (server_cert == nullptr) {
+              error = Error::SSLServerVerification;
+              return false;
+            }
+
+            if (server_hostname_verification_) {
+              if (!verify_host(server_cert)) {
+                error = Error::SSLServerHostnameVerification;
+                return false;
+              }
+            }
+          }
+        }
+
+        return true;
+      },
+      [&](SSL *ssl2) {
+#if defined(OPENSSL_IS_BORINGSSL)
+        SSL_set_tlsext_host_name(ssl2, host_.c_str());
+#else
+        // NOTE: Direct call instead of using the OpenSSL macro to suppress
+        // -Wold-style-cast warning
+        SSL_ctrl(ssl2, SSL_CTRL_SET_TLSEXT_HOSTNAME, TLSEXT_NAMETYPE_host_name,
+                 static_cast<void *>(const_cast<char *>(host_.c_str())));
+#endif
+        return true;
+      });
+
+  if (ssl) {
+    socket.ssl = ssl;
+    return true;
+  }
+
+  shutdown_socket(socket);
+  close_socket(socket);
+  return false;
+}
+
+inline void SSLClient::shutdown_ssl(Socket &socket, bool shutdown_gracefully) {
+  shutdown_ssl_impl(socket, shutdown_gracefully);
+}
+
+inline void SSLClient::shutdown_ssl_impl(Socket &socket,
+                                         bool shutdown_gracefully) {
+  if (socket.sock == INVALID_SOCKET) {
+    assert(socket.ssl == nullptr);
+    return;
+  }
+  if (socket.ssl) {
+    detail::ssl_delete(ctx_mutex_, socket.ssl, socket.sock,
+                       shutdown_gracefully);
+    socket.ssl = nullptr;
+  }
+  assert(socket.ssl == nullptr);
+}
+
+inline bool SSLClient::process_socket(
+    const Socket &socket,
+    std::chrono::time_point<std::chrono::steady_clock> start_time,
+    std::function<bool(Stream &strm)> callback) {
+  assert(socket.ssl);
+  return detail::process_client_socket_ssl(
+      socket.ssl, socket.sock, read_timeout_sec_, read_timeout_usec_,
+      write_timeout_sec_, write_timeout_usec_, max_timeout_msec_, start_time,
+      std::move(callback));
+}
+
+inline bool SSLClient::is_ssl() const { return true; }
+
+inline bool SSLClient::verify_host(X509 *server_cert) const {
+  /* Quote from RFC2818 section 3.1 "Server Identity"
+
+     If a subjectAltName extension of type dNSName is present, that MUST
+     be used as the identity. Otherwise, the (most specific) Common Name
+     field in the Subject field of the certificate MUST be used. Although
+     the use of the Common Name is existing practice, it is deprecated and
+     Certification Authorities are encouraged to use the dNSName instead.
+
+     Matching is performed using the matching rules specified by
+     [RFC2459].  If more than one identity of a given type is present in
+     the certificate (e.g., more than one dNSName name, a match in any one
+     of the set is considered acceptable.) Names may contain the wildcard
+     character * which is considered to match any single domain name
+     component or component fragment. E.g., *.a.com matches foo.a.com but
+     not bar.foo.a.com. f*.com matches foo.com but not bar.com.
+
+     In some cases, the URI is specified as an IP address rather than a
+     hostname. In this case, the iPAddress subjectAltName must be present
+     in the certificate and must exactly match the IP in the URI.
+
+  */
+  return verify_host_with_subject_alt_name(server_cert) ||
+         verify_host_with_common_name(server_cert);
+}
+
+inline bool
+SSLClient::verify_host_with_subject_alt_name(X509 *server_cert) const {
+  auto ret = false;
+
+  auto type = GEN_DNS;
+
+  struct in6_addr addr6{};
+  struct in_addr addr{};
+  size_t addr_len = 0;
+
+#ifndef __MINGW32__
+  if (inet_pton(AF_INET6, host_.c_str(), &addr6)) {
+    type = GEN_IPADD;
+    addr_len = sizeof(struct in6_addr);
+  } else if (inet_pton(AF_INET, host_.c_str(), &addr)) {
+    type = GEN_IPADD;
+    addr_len = sizeof(struct in_addr);
+  }
+#endif
+
+  auto alt_names = static_cast<const struct stack_st_GENERAL_NAME *>(
+      X509_get_ext_d2i(server_cert, NID_subject_alt_name, nullptr, nullptr));
+
+  if (alt_names) {
+    auto dsn_matched = false;
+    auto ip_matched = false;
+
+    auto count = sk_GENERAL_NAME_num(alt_names);
+
+    for (decltype(count) i = 0; i < count && !dsn_matched; i++) {
+      auto val = sk_GENERAL_NAME_value(alt_names, i);
+      if (val->type == type) {
+        auto name =
+            reinterpret_cast<const char *>(ASN1_STRING_get0_data(val->d.ia5));
+        auto name_len = static_cast<size_t>(ASN1_STRING_length(val->d.ia5));
+
+        switch (type) {
+        case GEN_DNS: dsn_matched = check_host_name(name, name_len); break;
+
+        case GEN_IPADD:
+          if (!memcmp(&addr6, name, addr_len) ||
+              !memcmp(&addr, name, addr_len)) {
+            ip_matched = true;
+          }
+          break;
+        }
+      }
+    }
+
+    if (dsn_matched || ip_matched) { ret = true; }
+  }
+
+  GENERAL_NAMES_free(const_cast<STACK_OF(GENERAL_NAME) *>(
+      reinterpret_cast<const STACK_OF(GENERAL_NAME) *>(alt_names)));
+  return ret;
+}
+
+inline bool SSLClient::verify_host_with_common_name(X509 *server_cert) const {
+  const auto subject_name = X509_get_subject_name(server_cert);
+
+  if (subject_name != nullptr) {
+    char name[BUFSIZ];
+    auto name_len = X509_NAME_get_text_by_NID(subject_name, NID_commonName,
+                                              name, sizeof(name));
+
+    if (name_len != -1) {
+      return check_host_name(name, static_cast<size_t>(name_len));
+    }
+  }
+
+  return false;
+}
+
+inline bool SSLClient::check_host_name(const char *pattern,
+                                       size_t pattern_len) const {
+  if (host_.size() == pattern_len && host_ == pattern) { return true; }
+
+  // Wildcard match
+  // https://bugs.launchpad.net/ubuntu/+source/firefox-3.0/+bug/376484
+  std::vector<std::string> pattern_components;
+  detail::split(&pattern[0], &pattern[pattern_len], '.',
+                [&](const char *b, const char *e) {
+                  pattern_components.emplace_back(b, e);
+                });
+
+  if (host_components_.size() != pattern_components.size()) { return false; }
+
+  auto itr = pattern_components.begin();
+  for (const auto &h : host_components_) {
+    auto &p = *itr;
+    if (p != h && p != "*") {
+      auto partial_match = (p.size() > 0 && p[p.size() - 1] == '*' &&
+                            !p.compare(0, p.size() - 1, h));
+      if (!partial_match) { return false; }
+    }
+    ++itr;
+  }
+
+  return true;
+}
+#endif
+
+// Universal client implementation
+inline Client::Client(const std::string &scheme_host_port)
+    : Client(scheme_host_port, std::string(), std::string()) {}
+
+inline Client::Client(const std::string &scheme_host_port,
+                      const std::string &client_cert_path,
+                      const std::string &client_key_path) {
+  const static std::regex re(
+      R"((?:([a-z]+):\/\/)?(?:\[([a-fA-F\d:]+)\]|([^:/?#]+))(?::(\d+))?)");
+
+  std::smatch m;
+  if (std::regex_match(scheme_host_port, m, re)) {
+    auto scheme = m[1].str();
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+    if (!scheme.empty() && (scheme != "http" && scheme != "https")) {
+#else
+    if (!scheme.empty() && scheme != "http") {
+#endif
+#ifndef CPPHTTPLIB_NO_EXCEPTIONS
+      std::string msg = "'" + scheme + "' scheme is not supported.";
+      throw std::invalid_argument(msg);
+#endif
+      return;
+    }
+
+    auto is_ssl = scheme == "https";
+
+    auto host = m[2].str();
+    if (host.empty()) { host = m[3].str(); }
+
+    auto port_str = m[4].str();
+    auto port = !port_str.empty() ? std::stoi(port_str) : (is_ssl ? 443 : 80);
+
+    if (is_ssl) {
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+      cli_ = detail::make_unique<SSLClient>(host, port, client_cert_path,
+                                            client_key_path);
+      is_ssl_ = is_ssl;
+#endif
+    } else {
+      cli_ = detail::make_unique<ClientImpl>(host, port, client_cert_path,
+                                             client_key_path);
+    }
+  } else {
+    // NOTE: Update TEST(UniversalClientImplTest, Ipv6LiteralAddress)
+    // if port param below changes.
+    cli_ = detail::make_unique<ClientImpl>(scheme_host_port, 80,
+                                           client_cert_path, client_key_path);
+  }
+} // namespace detail
+
+inline Client::Client(const std::string &host, int port)
+    : cli_(detail::make_unique<ClientImpl>(host, port)) {}
+
+inline Client::Client(const std::string &host, int port,
+                      const std::string &client_cert_path,
+                      const std::string &client_key_path)
+    : cli_(detail::make_unique<ClientImpl>(host, port, client_cert_path,
+                                           client_key_path)) {}
+
+inline Client::~Client() = default;
+
+inline bool Client::is_valid() const {
+  return cli_ != nullptr && cli_->is_valid();
+}
+
+inline Result Client::Get(const std::string &path) { return cli_->Get(path); }
+inline Result Client::Get(const std::string &path, const Headers &headers) {
+  return cli_->Get(path, headers);
+}
+inline Result Client::Get(const std::string &path, Progress progress) {
+  return cli_->Get(path, std::move(progress));
+}
+inline Result Client::Get(const std::string &path, const Headers &headers,
+                          Progress progress) {
+  return cli_->Get(path, headers, std::move(progress));
+}
+inline Result Client::Get(const std::string &path,
+                          ContentReceiver content_receiver) {
+  return cli_->Get(path, std::move(content_receiver));
+}
+inline Result Client::Get(const std::string &path, const Headers &headers,
+                          ContentReceiver content_receiver) {
+  return cli_->Get(path, headers, std::move(content_receiver));
+}
+inline Result Client::Get(const std::string &path,
+                          ContentReceiver content_receiver, Progress progress) {
+  return cli_->Get(path, std::move(content_receiver), std::move(progress));
+}
+inline Result Client::Get(const std::string &path, const Headers &headers,
+                          ContentReceiver content_receiver, Progress progress) {
+  return cli_->Get(path, headers, std::move(content_receiver),
+                   std::move(progress));
+}
+inline Result Client::Get(const std::string &path,
+                          ResponseHandler response_handler,
+                          ContentReceiver content_receiver) {
+  return cli_->Get(path, std::move(response_handler),
+                   std::move(content_receiver));
+}
+inline Result Client::Get(const std::string &path, const Headers &headers,
+                          ResponseHandler response_handler,
+                          ContentReceiver content_receiver) {
+  return cli_->Get(path, headers, std::move(response_handler),
+                   std::move(content_receiver));
+}
+inline Result Client::Get(const std::string &path,
+                          ResponseHandler response_handler,
+                          ContentReceiver content_receiver, Progress progress) {
+  return cli_->Get(path, std::move(response_handler),
+                   std::move(content_receiver), std::move(progress));
+}
+inline Result Client::Get(const std::string &path, const Headers &headers,
+                          ResponseHandler response_handler,
+                          ContentReceiver content_receiver, Progress progress) {
+  return cli_->Get(path, headers, std::move(response_handler),
+                   std::move(content_receiver), std::move(progress));
+}
+inline Result Client::Get(const std::string &path, const Params &params,
+                          const Headers &headers, Progress progress) {
+  return cli_->Get(path, params, headers, std::move(progress));
+}
+inline Result Client::Get(const std::string &path, const Params &params,
+                          const Headers &headers,
+                          ContentReceiver content_receiver, Progress progress) {
+  return cli_->Get(path, params, headers, std::move(content_receiver),
+                   std::move(progress));
+}
+inline Result Client::Get(const std::string &path, const Params &params,
+                          const Headers &headers,
+                          ResponseHandler response_handler,
+                          ContentReceiver content_receiver, Progress progress) {
+  return cli_->Get(path, params, headers, std::move(response_handler),
+                   std::move(content_receiver), std::move(progress));
+}
+
+inline Result Client::Head(const std::string &path) { return cli_->Head(path); }
+inline Result Client::Head(const std::string &path, const Headers &headers) {
+  return cli_->Head(path, headers);
+}
+
+inline Result Client::Post(const std::string &path) { return cli_->Post(path); }
+inline Result Client::Post(const std::string &path, const Headers &headers) {
+  return cli_->Post(path, headers);
+}
+inline Result Client::Post(const std::string &path, const char *body,
+                           size_t content_length,
+                           const std::string &content_type) {
+  return cli_->Post(path, body, content_length, content_type);
+}
+inline Result Client::Post(const std::string &path, const Headers &headers,
+                           const char *body, size_t content_length,
+                           const std::string &content_type) {
+  return cli_->Post(path, headers, body, content_length, content_type);
+}
+inline Result Client::Post(const std::string &path, const Headers &headers,
+                           const char *body, size_t content_length,
+                           const std::string &content_type, Progress progress) {
+  return cli_->Post(path, headers, body, content_length, content_type,
+                    progress);
+}
+inline Result Client::Post(const std::string &path, const std::string &body,
+                           const std::string &content_type) {
+  return cli_->Post(path, body, content_type);
+}
+inline Result Client::Post(const std::string &path, const std::string &body,
+                           const std::string &content_type, Progress progress) {
+  return cli_->Post(path, body, content_type, progress);
+}
+inline Result Client::Post(const std::string &path, const Headers &headers,
+                           const std::string &body,
+                           const std::string &content_type) {
+  return cli_->Post(path, headers, body, content_type);
+}
+inline Result Client::Post(const std::string &path, const Headers &headers,
+                           const std::string &body,
+                           const std::string &content_type, Progress progress) {
+  return cli_->Post(path, headers, body, content_type, progress);
+}
+inline Result Client::Post(const std::string &path, size_t content_length,
+                           ContentProvider content_provider,
+                           const std::string &content_type) {
+  return cli_->Post(path, content_length, std::move(content_provider),
+                    content_type);
+}
+inline Result Client::Post(const std::string &path,
+                           ContentProviderWithoutLength content_provider,
+                           const std::string &content_type) {
+  return cli_->Post(path, std::move(content_provider), content_type);
+}
+inline Result Client::Post(const std::string &path, const Headers &headers,
+                           size_t content_length,
+                           ContentProvider content_provider,
+                           const std::string &content_type) {
+  return cli_->Post(path, headers, content_length, std::move(content_provider),
+                    content_type);
+}
+inline Result Client::Post(const std::string &path, const Headers &headers,
+                           ContentProviderWithoutLength content_provider,
+                           const std::string &content_type) {
+  return cli_->Post(path, headers, std::move(content_provider), content_type);
+}
+inline Result Client::Post(const std::string &path, const Params &params) {
+  return cli_->Post(path, params);
+}
+inline Result Client::Post(const std::string &path, const Headers &headers,
+                           const Params &params) {
+  return cli_->Post(path, headers, params);
+}
+inline Result Client::Post(const std::string &path, const Headers &headers,
+                           const Params &params, Progress progress) {
+  return cli_->Post(path, headers, params, progress);
+}
+inline Result Client::Post(const std::string &path,
+                           const MultipartFormDataItems &items) {
+  return cli_->Post(path, items);
+}
+inline Result Client::Post(const std::string &path, const Headers &headers,
+                           const MultipartFormDataItems &items) {
+  return cli_->Post(path, headers, items);
+}
+inline Result Client::Post(const std::string &path, const Headers &headers,
+                           const MultipartFormDataItems &items,
+                           const std::string &boundary) {
+  return cli_->Post(path, headers, items, boundary);
+}
+inline Result
+Client::Post(const std::string &path, const Headers &headers,
+             const MultipartFormDataItems &items,
+             const MultipartFormDataProviderItems &provider_items) {
+  return cli_->Post(path, headers, items, provider_items);
+}
+inline Result Client::Put(const std::string &path) { return cli_->Put(path); }
+inline Result Client::Put(const std::string &path, const char *body,
+                          size_t content_length,
+                          const std::string &content_type) {
+  return cli_->Put(path, body, content_length, content_type);
+}
+inline Result Client::Put(const std::string &path, const Headers &headers,
+                          const char *body, size_t content_length,
+                          const std::string &content_type) {
+  return cli_->Put(path, headers, body, content_length, content_type);
+}
+inline Result Client::Put(const std::string &path, const Headers &headers,
+                          const char *body, size_t content_length,
+                          const std::string &content_type, Progress progress) {
+  return cli_->Put(path, headers, body, content_length, content_type, progress);
+}
+inline Result Client::Put(const std::string &path, const std::string &body,
+                          const std::string &content_type) {
+  return cli_->Put(path, body, content_type);
+}
+inline Result Client::Put(const std::string &path, const std::string &body,
+                          const std::string &content_type, Progress progress) {
+  return cli_->Put(path, body, content_type, progress);
+}
+inline Result Client::Put(const std::string &path, const Headers &headers,
+                          const std::string &body,
+                          const std::string &content_type) {
+  return cli_->Put(path, headers, body, content_type);
+}
+inline Result Client::Put(const std::string &path, const Headers &headers,
+                          const std::string &body,
+                          const std::string &content_type, Progress progress) {
+  return cli_->Put(path, headers, body, content_type, progress);
+}
+inline Result Client::Put(const std::string &path, size_t content_length,
+                          ContentProvider content_provider,
+                          const std::string &content_type) {
+  return cli_->Put(path, content_length, std::move(content_provider),
+                   content_type);
+}
+inline Result Client::Put(const std::string &path,
+                          ContentProviderWithoutLength content_provider,
+                          const std::string &content_type) {
+  return cli_->Put(path, std::move(content_provider), content_type);
+}
+inline Result Client::Put(const std::string &path, const Headers &headers,
+                          size_t content_length,
+                          ContentProvider content_provider,
+                          const std::string &content_type) {
+  return cli_->Put(path, headers, content_length, std::move(content_provider),
+                   content_type);
+}
+inline Result Client::Put(const std::string &path, const Headers &headers,
+                          ContentProviderWithoutLength content_provider,
+                          const std::string &content_type) {
+  return cli_->Put(path, headers, std::move(content_provider), content_type);
+}
+inline Result Client::Put(const std::string &path, const Params &params) {
+  return cli_->Put(path, params);
+}
+inline Result Client::Put(const std::string &path, const Headers &headers,
+                          const Params &params) {
+  return cli_->Put(path, headers, params);
+}
+inline Result Client::Put(const std::string &path, const Headers &headers,
+                          const Params &params, Progress progress) {
+  return cli_->Put(path, headers, params, progress);
+}
+inline Result Client::Put(const std::string &path,
+                          const MultipartFormDataItems &items) {
+  return cli_->Put(path, items);
+}
+inline Result Client::Put(const std::string &path, const Headers &headers,
+                          const MultipartFormDataItems &items) {
+  return cli_->Put(path, headers, items);
+}
+inline Result Client::Put(const std::string &path, const Headers &headers,
+                          const MultipartFormDataItems &items,
+                          const std::string &boundary) {
+  return cli_->Put(path, headers, items, boundary);
+}
+inline Result
+Client::Put(const std::string &path, const Headers &headers,
+            const MultipartFormDataItems &items,
+            const MultipartFormDataProviderItems &provider_items) {
+  return cli_->Put(path, headers, items, provider_items);
+}
+inline Result Client::Patch(const std::string &path) {
+  return cli_->Patch(path);
+}
+inline Result Client::Patch(const std::string &path, const char *body,
+                            size_t content_length,
+                            const std::string &content_type) {
+  return cli_->Patch(path, body, content_length, content_type);
+}
+inline Result Client::Patch(const std::string &path, const char *body,
+                            size_t content_length,
+                            const std::string &content_type,
+                            Progress progress) {
+  return cli_->Patch(path, body, content_length, content_type, progress);
+}
+inline Result Client::Patch(const std::string &path, const Headers &headers,
+                            const char *body, size_t content_length,
+                            const std::string &content_type) {
+  return cli_->Patch(path, headers, body, content_length, content_type);
+}
+inline Result Client::Patch(const std::string &path, const Headers &headers,
+                            const char *body, size_t content_length,
+                            const std::string &content_type,
+                            Progress progress) {
+  return cli_->Patch(path, headers, body, content_length, content_type,
+                     progress);
+}
+inline Result Client::Patch(const std::string &path, const std::string &body,
+                            const std::string &content_type) {
+  return cli_->Patch(path, body, content_type);
+}
+inline Result Client::Patch(const std::string &path, const std::string &body,
+                            const std::string &content_type,
+                            Progress progress) {
+  return cli_->Patch(path, body, content_type, progress);
+}
+inline Result Client::Patch(const std::string &path, const Headers &headers,
+                            const std::string &body,
+                            const std::string &content_type) {
+  return cli_->Patch(path, headers, body, content_type);
+}
+inline Result Client::Patch(const std::string &path, const Headers &headers,
+                            const std::string &body,
+                            const std::string &content_type,
+                            Progress progress) {
+  return cli_->Patch(path, headers, body, content_type, progress);
+}
+inline Result Client::Patch(const std::string &path, size_t content_length,
+                            ContentProvider content_provider,
+                            const std::string &content_type) {
+  return cli_->Patch(path, content_length, std::move(content_provider),
+                     content_type);
+}
+inline Result Client::Patch(const std::string &path,
+                            ContentProviderWithoutLength content_provider,
+                            const std::string &content_type) {
+  return cli_->Patch(path, std::move(content_provider), content_type);
+}
+inline Result Client::Patch(const std::string &path, const Headers &headers,
+                            size_t content_length,
+                            ContentProvider content_provider,
+                            const std::string &content_type) {
+  return cli_->Patch(path, headers, content_length, std::move(content_provider),
+                     content_type);
+}
+inline Result Client::Patch(const std::string &path, const Headers &headers,
+                            ContentProviderWithoutLength content_provider,
+                            const std::string &content_type) {
+  return cli_->Patch(path, headers, std::move(content_provider), content_type);
+}
+inline Result Client::Delete(const std::string &path) {
+  return cli_->Delete(path);
+}
+inline Result Client::Delete(const std::string &path, const Headers &headers) {
+  return cli_->Delete(path, headers);
+}
+inline Result Client::Delete(const std::string &path, const char *body,
+                             size_t content_length,
+                             const std::string &content_type) {
+  return cli_->Delete(path, body, content_length, content_type);
+}
+inline Result Client::Delete(const std::string &path, const char *body,
+                             size_t content_length,
+                             const std::string &content_type,
+                             Progress progress) {
+  return cli_->Delete(path, body, content_length, content_type, progress);
+}
+inline Result Client::Delete(const std::string &path, const Headers &headers,
+                             const char *body, size_t content_length,
+                             const std::string &content_type) {
+  return cli_->Delete(path, headers, body, content_length, content_type);
+}
+inline Result Client::Delete(const std::string &path, const Headers &headers,
+                             const char *body, size_t content_length,
+                             const std::string &content_type,
+                             Progress progress) {
+  return cli_->Delete(path, headers, body, content_length, content_type,
+                      progress);
+}
+inline Result Client::Delete(const std::string &path, const std::string &body,
+                             const std::string &content_type) {
+  return cli_->Delete(path, body, content_type);
+}
+inline Result Client::Delete(const std::string &path, const std::string &body,
+                             const std::string &content_type,
+                             Progress progress) {
+  return cli_->Delete(path, body, content_type, progress);
+}
+inline Result Client::Delete(const std::string &path, const Headers &headers,
+                             const std::string &body,
+                             const std::string &content_type) {
+  return cli_->Delete(path, headers, body, content_type);
+}
+inline Result Client::Delete(const std::string &path, const Headers &headers,
+                             const std::string &body,
+                             const std::string &content_type,
+                             Progress progress) {
+  return cli_->Delete(path, headers, body, content_type, progress);
+}
+inline Result Client::Options(const std::string &path) {
+  return cli_->Options(path);
+}
+inline Result Client::Options(const std::string &path, const Headers &headers) {
+  return cli_->Options(path, headers);
+}
+
+inline bool Client::send(Request &req, Response &res, Error &error) {
+  return cli_->send(req, res, error);
+}
+
+inline Result Client::send(const Request &req) { return cli_->send(req); }
+
+inline void Client::stop() { cli_->stop(); }
+
+inline std::string Client::host() const { return cli_->host(); }
+
+inline int Client::port() const { return cli_->port(); }
+
+inline size_t Client::is_socket_open() const { return cli_->is_socket_open(); }
+
+inline socket_t Client::socket() const { return cli_->socket(); }
+
+inline void
+Client::set_hostname_addr_map(std::map<std::string, std::string> addr_map) {
+  cli_->set_hostname_addr_map(std::move(addr_map));
+}
+
+inline void Client::set_default_headers(Headers headers) {
+  cli_->set_default_headers(std::move(headers));
+}
+
+inline void Client::set_header_writer(
+    std::function<ssize_t(Stream &, Headers &)> const &writer) {
+  cli_->set_header_writer(writer);
+}
+
+inline void Client::set_address_family(int family) {
+  cli_->set_address_family(family);
+}
+
+inline void Client::set_tcp_nodelay(bool on) { cli_->set_tcp_nodelay(on); }
+
+inline void Client::set_socket_options(SocketOptions socket_options) {
+  cli_->set_socket_options(std::move(socket_options));
+}
+
+inline void Client::set_connection_timeout(time_t sec, time_t usec) {
+  cli_->set_connection_timeout(sec, usec);
+}
+
+inline void Client::set_read_timeout(time_t sec, time_t usec) {
+  cli_->set_read_timeout(sec, usec);
+}
+
+inline void Client::set_write_timeout(time_t sec, time_t usec) {
+  cli_->set_write_timeout(sec, usec);
+}
+
+inline void Client::set_basic_auth(const std::string &username,
+                                   const std::string &password) {
+  cli_->set_basic_auth(username, password);
+}
+inline void Client::set_bearer_token_auth(const std::string &token) {
+  cli_->set_bearer_token_auth(token);
+}
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+inline void Client::set_digest_auth(const std::string &username,
+                                    const std::string &password) {
+  cli_->set_digest_auth(username, password);
+}
+#endif
+
+inline void Client::set_keep_alive(bool on) { cli_->set_keep_alive(on); }
+inline void Client::set_follow_location(bool on) {
+  cli_->set_follow_location(on);
+}
+
+inline void Client::set_url_encode(bool on) { cli_->set_url_encode(on); }
+
+inline void Client::set_compress(bool on) { cli_->set_compress(on); }
+
+inline void Client::set_decompress(bool on) { cli_->set_decompress(on); }
+
+inline void Client::set_interface(const std::string &intf) {
+  cli_->set_interface(intf);
+}
+
+inline void Client::set_proxy(const std::string &host, int port) {
+  cli_->set_proxy(host, port);
+}
+inline void Client::set_proxy_basic_auth(const std::string &username,
+                                         const std::string &password) {
+  cli_->set_proxy_basic_auth(username, password);
+}
+inline void Client::set_proxy_bearer_token_auth(const std::string &token) {
+  cli_->set_proxy_bearer_token_auth(token);
+}
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+inline void Client::set_proxy_digest_auth(const std::string &username,
+                                          const std::string &password) {
+  cli_->set_proxy_digest_auth(username, password);
+}
+#endif
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+inline void Client::enable_server_certificate_verification(bool enabled) {
+  cli_->enable_server_certificate_verification(enabled);
+}
+
+inline void Client::enable_server_hostname_verification(bool enabled) {
+  cli_->enable_server_hostname_verification(enabled);
+}
+
+inline void Client::set_server_certificate_verifier(
+    std::function<bool(SSL *ssl)> verifier) {
+  cli_->set_server_certificate_verifier(verifier);
+}
+#endif
+
+inline void Client::set_logger(Logger logger) {
+  cli_->set_logger(std::move(logger));
+}
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+inline void Client::set_ca_cert_path(const std::string &ca_cert_file_path,
+                                     const std::string &ca_cert_dir_path) {
+  cli_->set_ca_cert_path(ca_cert_file_path, ca_cert_dir_path);
+}
+
+inline void Client::set_ca_cert_store(X509_STORE *ca_cert_store) {
+  if (is_ssl_) {
+    static_cast<SSLClient &>(*cli_).set_ca_cert_store(ca_cert_store);
+  } else {
+    cli_->set_ca_cert_store(ca_cert_store);
+  }
+}
+
+inline void Client::load_ca_cert_store(const char *ca_cert, std::size_t size) {
+  set_ca_cert_store(cli_->create_ca_cert_store(ca_cert, size));
+}
+
+inline long Client::get_openssl_verify_result() const {
+  if (is_ssl_) {
+    return static_cast<SSLClient &>(*cli_).get_openssl_verify_result();
+  }
+  return -1; // NOTE: -1 doesn't match any of X509_V_ERR_???
+}
+
+inline SSL_CTX *Client::ssl_context() const {
+  if (is_ssl_) { return static_cast<SSLClient &>(*cli_).ssl_context(); }
+  return nullptr;
+}
+#endif
+
+// ----------------------------------------------------------------------------
+
+} // namespace httplib
+
+#if defined(_WIN32) && defined(CPPHTTPLIB_USE_POLL)
+#undef poll
+#endif
+
+#endif // CPPHTTPLIB_HTTPLIB_H
diff --git a/benchmark/cpp-httplib-v19/main.cpp b/benchmark/cpp-httplib-v19/main.cpp
new file mode 100644
index 0000000..86070a1
--- /dev/null
+++ b/benchmark/cpp-httplib-v19/main.cpp
@@ -0,0 +1,12 @@
+#include "./httplib.h"
+using namespace httplib;
+
+int main() {
+  Server svr;
+
+  svr.Get("/", [](const Request &, Response &res) {
+    res.set_content("Hello World!", "text/plain");
+  });
+
+  svr.listen("0.0.0.0", 8080);
+}
diff --git a/cmake/httplibConfig.cmake.in b/cmake/httplibConfig.cmake.in
index 93dff32..19dbe69 100644
--- a/cmake/httplibConfig.cmake.in
+++ b/cmake/httplibConfig.cmake.in
@@ -22,9 +22,11 @@ if(@HTTPLIB_IS_USING_OPENSSL@)
 		# Since we use both, we need to search for both.
 		find_dependency(OpenSSL @_HTTPLIB_OPENSSL_MIN_VER@ COMPONENTS Crypto SSL)
 	endif()
+	set(httplib_OpenSSL_FOUND ${OpenSSL_FOUND})
 endif()
 if(@HTTPLIB_IS_USING_ZLIB@)
 	find_dependency(ZLIB)
+	set(httplib_ZLIB_FOUND ${ZLIB_FOUND})
 endif()
 
 if(@HTTPLIB_IS_USING_BROTLI@)
@@ -33,6 +35,30 @@ if(@HTTPLIB_IS_USING_BROTLI@)
 	list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}")
 	set(BROTLI_USE_STATIC_LIBS @BROTLI_USE_STATIC_LIBS@)
 	find_dependency(Brotli COMPONENTS common encoder decoder)
+	set(httplib_Brotli_FOUND ${Brotli_FOUND})
+endif()
+
+if(@HTTPLIB_IS_USING_ZSTD@)
+	set(httplib_fd_zstd_quiet_arg)
+	if(${CMAKE_FIND_PACKAGE_NAME}_FIND_QUIETLY)
+		set(httplib_fd_zstd_quiet_arg QUIET)
+	endif()
+	set(httplib_fd_zstd_required_arg)
+	if(${CMAKE_FIND_PACKAGE_NAME}_FIND_REQUIRED)
+		set(httplib_fd_zstd_required_arg REQUIRED)
+	endif()
+	find_package(zstd QUIET)
+	if(NOT zstd_FOUND)
+		find_package(PkgConfig ${httplib_fd_zstd_quiet_arg} ${httplib_fd_zstd_required_arg})
+		if(PKG_CONFIG_FOUND)
+			pkg_check_modules(zstd ${httplib_fd_zstd_quiet_arg} ${httplib_fd_zstd_required_arg} IMPORTED_TARGET libzstd)
+
+			if(TARGET PkgConfig::zstd)
+				add_library(zstd::libzstd ALIAS PkgConfig::zstd)
+			endif()
+		endif()
+	endif()
+	set(httplib_zstd_FOUND ${zstd_FOUND})
 endif()
 
 # Mildly useful for end-users
@@ -42,11 +68,6 @@ set_and_check(HTTPLIB_INCLUDE_DIR "@PACKAGE_CMAKE_INSTALL_FULL_INCLUDEDIR@")
 # This is helpful if you're using Cmake's pre-compiled header feature
 set_and_check(HTTPLIB_HEADER_PATH "@PACKAGE_CMAKE_INSTALL_FULL_INCLUDEDIR@/httplib.h")
 
-# Consider each library support as a "component"
-set(httplib_OpenSSL_FOUND @HTTPLIB_IS_USING_OPENSSL@)
-set(httplib_ZLIB_FOUND @HTTPLIB_IS_USING_ZLIB@)
-set(httplib_Brotli_FOUND @HTTPLIB_IS_USING_BROTLI@)
-
 check_required_components(httplib)
 
 # Brings in the target library, but only if all required components are found
diff --git a/docker/main.cc b/docker/main.cc
index 512b266..62d0c74 100644
--- a/docker/main.cc
+++ b/docker/main.cc
@@ -1,7 +1,7 @@
 //
 //  main.cc
 //
-//  Copyright (c) 2024 Yuji Hirose. All rights reserved.
+//  Copyright (c) 2025 Yuji Hirose. All rights reserved.
 //  MIT License
 //
 
@@ -41,7 +41,7 @@ std::string log(auto &req, auto &res) {
   auto http_referer = "-"; // TODO:
   auto http_user_agent = req.get_header_value("User-Agent", "-");
 
-  // NOTE: From NGINX defualt access log format
+  // NOTE: From NGINX default access log format
   // log_format combined '$remote_addr - $remote_user [$time_local] '
   //                     '"$request" $status $body_bytes_sent '
   //                     '"$http_referer" "$http_user_agent"';
diff --git a/example/server_and_client.cc b/example/server_and_client.cc
index 66cb8b6..34bf852 100644
--- a/example/server_and_client.cc
+++ b/example/server_and_client.cc
@@ -1,7 +1,7 @@
 //
 //  server_and_client.cc
 //
-//  Copyright (c) 2024 Yuji Hirose. All rights reserved.
+//  Copyright (c) 2025 Yuji Hirose. All rights reserved.
 //  MIT License
 //
 
diff --git a/example/ssesvr.cc b/example/ssesvr.cc
index 5b0e0b9..547b864 100644
--- a/example/ssesvr.cc
+++ b/example/ssesvr.cc
@@ -12,8 +12,7 @@ using namespace std;
 
 class EventDispatcher {
 public:
-  EventDispatcher() {
-  }
+  EventDispatcher() {}
 
   void wait_event(DataSink *sink) {
     unique_lock<mutex> lk(m_);
diff --git a/httplib.h b/httplib.h
index 47cceeb..ae4507d 100644
--- a/httplib.h
+++ b/httplib.h
@@ -1,14 +1,14 @@
 //
 //  httplib.h
 //
-//  Copyright (c) 2024 Yuji Hirose. All rights reserved.
+//  Copyright (c) 2025 Yuji Hirose. All rights reserved.
 //  MIT License
 //
 
 #ifndef CPPHTTPLIB_HTTPLIB_H
 #define CPPHTTPLIB_HTTPLIB_H
 
-#define CPPHTTPLIB_VERSION "0.18.4"
+#define CPPHTTPLIB_VERSION "0.20.1"
 
 /*
  * Configuration
@@ -66,6 +66,10 @@
 #define CPPHTTPLIB_CLIENT_WRITE_TIMEOUT_USECOND 0
 #endif
 
+#ifndef CPPHTTPLIB_CLIENT_MAX_TIMEOUT_MSECOND
+#define CPPHTTPLIB_CLIENT_MAX_TIMEOUT_MSECOND 0
+#endif
+
 #ifndef CPPHTTPLIB_IDLE_INTERVAL_SECOND
 #define CPPHTTPLIB_IDLE_INTERVAL_SECOND 0
 #endif
@@ -141,6 +145,10 @@
 #define CPPHTTPLIB_LISTEN_BACKLOG 5
 #endif
 
+#ifndef CPPHTTPLIB_MAX_LINE_LENGTH
+#define CPPHTTPLIB_MAX_LINE_LENGTH 32768
+#endif
+
 /*
  * Headers
  */
@@ -184,14 +192,16 @@ using ssize_t = long;
 #include <winsock2.h>
 #include <ws2tcpip.h>
 
+// afunix.h uses types declared in winsock2.h, so has to be included after it.
+#include <afunix.h>
+
 #ifndef WSA_FLAG_NO_HANDLE_INHERIT
 #define WSA_FLAG_NO_HANDLE_INHERIT 0x80
 #endif
 
+using nfds_t = unsigned long;
 using socket_t = SOCKET;
-#ifdef CPPHTTPLIB_USE_POLL
-#define poll(fds, nfds, timeout) WSAPoll(fds, nfds, timeout)
-#endif
+using socklen_t = int;
 
 #else // not _WIN32
 
@@ -211,14 +221,11 @@ using socket_t = SOCKET;
 #ifdef __linux__
 #include <resolv.h>
 #endif
-#include <netinet/tcp.h>
-#ifdef CPPHTTPLIB_USE_POLL
-#include <poll.h>
-#endif
 #include <csignal>
+#include <netinet/tcp.h>
+#include <poll.h>
 #include <pthread.h>
 #include <sys/mman.h>
-#include <sys/select.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <unistd.h>
@@ -240,7 +247,6 @@ using socket_t = int;
 #include <errno.h>
 #include <exception>
 #include <fcntl.h>
-#include <fstream>
 #include <functional>
 #include <iomanip>
 #include <iostream>
@@ -313,6 +319,10 @@ using socket_t = int;
 #include <brotli/encode.h>
 #endif
 
+#ifdef CPPHTTPLIB_ZSTD_SUPPORT
+#include <zstd.h>
+#endif
+
 /*
  * Declaration
  */
@@ -428,6 +438,15 @@ private:
 
 } // namespace detail
 
+enum SSLVerifierResponse {
+  // no decision has been made, use the built-in certificate verifier
+  NoDecisionMade,
+  // connection certificate is verified and accepted
+  CertificateAccepted,
+  // connection certificate was processed but is rejected
+  CertificateRejected
+};
+
 enum StatusCode {
   // Information responses
   Continue_100 = 100,
@@ -628,6 +647,7 @@ struct Request {
   Ranges ranges;
   Match matches;
   std::unordered_map<std::string, std::string> path_params;
+  std::function<bool()> is_connection_closed = []() { return true; };
 
   // for client
   ResponseHandler response_handler;
@@ -661,6 +681,8 @@ struct Request {
   ContentProvider content_provider_;
   bool is_chunked_content_provider_ = false;
   size_t authorization_count_ = 0;
+  std::chrono::time_point<std::chrono::steady_clock> start_time_ =
+      (std::chrono::steady_clock::time_point::min)();
 };
 
 struct Response {
@@ -726,7 +748,8 @@ public:
   virtual ~Stream() = default;
 
   virtual bool is_readable() const = 0;
-  virtual bool is_writable() const = 0;
+  virtual bool wait_readable() const = 0;
+  virtual bool wait_writable() const = 0;
 
   virtual ssize_t read(char *ptr, size_t size) = 0;
   virtual ssize_t write(const char *ptr, size_t size) = 0;
@@ -734,6 +757,8 @@ public:
   virtual void get_local_ip_and_port(std::string &ip, int &port) const = 0;
   virtual socket_t socket() const = 0;
 
+  virtual time_t duration() const = 0;
+
   ssize_t write(const char *ptr);
   ssize_t write(const std::string &s);
 };
@@ -837,6 +862,16 @@ using Logger = std::function<void(const Request &, const Response &)>;
 
 using SocketOptions = std::function<void(socket_t sock)>;
 
+namespace detail {
+
+bool set_socket_opt_impl(socket_t sock, int level, int optname,
+                         const void *optval, socklen_t optlen);
+bool set_socket_opt(socket_t sock, int level, int optname, int opt);
+bool set_socket_opt_time(socket_t sock, int level, int optname, time_t sec,
+                         time_t usec);
+
+} // namespace detail
+
 void default_socket_options(socket_t sock);
 
 const char *status_message(int status);
@@ -857,7 +892,7 @@ public:
  * Captures parameters in request path and stores them in Request::path_params
  *
  * Capture name is a substring of a pattern from : to /.
- * The rest of the pattern is matched agains the request path directly
+ * The rest of the pattern is matched against the request path directly
  * Parameters are captured starting from the next character after
  * the end of the last matched static pattern fragment until the next /.
  *
@@ -1052,8 +1087,7 @@ private:
   bool listen_internal();
 
   bool routing(Request &req, Response &res, Stream &strm);
-  bool handle_file_request(const Request &req, Response &res,
-                           bool head = false);
+  bool handle_file_request(const Request &req, Response &res);
   bool dispatch_request(Request &req, Response &res,
                         const Handlers &handlers) const;
   bool dispatch_request_for_content_reader(
@@ -1087,7 +1121,7 @@ private:
   virtual bool process_and_close_socket(socket_t sock);
 
   std::atomic<bool> is_running_{false};
-  std::atomic<bool> is_decommisioned{false};
+  std::atomic<bool> is_decommissioned{false};
 
   struct MountPointEntry {
     std::string mount_point;
@@ -1420,6 +1454,10 @@ public:
   template <class Rep, class Period>
   void set_write_timeout(const std::chrono::duration<Rep, Period> &duration);
 
+  void set_max_timeout(time_t msec);
+  template <class Rep, class Period>
+  void set_max_timeout(const std::chrono::duration<Rep, Period> &duration);
+
   void set_basic_auth(const std::string &username, const std::string &password);
   void set_bearer_token_auth(const std::string &token);
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
@@ -1457,7 +1495,8 @@ public:
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
   void enable_server_certificate_verification(bool enabled);
   void enable_server_hostname_verification(bool enabled);
-  void set_server_certificate_verifier(std::function<bool(SSL *ssl)> verifier);
+  void set_server_certificate_verifier(
+      std::function<SSLVerifierResponse(SSL *ssl)> verifier);
 #endif
 
   void set_logger(Logger logger);
@@ -1528,6 +1567,7 @@ protected:
   time_t read_timeout_usec_ = CPPHTTPLIB_CLIENT_READ_TIMEOUT_USECOND;
   time_t write_timeout_sec_ = CPPHTTPLIB_CLIENT_WRITE_TIMEOUT_SECOND;
   time_t write_timeout_usec_ = CPPHTTPLIB_CLIENT_WRITE_TIMEOUT_USECOND;
+  time_t max_timeout_msec_ = CPPHTTPLIB_CLIENT_MAX_TIMEOUT_MSECOND;
 
   std::string basic_auth_username_;
   std::string basic_auth_password_;
@@ -1573,7 +1613,7 @@ protected:
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
   bool server_certificate_verification_ = true;
   bool server_hostname_verification_ = true;
-  std::function<bool(SSL *ssl)> server_certificate_verifier_;
+  std::function<SSLVerifierResponse(SSL *ssl)> server_certificate_verifier_;
 #endif
 
   Logger logger_;
@@ -1582,9 +1622,6 @@ private:
   bool send_(Request &req, Response &res, Error &error);
   Result send_(Request &&req);
 
-#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
-  bool is_ssl_peer_could_be_closed(SSL *ssl) const;
-#endif
   socket_t create_client_socket(Error &error) const;
   bool read_response_line(Stream &strm, const Request &req,
                           Response &res) const;
@@ -1610,8 +1647,10 @@ private:
 
   std::string adjust_host_string(const std::string &host) const;
 
-  virtual bool process_socket(const Socket &socket,
-                              std::function<bool(Stream &strm)> callback);
+  virtual bool
+  process_socket(const Socket &socket,
+                 std::chrono::time_point<std::chrono::steady_clock> start_time,
+                 std::function<bool(Stream &strm)> callback);
   virtual bool is_ssl() const;
 };
 
@@ -1853,6 +1892,10 @@ public:
   template <class Rep, class Period>
   void set_write_timeout(const std::chrono::duration<Rep, Period> &duration);
 
+  void set_max_timeout(time_t msec);
+  template <class Rep, class Period>
+  void set_max_timeout(const std::chrono::duration<Rep, Period> &duration);
+
   void set_basic_auth(const std::string &username, const std::string &password);
   void set_bearer_token_auth(const std::string &token);
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
@@ -1883,7 +1926,8 @@ public:
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
   void enable_server_certificate_verification(bool enabled);
   void enable_server_hostname_verification(bool enabled);
-  void set_server_certificate_verifier(std::function<bool(SSL *ssl)> verifier);
+  void set_server_certificate_verifier(
+      std::function<SSLVerifierResponse(SSL *ssl)> verifier);
 #endif
 
   void set_logger(Logger logger);
@@ -1970,12 +2014,16 @@ private:
   void shutdown_ssl(Socket &socket, bool shutdown_gracefully) override;
   void shutdown_ssl_impl(Socket &socket, bool shutdown_gracefully);
 
-  bool process_socket(const Socket &socket,
-                      std::function<bool(Stream &strm)> callback) override;
+  bool
+  process_socket(const Socket &socket,
+                 std::chrono::time_point<std::chrono::steady_clock> start_time,
+                 std::function<bool(Stream &strm)> callback) override;
   bool is_ssl() const override;
 
-  bool connect_with_proxy(Socket &sock, Response &res, bool &success,
-                          Error &error);
+  bool connect_with_proxy(
+      Socket &sock,
+      std::chrono::time_point<std::chrono::steady_clock> start_time,
+      Response &res, bool &success, Error &error);
   bool initialize_ssl(Socket &socket, Error &error);
 
   bool load_certs();
@@ -2012,18 +2060,40 @@ inline void duration_to_sec_and_usec(const T &duration, U callback) {
   callback(static_cast<time_t>(sec), static_cast<time_t>(usec));
 }
 
+template <size_t N> inline constexpr size_t str_len(const char (&)[N]) {
+  return N - 1;
+}
+
+inline bool is_numeric(const std::string &str) {
+  return !str.empty() &&
+         std::all_of(str.cbegin(), str.cend(),
+                     [](unsigned char c) { return std::isdigit(c); });
+}
+
 inline uint64_t get_header_value_u64(const Headers &headers,
                                      const std::string &key, uint64_t def,
-                                     size_t id) {
+                                     size_t id, bool &is_invalid_value) {
+  is_invalid_value = false;
   auto rng = headers.equal_range(key);
   auto it = rng.first;
   std::advance(it, static_cast<ssize_t>(id));
   if (it != rng.second) {
-    return std::strtoull(it->second.data(), nullptr, 10);
+    if (is_numeric(it->second)) {
+      return std::strtoull(it->second.data(), nullptr, 10);
+    } else {
+      is_invalid_value = true;
+    }
   }
   return def;
 }
 
+inline uint64_t get_header_value_u64(const Headers &headers,
+                                     const std::string &key, uint64_t def,
+                                     size_t id) {
+  bool dummy = false;
+  return get_header_value_u64(headers, key, def, id, dummy);
+}
+
 } // namespace detail
 
 inline uint64_t Request::get_header_value_u64(const std::string &key,
@@ -2036,22 +2106,45 @@ inline uint64_t Response::get_header_value_u64(const std::string &key,
   return detail::get_header_value_u64(headers, key, def, id);
 }
 
-inline void default_socket_options(socket_t sock) {
-  int opt = 1;
+namespace detail {
+
+inline bool set_socket_opt_impl(socket_t sock, int level, int optname,
+                                const void *optval, socklen_t optlen) {
+  return setsockopt(sock, level, optname,
 #ifdef _WIN32
-  setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
-             reinterpret_cast<const char *>(&opt), sizeof(opt));
-  setsockopt(sock, SOL_SOCKET, SO_EXCLUSIVEADDRUSE,
-             reinterpret_cast<const char *>(&opt), sizeof(opt));
+                    reinterpret_cast<const char *>(optval),
 #else
+                    optval,
+#endif
+                    optlen) == 0;
+}
+
+inline bool set_socket_opt(socket_t sock, int level, int optname, int optval) {
+  return set_socket_opt_impl(sock, level, optname, &optval, sizeof(optval));
+}
+
+inline bool set_socket_opt_time(socket_t sock, int level, int optname,
+                                time_t sec, time_t usec) {
+#ifdef _WIN32
+  auto timeout = static_cast<uint32_t>(sec * 1000 + usec / 1000);
+#else
+  timeval timeout;
+  timeout.tv_sec = static_cast<long>(sec);
+  timeout.tv_usec = static_cast<decltype(timeout.tv_usec)>(usec);
+#endif
+  return set_socket_opt_impl(sock, level, optname, &timeout, sizeof(timeout));
+}
+
+} // namespace detail
+
+inline void default_socket_options(socket_t sock) {
+  detail::set_socket_opt(sock, SOL_SOCKET,
 #ifdef SO_REUSEPORT
-  setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
-             reinterpret_cast<const void *>(&opt), sizeof(opt));
+                         SO_REUSEPORT,
 #else
-  setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
-             reinterpret_cast<const void *>(&opt), sizeof(opt));
-#endif
+                         SO_REUSEADDR,
 #endif
+                         1);
 }
 
 inline const char *status_message(int status) {
@@ -2132,9 +2225,9 @@ inline const char *status_message(int status) {
 
 inline std::string get_bearer_token_auth(const Request &req) {
   if (req.has_header("Authorization")) {
-    static std::string BearerHeaderPrefix = "Bearer ";
+    constexpr auto bearer_header_prefix_len = detail::str_len("Bearer ");
     return req.get_header_value("Authorization")
-        .substr(BearerHeaderPrefix.length());
+        .substr(bearer_header_prefix_len);
   }
   return "";
 }
@@ -2223,6 +2316,14 @@ inline void ClientImpl::set_write_timeout(
       duration, [&](time_t sec, time_t usec) { set_write_timeout(sec, usec); });
 }
 
+template <class Rep, class Period>
+inline void ClientImpl::set_max_timeout(
+    const std::chrono::duration<Rep, Period> &duration) {
+  auto msec =
+      std::chrono::duration_cast<std::chrono::milliseconds>(duration).count();
+  set_max_timeout(msec);
+}
+
 template <class Rep, class Period>
 inline void Client::set_connection_timeout(
     const std::chrono::duration<Rep, Period> &duration) {
@@ -2241,6 +2342,12 @@ Client::set_write_timeout(const std::chrono::duration<Rep, Period> &duration) {
   cli_->set_write_timeout(duration);
 }
 
+template <class Rep, class Period>
+inline void
+Client::set_max_timeout(const std::chrono::duration<Rep, Period> &duration) {
+  cli_->set_max_timeout(duration);
+}
+
 /*
  * Forward declarations and types that will be part of the .h file if split into
  * .h + .cc.
@@ -2295,8 +2402,6 @@ std::string encode_query_param(const std::string &value);
 
 std::string decode_url(const std::string &s, bool convert_plus_to_space);
 
-void read_file(const std::string &path, std::string &out);
-
 std::string trim_copy(const std::string &s);
 
 void divide(
@@ -2315,10 +2420,12 @@ void split(const char *b, const char *e, char d,
 void split(const char *b, const char *e, char d, size_t m,
            std::function<void(const char *, const char *)> fn);
 
-bool process_client_socket(socket_t sock, time_t read_timeout_sec,
-                           time_t read_timeout_usec, time_t write_timeout_sec,
-                           time_t write_timeout_usec,
-                           std::function<bool(Stream &)> callback);
+bool process_client_socket(
+    socket_t sock, time_t read_timeout_sec, time_t read_timeout_usec,
+    time_t write_timeout_sec, time_t write_timeout_usec,
+    time_t max_timeout_msec,
+    std::chrono::time_point<std::chrono::steady_clock> start_time,
+    std::function<bool(Stream &)> callback);
 
 socket_t create_client_socket(const std::string &host, const std::string &ip,
                               int port, int address_family, bool tcp_nodelay,
@@ -2350,7 +2457,7 @@ ssize_t send_socket(socket_t sock, const void *ptr, size_t size, int flags);
 
 ssize_t read_socket(socket_t sock, void *ptr, size_t size, int flags);
 
-enum class EncodingType { None = 0, Gzip, Brotli };
+enum class EncodingType { None = 0, Gzip, Brotli, Zstd };
 
 EncodingType encoding_type(const Request &req, const Response &res);
 
@@ -2360,12 +2467,14 @@ public:
   ~BufferStream() override = default;
 
   bool is_readable() const override;
-  bool is_writable() const override;
+  bool wait_readable() const override;
+  bool wait_writable() const override;
   ssize_t read(char *ptr, size_t size) override;
   ssize_t write(const char *ptr, size_t size) override;
   void get_remote_ip_and_port(std::string &ip, int &port) const override;
   void get_local_ip_and_port(std::string &ip, int &port) const override;
   socket_t socket() const override;
+  time_t duration() const override;
 
   const std::string &get_buffer() const;
 
@@ -2461,6 +2570,34 @@ private:
 };
 #endif
 
+#ifdef CPPHTTPLIB_ZSTD_SUPPORT
+class zstd_compressor : public compressor {
+public:
+  zstd_compressor();
+  ~zstd_compressor();
+
+  bool compress(const char *data, size_t data_length, bool last,
+                Callback callback) override;
+
+private:
+  ZSTD_CCtx *ctx_ = nullptr;
+};
+
+class zstd_decompressor : public decompressor {
+public:
+  zstd_decompressor();
+  ~zstd_decompressor();
+
+  bool is_valid() const override;
+
+  bool decompress(const char *data, size_t data_length,
+                  Callback callback) override;
+
+private:
+  ZSTD_DCtx *ctx_ = nullptr;
+};
+#endif
+
 // NOTE: until the read size reaches `fixed_buffer_size`, use `fixed_buffer`
 // to store data. The call can set memory on stack for performance.
 class stream_line_reader {
@@ -2479,7 +2616,7 @@ private:
   char *fixed_buffer_;
   const size_t fixed_buffer_size_;
   size_t fixed_buffer_used_size_ = 0;
-  std::string glowable_buffer_;
+  std::string growable_buffer_;
 };
 
 class mmap {
@@ -2532,7 +2669,7 @@ inline bool is_obs_text(char c) { return 128 <= static_cast<unsigned char>(c); }
 inline bool is_field_vchar(char c) { return is_vchar(c) || is_obs_text(c); }
 
 inline bool is_field_content(const std::string &s) {
-  if (s.empty()) { return false; }
+  if (s.empty()) { return true; }
 
   if (s.size() == 1) {
     return is_field_vchar(s[0]);
@@ -2558,7 +2695,7 @@ inline bool is_field_content(const std::string &s) {
 
 inline bool is_field_value(const std::string &s) { return is_field_content(s); }
 
-}; // namespace fields
+} // namespace fields
 
 } // namespace detail
 
@@ -2820,18 +2957,9 @@ inline std::string decode_url(const std::string &s,
   return result;
 }
 
-inline void read_file(const std::string &path, std::string &out) {
-  std::ifstream fs(path, std::ios_base::binary);
-  fs.seekg(0, std::ios_base::end);
-  auto size = fs.tellg();
-  fs.seekg(0);
-  out.resize(static_cast<size_t>(size));
-  fs.read(&out[0], static_cast<std::streamsize>(size));
-}
-
 inline std::string file_extension(const std::string &path) {
   std::smatch m;
-  static auto re = std::regex("\\.([a-zA-Z0-9]+)$");
+  thread_local auto re = std::regex("\\.([a-zA-Z0-9]+)$");
   if (std::regex_search(path, m, re)) { return m[1].str(); }
   return std::string();
 }
@@ -2915,18 +3043,18 @@ inline stream_line_reader::stream_line_reader(Stream &strm, char *fixed_buffer,
       fixed_buffer_size_(fixed_buffer_size) {}
 
 inline const char *stream_line_reader::ptr() const {
-  if (glowable_buffer_.empty()) {
+  if (growable_buffer_.empty()) {
     return fixed_buffer_;
   } else {
-    return glowable_buffer_.data();
+    return growable_buffer_.data();
   }
 }
 
 inline size_t stream_line_reader::size() const {
-  if (glowable_buffer_.empty()) {
+  if (growable_buffer_.empty()) {
     return fixed_buffer_used_size_;
   } else {
-    return glowable_buffer_.size();
+    return growable_buffer_.size();
   }
 }
 
@@ -2937,13 +3065,18 @@ inline bool stream_line_reader::end_with_crlf() const {
 
 inline bool stream_line_reader::getline() {
   fixed_buffer_used_size_ = 0;
-  glowable_buffer_.clear();
+  growable_buffer_.clear();
 
 #ifndef CPPHTTPLIB_ALLOW_LF_AS_LINE_TERMINATOR
   char prev_byte = 0;
 #endif
 
   for (size_t i = 0;; i++) {
+    if (size() >= CPPHTTPLIB_MAX_LINE_LENGTH) {
+      // Treat exceptionally long lines as an error to
+      // prevent infinite loops/memory exhaustion
+      return false;
+    }
     char byte;
     auto n = strm_.read(&byte, 1);
 
@@ -2975,11 +3108,11 @@ inline void stream_line_reader::append(char c) {
     fixed_buffer_[fixed_buffer_used_size_++] = c;
     fixed_buffer_[fixed_buffer_used_size_] = '\0';
   } else {
-    if (glowable_buffer_.empty()) {
+    if (growable_buffer_.empty()) {
       assert(fixed_buffer_[fixed_buffer_used_size_] == '\0');
-      glowable_buffer_.assign(fixed_buffer_, fixed_buffer_used_size_);
+      growable_buffer_.assign(fixed_buffer_, fixed_buffer_used_size_);
     }
-    glowable_buffer_ += c;
+    growable_buffer_ += c;
   }
 }
 
@@ -3156,72 +3289,43 @@ inline ssize_t send_socket(socket_t sock, const void *ptr, size_t size,
   });
 }
 
-inline ssize_t select_read(socket_t sock, time_t sec, time_t usec) {
-#ifdef CPPHTTPLIB_USE_POLL
-  struct pollfd pfd_read;
-  pfd_read.fd = sock;
-  pfd_read.events = POLLIN;
-
-  auto timeout = static_cast<int>(sec * 1000 + usec / 1000);
-
-  return handle_EINTR([&]() { return poll(&pfd_read, 1, timeout); });
+inline int poll_wrapper(struct pollfd *fds, nfds_t nfds, int timeout) {
+#ifdef _WIN32
+  return ::WSAPoll(fds, nfds, timeout);
 #else
-#ifndef _WIN32
-  if (sock >= FD_SETSIZE) { return -1; }
-#endif
-
-  fd_set fds;
-  FD_ZERO(&fds);
-  FD_SET(sock, &fds);
-
-  timeval tv;
-  tv.tv_sec = static_cast<long>(sec);
-  tv.tv_usec = static_cast<decltype(tv.tv_usec)>(usec);
-
-  return handle_EINTR([&]() {
-    return select(static_cast<int>(sock + 1), &fds, nullptr, nullptr, &tv);
-  });
+  return ::poll(fds, nfds, timeout);
 #endif
 }
 
-inline ssize_t select_write(socket_t sock, time_t sec, time_t usec) {
-#ifdef CPPHTTPLIB_USE_POLL
-  struct pollfd pfd_read;
-  pfd_read.fd = sock;
-  pfd_read.events = POLLOUT;
+template <bool Read>
+inline ssize_t select_impl(socket_t sock, time_t sec, time_t usec) {
+  struct pollfd pfd;
+  pfd.fd = sock;
+  pfd.events = (Read ? POLLIN : POLLOUT);
 
   auto timeout = static_cast<int>(sec * 1000 + usec / 1000);
 
-  return handle_EINTR([&]() { return poll(&pfd_read, 1, timeout); });
-#else
-#ifndef _WIN32
-  if (sock >= FD_SETSIZE) { return -1; }
-#endif
+  return handle_EINTR([&]() { return poll_wrapper(&pfd, 1, timeout); });
+}
 
-  fd_set fds;
-  FD_ZERO(&fds);
-  FD_SET(sock, &fds);
+inline ssize_t select_read(socket_t sock, time_t sec, time_t usec) {
+  return select_impl<true>(sock, sec, usec);
+}
 
-  timeval tv;
-  tv.tv_sec = static_cast<long>(sec);
-  tv.tv_usec = static_cast<decltype(tv.tv_usec)>(usec);
-
-  return handle_EINTR([&]() {
-    return select(static_cast<int>(sock + 1), nullptr, &fds, nullptr, &tv);
-  });
-#endif
+inline ssize_t select_write(socket_t sock, time_t sec, time_t usec) {
+  return select_impl<false>(sock, sec, usec);
 }
 
 inline Error wait_until_socket_is_ready(socket_t sock, time_t sec,
                                         time_t usec) {
-#ifdef CPPHTTPLIB_USE_POLL
   struct pollfd pfd_read;
   pfd_read.fd = sock;
   pfd_read.events = POLLIN | POLLOUT;
 
   auto timeout = static_cast<int>(sec * 1000 + usec / 1000);
 
-  auto poll_res = handle_EINTR([&]() { return poll(&pfd_read, 1, timeout); });
+  auto poll_res =
+      handle_EINTR([&]() { return poll_wrapper(&pfd_read, 1, timeout); });
 
   if (poll_res == 0) { return Error::ConnectionTimeout; }
 
@@ -3235,38 +3339,6 @@ inline Error wait_until_socket_is_ready(socket_t sock, time_t sec,
   }
 
   return Error::Connection;
-#else
-#ifndef _WIN32
-  if (sock >= FD_SETSIZE) { return Error::Connection; }
-#endif
-
-  fd_set fdsr;
-  FD_ZERO(&fdsr);
-  FD_SET(sock, &fdsr);
-
-  auto fdsw = fdsr;
-  auto fdse = fdsr;
-
-  timeval tv;
-  tv.tv_sec = static_cast<long>(sec);
-  tv.tv_usec = static_cast<decltype(tv.tv_usec)>(usec);
-
-  auto ret = handle_EINTR([&]() {
-    return select(static_cast<int>(sock + 1), &fdsr, &fdsw, &fdse, &tv);
-  });
-
-  if (ret == 0) { return Error::ConnectionTimeout; }
-
-  if (ret > 0 && (FD_ISSET(sock, &fdsr) || FD_ISSET(sock, &fdsw))) {
-    auto error = 0;
-    socklen_t len = sizeof(error);
-    auto res = getsockopt(sock, SOL_SOCKET, SO_ERROR,
-                          reinterpret_cast<char *>(&error), &len);
-    auto successful = res >= 0 && !error;
-    return successful ? Error::Success : Error::Connection;
-  }
-  return Error::Connection;
-#endif
 }
 
 inline bool is_socket_alive(socket_t sock) {
@@ -3283,16 +3355,21 @@ inline bool is_socket_alive(socket_t sock) {
 class SocketStream final : public Stream {
 public:
   SocketStream(socket_t sock, time_t read_timeout_sec, time_t read_timeout_usec,
-               time_t write_timeout_sec, time_t write_timeout_usec);
+               time_t write_timeout_sec, time_t write_timeout_usec,
+               time_t max_timeout_msec = 0,
+               std::chrono::time_point<std::chrono::steady_clock> start_time =
+                   (std::chrono::steady_clock::time_point::min)());
   ~SocketStream() override;
 
   bool is_readable() const override;
-  bool is_writable() const override;
+  bool wait_readable() const override;
+  bool wait_writable() const override;
   ssize_t read(char *ptr, size_t size) override;
   ssize_t write(const char *ptr, size_t size) override;
   void get_remote_ip_and_port(std::string &ip, int &port) const override;
   void get_local_ip_and_port(std::string &ip, int &port) const override;
   socket_t socket() const override;
+  time_t duration() const override;
 
 private:
   socket_t sock_;
@@ -3300,6 +3377,8 @@ private:
   time_t read_timeout_usec_;
   time_t write_timeout_sec_;
   time_t write_timeout_usec_;
+  time_t max_timeout_msec_;
+  const std::chrono::time_point<std::chrono::steady_clock> start_time_;
 
   std::vector<char> read_buff_;
   size_t read_buff_off_ = 0;
@@ -3311,18 +3390,23 @@ private:
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
 class SSLSocketStream final : public Stream {
 public:
-  SSLSocketStream(socket_t sock, SSL *ssl, time_t read_timeout_sec,
-                  time_t read_timeout_usec, time_t write_timeout_sec,
-                  time_t write_timeout_usec);
+  SSLSocketStream(
+      socket_t sock, SSL *ssl, time_t read_timeout_sec,
+      time_t read_timeout_usec, time_t write_timeout_sec,
+      time_t write_timeout_usec, time_t max_timeout_msec = 0,
+      std::chrono::time_point<std::chrono::steady_clock> start_time =
+          (std::chrono::steady_clock::time_point::min)());
   ~SSLSocketStream() override;
 
   bool is_readable() const override;
-  bool is_writable() const override;
+  bool wait_readable() const override;
+  bool wait_writable() const override;
   ssize_t read(char *ptr, size_t size) override;
   ssize_t write(const char *ptr, size_t size) override;
   void get_remote_ip_and_port(std::string &ip, int &port) const override;
   void get_local_ip_and_port(std::string &ip, int &port) const override;
   socket_t socket() const override;
+  time_t duration() const override;
 
 private:
   socket_t sock_;
@@ -3331,6 +3415,8 @@ private:
   time_t read_timeout_usec_;
   time_t write_timeout_sec_;
   time_t write_timeout_usec_;
+  time_t max_timeout_msec_;
+  const std::chrono::time_point<std::chrono::steady_clock> start_time_;
 };
 #endif
 
@@ -3401,13 +3487,15 @@ process_server_socket(const std::atomic<socket_t> &svr_sock, socket_t sock,
       });
 }
 
-inline bool process_client_socket(socket_t sock, time_t read_timeout_sec,
-                                  time_t read_timeout_usec,
-                                  time_t write_timeout_sec,
-                                  time_t write_timeout_usec,
-                                  std::function<bool(Stream &)> callback) {
+inline bool process_client_socket(
+    socket_t sock, time_t read_timeout_sec, time_t read_timeout_usec,
+    time_t write_timeout_sec, time_t write_timeout_usec,
+    time_t max_timeout_msec,
+    std::chrono::time_point<std::chrono::steady_clock> start_time,
+    std::function<bool(Stream &)> callback) {
   SocketStream strm(sock, read_timeout_sec, read_timeout_usec,
-                    write_timeout_sec, write_timeout_usec);
+                    write_timeout_sec, write_timeout_usec, max_timeout_msec,
+                    start_time);
   return callback(strm);
 }
 
@@ -3463,7 +3551,6 @@ socket_t create_socket(const std::string &host, const std::string &ip, int port,
     hints.ai_flags = socket_flags;
   }
 
-#ifndef _WIN32
   if (hints.ai_family == AF_UNIX) {
     const auto addrlen = host.length();
     if (addrlen > sizeof(sockaddr_un::sun_path)) { return INVALID_SOCKET; }
@@ -3487,11 +3574,19 @@ socket_t create_socket(const std::string &host, const std::string &ip, int port,
           sizeof(addr) - sizeof(addr.sun_path) + addrlen);
 
 #ifndef SOCK_CLOEXEC
+#ifndef _WIN32
       fcntl(sock, F_SETFD, FD_CLOEXEC);
+#endif
 #endif
 
       if (socket_options) { socket_options(sock); }
 
+#ifdef _WIN32
+      // Setting SO_REUSEADDR seems not to work well with AF_UNIX on windows, so
+      // remove the option.
+      detail::set_socket_opt(sock, SOL_SOCKET, SO_REUSEADDR, 0);
+#endif
+
       bool dummy;
       if (!bind_or_connect(sock, hints, dummy)) {
         close_socket(sock);
@@ -3500,7 +3595,6 @@ socket_t create_socket(const std::string &host, const std::string &ip, int port,
     }
     return sock;
   }
-#endif
 
   auto service = std::to_string(port);
 
@@ -3554,26 +3648,10 @@ socket_t create_socket(const std::string &host, const std::string &ip, int port,
     }
 #endif
 
-    if (tcp_nodelay) {
-      auto opt = 1;
-#ifdef _WIN32
-      setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
-                 reinterpret_cast<const char *>(&opt), sizeof(opt));
-#else
-      setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
-                 reinterpret_cast<const void *>(&opt), sizeof(opt));
-#endif
-    }
+    if (tcp_nodelay) { set_socket_opt(sock, IPPROTO_TCP, TCP_NODELAY, 1); }
 
     if (rp->ai_family == AF_INET6) {
-      auto opt = ipv6_v6only ? 1 : 0;
-#ifdef _WIN32
-      setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
-                 reinterpret_cast<const char *>(&opt), sizeof(opt));
-#else
-      setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
-                 reinterpret_cast<const void *>(&opt), sizeof(opt));
-#endif
+      set_socket_opt(sock, IPPROTO_IPV6, IPV6_V6ONLY, ipv6_v6only ? 1 : 0);
     }
 
     if (socket_options) { socket_options(sock); }
@@ -3716,36 +3794,10 @@ inline socket_t create_client_socket(
         }
 
         set_nonblocking(sock2, false);
-
-        {
-#ifdef _WIN32
-          auto timeout = static_cast<uint32_t>(read_timeout_sec * 1000 +
-                                               read_timeout_usec / 1000);
-          setsockopt(sock2, SOL_SOCKET, SO_RCVTIMEO,
-                     reinterpret_cast<const char *>(&timeout), sizeof(timeout));
-#else
-          timeval tv;
-          tv.tv_sec = static_cast<long>(read_timeout_sec);
-          tv.tv_usec = static_cast<decltype(tv.tv_usec)>(read_timeout_usec);
-          setsockopt(sock2, SOL_SOCKET, SO_RCVTIMEO,
-                     reinterpret_cast<const void *>(&tv), sizeof(tv));
-#endif
-        }
-        {
-
-#ifdef _WIN32
-          auto timeout = static_cast<uint32_t>(write_timeout_sec * 1000 +
-                                               write_timeout_usec / 1000);
-          setsockopt(sock2, SOL_SOCKET, SO_SNDTIMEO,
-                     reinterpret_cast<const char *>(&timeout), sizeof(timeout));
-#else
-          timeval tv;
-          tv.tv_sec = static_cast<long>(write_timeout_sec);
-          tv.tv_usec = static_cast<decltype(tv.tv_usec)>(write_timeout_usec);
-          setsockopt(sock2, SOL_SOCKET, SO_SNDTIMEO,
-                     reinterpret_cast<const void *>(&tv), sizeof(tv));
-#endif
-        }
+        set_socket_opt_time(sock2, SOL_SOCKET, SO_RCVTIMEO, read_timeout_sec,
+                            read_timeout_usec);
+        set_socket_opt_time(sock2, SOL_SOCKET, SO_SNDTIMEO, write_timeout_sec,
+                            write_timeout_usec);
 
         error = Error::Success;
         return true;
@@ -3948,6 +4000,12 @@ inline EncodingType encoding_type(const Request &req, const Response &res) {
   if (ret) { return EncodingType::Gzip; }
 #endif
 
+#ifdef CPPHTTPLIB_ZSTD_SUPPORT
+  // TODO: 'Accept-Encoding' has zstd, not zstd;q=0
+  ret = s.find("zstd") != std::string::npos;
+  if (ret) { return EncodingType::Zstd; }
+#endif
+
   return EncodingType::None;
 }
 
@@ -4156,6 +4214,61 @@ inline bool brotli_decompressor::decompress(const char *data,
 }
 #endif
 
+#ifdef CPPHTTPLIB_ZSTD_SUPPORT
+inline zstd_compressor::zstd_compressor() {
+  ctx_ = ZSTD_createCCtx();
+  ZSTD_CCtx_setParameter(ctx_, ZSTD_c_compressionLevel, ZSTD_fast);
+}
+
+inline zstd_compressor::~zstd_compressor() { ZSTD_freeCCtx(ctx_); }
+
+inline bool zstd_compressor::compress(const char *data, size_t data_length,
+                                      bool last, Callback callback) {
+  std::array<char, CPPHTTPLIB_COMPRESSION_BUFSIZ> buff{};
+
+  ZSTD_EndDirective mode = last ? ZSTD_e_end : ZSTD_e_continue;
+  ZSTD_inBuffer input = {data, data_length, 0};
+
+  bool finished;
+  do {
+    ZSTD_outBuffer output = {buff.data(), CPPHTTPLIB_COMPRESSION_BUFSIZ, 0};
+    size_t const remaining = ZSTD_compressStream2(ctx_, &output, &input, mode);
+
+    if (ZSTD_isError(remaining)) { return false; }
+
+    if (!callback(buff.data(), output.pos)) { return false; }
+
+    finished = last ? (remaining == 0) : (input.pos == input.size);
+
+  } while (!finished);
+
+  return true;
+}
+
+inline zstd_decompressor::zstd_decompressor() { ctx_ = ZSTD_createDCtx(); }
+
+inline zstd_decompressor::~zstd_decompressor() { ZSTD_freeDCtx(ctx_); }
+
+inline bool zstd_decompressor::is_valid() const { return ctx_ != nullptr; }
+
+inline bool zstd_decompressor::decompress(const char *data, size_t data_length,
+                                          Callback callback) {
+  std::array<char, CPPHTTPLIB_COMPRESSION_BUFSIZ> buff{};
+  ZSTD_inBuffer input = {data, data_length, 0};
+
+  while (input.pos < input.size) {
+    ZSTD_outBuffer output = {buff.data(), CPPHTTPLIB_COMPRESSION_BUFSIZ, 0};
+    size_t const remaining = ZSTD_decompressStream(ctx_, &output, &input);
+
+    if (ZSTD_isError(remaining)) { return false; }
+
+    if (!callback(buff.data(), output.pos)) { return false; }
+  }
+
+  return true;
+}
+#endif
+
 inline bool has_header(const Headers &headers, const std::string &key) {
   return headers.find(key) != headers.end();
 }
@@ -4182,6 +4295,9 @@ inline bool parse_header(const char *beg, const char *end, T fn) {
     p++;
   }
 
+  auto name = std::string(beg, p);
+  if (!detail::fields::is_field_name(name)) { return false; }
+
   if (p == end) { return false; }
 
   auto key_end = p;
@@ -4197,22 +4313,17 @@ inline bool parse_header(const char *beg, const char *end, T fn) {
     if (!key_len) { return false; }
 
     auto key = std::string(beg, key_end);
-    auto val = case_ignore::equal(key, "Location")
-                   ? std::string(p, end)
-                   : decode_url(std::string(p, end), false);
+    auto val = std::string(p, end);
 
-    // NOTE: From RFC 9110:
-    // Field values containing CR, LF, or NUL characters are
-    // invalid and dangerous, due to the varying ways that
-    // implementations might parse and interpret those
-    // characters; a recipient of CR, LF, or NUL within a field
-    // value MUST either reject the message or replace each of
-    // those characters with SP before further processing or
-    // forwarding of that message.
-    static const std::string CR_LF_NUL("\r\n\0", 3);
-    if (val.find_first_of(CR_LF_NUL) != std::string::npos) { return false; }
+    if (!detail::fields::is_field_value(val)) { return false; }
+
+    if (case_ignore::equal(key, "Location") ||
+        case_ignore::equal(key, "Referer")) {
+      fn(key, val);
+    } else {
+      fn(key, decode_url(val, false));
+    }
 
-    fn(key, val);
     return true;
   }
 
@@ -4248,7 +4359,7 @@ inline bool read_headers(Stream &strm, Headers &headers) {
     auto end = line_reader.ptr() + line_reader.size() - line_terminator_len;
 
     if (!parse_header(line_reader.ptr(), end,
-                      [&](const std::string &key, std::string &val) {
+                      [&](const std::string &key, const std::string &val) {
                         headers.emplace(key, val);
                       })) {
       return false;
@@ -4297,7 +4408,8 @@ inline bool read_content_without_length(Stream &strm,
   uint64_t r = 0;
   for (;;) {
     auto n = strm.read(buf, CPPHTTPLIB_RECV_BUFSIZ);
-    if (n <= 0) { return true; }
+    if (n == 0) { return true; }
+    if (n < 0) { return false; }
 
     if (!out(buf, static_cast<size_t>(n), r, 0)) { return false; }
     r += static_cast<uint64_t>(n);
@@ -4340,7 +4452,7 @@ inline bool read_content_chunked(Stream &strm, T &x,
 
   assert(chunk_len == 0);
 
-  // NOTE: In RFC 9112, '7.1 Chunked Transfer Coding' mentiones "The chunked
+  // NOTE: In RFC 9112, '7.1 Chunked Transfer Coding' mentions "The chunked
   // transfer coding is complete when a chunk with a chunk-size of zero is
   // received, possibly followed by a trailer section, and finally terminated by
   // an empty line". https://www.rfc-editor.org/rfc/rfc9112.html#section-7.1
@@ -4350,8 +4462,8 @@ inline bool read_content_chunked(Stream &strm, T &x,
   // to be ok whether the final CRLF exists or not in the chunked data.
   // https://www.rfc-editor.org/rfc/rfc9112.html#section-7.1.3
   //
-  // According to the reference code in RFC 9112, cpp-htpplib now allows
-  // chuncked transfer coding data without the final CRLF.
+  // According to the reference code in RFC 9112, cpp-httplib now allows
+  // chunked transfer coding data without the final CRLF.
   if (!line_reader.getline()) { return true; }
 
   while (strcmp(line_reader.ptr(), "\r\n") != 0) {
@@ -4398,6 +4510,13 @@ bool prepare_content_receiver(T &x, int &status,
 #else
       status = StatusCode::UnsupportedMediaType_415;
       return false;
+#endif
+    } else if (encoding == "zstd") {
+#ifdef CPPHTTPLIB_ZSTD_SUPPORT
+      decompressor = detail::make_unique<zstd_decompressor>();
+#else
+      status = StatusCode::UnsupportedMediaType_415;
+      return false;
 #endif
     }
 
@@ -4440,8 +4559,14 @@ bool read_content(Stream &strm, T &x, size_t payload_max_length, int &status,
         } else if (!has_header(x.headers, "Content-Length")) {
           ret = read_content_without_length(strm, out);
         } else {
-          auto len = get_header_value_u64(x.headers, "Content-Length", 0, 0);
-          if (len > payload_max_length) {
+          auto is_invalid_value = false;
+          auto len = get_header_value_u64(
+              x.headers, "Content-Length",
+              (std::numeric_limits<uint64_t>::max)(), 0, is_invalid_value);
+
+          if (is_invalid_value) {
+            ret = false;
+          } else if (len > payload_max_length) {
             exceed_payload_max_length = true;
             skip_content_with_length(strm, len);
             ret = false;
@@ -4515,7 +4640,7 @@ inline bool write_content(Stream &strm, const ContentProvider &content_provider,
 
   data_sink.write = [&](const char *d, size_t l) -> bool {
     if (ok) {
-      if (strm.is_writable() && write_data(strm, d, l)) {
+      if (write_data(strm, d, l)) {
         offset += l;
       } else {
         ok = false;
@@ -4524,10 +4649,10 @@ inline bool write_content(Stream &strm, const ContentProvider &content_provider,
     return ok;
   };
 
-  data_sink.is_writable = [&]() -> bool { return strm.is_writable(); };
+  data_sink.is_writable = [&]() -> bool { return strm.wait_writable(); };
 
   while (offset < end_offset && !is_shutting_down()) {
-    if (!strm.is_writable()) {
+    if (!strm.wait_writable()) {
       error = Error::Write;
       return false;
     } else if (!content_provider(offset, end_offset - offset, data_sink)) {
@@ -4565,17 +4690,17 @@ write_content_without_length(Stream &strm,
   data_sink.write = [&](const char *d, size_t l) -> bool {
     if (ok) {
       offset += l;
-      if (!strm.is_writable() || !write_data(strm, d, l)) { ok = false; }
+      if (!write_data(strm, d, l)) { ok = false; }
     }
     return ok;
   };
 
-  data_sink.is_writable = [&]() -> bool { return strm.is_writable(); };
+  data_sink.is_writable = [&]() -> bool { return strm.wait_writable(); };
 
   data_sink.done = [&](void) { data_available = false; };
 
   while (data_available && !is_shutting_down()) {
-    if (!strm.is_writable()) {
+    if (!strm.wait_writable()) {
       return false;
     } else if (!content_provider(offset, 0, data_sink)) {
       return false;
@@ -4610,10 +4735,7 @@ write_content_chunked(Stream &strm, const ContentProvider &content_provider,
           // Emit chunked response header and footer for each chunk
           auto chunk =
               from_i_to_hex(payload.size()) + "\r\n" + payload + "\r\n";
-          if (!strm.is_writable() ||
-              !write_data(strm, chunk.data(), chunk.size())) {
-            ok = false;
-          }
+          if (!write_data(strm, chunk.data(), chunk.size())) { ok = false; }
         }
       } else {
         ok = false;
@@ -4622,7 +4744,7 @@ write_content_chunked(Stream &strm, const ContentProvider &content_provider,
     return ok;
   };
 
-  data_sink.is_writable = [&]() -> bool { return strm.is_writable(); };
+  data_sink.is_writable = [&]() -> bool { return strm.wait_writable(); };
 
   auto done_with_trailer = [&](const Headers *trailer) {
     if (!ok) { return; }
@@ -4642,17 +4764,14 @@ write_content_chunked(Stream &strm, const ContentProvider &content_provider,
     if (!payload.empty()) {
       // Emit chunked response header and footer for each chunk
       auto chunk = from_i_to_hex(payload.size()) + "\r\n" + payload + "\r\n";
-      if (!strm.is_writable() ||
-          !write_data(strm, chunk.data(), chunk.size())) {
+      if (!write_data(strm, chunk.data(), chunk.size())) {
         ok = false;
         return;
       }
     }
 
-    static const std::string done_marker("0\r\n");
-    if (!write_data(strm, done_marker.data(), done_marker.size())) {
-      ok = false;
-    }
+    constexpr const char done_marker[] = "0\r\n";
+    if (!write_data(strm, done_marker, str_len(done_marker))) { ok = false; }
 
     // Trailer
     if (trailer) {
@@ -4664,8 +4783,8 @@ write_content_chunked(Stream &strm, const ContentProvider &content_provider,
       }
     }
 
-    static const std::string crlf("\r\n");
-    if (!write_data(strm, crlf.data(), crlf.size())) { ok = false; }
+    constexpr const char crlf[] = "\r\n";
+    if (!write_data(strm, crlf, str_len(crlf))) { ok = false; }
   };
 
   data_sink.done = [&](void) { done_with_trailer(nullptr); };
@@ -4675,7 +4794,7 @@ write_content_chunked(Stream &strm, const ContentProvider &content_provider,
   };
 
   while (data_available && !is_shutting_down()) {
-    if (!strm.is_writable()) {
+    if (!strm.wait_writable()) {
       error = Error::Write;
       return false;
     } else if (!content_provider(offset, 0, data_sink)) {
@@ -4907,13 +5026,13 @@ public:
             return false;
           }
 
-          static const std::string header_content_type = "Content-Type:";
+          constexpr const char header_content_type[] = "Content-Type:";
 
           if (start_with_case_ignore(header, header_content_type)) {
             file_.content_type =
-                trim_copy(header.substr(header_content_type.size()));
+                trim_copy(header.substr(str_len(header_content_type)));
           } else {
-            static const std::regex re_content_disposition(
+            thread_local const std::regex re_content_disposition(
                 R"~(^Content-Disposition:\s*form-data;\s*(.*)$)~",
                 std::regex_constants::icase);
 
@@ -4935,8 +5054,8 @@ public:
 
               it = params.find("filename*");
               if (it != params.end()) {
-                // Only allow UTF-8 enconnding...
-                static const std::regex re_rfc5987_encoding(
+                // Only allow UTF-8 encoding...
+                thread_local const std::regex re_rfc5987_encoding(
                     R"~(^UTF-8''(.+?)$)~", std::regex_constants::icase);
 
                 std::smatch m2;
@@ -5008,10 +5127,10 @@ private:
     file_.content_type.clear();
   }
 
-  bool start_with_case_ignore(const std::string &a,
-                              const std::string &b) const {
-    if (a.size() < b.size()) { return false; }
-    for (size_t i = 0; i < b.size(); i++) {
+  bool start_with_case_ignore(const std::string &a, const char *b) const {
+    const auto b_len = strlen(b);
+    if (a.size() < b_len) { return false; }
+    for (size_t i = 0; i < b_len; i++) {
       if (case_ignore::to_lower(a[i]) != case_ignore::to_lower(b[i])) {
         return false;
       }
@@ -5098,19 +5217,18 @@ private:
 };
 
 inline std::string random_string(size_t length) {
-  static const char data[] =
+  constexpr const char data[] =
       "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
 
-  // std::random_device might actually be deterministic on some
-  // platforms, but due to lack of support in the c++ standard library,
-  // doing better requires either some ugly hacks or breaking portability.
-  static std::random_device seed_gen;
-
-  // Request 128 bits of entropy for initialization
-  static std::seed_seq seed_sequence{seed_gen(), seed_gen(), seed_gen(),
-                                     seed_gen()};
-
-  static std::mt19937 engine(seed_sequence);
+  thread_local auto engine([]() {
+    // std::random_device might actually be deterministic on some
+    // platforms, but due to lack of support in the c++ standard library,
+    // doing better requires either some ugly hacks or breaking portability.
+    std::random_device seed_gen;
+    // Request 128 bits of entropy for initialization
+    std::seed_seq seed_sequence{seed_gen(), seed_gen(), seed_gen(), seed_gen()};
+    return std::mt19937(seed_sequence);
+  }());
 
   std::string result;
   for (size_t i = 0; i < length; i++) {
@@ -5182,7 +5300,7 @@ serialize_multipart_formdata(const MultipartFormDataItems &items,
 
 inline bool range_error(Request &req, Response &res) {
   if (!req.ranges.empty() && 200 <= res.status && res.status < 300) {
-    ssize_t contant_len = static_cast<ssize_t>(
+    ssize_t content_len = static_cast<ssize_t>(
         res.content_length_ ? res.content_length_ : res.body.size());
 
     ssize_t prev_first_pos = -1;
@@ -5202,12 +5320,12 @@ inline bool range_error(Request &req, Response &res) {
 
       if (first_pos == -1 && last_pos == -1) {
         first_pos = 0;
-        last_pos = contant_len;
+        last_pos = content_len;
       }
 
       if (first_pos == -1) {
-        first_pos = contant_len - last_pos;
-        last_pos = contant_len - 1;
+        first_pos = content_len - last_pos;
+        last_pos = content_len - 1;
       }
 
       // NOTE: RFC-9110 '14.1.2. Byte Ranges':
@@ -5219,13 +5337,13 @@ inline bool range_error(Request &req, Response &res) {
       // with a value that is one less than the current length of the selected
       // representation).
       // https://www.rfc-editor.org/rfc/rfc9110.html#section-14.1.2-6
-      if (last_pos == -1 || last_pos >= contant_len) {
-        last_pos = contant_len - 1;
+      if (last_pos == -1 || last_pos >= content_len) {
+        last_pos = content_len - 1;
       }
 
       // Range must be within content length
       if (!(0 <= first_pos && first_pos <= last_pos &&
-            last_pos <= contant_len - 1)) {
+            last_pos <= content_len - 1)) {
         return true;
       }
 
@@ -5359,10 +5477,14 @@ write_multipart_ranges_data(Stream &strm, const Request &req, Response &res,
 
 inline bool expect_content(const Request &req) {
   if (req.method == "POST" || req.method == "PUT" || req.method == "PATCH" ||
-      req.method == "PRI" || req.method == "DELETE") {
+      req.method == "DELETE") {
     return true;
   }
-  // TODO: check if Content-Length is set
+  if (req.has_header("Content-Length") &&
+      req.get_header_value_u64("Content-Length") > 0) {
+    return true;
+  }
+  if (is_chunked_transfer_encoding(req.headers)) { return true; }
   return false;
 }
 
@@ -5407,9 +5529,76 @@ inline std::string SHA_256(const std::string &s) {
 inline std::string SHA_512(const std::string &s) {
   return message_digest(s, EVP_sha512());
 }
-#endif
 
-#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+inline std::pair<std::string, std::string> make_digest_authentication_header(
+    const Request &req, const std::map<std::string, std::string> &auth,
+    size_t cnonce_count, const std::string &cnonce, const std::string &username,
+    const std::string &password, bool is_proxy = false) {
+  std::string nc;
+  {
+    std::stringstream ss;
+    ss << std::setfill('0') << std::setw(8) << std::hex << cnonce_count;
+    nc = ss.str();
+  }
+
+  std::string qop;
+  if (auth.find("qop") != auth.end()) {
+    qop = auth.at("qop");
+    if (qop.find("auth-int") != std::string::npos) {
+      qop = "auth-int";
+    } else if (qop.find("auth") != std::string::npos) {
+      qop = "auth";
+    } else {
+      qop.clear();
+    }
+  }
+
+  std::string algo = "MD5";
+  if (auth.find("algorithm") != auth.end()) { algo = auth.at("algorithm"); }
+
+  std::string response;
+  {
+    auto H = algo == "SHA-256"   ? detail::SHA_256
+             : algo == "SHA-512" ? detail::SHA_512
+                                 : detail::MD5;
+
+    auto A1 = username + ":" + auth.at("realm") + ":" + password;
+
+    auto A2 = req.method + ":" + req.path;
+    if (qop == "auth-int") { A2 += ":" + H(req.body); }
+
+    if (qop.empty()) {
+      response = H(H(A1) + ":" + auth.at("nonce") + ":" + H(A2));
+    } else {
+      response = H(H(A1) + ":" + auth.at("nonce") + ":" + nc + ":" + cnonce +
+                   ":" + qop + ":" + H(A2));
+    }
+  }
+
+  auto opaque = (auth.find("opaque") != auth.end()) ? auth.at("opaque") : "";
+
+  auto field = "Digest username=\"" + username + "\", realm=\"" +
+               auth.at("realm") + "\", nonce=\"" + auth.at("nonce") +
+               "\", uri=\"" + req.path + "\", algorithm=" + algo +
+               (qop.empty() ? ", response=\""
+                            : ", qop=" + qop + ", nc=" + nc + ", cnonce=\"" +
+                                  cnonce + "\", response=\"") +
+               response + "\"" +
+               (opaque.empty() ? "" : ", opaque=\"" + opaque + "\"");
+
+  auto key = is_proxy ? "Proxy-Authorization" : "Authorization";
+  return std::make_pair(key, field);
+}
+
+inline bool is_ssl_peer_could_be_closed(SSL *ssl, socket_t sock) {
+  detail::set_nonblocking(sock, true);
+  auto se = detail::scope_exit([&]() { detail::set_nonblocking(sock, false); });
+
+  char buf[1];
+  return !SSL_peek(ssl, buf, 1) &&
+         SSL_get_error(ssl, 0) == SSL_ERROR_ZERO_RETURN;
+}
+
 #ifdef _WIN32
 // NOTE: This code came up with the following stackoverflow post:
 // https://stackoverflow.com/questions/9507184/can-openssl-on-windows-use-the-system-certificate-store
@@ -5548,74 +5737,13 @@ public:
 static WSInit wsinit_;
 #endif
 
-#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
-inline std::pair<std::string, std::string> make_digest_authentication_header(
-    const Request &req, const std::map<std::string, std::string> &auth,
-    size_t cnonce_count, const std::string &cnonce, const std::string &username,
-    const std::string &password, bool is_proxy = false) {
-  std::string nc;
-  {
-    std::stringstream ss;
-    ss << std::setfill('0') << std::setw(8) << std::hex << cnonce_count;
-    nc = ss.str();
-  }
-
-  std::string qop;
-  if (auth.find("qop") != auth.end()) {
-    qop = auth.at("qop");
-    if (qop.find("auth-int") != std::string::npos) {
-      qop = "auth-int";
-    } else if (qop.find("auth") != std::string::npos) {
-      qop = "auth";
-    } else {
-      qop.clear();
-    }
-  }
-
-  std::string algo = "MD5";
-  if (auth.find("algorithm") != auth.end()) { algo = auth.at("algorithm"); }
-
-  std::string response;
-  {
-    auto H = algo == "SHA-256"   ? detail::SHA_256
-             : algo == "SHA-512" ? detail::SHA_512
-                                 : detail::MD5;
-
-    auto A1 = username + ":" + auth.at("realm") + ":" + password;
-
-    auto A2 = req.method + ":" + req.path;
-    if (qop == "auth-int") { A2 += ":" + H(req.body); }
-
-    if (qop.empty()) {
-      response = H(H(A1) + ":" + auth.at("nonce") + ":" + H(A2));
-    } else {
-      response = H(H(A1) + ":" + auth.at("nonce") + ":" + nc + ":" + cnonce +
-                   ":" + qop + ":" + H(A2));
-    }
-  }
-
-  auto opaque = (auth.find("opaque") != auth.end()) ? auth.at("opaque") : "";
-
-  auto field = "Digest username=\"" + username + "\", realm=\"" +
-               auth.at("realm") + "\", nonce=\"" + auth.at("nonce") +
-               "\", uri=\"" + req.path + "\", algorithm=" + algo +
-               (qop.empty() ? ", response=\""
-                            : ", qop=" + qop + ", nc=" + nc + ", cnonce=\"" +
-                                  cnonce + "\", response=\"") +
-               response + "\"" +
-               (opaque.empty() ? "" : ", opaque=\"" + opaque + "\"");
-
-  auto key = is_proxy ? "Proxy-Authorization" : "Authorization";
-  return std::make_pair(key, field);
-}
-#endif
-
 inline bool parse_www_authenticate(const Response &res,
                                    std::map<std::string, std::string> &auth,
                                    bool is_proxy) {
   auto auth_key = is_proxy ? "Proxy-Authenticate" : "WWW-Authenticate";
   if (res.has_header(auth_key)) {
-    static auto re = std::regex(R"~((?:(?:,\s*)?(.+?)=(?:"(.*?)"|([^,]*))))~");
+    thread_local auto re =
+        std::regex(R"~((?:(?:,\s*)?(.+?)=(?:"(.*?)"|([^,]*))))~");
     auto s = res.get_header_value(auth_key);
     auto pos = s.find(' ');
     if (pos != std::string::npos) {
@@ -5699,7 +5827,7 @@ inline void hosted_at(const std::string &hostname,
 inline std::string append_query_params(const std::string &path,
                                        const Params &params) {
   std::string path_with_query = path;
-  const static std::regex re("[^?]+\\?.*");
+  thread_local const std::regex re("[^?]+\\?.*");
   auto delm = std::regex_match(path, re) ? '&' : '?';
   path_with_query += delm + detail::params_to_query_str(params);
   return path_with_query;
@@ -5928,23 +6056,54 @@ inline ssize_t Stream::write(const std::string &s) {
 
 namespace detail {
 
+inline void calc_actual_timeout(time_t max_timeout_msec, time_t duration_msec,
+                                time_t timeout_sec, time_t timeout_usec,
+                                time_t &actual_timeout_sec,
+                                time_t &actual_timeout_usec) {
+  auto timeout_msec = (timeout_sec * 1000) + (timeout_usec / 1000);
+
+  auto actual_timeout_msec =
+      (std::min)(max_timeout_msec - duration_msec, timeout_msec);
+
+  if (actual_timeout_msec < 0) { actual_timeout_msec = 0; }
+
+  actual_timeout_sec = actual_timeout_msec / 1000;
+  actual_timeout_usec = (actual_timeout_msec % 1000) * 1000;
+}
+
 // Socket stream implementation
-inline SocketStream::SocketStream(socket_t sock, time_t read_timeout_sec,
-                                  time_t read_timeout_usec,
-                                  time_t write_timeout_sec,
-                                  time_t write_timeout_usec)
+inline SocketStream::SocketStream(
+    socket_t sock, time_t read_timeout_sec, time_t read_timeout_usec,
+    time_t write_timeout_sec, time_t write_timeout_usec,
+    time_t max_timeout_msec,
+    std::chrono::time_point<std::chrono::steady_clock> start_time)
     : sock_(sock), read_timeout_sec_(read_timeout_sec),
       read_timeout_usec_(read_timeout_usec),
       write_timeout_sec_(write_timeout_sec),
-      write_timeout_usec_(write_timeout_usec), read_buff_(read_buff_size_, 0) {}
+      write_timeout_usec_(write_timeout_usec),
+      max_timeout_msec_(max_timeout_msec), start_time_(start_time),
+      read_buff_(read_buff_size_, 0) {}
 
 inline SocketStream::~SocketStream() = default;
 
 inline bool SocketStream::is_readable() const {
-  return select_read(sock_, read_timeout_sec_, read_timeout_usec_) > 0;
+  return read_buff_off_ < read_buff_content_size_;
 }
 
-inline bool SocketStream::is_writable() const {
+inline bool SocketStream::wait_readable() const {
+  if (max_timeout_msec_ <= 0) {
+    return select_read(sock_, read_timeout_sec_, read_timeout_usec_) > 0;
+  }
+
+  time_t read_timeout_sec;
+  time_t read_timeout_usec;
+  calc_actual_timeout(max_timeout_msec_, duration(), read_timeout_sec_,
+                      read_timeout_usec_, read_timeout_sec, read_timeout_usec);
+
+  return select_read(sock_, read_timeout_sec, read_timeout_usec) > 0;
+}
+
+inline bool SocketStream::wait_writable() const {
   return select_write(sock_, write_timeout_sec_, write_timeout_usec_) > 0 &&
          is_socket_alive(sock_);
 }
@@ -5971,7 +6130,7 @@ inline ssize_t SocketStream::read(char *ptr, size_t size) {
     }
   }
 
-  if (!is_readable()) { return -1; }
+  if (!wait_readable()) { return -1; }
 
   read_buff_off_ = 0;
   read_buff_content_size_ = 0;
@@ -5996,7 +6155,7 @@ inline ssize_t SocketStream::read(char *ptr, size_t size) {
 }
 
 inline ssize_t SocketStream::write(const char *ptr, size_t size) {
-  if (!is_writable()) { return -1; }
+  if (!wait_writable()) { return -1; }
 
 #if defined(_WIN32) && !defined(_WIN64)
   size =
@@ -6018,10 +6177,18 @@ inline void SocketStream::get_local_ip_and_port(std::string &ip,
 
 inline socket_t SocketStream::socket() const { return sock_; }
 
+inline time_t SocketStream::duration() const {
+  return std::chrono::duration_cast<std::chrono::milliseconds>(
+             std::chrono::steady_clock::now() - start_time_)
+      .count();
+}
+
 // Buffer stream implementation
 inline bool BufferStream::is_readable() const { return true; }
 
-inline bool BufferStream::is_writable() const { return true; }
+inline bool BufferStream::wait_readable() const { return true; }
+
+inline bool BufferStream::wait_writable() const { return true; }
 
 inline ssize_t BufferStream::read(char *ptr, size_t size) {
 #if defined(_MSC_VER) && _MSC_VER < 1910
@@ -6046,10 +6213,12 @@ inline void BufferStream::get_local_ip_and_port(std::string & /*ip*/,
 
 inline socket_t BufferStream::socket() const { return 0; }
 
+inline time_t BufferStream::duration() const { return 0; }
+
 inline const std::string &BufferStream::get_buffer() const { return buffer; }
 
 inline PathParamsMatcher::PathParamsMatcher(const std::string &pattern) {
-  static constexpr char marker[] = "/:";
+  constexpr const char marker[] = "/:";
 
   // One past the last ending position of a path param substring
   std::size_t last_param_end = 0;
@@ -6070,7 +6239,7 @@ inline PathParamsMatcher::PathParamsMatcher(const std::string &pattern) {
     static_fragments_.push_back(
         pattern.substr(last_param_end, marker_pos - last_param_end + 1));
 
-    const auto param_name_start = marker_pos + 2;
+    const auto param_name_start = marker_pos + str_len(marker);
 
     auto sep_pos = pattern.find(separator, param_name_start);
     if (sep_pos == std::string::npos) { sep_pos = pattern.length(); }
@@ -6377,12 +6546,12 @@ inline Server &Server::set_payload_max_length(size_t length) {
 inline bool Server::bind_to_port(const std::string &host, int port,
                                  int socket_flags) {
   auto ret = bind_internal(host, port, socket_flags);
-  if (ret == -1) { is_decommisioned = true; }
+  if (ret == -1) { is_decommissioned = true; }
   return ret >= 0;
 }
 inline int Server::bind_to_any_port(const std::string &host, int socket_flags) {
   auto ret = bind_internal(host, 0, socket_flags);
-  if (ret == -1) { is_decommisioned = true; }
+  if (ret == -1) { is_decommissioned = true; }
   return ret;
 }
 
@@ -6396,7 +6565,7 @@ inline bool Server::listen(const std::string &host, int port,
 inline bool Server::is_running() const { return is_running_; }
 
 inline void Server::wait_until_ready() const {
-  while (!is_running_ && !is_decommisioned) {
+  while (!is_running_ && !is_decommissioned) {
     std::this_thread::sleep_for(std::chrono::milliseconds{1});
   }
 }
@@ -6408,10 +6577,10 @@ inline void Server::stop() {
     detail::shutdown_socket(sock);
     detail::close_socket(sock);
   }
-  is_decommisioned = false;
+  is_decommissioned = false;
 }
 
-inline void Server::decommission() { is_decommisioned = true; }
+inline void Server::decommission() { is_decommissioned = true; }
 
 inline bool Server::parse_request_line(const char *s, Request &req) const {
   auto len = strlen(s);
@@ -6434,7 +6603,7 @@ inline bool Server::parse_request_line(const char *s, Request &req) const {
     if (count != 3) { return false; }
   }
 
-  static const std::set<std::string> methods{
+  thread_local const std::set<std::string> methods{
       "GET",     "HEAD",    "POST",  "PUT",   "DELETE",
       "CONNECT", "OPTIONS", "TRACE", "PATCH", "PRI"};
 
@@ -6588,6 +6757,10 @@ Server::write_content_with_provider(Stream &strm, const Request &req,
       } else if (type == detail::EncodingType::Brotli) {
 #ifdef CPPHTTPLIB_BROTLI_SUPPORT
         compressor = detail::make_unique<detail::brotli_compressor>();
+#endif
+      } else if (type == detail::EncodingType::Zstd) {
+#ifdef CPPHTTPLIB_ZSTD_SUPPORT
+        compressor = detail::make_unique<detail::zstd_compressor>();
 #endif
       } else {
         compressor = detail::make_unique<detail::nocompressor>();
@@ -6706,8 +6879,7 @@ Server::read_content_core(Stream &strm, Request &req, Response &res,
   return true;
 }
 
-inline bool Server::handle_file_request(const Request &req, Response &res,
-                                        bool head) {
+inline bool Server::handle_file_request(const Request &req, Response &res) {
   for (const auto &entry : base_dirs_) {
     // Prefix match
     if (!req.path.compare(0, entry.mount_point.size(), entry.mount_point)) {
@@ -6740,7 +6912,7 @@ inline bool Server::handle_file_request(const Request &req, Response &res,
                 return true;
               });
 
-          if (!head && file_request_handler_) {
+          if (req.method != "HEAD" && file_request_handler_) {
             file_request_handler_(req, res);
           }
 
@@ -6770,7 +6942,7 @@ Server::create_server_socket(const std::string &host, int port,
 
 inline int Server::bind_internal(const std::string &host, int port,
                                  int socket_flags) {
-  if (is_decommisioned) { return -1; }
+  if (is_decommissioned) { return -1; }
 
   if (!is_valid()) { return -1; }
 
@@ -6797,7 +6969,7 @@ inline int Server::bind_internal(const std::string &host, int port,
 }
 
 inline bool Server::listen_internal() {
-  if (is_decommisioned) { return false; }
+  if (is_decommissioned) { return false; }
 
   auto ret = true;
   is_running_ = true;
@@ -6821,7 +6993,7 @@ inline bool Server::listen_internal() {
 #endif
 
 #if defined _WIN32
-      // sockets conneced via WASAccept inherit flags NO_HANDLE_INHERIT,
+      // sockets connected via WASAccept inherit flags NO_HANDLE_INHERIT,
       // OVERLAPPED
       socket_t sock = WSAAccept(svr_sock_, nullptr, nullptr, nullptr, 0);
 #elif defined SOCK_CLOEXEC
@@ -6848,35 +7020,10 @@ inline bool Server::listen_internal() {
         break;
       }
 
-      {
-#ifdef _WIN32
-        auto timeout = static_cast<uint32_t>(read_timeout_sec_ * 1000 +
-                                             read_timeout_usec_ / 1000);
-        setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
-                   reinterpret_cast<const char *>(&timeout), sizeof(timeout));
-#else
-        timeval tv;
-        tv.tv_sec = static_cast<long>(read_timeout_sec_);
-        tv.tv_usec = static_cast<decltype(tv.tv_usec)>(read_timeout_usec_);
-        setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
-                   reinterpret_cast<const void *>(&tv), sizeof(tv));
-#endif
-      }
-      {
-
-#ifdef _WIN32
-        auto timeout = static_cast<uint32_t>(write_timeout_sec_ * 1000 +
-                                             write_timeout_usec_ / 1000);
-        setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO,
-                   reinterpret_cast<const char *>(&timeout), sizeof(timeout));
-#else
-        timeval tv;
-        tv.tv_sec = static_cast<long>(write_timeout_sec_);
-        tv.tv_usec = static_cast<decltype(tv.tv_usec)>(write_timeout_usec_);
-        setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO,
-                   reinterpret_cast<const void *>(&tv), sizeof(tv));
-#endif
-      }
+      detail::set_socket_opt_time(sock, SOL_SOCKET, SO_RCVTIMEO,
+                                  read_timeout_sec_, read_timeout_usec_);
+      detail::set_socket_opt_time(sock, SOL_SOCKET, SO_SNDTIMEO,
+                                  write_timeout_sec_, write_timeout_usec_);
 
       if (!task_queue->enqueue(
               [this, sock]() { process_and_close_socket(sock); })) {
@@ -6888,7 +7035,7 @@ inline bool Server::listen_internal() {
     task_queue->shutdown();
   }
 
-  is_decommisioned = !ret;
+  is_decommissioned = !ret;
   return ret;
 }
 
@@ -6899,9 +7046,8 @@ inline bool Server::routing(Request &req, Response &res, Stream &strm) {
   }
 
   // File handler
-  auto is_head_request = req.method == "HEAD";
-  if ((req.method == "GET" || is_head_request) &&
-      handle_file_request(req, res, is_head_request)) {
+  if ((req.method == "GET" || req.method == "HEAD") &&
+      handle_file_request(req, res)) {
     return true;
   }
 
@@ -7028,6 +7174,8 @@ inline void Server::apply_ranges(const Request &req, Response &res,
             res.set_header("Content-Encoding", "gzip");
           } else if (type == detail::EncodingType::Brotli) {
             res.set_header("Content-Encoding", "br");
+          } else if (type == detail::EncodingType::Zstd) {
+            res.set_header("Content-Encoding", "zstd");
           }
         }
       }
@@ -7067,6 +7215,11 @@ inline void Server::apply_ranges(const Request &req, Response &res,
 #ifdef CPPHTTPLIB_BROTLI_SUPPORT
         compressor = detail::make_unique<detail::brotli_compressor>();
         content_encoding = "br";
+#endif
+      } else if (type == detail::EncodingType::Zstd) {
+#ifdef CPPHTTPLIB_ZSTD_SUPPORT
+        compressor = detail::make_unique<detail::zstd_compressor>();
+        content_encoding = "zstd";
 #endif
       }
 
@@ -7122,28 +7275,6 @@ Server::process_request(Stream &strm, const std::string &remote_addr,
   res.version = "HTTP/1.1";
   res.headers = default_headers_;
 
-#ifdef _WIN32
-  // TODO: Increase FD_SETSIZE statically (libzmq), dynamically (MySQL).
-#else
-#ifndef CPPHTTPLIB_USE_POLL
-  // Socket file descriptor exceeded FD_SETSIZE...
-  if (strm.socket() >= FD_SETSIZE) {
-    Headers dummy;
-    detail::read_headers(strm, dummy);
-    res.status = StatusCode::InternalServerError_500;
-    return write_response(strm, close_connection, req, res);
-  }
-#endif
-#endif
-
-  // Check if the request URI doesn't exceed the limit
-  if (line_reader.size() > CPPHTTPLIB_REQUEST_URI_MAX_LENGTH) {
-    Headers dummy;
-    detail::read_headers(strm, dummy);
-    res.status = StatusCode::UriTooLong_414;
-    return write_response(strm, close_connection, req, res);
-  }
-
   // Request line and headers
   if (!parse_request_line(line_reader.ptr(), req) ||
       !detail::read_headers(strm, req.headers)) {
@@ -7151,6 +7282,14 @@ Server::process_request(Stream &strm, const std::string &remote_addr,
     return write_response(strm, close_connection, req, res);
   }
 
+  // Check if the request URI doesn't exceed the limit
+  if (req.target.size() > CPPHTTPLIB_REQUEST_URI_MAX_LENGTH) {
+    Headers dummy;
+    detail::read_headers(strm, dummy);
+    res.status = StatusCode::UriTooLong_414;
+    return write_response(strm, close_connection, req, res);
+  }
+
   if (req.get_header_value("Connection") == "close") {
     connection_closed = true;
   }
@@ -7197,6 +7336,12 @@ Server::process_request(Stream &strm, const std::string &remote_addr,
     }
   }
 
+  // Setup `is_connection_closed` method
+  auto sock = strm.socket();
+  req.is_connection_closed = [sock]() {
+    return !detail::is_socket_alive(sock);
+  };
+
   // Routing
   auto routed = false;
 #ifdef CPPHTTPLIB_NO_EXCEPTIONS
@@ -7322,6 +7467,16 @@ inline ClientImpl::ClientImpl(const std::string &host, int port,
       client_cert_path_(client_cert_path), client_key_path_(client_key_path) {}
 
 inline ClientImpl::~ClientImpl() {
+  // Wait until all the requests in flight are handled.
+  size_t retry_count = 10;
+  while (retry_count-- > 0) {
+    {
+      std::lock_guard<std::mutex> guard(socket_mutex_);
+      if (socket_requests_in_flight_ == 0) { break; }
+    }
+    std::this_thread::sleep_for(std::chrono::milliseconds{1});
+  }
+
   std::lock_guard<std::mutex> guard(socket_mutex_);
   shutdown_socket(socket_);
   close_socket(socket_);
@@ -7337,6 +7492,7 @@ inline void ClientImpl::copy_settings(const ClientImpl &rhs) {
   read_timeout_usec_ = rhs.read_timeout_usec_;
   write_timeout_sec_ = rhs.write_timeout_sec_;
   write_timeout_usec_ = rhs.write_timeout_usec_;
+  max_timeout_msec_ = rhs.max_timeout_msec_;
   basic_auth_username_ = rhs.basic_auth_username_;
   basic_auth_password_ = rhs.basic_auth_password_;
   bearer_token_auth_token_ = rhs.bearer_token_auth_token_;
@@ -7446,9 +7602,9 @@ inline bool ClientImpl::read_response_line(Stream &strm, const Request &req,
   if (!line_reader.getline()) { return false; }
 
 #ifdef CPPHTTPLIB_ALLOW_LF_AS_LINE_TERMINATOR
-  const static std::regex re("(HTTP/1\\.[01]) (\\d{3})(?: (.*?))?\r?\n");
+  thread_local const std::regex re("(HTTP/1\\.[01]) (\\d{3})(?: (.*?))?\r?\n");
 #else
-  const static std::regex re("(HTTP/1\\.[01]) (\\d{3})(?: (.*?))?\r\n");
+  thread_local const std::regex re("(HTTP/1\\.[01]) (\\d{3})(?: (.*?))?\r\n");
 #endif
 
   std::cmatch m;
@@ -7483,18 +7639,6 @@ inline bool ClientImpl::send(Request &req, Response &res, Error &error) {
   return ret;
 }
 
-#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
-inline bool ClientImpl::is_ssl_peer_could_be_closed(SSL *ssl) const {
-  detail::set_nonblocking(socket_.sock, true);
-  auto se = detail::scope_exit(
-      [&]() { detail::set_nonblocking(socket_.sock, false); });
-
-  char buf[1];
-  return !SSL_peek(ssl, buf, 1) &&
-         SSL_get_error(ssl, 0) == SSL_ERROR_ZERO_RETURN;
-}
-#endif
-
 inline bool ClientImpl::send_(Request &req, Response &res, Error &error) {
   {
     std::lock_guard<std::mutex> guard(socket_mutex_);
@@ -7509,12 +7653,14 @@ inline bool ClientImpl::send_(Request &req, Response &res, Error &error) {
 
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
       if (is_alive && is_ssl()) {
-        if (is_ssl_peer_could_be_closed(socket_.ssl)) { is_alive = false; }
+        if (detail::is_ssl_peer_could_be_closed(socket_.ssl, socket_.sock)) {
+          is_alive = false;
+        }
       }
 #endif
 
       if (!is_alive) {
-        // Attempt to avoid sigpipe by shutting down nongracefully if it seems
+        // Attempt to avoid sigpipe by shutting down non-gracefully if it seems
         // like the other side has already closed the connection Also, there
         // cannot be any requests in flight from other threads since we locked
         // request_mutex_, so safe to close everything immediately
@@ -7534,7 +7680,8 @@ inline bool ClientImpl::send_(Request &req, Response &res, Error &error) {
         auto &scli = static_cast<SSLClient &>(*this);
         if (!proxy_host_.empty() && proxy_port_ != -1) {
           auto success = false;
-          if (!scli.connect_with_proxy(socket_, res, success, error)) {
+          if (!scli.connect_with_proxy(socket_, req.start_time_, res, success,
+                                       error)) {
             return success;
           }
         }
@@ -7580,7 +7727,7 @@ inline bool ClientImpl::send_(Request &req, Response &res, Error &error) {
     }
   });
 
-  ret = process_socket(socket_, [&](Stream &strm) {
+  ret = process_socket(socket_, req.start_time_, [&](Stream &strm) {
     return handle_request(strm, req, res, close_connection, error);
   });
 
@@ -7689,7 +7836,7 @@ inline bool ClientImpl::redirect(Request &req, Response &res, Error &error) {
   auto location = res.get_header_value("location");
   if (location.empty()) { return false; }
 
-  const static std::regex re(
+  thread_local const std::regex re(
       R"((?:(https?):)?(?://(?:\[([a-fA-F\d:]+)\]|([^:/?#]+))(?::(\d+))?)?([^?#]*)(\?[^#]*)?(?:#.*)?)");
 
   std::smatch m;
@@ -7798,6 +7945,10 @@ inline bool ClientImpl::write_request(Stream &strm, Request &req,
 #ifdef CPPHTTPLIB_ZLIB_SUPPORT
       if (!accept_encoding.empty()) { accept_encoding += ", "; }
       accept_encoding += "gzip, deflate";
+#endif
+#ifdef CPPHTTPLIB_ZSTD_SUPPORT
+      if (!accept_encoding.empty()) { accept_encoding += ", "; }
+      accept_encoding += "zstd";
 #endif
       req.set_header("Accept-Encoding", accept_encoding);
     }
@@ -7989,6 +8140,9 @@ inline Result ClientImpl::send_with_content_provider(
   req.headers = headers;
   req.path = path;
   req.progress = progress;
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
 
   auto error = Error::Success;
 
@@ -8015,7 +8169,7 @@ inline bool ClientImpl::process_request(Stream &strm, Request &req,
   if (is_ssl()) {
     auto is_proxy_enabled = !proxy_host_.empty() && proxy_port_ != -1;
     if (!is_proxy_enabled) {
-      if (is_ssl_peer_could_be_closed(socket_.ssl)) {
+      if (detail::is_ssl_peer_could_be_closed(socket_.ssl, socket_.sock)) {
         error = Error::SSLPeerCouldBeClosed_;
         return false;
       }
@@ -8140,12 +8294,13 @@ inline ContentProviderWithoutLength ClientImpl::get_multipart_content_provider(
   };
 }
 
-inline bool
-ClientImpl::process_socket(const Socket &socket,
-                           std::function<bool(Stream &strm)> callback) {
+inline bool ClientImpl::process_socket(
+    const Socket &socket,
+    std::chrono::time_point<std::chrono::steady_clock> start_time,
+    std::function<bool(Stream &strm)> callback) {
   return detail::process_client_socket(
       socket.sock, read_timeout_sec_, read_timeout_usec_, write_timeout_sec_,
-      write_timeout_usec_, std::move(callback));
+      write_timeout_usec_, max_timeout_msec_, start_time, std::move(callback));
 }
 
 inline bool ClientImpl::is_ssl() const { return false; }
@@ -8169,6 +8324,9 @@ inline Result ClientImpl::Get(const std::string &path, const Headers &headers,
   req.path = path;
   req.headers = headers;
   req.progress = std::move(progress);
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
 
   return send_(std::move(req));
 }
@@ -8234,6 +8392,9 @@ inline Result ClientImpl::Get(const std::string &path, const Headers &headers,
         return content_receiver(data, data_length);
       };
   req.progress = std::move(progress);
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
 
   return send_(std::move(req));
 }
@@ -8279,6 +8440,9 @@ inline Result ClientImpl::Head(const std::string &path,
   req.method = "HEAD";
   req.headers = headers;
   req.path = path;
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
 
   return send_(std::move(req));
 }
@@ -8696,6 +8860,9 @@ inline Result ClientImpl::Delete(const std::string &path,
   req.headers = headers;
   req.path = path;
   req.progress = progress;
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
 
   if (!content_type.empty()) { req.set_header("Content-Type", content_type); }
   req.body.assign(body, content_length);
@@ -8743,6 +8910,9 @@ inline Result ClientImpl::Options(const std::string &path,
   req.method = "OPTIONS";
   req.headers = headers;
   req.path = path;
+  if (max_timeout_msec_ > 0) {
+    req.start_time_ = std::chrono::steady_clock::now();
+  }
 
   return send_(std::move(req));
 }
@@ -8796,6 +8966,10 @@ inline void ClientImpl::set_write_timeout(time_t sec, time_t usec) {
   write_timeout_usec_ = usec;
 }
 
+inline void ClientImpl::set_max_timeout(time_t msec) {
+  max_timeout_msec_ = msec;
+}
+
 inline void ClientImpl::set_basic_auth(const std::string &username,
                                        const std::string &password) {
   basic_auth_username_ = username;
@@ -8921,7 +9095,7 @@ inline void ClientImpl::enable_server_hostname_verification(bool enabled) {
 }
 
 inline void ClientImpl::set_server_certificate_verifier(
-    std::function<bool(SSL *ssl)> verifier) {
+    std::function<SSLVerifierResponse(SSL *ssl)> verifier) {
   server_certificate_verifier_ = verifier;
 }
 #endif
@@ -8974,22 +9148,13 @@ inline void ssl_delete(std::mutex &ctx_mutex, SSL *ssl, socket_t sock,
   // Note that it is not always possible to avoid SIGPIPE, this is merely a
   // best-efforts.
   if (shutdown_gracefully) {
-#ifdef _WIN32
     (void)(sock);
-    SSL_shutdown(ssl);
-#else
-    timeval tv;
-    tv.tv_sec = 1;
-    tv.tv_usec = 0;
-    setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
-               reinterpret_cast<const void *>(&tv), sizeof(tv));
-
-    auto ret = SSL_shutdown(ssl);
-    while (ret == 0) {
-      std::this_thread::sleep_for(std::chrono::milliseconds{100});
-      ret = SSL_shutdown(ssl);
+    // SSL_shutdown() returns 0 on first call (indicating close_notify alert
+    // sent) and 1 on subsequent call (indicating close_notify alert received)
+    if (SSL_shutdown(ssl) == 0) {
+      // Expected to return 1, but even if it doesn't, we free ssl
+      SSL_shutdown(ssl);
     }
-#endif
   }
 
   std::lock_guard<std::mutex> guard(ctx_mutex);
@@ -9034,51 +9199,59 @@ inline bool process_server_socket_ssl(
 }
 
 template <typename T>
-inline bool
-process_client_socket_ssl(SSL *ssl, socket_t sock, time_t read_timeout_sec,
-                          time_t read_timeout_usec, time_t write_timeout_sec,
-                          time_t write_timeout_usec, T callback) {
+inline bool process_client_socket_ssl(
+    SSL *ssl, socket_t sock, time_t read_timeout_sec, time_t read_timeout_usec,
+    time_t write_timeout_sec, time_t write_timeout_usec,
+    time_t max_timeout_msec,
+    std::chrono::time_point<std::chrono::steady_clock> start_time, T callback) {
   SSLSocketStream strm(sock, ssl, read_timeout_sec, read_timeout_usec,
-                       write_timeout_sec, write_timeout_usec);
+                       write_timeout_sec, write_timeout_usec, max_timeout_msec,
+                       start_time);
   return callback(strm);
 }
 
-class SSLInit {
-public:
-  SSLInit() {
-    OPENSSL_init_ssl(
-        OPENSSL_INIT_LOAD_SSL_STRINGS | OPENSSL_INIT_LOAD_CRYPTO_STRINGS, NULL);
-  }
-};
-
 // SSL socket stream implementation
-inline SSLSocketStream::SSLSocketStream(socket_t sock, SSL *ssl,
-                                        time_t read_timeout_sec,
-                                        time_t read_timeout_usec,
-                                        time_t write_timeout_sec,
-                                        time_t write_timeout_usec)
+inline SSLSocketStream::SSLSocketStream(
+    socket_t sock, SSL *ssl, time_t read_timeout_sec, time_t read_timeout_usec,
+    time_t write_timeout_sec, time_t write_timeout_usec,
+    time_t max_timeout_msec,
+    std::chrono::time_point<std::chrono::steady_clock> start_time)
     : sock_(sock), ssl_(ssl), read_timeout_sec_(read_timeout_sec),
       read_timeout_usec_(read_timeout_usec),
       write_timeout_sec_(write_timeout_sec),
-      write_timeout_usec_(write_timeout_usec) {
+      write_timeout_usec_(write_timeout_usec),
+      max_timeout_msec_(max_timeout_msec), start_time_(start_time) {
   SSL_clear_mode(ssl, SSL_MODE_AUTO_RETRY);
 }
 
 inline SSLSocketStream::~SSLSocketStream() = default;
 
 inline bool SSLSocketStream::is_readable() const {
-  return detail::select_read(sock_, read_timeout_sec_, read_timeout_usec_) > 0;
+  return SSL_pending(ssl_) > 0;
 }
 
-inline bool SSLSocketStream::is_writable() const {
+inline bool SSLSocketStream::wait_readable() const {
+  if (max_timeout_msec_ <= 0) {
+    return select_read(sock_, read_timeout_sec_, read_timeout_usec_) > 0;
+  }
+
+  time_t read_timeout_sec;
+  time_t read_timeout_usec;
+  calc_actual_timeout(max_timeout_msec_, duration(), read_timeout_sec_,
+                      read_timeout_usec_, read_timeout_sec, read_timeout_usec);
+
+  return select_read(sock_, read_timeout_sec, read_timeout_usec) > 0;
+}
+
+inline bool SSLSocketStream::wait_writable() const {
   return select_write(sock_, write_timeout_sec_, write_timeout_usec_) > 0 &&
-         is_socket_alive(sock_);
+         is_socket_alive(sock_) && !is_ssl_peer_could_be_closed(ssl_, sock_);
 }
 
 inline ssize_t SSLSocketStream::read(char *ptr, size_t size) {
   if (SSL_pending(ssl_) > 0) {
     return SSL_read(ssl_, ptr, static_cast<int>(size));
-  } else if (is_readable()) {
+  } else if (wait_readable()) {
     auto ret = SSL_read(ssl_, ptr, static_cast<int>(size));
     if (ret < 0) {
       auto err = SSL_get_error(ssl_, ret);
@@ -9092,7 +9265,7 @@ inline ssize_t SSLSocketStream::read(char *ptr, size_t size) {
 #endif
         if (SSL_pending(ssl_) > 0) {
           return SSL_read(ssl_, ptr, static_cast<int>(size));
-        } else if (is_readable()) {
+        } else if (wait_readable()) {
           std::this_thread::sleep_for(std::chrono::microseconds{10});
           ret = SSL_read(ssl_, ptr, static_cast<int>(size));
           if (ret >= 0) { return ret; }
@@ -9103,12 +9276,13 @@ inline ssize_t SSLSocketStream::read(char *ptr, size_t size) {
       }
     }
     return ret;
+  } else {
+    return -1;
   }
-  return -1;
 }
 
 inline ssize_t SSLSocketStream::write(const char *ptr, size_t size) {
-  if (is_writable()) {
+  if (wait_writable()) {
     auto handle_size = static_cast<int>(
         std::min<size_t>(size, (std::numeric_limits<int>::max)()));
 
@@ -9123,7 +9297,7 @@ inline ssize_t SSLSocketStream::write(const char *ptr, size_t size) {
 #else
       while (--n >= 0 && err == SSL_ERROR_WANT_WRITE) {
 #endif
-        if (is_writable()) {
+        if (wait_writable()) {
           std::this_thread::sleep_for(std::chrono::microseconds{10});
           ret = SSL_write(ssl_, ptr, static_cast<int>(handle_size));
           if (ret >= 0) { return ret; }
@@ -9150,7 +9324,11 @@ inline void SSLSocketStream::get_local_ip_and_port(std::string &ip,
 
 inline socket_t SSLSocketStream::socket() const { return sock_; }
 
-static SSLInit sslinit_;
+inline time_t SSLSocketStream::duration() const {
+  return std::chrono::duration_cast<std::chrono::milliseconds>(
+             std::chrono::steady_clock::now() - start_time_)
+      .count();
+}
 
 } // namespace detail
 
@@ -9390,16 +9568,22 @@ inline bool SSLClient::create_and_connect_socket(Socket &socket, Error &error) {
 }
 
 // Assumes that socket_mutex_ is locked and that there are no requests in flight
-inline bool SSLClient::connect_with_proxy(Socket &socket, Response &res,
-                                          bool &success, Error &error) {
+inline bool SSLClient::connect_with_proxy(
+    Socket &socket,
+    std::chrono::time_point<std::chrono::steady_clock> start_time,
+    Response &res, bool &success, Error &error) {
   success = true;
   Response proxy_res;
   if (!detail::process_client_socket(
           socket.sock, read_timeout_sec_, read_timeout_usec_,
-          write_timeout_sec_, write_timeout_usec_, [&](Stream &strm) {
+          write_timeout_sec_, write_timeout_usec_, max_timeout_msec_,
+          start_time, [&](Stream &strm) {
             Request req2;
             req2.method = "CONNECT";
             req2.path = host_and_port_;
+            if (max_timeout_msec_ > 0) {
+              req2.start_time_ = std::chrono::steady_clock::now();
+            }
             return process_request(strm, req2, proxy_res, false, error);
           })) {
     // Thread-safe to close everything because we are assuming there are no
@@ -9419,7 +9603,8 @@ inline bool SSLClient::connect_with_proxy(Socket &socket, Response &res,
         proxy_res = Response();
         if (!detail::process_client_socket(
                 socket.sock, read_timeout_sec_, read_timeout_usec_,
-                write_timeout_sec_, write_timeout_usec_, [&](Stream &strm) {
+                write_timeout_sec_, write_timeout_usec_, max_timeout_msec_,
+                start_time, [&](Stream &strm) {
                   Request req3;
                   req3.method = "CONNECT";
                   req3.path = host_and_port_;
@@ -9427,6 +9612,9 @@ inline bool SSLClient::connect_with_proxy(Socket &socket, Response &res,
                       req3, auth, 1, detail::random_string(10),
                       proxy_digest_auth_username_, proxy_digest_auth_password_,
                       true));
+                  if (max_timeout_msec_ > 0) {
+                    req3.start_time_ = std::chrono::steady_clock::now();
+                  }
                   return process_request(strm, req3, proxy_res, false, error);
                 })) {
           // Thread-safe to close everything because we are assuming there are
@@ -9510,12 +9698,18 @@ inline bool SSLClient::initialize_ssl(Socket &socket, Error &error) {
         }
 
         if (server_certificate_verification_) {
+          auto verification_status = SSLVerifierResponse::NoDecisionMade;
+
           if (server_certificate_verifier_) {
-            if (!server_certificate_verifier_(ssl2)) {
-              error = Error::SSLServerVerification;
-              return false;
-            }
-          } else {
+            verification_status = server_certificate_verifier_(ssl2);
+          }
+
+          if (verification_status == SSLVerifierResponse::CertificateRejected) {
+            error = Error::SSLServerVerification;
+            return false;
+          }
+
+          if (verification_status == SSLVerifierResponse::NoDecisionMade) {
             verify_result_ = SSL_get_verify_result(ssl2);
 
             if (verify_result_ != X509_V_OK) {
@@ -9582,13 +9776,15 @@ inline void SSLClient::shutdown_ssl_impl(Socket &socket,
   assert(socket.ssl == nullptr);
 }
 
-inline bool
-SSLClient::process_socket(const Socket &socket,
-                          std::function<bool(Stream &strm)> callback) {
+inline bool SSLClient::process_socket(
+    const Socket &socket,
+    std::chrono::time_point<std::chrono::steady_clock> start_time,
+    std::function<bool(Stream &strm)> callback) {
   assert(socket.ssl);
   return detail::process_client_socket_ssl(
       socket.ssl, socket.sock, read_timeout_sec_, read_timeout_usec_,
-      write_timeout_sec_, write_timeout_usec_, std::move(callback));
+      write_timeout_sec_, write_timeout_usec_, max_timeout_msec_, start_time,
+      std::move(callback));
 }
 
 inline bool SSLClient::is_ssl() const { return true; }
@@ -9625,8 +9821,8 @@ SSLClient::verify_host_with_subject_alt_name(X509 *server_cert) const {
 
   auto type = GEN_DNS;
 
-  struct in6_addr addr6{};
-  struct in_addr addr{};
+  struct in6_addr addr6 = {};
+  struct in_addr addr = {};
   size_t addr_len = 0;
 
 #ifndef __MINGW32__
@@ -10274,7 +10470,7 @@ inline void Client::enable_server_hostname_verification(bool enabled) {
 }
 
 inline void Client::set_server_certificate_verifier(
-    std::function<bool(SSL *ssl)> verifier) {
+    std::function<SSLVerifierResponse(SSL *ssl)> verifier) {
   cli_->set_server_certificate_verifier(verifier);
 }
 #endif
@@ -10318,8 +10514,4 @@ inline SSL_CTX *Client::ssl_context() const {
 
 } // namespace httplib
 
-#if defined(_WIN32) && defined(CPPHTTPLIB_USE_POLL)
-#undef poll
-#endif
-
 #endif // CPPHTTPLIB_HTTPLIB_H
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index a9982b9..d4e684c 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -26,7 +26,7 @@ endif()
 
 find_package(CURL REQUIRED)
 
-add_executable(httplib-test test.cc)
+add_executable(httplib-test test.cc include_httplib.cc $<$<BOOL:${WIN32}>:include_windows_h.cc>)
 target_compile_options(httplib-test PRIVATE "$<$<CXX_COMPILER_ID:MSVC>:/utf-8;/bigobj>")
 target_link_libraries(httplib-test PRIVATE httplib GTest::gtest_main CURL::libcurl)
 gtest_discover_tests(httplib-test)
diff --git a/test/Makefile b/test/Makefile
index 587a675..3107702 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -1,5 +1,5 @@
 CXX = clang++
-CXXFLAGS = -g -std=c++11 -I. -Wall -Wextra -Wtype-limits -Wconversion -Wshadow # -fno-exceptions -DCPPHTTPLIB_NO_EXCEPTIONS -fsanitize=address
+CXXFLAGS = -g -std=c++11 -I. -Wall -Wextra -Wtype-limits -Wconversion -Wshadow $(EXTRA_CXXFLAGS) # -fno-exceptions -DCPPHTTPLIB_NO_EXCEPTIONS -fsanitize=address
 
 PREFIX ?= $(shell brew --prefix)
 
@@ -18,7 +18,10 @@ ZLIB_SUPPORT = -DCPPHTTPLIB_ZLIB_SUPPORT -lz
 BROTLI_DIR = $(PREFIX)/opt/brotli
 BROTLI_SUPPORT = -DCPPHTTPLIB_BROTLI_SUPPORT -I$(BROTLI_DIR)/include -L$(BROTLI_DIR)/lib -lbrotlicommon -lbrotlienc -lbrotlidec
 
-TEST_ARGS = gtest/gtest-all.cc gtest/gtest_main.cc $(OPENSSL_SUPPORT) $(ZLIB_SUPPORT) $(BROTLI_SUPPORT) -pthread -lcurl
+ZSTD_DIR = $(PREFIX)/opt/zstd
+ZSTD_SUPPORT = -DCPPHTTPLIB_ZSTD_SUPPORT -I$(ZSTD_DIR)/include -L$(ZSTD_DIR)/lib -lzstd
+
+TEST_ARGS = gtest/src/gtest-all.cc gtest/src/gtest_main.cc -Igtest -Igtest/include $(OPENSSL_SUPPORT) $(ZLIB_SUPPORT) $(BROTLI_SUPPORT) $(ZSTD_SUPPORT) -pthread -lcurl
 
 # By default, use standalone_fuzz_target_runner.
 # This runner does no fuzzing, but simply executes the inputs
@@ -28,6 +31,11 @@ TEST_ARGS = gtest/gtest-all.cc gtest/gtest_main.cc $(OPENSSL_SUPPORT) $(ZLIB_SUP
 # OSS-Fuzz will define its own value for LIB_FUZZING_ENGINE.
 LIB_FUZZING_ENGINE ?= standalone_fuzz_target_runner.o
 
+CLANG_FORMAT = clang-format
+REALPATH = $(shell which grealpath 2>/dev/null || which realpath 2>/dev/null)
+STYLE_CHECK_FILES = $(filter-out httplib.h httplib.cc, \
+	$(wildcard example/*.h example/*.cc fuzzing/*.h fuzzing/*.cc *.h *.cc ../httplib.h))
+
 all : test test_split
 	./test
 
@@ -36,12 +44,38 @@ proxy : test_proxy
 
 test : test.cc include_httplib.cc ../httplib.h Makefile cert.pem
 	$(CXX) -o $@ -I.. $(CXXFLAGS) test.cc include_httplib.cc $(TEST_ARGS)
+	@file $@
 
 # Note: The intention of test_split is to verify that it works to compile and
 # link the split httplib.h, so there is normally no need to execute it.
 test_split : test.cc ../httplib.h httplib.cc Makefile cert.pem
 	$(CXX) -o $@ $(CXXFLAGS) test.cc httplib.cc $(TEST_ARGS)
 
+check_abi:
+	@./check-shared-library-abi-compatibility.sh
+
+.PHONY: style_check
+style_check: $(STYLE_CHECK_FILES)
+	@for file in $(STYLE_CHECK_FILES); do \
+		$(CLANG_FORMAT) $$file > $$file.formatted; \
+		if ! diff -u $$file $$file.formatted; then \
+			file2=$$($(REALPATH) --relative-to=.. $$file); \
+			printf "\n%*s\n" 80 | tr ' ' '#'; \
+			printf "##%*s##\n" 76; \
+			printf "##   %-70s   ##\n" "$$file2 not properly formatted. Please run clang-format."; \
+			printf "##%*s##\n" 76; \
+			printf "%*s\n\n" 80 | tr ' ' '#'; \
+			failed=1; \
+		fi; \
+		rm -f $$file.formatted; \
+	done; \
+	if [ -n "$$failed" ]; then \
+		echo "Style check failed for one or more files. See above for details."; \
+		false; \
+	else \
+		echo "All files are properly formatted."; \
+	fi
+
 test_proxy : test_proxy.cc ../httplib.h Makefile cert.pem
 	$(CXX) -o $@ -I.. $(CXXFLAGS) test_proxy.cc $(TEST_ARGS)
 
@@ -53,6 +87,7 @@ fuzz_test: server_fuzzer
 # Fuzz target, so that you can choose which $(LIB_FUZZING_ENGINE) to use.
 server_fuzzer : fuzzing/server_fuzzer.cc ../httplib.h standalone_fuzz_target_runner.o
 	$(CXX) -o $@ -I.. $(CXXFLAGS) $< $(OPENSSL_SUPPORT) $(ZLIB_SUPPORT) $(BROTLI_SUPPORT) $(LIB_FUZZING_ENGINE) -pthread
+	@file $@
 
 # Standalone fuzz runner, which just reads inputs from fuzzing/corpus/ dir and
 # feeds it to server_fuzzer.
@@ -66,5 +101,5 @@ cert.pem:
 	./gen-certs.sh
 
 clean:
-	rm -f test test_split test_proxy server_fuzzer *.pem *.0 *.o *.1 *.srl httplib.h httplib.cc
+	rm -rf test test_split test_proxy server_fuzzer *.pem *.0 *.o *.1 *.srl httplib.h httplib.cc _build* *.dSYM
 
diff --git a/test/fuzzing/server_fuzzer.cc b/test/fuzzing/server_fuzzer.cc
index 3cffbae..a0f7c0e 100644
--- a/test/fuzzing/server_fuzzer.cc
+++ b/test/fuzzing/server_fuzzer.cc
@@ -25,7 +25,9 @@ public:
 
   bool is_readable() const override { return true; }
 
-  bool is_writable() const override { return true; }
+  bool wait_readable() const override { return true; }
+
+  bool wait_writable() const override { return true; }
 
   void get_remote_ip_and_port(std::string &ip, int &port) const override {
     ip = "127.0.0.1";
@@ -39,6 +41,8 @@ public:
 
   socket_t socket() const override { return 0; }
 
+  time_t duration() const override { return 0; };
+
 private:
   const uint8_t *data_;
   size_t size_;
diff --git a/test/gtest/gtest-all.cc b/test/gtest/gtest-all.cc
deleted file mode 100644
index 24e669e..0000000
--- a/test/gtest/gtest-all.cc
+++ /dev/null
@@ -1,12501 +0,0 @@
-// Copyright 2008, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-//
-// Google C++ Testing and Mocking Framework (Google Test)
-//
-// Sometimes it's desirable to build Google Test by compiling a single file.
-// This file serves this purpose.
-
-// This line ensures that gtest.h can be compiled on its own, even
-// when it's fused.
-#include "gtest/gtest.h"
-
-// The following lines pull in the real gtest *.cc files.
-// Copyright 2005, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-//
-// The Google C++ Testing and Mocking Framework (Google Test)
-
-// Copyright 2007, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-//
-// Utilities for testing Google Test itself and code that uses Google Test
-// (e.g. frameworks built on top of Google Test).
-
-// GOOGLETEST_CM0004 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_SPI_H_
-#define GOOGLETEST_INCLUDE_GTEST_GTEST_SPI_H_
-
-
-GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
-/* class A needs to have dll-interface to be used by clients of class B */)
-
-namespace testing {
-
-// This helper class can be used to mock out Google Test failure reporting
-// so that we can test Google Test or code that builds on Google Test.
-//
-// An object of this class appends a TestPartResult object to the
-// TestPartResultArray object given in the constructor whenever a Google Test
-// failure is reported. It can either intercept only failures that are
-// generated in the same thread that created this object or it can intercept
-// all generated failures. The scope of this mock object can be controlled with
-// the second argument to the two arguments constructor.
-class GTEST_API_ ScopedFakeTestPartResultReporter
-    : public TestPartResultReporterInterface {
- public:
-  // The two possible mocking modes of this object.
-  enum InterceptMode {
-    INTERCEPT_ONLY_CURRENT_THREAD,  // Intercepts only thread local failures.
-    INTERCEPT_ALL_THREADS           // Intercepts all failures.
-  };
-
-  // The c'tor sets this object as the test part result reporter used
-  // by Google Test.  The 'result' parameter specifies where to report the
-  // results. This reporter will only catch failures generated in the current
-  // thread. DEPRECATED
-  explicit ScopedFakeTestPartResultReporter(TestPartResultArray* result);
-
-  // Same as above, but you can choose the interception scope of this object.
-  ScopedFakeTestPartResultReporter(InterceptMode intercept_mode,
-                                   TestPartResultArray* result);
-
-  // The d'tor restores the previous test part result reporter.
-  ~ScopedFakeTestPartResultReporter() override;
-
-  // Appends the TestPartResult object to the TestPartResultArray
-  // received in the constructor.
-  //
-  // This method is from the TestPartResultReporterInterface
-  // interface.
-  void ReportTestPartResult(const TestPartResult& result) override;
-
- private:
-  void Init();
-
-  const InterceptMode intercept_mode_;
-  TestPartResultReporterInterface* old_reporter_;
-  TestPartResultArray* const result_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ScopedFakeTestPartResultReporter);
-};
-
-namespace internal {
-
-// A helper class for implementing EXPECT_FATAL_FAILURE() and
-// EXPECT_NONFATAL_FAILURE().  Its destructor verifies that the given
-// TestPartResultArray contains exactly one failure that has the given
-// type and contains the given substring.  If that's not the case, a
-// non-fatal failure will be generated.
-class GTEST_API_ SingleFailureChecker {
- public:
-  // The constructor remembers the arguments.
-  SingleFailureChecker(const TestPartResultArray* results,
-                       TestPartResult::Type type, const std::string& substr);
-  ~SingleFailureChecker();
- private:
-  const TestPartResultArray* const results_;
-  const TestPartResult::Type type_;
-  const std::string substr_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(SingleFailureChecker);
-};
-
-}  // namespace internal
-
-}  // namespace testing
-
-GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
-
-// A set of macros for testing Google Test assertions or code that's expected
-// to generate Google Test fatal failures.  It verifies that the given
-// statement will cause exactly one fatal Google Test failure with 'substr'
-// being part of the failure message.
-//
-// There are two different versions of this macro. EXPECT_FATAL_FAILURE only
-// affects and considers failures generated in the current thread and
-// EXPECT_FATAL_FAILURE_ON_ALL_THREADS does the same but for all threads.
-//
-// The verification of the assertion is done correctly even when the statement
-// throws an exception or aborts the current function.
-//
-// Known restrictions:
-//   - 'statement' cannot reference local non-static variables or
-//     non-static members of the current object.
-//   - 'statement' cannot return a value.
-//   - You cannot stream a failure message to this macro.
-//
-// Note that even though the implementations of the following two
-// macros are much alike, we cannot refactor them to use a common
-// helper macro, due to some peculiarity in how the preprocessor
-// works.  The AcceptsMacroThatExpandsToUnprotectedComma test in
-// gtest_unittest.cc will fail to compile if we do that.
-#define EXPECT_FATAL_FAILURE(statement, substr) \
-  do { \
-    class GTestExpectFatalFailureHelper {\
-     public:\
-      static void Execute() { statement; }\
-    };\
-    ::testing::TestPartResultArray gtest_failures;\
-    ::testing::internal::SingleFailureChecker gtest_checker(\
-        &gtest_failures, ::testing::TestPartResult::kFatalFailure, (substr));\
-    {\
-      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(\
-          ::testing::ScopedFakeTestPartResultReporter:: \
-          INTERCEPT_ONLY_CURRENT_THREAD, &gtest_failures);\
-      GTestExpectFatalFailureHelper::Execute();\
-    }\
-  } while (::testing::internal::AlwaysFalse())
-
-#define EXPECT_FATAL_FAILURE_ON_ALL_THREADS(statement, substr) \
-  do { \
-    class GTestExpectFatalFailureHelper {\
-     public:\
-      static void Execute() { statement; }\
-    };\
-    ::testing::TestPartResultArray gtest_failures;\
-    ::testing::internal::SingleFailureChecker gtest_checker(\
-        &gtest_failures, ::testing::TestPartResult::kFatalFailure, (substr));\
-    {\
-      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(\
-          ::testing::ScopedFakeTestPartResultReporter:: \
-          INTERCEPT_ALL_THREADS, &gtest_failures);\
-      GTestExpectFatalFailureHelper::Execute();\
-    }\
-  } while (::testing::internal::AlwaysFalse())
-
-// A macro for testing Google Test assertions or code that's expected to
-// generate Google Test non-fatal failures.  It asserts that the given
-// statement will cause exactly one non-fatal Google Test failure with 'substr'
-// being part of the failure message.
-//
-// There are two different versions of this macro. EXPECT_NONFATAL_FAILURE only
-// affects and considers failures generated in the current thread and
-// EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS does the same but for all threads.
-//
-// 'statement' is allowed to reference local variables and members of
-// the current object.
-//
-// The verification of the assertion is done correctly even when the statement
-// throws an exception or aborts the current function.
-//
-// Known restrictions:
-//   - You cannot stream a failure message to this macro.
-//
-// Note that even though the implementations of the following two
-// macros are much alike, we cannot refactor them to use a common
-// helper macro, due to some peculiarity in how the preprocessor
-// works.  If we do that, the code won't compile when the user gives
-// EXPECT_NONFATAL_FAILURE() a statement that contains a macro that
-// expands to code containing an unprotected comma.  The
-// AcceptsMacroThatExpandsToUnprotectedComma test in gtest_unittest.cc
-// catches that.
-//
-// For the same reason, we have to write
-//   if (::testing::internal::AlwaysTrue()) { statement; }
-// instead of
-//   GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement)
-// to avoid an MSVC warning on unreachable code.
-#define EXPECT_NONFATAL_FAILURE(statement, substr) \
-  do {\
-    ::testing::TestPartResultArray gtest_failures;\
-    ::testing::internal::SingleFailureChecker gtest_checker(\
-        &gtest_failures, ::testing::TestPartResult::kNonFatalFailure, \
-        (substr));\
-    {\
-      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(\
-          ::testing::ScopedFakeTestPartResultReporter:: \
-          INTERCEPT_ONLY_CURRENT_THREAD, &gtest_failures);\
-      if (::testing::internal::AlwaysTrue()) { statement; }\
-    }\
-  } while (::testing::internal::AlwaysFalse())
-
-#define EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS(statement, substr) \
-  do {\
-    ::testing::TestPartResultArray gtest_failures;\
-    ::testing::internal::SingleFailureChecker gtest_checker(\
-        &gtest_failures, ::testing::TestPartResult::kNonFatalFailure, \
-        (substr));\
-    {\
-      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(\
-          ::testing::ScopedFakeTestPartResultReporter::INTERCEPT_ALL_THREADS, \
-          &gtest_failures);\
-      if (::testing::internal::AlwaysTrue()) { statement; }\
-    }\
-  } while (::testing::internal::AlwaysFalse())
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_SPI_H_
-
-#include <ctype.h>
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <wchar.h>
-#include <wctype.h>
-
-#include <algorithm>
-#include <chrono>  // NOLINT
-#include <cmath>
-#include <cstdint>
-#include <iomanip>
-#include <limits>
-#include <list>
-#include <map>
-#include <ostream>  // NOLINT
-#include <sstream>
-#include <vector>
-
-#if GTEST_OS_LINUX
-
-# include <fcntl.h>  // NOLINT
-# include <limits.h>  // NOLINT
-# include <sched.h>  // NOLINT
-// Declares vsnprintf().  This header is not available on Windows.
-# include <strings.h>  // NOLINT
-# include <sys/mman.h>  // NOLINT
-# include <sys/time.h>  // NOLINT
-# include <unistd.h>  // NOLINT
-# include <string>
-
-#elif GTEST_OS_ZOS
-# include <sys/time.h>  // NOLINT
-
-// On z/OS we additionally need strings.h for strcasecmp.
-# include <strings.h>  // NOLINT
-
-#elif GTEST_OS_WINDOWS_MOBILE  // We are on Windows CE.
-
-# include <windows.h>  // NOLINT
-# undef min
-
-#elif GTEST_OS_WINDOWS  // We are on Windows proper.
-
-# include <windows.h>  // NOLINT
-# undef min
-
-#ifdef _MSC_VER
-# include <crtdbg.h>  // NOLINT
-#endif
-
-# include <io.h>  // NOLINT
-# include <sys/timeb.h>  // NOLINT
-# include <sys/types.h>  // NOLINT
-# include <sys/stat.h>  // NOLINT
-
-# if GTEST_OS_WINDOWS_MINGW
-#  include <sys/time.h>  // NOLINT
-# endif  // GTEST_OS_WINDOWS_MINGW
-
-#else
-
-// cpplint thinks that the header is already included, so we want to
-// silence it.
-# include <sys/time.h>  // NOLINT
-# include <unistd.h>  // NOLINT
-
-#endif  // GTEST_OS_LINUX
-
-#if GTEST_HAS_EXCEPTIONS
-# include <stdexcept>
-#endif
-
-#if GTEST_CAN_STREAM_RESULTS_
-# include <arpa/inet.h>  // NOLINT
-# include <netdb.h>  // NOLINT
-# include <sys/socket.h>  // NOLINT
-# include <sys/types.h>  // NOLINT
-#endif
-
-// Copyright 2005, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// Utility functions and classes used by the Google C++ testing framework.//
-// This file contains purely Google Test's internal implementation.  Please
-// DO NOT #INCLUDE IT IN A USER PROGRAM.
-
-#ifndef GOOGLETEST_SRC_GTEST_INTERNAL_INL_H_
-#define GOOGLETEST_SRC_GTEST_INTERNAL_INL_H_
-
-#ifndef _WIN32_WCE
-# include <errno.h>
-#endif  // !_WIN32_WCE
-#include <stddef.h>
-#include <stdlib.h>  // For strtoll/_strtoul64/malloc/free.
-#include <string.h>  // For memmove.
-
-#include <algorithm>
-#include <cstdint>
-#include <memory>
-#include <string>
-#include <vector>
-
-
-#if GTEST_CAN_STREAM_RESULTS_
-# include <arpa/inet.h>  // NOLINT
-# include <netdb.h>  // NOLINT
-#endif
-
-#if GTEST_OS_WINDOWS
-# include <windows.h>  // NOLINT
-#endif  // GTEST_OS_WINDOWS
-
-
-GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
-/* class A needs to have dll-interface to be used by clients of class B */)
-
-namespace testing {
-
-// Declares the flags.
-//
-// We don't want the users to modify this flag in the code, but want
-// Google Test's own unit tests to be able to access it. Therefore we
-// declare it here as opposed to in gtest.h.
-GTEST_DECLARE_bool_(death_test_use_fork);
-
-namespace internal {
-
-// The value of GetTestTypeId() as seen from within the Google Test
-// library.  This is solely for testing GetTestTypeId().
-GTEST_API_ extern const TypeId kTestTypeIdInGoogleTest;
-
-// Names of the flags (needed for parsing Google Test flags).
-const char kAlsoRunDisabledTestsFlag[] = "also_run_disabled_tests";
-const char kBreakOnFailureFlag[] = "break_on_failure";
-const char kCatchExceptionsFlag[] = "catch_exceptions";
-const char kColorFlag[] = "color";
-const char kFailFast[] = "fail_fast";
-const char kFilterFlag[] = "filter";
-const char kListTestsFlag[] = "list_tests";
-const char kOutputFlag[] = "output";
-const char kBriefFlag[] = "brief";
-const char kPrintTimeFlag[] = "print_time";
-const char kPrintUTF8Flag[] = "print_utf8";
-const char kRandomSeedFlag[] = "random_seed";
-const char kRepeatFlag[] = "repeat";
-const char kShuffleFlag[] = "shuffle";
-const char kStackTraceDepthFlag[] = "stack_trace_depth";
-const char kStreamResultToFlag[] = "stream_result_to";
-const char kThrowOnFailureFlag[] = "throw_on_failure";
-const char kFlagfileFlag[] = "flagfile";
-
-// A valid random seed must be in [1, kMaxRandomSeed].
-const int kMaxRandomSeed = 99999;
-
-// g_help_flag is true if and only if the --help flag or an equivalent form
-// is specified on the command line.
-GTEST_API_ extern bool g_help_flag;
-
-// Returns the current time in milliseconds.
-GTEST_API_ TimeInMillis GetTimeInMillis();
-
-// Returns true if and only if Google Test should use colors in the output.
-GTEST_API_ bool ShouldUseColor(bool stdout_is_tty);
-
-// Formats the given time in milliseconds as seconds.
-GTEST_API_ std::string FormatTimeInMillisAsSeconds(TimeInMillis ms);
-
-// Converts the given time in milliseconds to a date string in the ISO 8601
-// format, without the timezone information.  N.B.: due to the use the
-// non-reentrant localtime() function, this function is not thread safe.  Do
-// not use it in any code that can be called from multiple threads.
-GTEST_API_ std::string FormatEpochTimeInMillisAsIso8601(TimeInMillis ms);
-
-// Parses a string for an Int32 flag, in the form of "--flag=value".
-//
-// On success, stores the value of the flag in *value, and returns
-// true.  On failure, returns false without changing *value.
-GTEST_API_ bool ParseInt32Flag(
-    const char* str, const char* flag, int32_t* value);
-
-// Returns a random seed in range [1, kMaxRandomSeed] based on the
-// given --gtest_random_seed flag value.
-inline int GetRandomSeedFromFlag(int32_t random_seed_flag) {
-  const unsigned int raw_seed = (random_seed_flag == 0) ?
-      static_cast<unsigned int>(GetTimeInMillis()) :
-      static_cast<unsigned int>(random_seed_flag);
-
-  // Normalizes the actual seed to range [1, kMaxRandomSeed] such that
-  // it's easy to type.
-  const int normalized_seed =
-      static_cast<int>((raw_seed - 1U) %
-                       static_cast<unsigned int>(kMaxRandomSeed)) + 1;
-  return normalized_seed;
-}
-
-// Returns the first valid random seed after 'seed'.  The behavior is
-// undefined if 'seed' is invalid.  The seed after kMaxRandomSeed is
-// considered to be 1.
-inline int GetNextRandomSeed(int seed) {
-  GTEST_CHECK_(1 <= seed && seed <= kMaxRandomSeed)
-      << "Invalid random seed " << seed << " - must be in [1, "
-      << kMaxRandomSeed << "].";
-  const int next_seed = seed + 1;
-  return (next_seed > kMaxRandomSeed) ? 1 : next_seed;
-}
-
-// This class saves the values of all Google Test flags in its c'tor, and
-// restores them in its d'tor.
-class GTestFlagSaver {
- public:
-  // The c'tor.
-  GTestFlagSaver() {
-    also_run_disabled_tests_ = GTEST_FLAG(also_run_disabled_tests);
-    break_on_failure_ = GTEST_FLAG(break_on_failure);
-    catch_exceptions_ = GTEST_FLAG(catch_exceptions);
-    color_ = GTEST_FLAG(color);
-    death_test_style_ = GTEST_FLAG(death_test_style);
-    death_test_use_fork_ = GTEST_FLAG(death_test_use_fork);
-    fail_fast_ = GTEST_FLAG(fail_fast);
-    filter_ = GTEST_FLAG(filter);
-    internal_run_death_test_ = GTEST_FLAG(internal_run_death_test);
-    list_tests_ = GTEST_FLAG(list_tests);
-    output_ = GTEST_FLAG(output);
-    brief_ = GTEST_FLAG(brief);
-    print_time_ = GTEST_FLAG(print_time);
-    print_utf8_ = GTEST_FLAG(print_utf8);
-    random_seed_ = GTEST_FLAG(random_seed);
-    repeat_ = GTEST_FLAG(repeat);
-    shuffle_ = GTEST_FLAG(shuffle);
-    stack_trace_depth_ = GTEST_FLAG(stack_trace_depth);
-    stream_result_to_ = GTEST_FLAG(stream_result_to);
-    throw_on_failure_ = GTEST_FLAG(throw_on_failure);
-  }
-
-  // The d'tor is not virtual.  DO NOT INHERIT FROM THIS CLASS.
-  ~GTestFlagSaver() {
-    GTEST_FLAG(also_run_disabled_tests) = also_run_disabled_tests_;
-    GTEST_FLAG(break_on_failure) = break_on_failure_;
-    GTEST_FLAG(catch_exceptions) = catch_exceptions_;
-    GTEST_FLAG(color) = color_;
-    GTEST_FLAG(death_test_style) = death_test_style_;
-    GTEST_FLAG(death_test_use_fork) = death_test_use_fork_;
-    GTEST_FLAG(filter) = filter_;
-    GTEST_FLAG(fail_fast) = fail_fast_;
-    GTEST_FLAG(internal_run_death_test) = internal_run_death_test_;
-    GTEST_FLAG(list_tests) = list_tests_;
-    GTEST_FLAG(output) = output_;
-    GTEST_FLAG(brief) = brief_;
-    GTEST_FLAG(print_time) = print_time_;
-    GTEST_FLAG(print_utf8) = print_utf8_;
-    GTEST_FLAG(random_seed) = random_seed_;
-    GTEST_FLAG(repeat) = repeat_;
-    GTEST_FLAG(shuffle) = shuffle_;
-    GTEST_FLAG(stack_trace_depth) = stack_trace_depth_;
-    GTEST_FLAG(stream_result_to) = stream_result_to_;
-    GTEST_FLAG(throw_on_failure) = throw_on_failure_;
-  }
-
- private:
-  // Fields for saving the original values of flags.
-  bool also_run_disabled_tests_;
-  bool break_on_failure_;
-  bool catch_exceptions_;
-  std::string color_;
-  std::string death_test_style_;
-  bool death_test_use_fork_;
-  bool fail_fast_;
-  std::string filter_;
-  std::string internal_run_death_test_;
-  bool list_tests_;
-  std::string output_;
-  bool brief_;
-  bool print_time_;
-  bool print_utf8_;
-  int32_t random_seed_;
-  int32_t repeat_;
-  bool shuffle_;
-  int32_t stack_trace_depth_;
-  std::string stream_result_to_;
-  bool throw_on_failure_;
-} GTEST_ATTRIBUTE_UNUSED_;
-
-// Converts a Unicode code point to a narrow string in UTF-8 encoding.
-// code_point parameter is of type UInt32 because wchar_t may not be
-// wide enough to contain a code point.
-// If the code_point is not a valid Unicode code point
-// (i.e. outside of Unicode range U+0 to U+10FFFF) it will be converted
-// to "(Invalid Unicode 0xXXXXXXXX)".
-GTEST_API_ std::string CodePointToUtf8(uint32_t code_point);
-
-// Converts a wide string to a narrow string in UTF-8 encoding.
-// The wide string is assumed to have the following encoding:
-//   UTF-16 if sizeof(wchar_t) == 2 (on Windows, Cygwin)
-//   UTF-32 if sizeof(wchar_t) == 4 (on Linux)
-// Parameter str points to a null-terminated wide string.
-// Parameter num_chars may additionally limit the number
-// of wchar_t characters processed. -1 is used when the entire string
-// should be processed.
-// If the string contains code points that are not valid Unicode code points
-// (i.e. outside of Unicode range U+0 to U+10FFFF) they will be output
-// as '(Invalid Unicode 0xXXXXXXXX)'. If the string is in UTF16 encoding
-// and contains invalid UTF-16 surrogate pairs, values in those pairs
-// will be encoded as individual Unicode characters from Basic Normal Plane.
-GTEST_API_ std::string WideStringToUtf8(const wchar_t* str, int num_chars);
-
-// Reads the GTEST_SHARD_STATUS_FILE environment variable, and creates the file
-// if the variable is present. If a file already exists at this location, this
-// function will write over it. If the variable is present, but the file cannot
-// be created, prints an error and exits.
-void WriteToShardStatusFileIfNeeded();
-
-// Checks whether sharding is enabled by examining the relevant
-// environment variable values. If the variables are present,
-// but inconsistent (e.g., shard_index >= total_shards), prints
-// an error and exits. If in_subprocess_for_death_test, sharding is
-// disabled because it must only be applied to the original test
-// process. Otherwise, we could filter out death tests we intended to execute.
-GTEST_API_ bool ShouldShard(const char* total_shards_str,
-                            const char* shard_index_str,
-                            bool in_subprocess_for_death_test);
-
-// Parses the environment variable var as a 32-bit integer. If it is unset,
-// returns default_val. If it is not a 32-bit integer, prints an error and
-// and aborts.
-GTEST_API_ int32_t Int32FromEnvOrDie(const char* env_var, int32_t default_val);
-
-// Given the total number of shards, the shard index, and the test id,
-// returns true if and only if the test should be run on this shard. The test id
-// is some arbitrary but unique non-negative integer assigned to each test
-// method. Assumes that 0 <= shard_index < total_shards.
-GTEST_API_ bool ShouldRunTestOnShard(
-    int total_shards, int shard_index, int test_id);
-
-// STL container utilities.
-
-// Returns the number of elements in the given container that satisfy
-// the given predicate.
-template <class Container, typename Predicate>
-inline int CountIf(const Container& c, Predicate predicate) {
-  // Implemented as an explicit loop since std::count_if() in libCstd on
-  // Solaris has a non-standard signature.
-  int count = 0;
-  for (typename Container::const_iterator it = c.begin(); it != c.end(); ++it) {
-    if (predicate(*it))
-      ++count;
-  }
-  return count;
-}
-
-// Applies a function/functor to each element in the container.
-template <class Container, typename Functor>
-void ForEach(const Container& c, Functor functor) {
-  std::for_each(c.begin(), c.end(), functor);
-}
-
-// Returns the i-th element of the vector, or default_value if i is not
-// in range [0, v.size()).
-template <typename E>
-inline E GetElementOr(const std::vector<E>& v, int i, E default_value) {
-  return (i < 0 || i >= static_cast<int>(v.size())) ? default_value
-                                                    : v[static_cast<size_t>(i)];
-}
-
-// Performs an in-place shuffle of a range of the vector's elements.
-// 'begin' and 'end' are element indices as an STL-style range;
-// i.e. [begin, end) are shuffled, where 'end' == size() means to
-// shuffle to the end of the vector.
-template <typename E>
-void ShuffleRange(internal::Random* random, int begin, int end,
-                  std::vector<E>* v) {
-  const int size = static_cast<int>(v->size());
-  GTEST_CHECK_(0 <= begin && begin <= size)
-      << "Invalid shuffle range start " << begin << ": must be in range [0, "
-      << size << "].";
-  GTEST_CHECK_(begin <= end && end <= size)
-      << "Invalid shuffle range finish " << end << ": must be in range ["
-      << begin << ", " << size << "].";
-
-  // Fisher-Yates shuffle, from
-  // http://en.wikipedia.org/wiki/Fisher-Yates_shuffle
-  for (int range_width = end - begin; range_width >= 2; range_width--) {
-    const int last_in_range = begin + range_width - 1;
-    const int selected =
-        begin +
-        static_cast<int>(random->Generate(static_cast<uint32_t>(range_width)));
-    std::swap((*v)[static_cast<size_t>(selected)],
-              (*v)[static_cast<size_t>(last_in_range)]);
-  }
-}
-
-// Performs an in-place shuffle of the vector's elements.
-template <typename E>
-inline void Shuffle(internal::Random* random, std::vector<E>* v) {
-  ShuffleRange(random, 0, static_cast<int>(v->size()), v);
-}
-
-// A function for deleting an object.  Handy for being used as a
-// functor.
-template <typename T>
-static void Delete(T* x) {
-  delete x;
-}
-
-// A predicate that checks the key of a TestProperty against a known key.
-//
-// TestPropertyKeyIs is copyable.
-class TestPropertyKeyIs {
- public:
-  // Constructor.
-  //
-  // TestPropertyKeyIs has NO default constructor.
-  explicit TestPropertyKeyIs(const std::string& key) : key_(key) {}
-
-  // Returns true if and only if the test name of test property matches on key_.
-  bool operator()(const TestProperty& test_property) const {
-    return test_property.key() == key_;
-  }
-
- private:
-  std::string key_;
-};
-
-// Class UnitTestOptions.
-//
-// This class contains functions for processing options the user
-// specifies when running the tests.  It has only static members.
-//
-// In most cases, the user can specify an option using either an
-// environment variable or a command line flag.  E.g. you can set the
-// test filter using either GTEST_FILTER or --gtest_filter.  If both
-// the variable and the flag are present, the latter overrides the
-// former.
-class GTEST_API_ UnitTestOptions {
- public:
-  // Functions for processing the gtest_output flag.
-
-  // Returns the output format, or "" for normal printed output.
-  static std::string GetOutputFormat();
-
-  // Returns the absolute path of the requested output file, or the
-  // default (test_detail.xml in the original working directory) if
-  // none was explicitly specified.
-  static std::string GetAbsolutePathToOutputFile();
-
-  // Functions for processing the gtest_filter flag.
-
-  // Returns true if and only if the user-specified filter matches the test
-  // suite name and the test name.
-  static bool FilterMatchesTest(const std::string& test_suite_name,
-                                const std::string& test_name);
-
-#if GTEST_OS_WINDOWS
-  // Function for supporting the gtest_catch_exception flag.
-
-  // Returns EXCEPTION_EXECUTE_HANDLER if Google Test should handle the
-  // given SEH exception, or EXCEPTION_CONTINUE_SEARCH otherwise.
-  // This function is useful as an __except condition.
-  static int GTestShouldProcessSEH(DWORD exception_code);
-#endif  // GTEST_OS_WINDOWS
-
-  // Returns true if "name" matches the ':' separated list of glob-style
-  // filters in "filter".
-  static bool MatchesFilter(const std::string& name, const char* filter);
-};
-
-// Returns the current application's name, removing directory path if that
-// is present.  Used by UnitTestOptions::GetOutputFile.
-GTEST_API_ FilePath GetCurrentExecutableName();
-
-// The role interface for getting the OS stack trace as a string.
-class OsStackTraceGetterInterface {
- public:
-  OsStackTraceGetterInterface() {}
-  virtual ~OsStackTraceGetterInterface() {}
-
-  // Returns the current OS stack trace as an std::string.  Parameters:
-  //
-  //   max_depth  - the maximum number of stack frames to be included
-  //                in the trace.
-  //   skip_count - the number of top frames to be skipped; doesn't count
-  //                against max_depth.
-  virtual std::string CurrentStackTrace(int max_depth, int skip_count) = 0;
-
-  // UponLeavingGTest() should be called immediately before Google Test calls
-  // user code. It saves some information about the current stack that
-  // CurrentStackTrace() will use to find and hide Google Test stack frames.
-  virtual void UponLeavingGTest() = 0;
-
-  // This string is inserted in place of stack frames that are part of
-  // Google Test's implementation.
-  static const char* const kElidedFramesMarker;
-
- private:
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(OsStackTraceGetterInterface);
-};
-
-// A working implementation of the OsStackTraceGetterInterface interface.
-class OsStackTraceGetter : public OsStackTraceGetterInterface {
- public:
-  OsStackTraceGetter() {}
-
-  std::string CurrentStackTrace(int max_depth, int skip_count) override;
-  void UponLeavingGTest() override;
-
- private:
-#if GTEST_HAS_ABSL
-  Mutex mutex_;  // Protects all internal state.
-
-  // We save the stack frame below the frame that calls user code.
-  // We do this because the address of the frame immediately below
-  // the user code changes between the call to UponLeavingGTest()
-  // and any calls to the stack trace code from within the user code.
-  void* caller_frame_ = nullptr;
-#endif  // GTEST_HAS_ABSL
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(OsStackTraceGetter);
-};
-
-// Information about a Google Test trace point.
-struct TraceInfo {
-  const char* file;
-  int line;
-  std::string message;
-};
-
-// This is the default global test part result reporter used in UnitTestImpl.
-// This class should only be used by UnitTestImpl.
-class DefaultGlobalTestPartResultReporter
-  : public TestPartResultReporterInterface {
- public:
-  explicit DefaultGlobalTestPartResultReporter(UnitTestImpl* unit_test);
-  // Implements the TestPartResultReporterInterface. Reports the test part
-  // result in the current test.
-  void ReportTestPartResult(const TestPartResult& result) override;
-
- private:
-  UnitTestImpl* const unit_test_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(DefaultGlobalTestPartResultReporter);
-};
-
-// This is the default per thread test part result reporter used in
-// UnitTestImpl. This class should only be used by UnitTestImpl.
-class DefaultPerThreadTestPartResultReporter
-    : public TestPartResultReporterInterface {
- public:
-  explicit DefaultPerThreadTestPartResultReporter(UnitTestImpl* unit_test);
-  // Implements the TestPartResultReporterInterface. The implementation just
-  // delegates to the current global test part result reporter of *unit_test_.
-  void ReportTestPartResult(const TestPartResult& result) override;
-
- private:
-  UnitTestImpl* const unit_test_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(DefaultPerThreadTestPartResultReporter);
-};
-
-// The private implementation of the UnitTest class.  We don't protect
-// the methods under a mutex, as this class is not accessible by a
-// user and the UnitTest class that delegates work to this class does
-// proper locking.
-class GTEST_API_ UnitTestImpl {
- public:
-  explicit UnitTestImpl(UnitTest* parent);
-  virtual ~UnitTestImpl();
-
-  // There are two different ways to register your own TestPartResultReporter.
-  // You can register your own repoter to listen either only for test results
-  // from the current thread or for results from all threads.
-  // By default, each per-thread test result repoter just passes a new
-  // TestPartResult to the global test result reporter, which registers the
-  // test part result for the currently running test.
-
-  // Returns the global test part result reporter.
-  TestPartResultReporterInterface* GetGlobalTestPartResultReporter();
-
-  // Sets the global test part result reporter.
-  void SetGlobalTestPartResultReporter(
-      TestPartResultReporterInterface* reporter);
-
-  // Returns the test part result reporter for the current thread.
-  TestPartResultReporterInterface* GetTestPartResultReporterForCurrentThread();
-
-  // Sets the test part result reporter for the current thread.
-  void SetTestPartResultReporterForCurrentThread(
-      TestPartResultReporterInterface* reporter);
-
-  // Gets the number of successful test suites.
-  int successful_test_suite_count() const;
-
-  // Gets the number of failed test suites.
-  int failed_test_suite_count() const;
-
-  // Gets the number of all test suites.
-  int total_test_suite_count() const;
-
-  // Gets the number of all test suites that contain at least one test
-  // that should run.
-  int test_suite_to_run_count() const;
-
-  // Gets the number of successful tests.
-  int successful_test_count() const;
-
-  // Gets the number of skipped tests.
-  int skipped_test_count() const;
-
-  // Gets the number of failed tests.
-  int failed_test_count() const;
-
-  // Gets the number of disabled tests that will be reported in the XML report.
-  int reportable_disabled_test_count() const;
-
-  // Gets the number of disabled tests.
-  int disabled_test_count() const;
-
-  // Gets the number of tests to be printed in the XML report.
-  int reportable_test_count() const;
-
-  // Gets the number of all tests.
-  int total_test_count() const;
-
-  // Gets the number of tests that should run.
-  int test_to_run_count() const;
-
-  // Gets the time of the test program start, in ms from the start of the
-  // UNIX epoch.
-  TimeInMillis start_timestamp() const { return start_timestamp_; }
-
-  // Gets the elapsed time, in milliseconds.
-  TimeInMillis elapsed_time() const { return elapsed_time_; }
-
-  // Returns true if and only if the unit test passed (i.e. all test suites
-  // passed).
-  bool Passed() const { return !Failed(); }
-
-  // Returns true if and only if the unit test failed (i.e. some test suite
-  // failed or something outside of all tests failed).
-  bool Failed() const {
-    return failed_test_suite_count() > 0 || ad_hoc_test_result()->Failed();
-  }
-
-  // Gets the i-th test suite among all the test suites. i can range from 0 to
-  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
-  const TestSuite* GetTestSuite(int i) const {
-    const int index = GetElementOr(test_suite_indices_, i, -1);
-    return index < 0 ? nullptr : test_suites_[static_cast<size_t>(i)];
-  }
-
-  //  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  const TestCase* GetTestCase(int i) const { return GetTestSuite(i); }
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  // Gets the i-th test suite among all the test suites. i can range from 0 to
-  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
-  TestSuite* GetMutableSuiteCase(int i) {
-    const int index = GetElementOr(test_suite_indices_, i, -1);
-    return index < 0 ? nullptr : test_suites_[static_cast<size_t>(index)];
-  }
-
-  // Provides access to the event listener list.
-  TestEventListeners* listeners() { return &listeners_; }
-
-  // Returns the TestResult for the test that's currently running, or
-  // the TestResult for the ad hoc test if no test is running.
-  TestResult* current_test_result();
-
-  // Returns the TestResult for the ad hoc test.
-  const TestResult* ad_hoc_test_result() const { return &ad_hoc_test_result_; }
-
-  // Sets the OS stack trace getter.
-  //
-  // Does nothing if the input and the current OS stack trace getter
-  // are the same; otherwise, deletes the old getter and makes the
-  // input the current getter.
-  void set_os_stack_trace_getter(OsStackTraceGetterInterface* getter);
-
-  // Returns the current OS stack trace getter if it is not NULL;
-  // otherwise, creates an OsStackTraceGetter, makes it the current
-  // getter, and returns it.
-  OsStackTraceGetterInterface* os_stack_trace_getter();
-
-  // Returns the current OS stack trace as an std::string.
-  //
-  // The maximum number of stack frames to be included is specified by
-  // the gtest_stack_trace_depth flag.  The skip_count parameter
-  // specifies the number of top frames to be skipped, which doesn't
-  // count against the number of frames to be included.
-  //
-  // For example, if Foo() calls Bar(), which in turn calls
-  // CurrentOsStackTraceExceptTop(1), Foo() will be included in the
-  // trace but Bar() and CurrentOsStackTraceExceptTop() won't.
-  std::string CurrentOsStackTraceExceptTop(int skip_count) GTEST_NO_INLINE_;
-
-  // Finds and returns a TestSuite with the given name.  If one doesn't
-  // exist, creates one and returns it.
-  //
-  // Arguments:
-  //
-  //   test_suite_name: name of the test suite
-  //   type_param:      the name of the test's type parameter, or NULL if
-  //                    this is not a typed or a type-parameterized test.
-  //   set_up_tc:       pointer to the function that sets up the test suite
-  //   tear_down_tc:    pointer to the function that tears down the test suite
-  TestSuite* GetTestSuite(const char* test_suite_name, const char* type_param,
-                          internal::SetUpTestSuiteFunc set_up_tc,
-                          internal::TearDownTestSuiteFunc tear_down_tc);
-
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  TestCase* GetTestCase(const char* test_case_name, const char* type_param,
-                        internal::SetUpTestSuiteFunc set_up_tc,
-                        internal::TearDownTestSuiteFunc tear_down_tc) {
-    return GetTestSuite(test_case_name, type_param, set_up_tc, tear_down_tc);
-  }
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  // Adds a TestInfo to the unit test.
-  //
-  // Arguments:
-  //
-  //   set_up_tc:    pointer to the function that sets up the test suite
-  //   tear_down_tc: pointer to the function that tears down the test suite
-  //   test_info:    the TestInfo object
-  void AddTestInfo(internal::SetUpTestSuiteFunc set_up_tc,
-                   internal::TearDownTestSuiteFunc tear_down_tc,
-                   TestInfo* test_info) {
-#if GTEST_HAS_DEATH_TEST
-    // In order to support thread-safe death tests, we need to
-    // remember the original working directory when the test program
-    // was first invoked.  We cannot do this in RUN_ALL_TESTS(), as
-    // the user may have changed the current directory before calling
-    // RUN_ALL_TESTS().  Therefore we capture the current directory in
-    // AddTestInfo(), which is called to register a TEST or TEST_F
-    // before main() is reached.
-    if (original_working_dir_.IsEmpty()) {
-      original_working_dir_.Set(FilePath::GetCurrentDir());
-      GTEST_CHECK_(!original_working_dir_.IsEmpty())
-          << "Failed to get the current working directory.";
-    }
-#endif  // GTEST_HAS_DEATH_TEST
-
-    GetTestSuite(test_info->test_suite_name(), test_info->type_param(),
-                 set_up_tc, tear_down_tc)
-        ->AddTestInfo(test_info);
-  }
-
-  // Returns ParameterizedTestSuiteRegistry object used to keep track of
-  // value-parameterized tests and instantiate and register them.
-  internal::ParameterizedTestSuiteRegistry& parameterized_test_registry() {
-    return parameterized_test_registry_;
-  }
-
-  std::set<std::string>* ignored_parameterized_test_suites() {
-    return &ignored_parameterized_test_suites_;
-  }
-
-  // Returns TypeParameterizedTestSuiteRegistry object used to keep track of
-  // type-parameterized tests and instantiations of them.
-  internal::TypeParameterizedTestSuiteRegistry&
-  type_parameterized_test_registry() {
-    return type_parameterized_test_registry_;
-  }
-
-  // Sets the TestSuite object for the test that's currently running.
-  void set_current_test_suite(TestSuite* a_current_test_suite) {
-    current_test_suite_ = a_current_test_suite;
-  }
-
-  // Sets the TestInfo object for the test that's currently running.  If
-  // current_test_info is NULL, the assertion results will be stored in
-  // ad_hoc_test_result_.
-  void set_current_test_info(TestInfo* a_current_test_info) {
-    current_test_info_ = a_current_test_info;
-  }
-
-  // Registers all parameterized tests defined using TEST_P and
-  // INSTANTIATE_TEST_SUITE_P, creating regular tests for each test/parameter
-  // combination. This method can be called more then once; it has guards
-  // protecting from registering the tests more then once.  If
-  // value-parameterized tests are disabled, RegisterParameterizedTests is
-  // present but does nothing.
-  void RegisterParameterizedTests();
-
-  // Runs all tests in this UnitTest object, prints the result, and
-  // returns true if all tests are successful.  If any exception is
-  // thrown during a test, this test is considered to be failed, but
-  // the rest of the tests will still be run.
-  bool RunAllTests();
-
-  // Clears the results of all tests, except the ad hoc tests.
-  void ClearNonAdHocTestResult() {
-    ForEach(test_suites_, TestSuite::ClearTestSuiteResult);
-  }
-
-  // Clears the results of ad-hoc test assertions.
-  void ClearAdHocTestResult() {
-    ad_hoc_test_result_.Clear();
-  }
-
-  // Adds a TestProperty to the current TestResult object when invoked in a
-  // context of a test or a test suite, or to the global property set. If the
-  // result already contains a property with the same key, the value will be
-  // updated.
-  void RecordProperty(const TestProperty& test_property);
-
-  enum ReactionToSharding {
-    HONOR_SHARDING_PROTOCOL,
-    IGNORE_SHARDING_PROTOCOL
-  };
-
-  // Matches the full name of each test against the user-specified
-  // filter to decide whether the test should run, then records the
-  // result in each TestSuite and TestInfo object.
-  // If shard_tests == HONOR_SHARDING_PROTOCOL, further filters tests
-  // based on sharding variables in the environment.
-  // Returns the number of tests that should run.
-  int FilterTests(ReactionToSharding shard_tests);
-
-  // Prints the names of the tests matching the user-specified filter flag.
-  void ListTestsMatchingFilter();
-
-  const TestSuite* current_test_suite() const { return current_test_suite_; }
-  TestInfo* current_test_info() { return current_test_info_; }
-  const TestInfo* current_test_info() const { return current_test_info_; }
-
-  // Returns the vector of environments that need to be set-up/torn-down
-  // before/after the tests are run.
-  std::vector<Environment*>& environments() { return environments_; }
-
-  // Getters for the per-thread Google Test trace stack.
-  std::vector<TraceInfo>& gtest_trace_stack() {
-    return *(gtest_trace_stack_.pointer());
-  }
-  const std::vector<TraceInfo>& gtest_trace_stack() const {
-    return gtest_trace_stack_.get();
-  }
-
-#if GTEST_HAS_DEATH_TEST
-  void InitDeathTestSubprocessControlInfo() {
-    internal_run_death_test_flag_.reset(ParseInternalRunDeathTestFlag());
-  }
-  // Returns a pointer to the parsed --gtest_internal_run_death_test
-  // flag, or NULL if that flag was not specified.
-  // This information is useful only in a death test child process.
-  // Must not be called before a call to InitGoogleTest.
-  const InternalRunDeathTestFlag* internal_run_death_test_flag() const {
-    return internal_run_death_test_flag_.get();
-  }
-
-  // Returns a pointer to the current death test factory.
-  internal::DeathTestFactory* death_test_factory() {
-    return death_test_factory_.get();
-  }
-
-  void SuppressTestEventsIfInSubprocess();
-
-  friend class ReplaceDeathTestFactory;
-#endif  // GTEST_HAS_DEATH_TEST
-
-  // Initializes the event listener performing XML output as specified by
-  // UnitTestOptions. Must not be called before InitGoogleTest.
-  void ConfigureXmlOutput();
-
-#if GTEST_CAN_STREAM_RESULTS_
-  // Initializes the event listener for streaming test results to a socket.
-  // Must not be called before InitGoogleTest.
-  void ConfigureStreamingOutput();
-#endif
-
-  // Performs initialization dependent upon flag values obtained in
-  // ParseGoogleTestFlagsOnly.  Is called from InitGoogleTest after the call to
-  // ParseGoogleTestFlagsOnly.  In case a user neglects to call InitGoogleTest
-  // this function is also called from RunAllTests.  Since this function can be
-  // called more than once, it has to be idempotent.
-  void PostFlagParsingInit();
-
-  // Gets the random seed used at the start of the current test iteration.
-  int random_seed() const { return random_seed_; }
-
-  // Gets the random number generator.
-  internal::Random* random() { return &random_; }
-
-  // Shuffles all test suites, and the tests within each test suite,
-  // making sure that death tests are still run first.
-  void ShuffleTests();
-
-  // Restores the test suites and tests to their order before the first shuffle.
-  void UnshuffleTests();
-
-  // Returns the value of GTEST_FLAG(catch_exceptions) at the moment
-  // UnitTest::Run() starts.
-  bool catch_exceptions() const { return catch_exceptions_; }
-
- private:
-  friend class ::testing::UnitTest;
-
-  // Used by UnitTest::Run() to capture the state of
-  // GTEST_FLAG(catch_exceptions) at the moment it starts.
-  void set_catch_exceptions(bool value) { catch_exceptions_ = value; }
-
-  // The UnitTest object that owns this implementation object.
-  UnitTest* const parent_;
-
-  // The working directory when the first TEST() or TEST_F() was
-  // executed.
-  internal::FilePath original_working_dir_;
-
-  // The default test part result reporters.
-  DefaultGlobalTestPartResultReporter default_global_test_part_result_reporter_;
-  DefaultPerThreadTestPartResultReporter
-      default_per_thread_test_part_result_reporter_;
-
-  // Points to (but doesn't own) the global test part result reporter.
-  TestPartResultReporterInterface* global_test_part_result_repoter_;
-
-  // Protects read and write access to global_test_part_result_reporter_.
-  internal::Mutex global_test_part_result_reporter_mutex_;
-
-  // Points to (but doesn't own) the per-thread test part result reporter.
-  internal::ThreadLocal<TestPartResultReporterInterface*>
-      per_thread_test_part_result_reporter_;
-
-  // The vector of environments that need to be set-up/torn-down
-  // before/after the tests are run.
-  std::vector<Environment*> environments_;
-
-  // The vector of TestSuites in their original order.  It owns the
-  // elements in the vector.
-  std::vector<TestSuite*> test_suites_;
-
-  // Provides a level of indirection for the test suite list to allow
-  // easy shuffling and restoring the test suite order.  The i-th
-  // element of this vector is the index of the i-th test suite in the
-  // shuffled order.
-  std::vector<int> test_suite_indices_;
-
-  // ParameterizedTestRegistry object used to register value-parameterized
-  // tests.
-  internal::ParameterizedTestSuiteRegistry parameterized_test_registry_;
-  internal::TypeParameterizedTestSuiteRegistry
-      type_parameterized_test_registry_;
-
-  // The set holding the name of parameterized
-  // test suites that may go uninstantiated.
-  std::set<std::string> ignored_parameterized_test_suites_;
-
-  // Indicates whether RegisterParameterizedTests() has been called already.
-  bool parameterized_tests_registered_;
-
-  // Index of the last death test suite registered.  Initially -1.
-  int last_death_test_suite_;
-
-  // This points to the TestSuite for the currently running test.  It
-  // changes as Google Test goes through one test suite after another.
-  // When no test is running, this is set to NULL and Google Test
-  // stores assertion results in ad_hoc_test_result_.  Initially NULL.
-  TestSuite* current_test_suite_;
-
-  // This points to the TestInfo for the currently running test.  It
-  // changes as Google Test goes through one test after another.  When
-  // no test is running, this is set to NULL and Google Test stores
-  // assertion results in ad_hoc_test_result_.  Initially NULL.
-  TestInfo* current_test_info_;
-
-  // Normally, a user only writes assertions inside a TEST or TEST_F,
-  // or inside a function called by a TEST or TEST_F.  Since Google
-  // Test keeps track of which test is current running, it can
-  // associate such an assertion with the test it belongs to.
-  //
-  // If an assertion is encountered when no TEST or TEST_F is running,
-  // Google Test attributes the assertion result to an imaginary "ad hoc"
-  // test, and records the result in ad_hoc_test_result_.
-  TestResult ad_hoc_test_result_;
-
-  // The list of event listeners that can be used to track events inside
-  // Google Test.
-  TestEventListeners listeners_;
-
-  // The OS stack trace getter.  Will be deleted when the UnitTest
-  // object is destructed.  By default, an OsStackTraceGetter is used,
-  // but the user can set this field to use a custom getter if that is
-  // desired.
-  OsStackTraceGetterInterface* os_stack_trace_getter_;
-
-  // True if and only if PostFlagParsingInit() has been called.
-  bool post_flag_parse_init_performed_;
-
-  // The random number seed used at the beginning of the test run.
-  int random_seed_;
-
-  // Our random number generator.
-  internal::Random random_;
-
-  // The time of the test program start, in ms from the start of the
-  // UNIX epoch.
-  TimeInMillis start_timestamp_;
-
-  // How long the test took to run, in milliseconds.
-  TimeInMillis elapsed_time_;
-
-#if GTEST_HAS_DEATH_TEST
-  // The decomposed components of the gtest_internal_run_death_test flag,
-  // parsed when RUN_ALL_TESTS is called.
-  std::unique_ptr<InternalRunDeathTestFlag> internal_run_death_test_flag_;
-  std::unique_ptr<internal::DeathTestFactory> death_test_factory_;
-#endif  // GTEST_HAS_DEATH_TEST
-
-  // A per-thread stack of traces created by the SCOPED_TRACE() macro.
-  internal::ThreadLocal<std::vector<TraceInfo> > gtest_trace_stack_;
-
-  // The value of GTEST_FLAG(catch_exceptions) at the moment RunAllTests()
-  // starts.
-  bool catch_exceptions_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(UnitTestImpl);
-};  // class UnitTestImpl
-
-// Convenience function for accessing the global UnitTest
-// implementation object.
-inline UnitTestImpl* GetUnitTestImpl() {
-  return UnitTest::GetInstance()->impl();
-}
-
-#if GTEST_USES_SIMPLE_RE
-
-// Internal helper functions for implementing the simple regular
-// expression matcher.
-GTEST_API_ bool IsInSet(char ch, const char* str);
-GTEST_API_ bool IsAsciiDigit(char ch);
-GTEST_API_ bool IsAsciiPunct(char ch);
-GTEST_API_ bool IsRepeat(char ch);
-GTEST_API_ bool IsAsciiWhiteSpace(char ch);
-GTEST_API_ bool IsAsciiWordChar(char ch);
-GTEST_API_ bool IsValidEscape(char ch);
-GTEST_API_ bool AtomMatchesChar(bool escaped, char pattern, char ch);
-GTEST_API_ bool ValidateRegex(const char* regex);
-GTEST_API_ bool MatchRegexAtHead(const char* regex, const char* str);
-GTEST_API_ bool MatchRepetitionAndRegexAtHead(
-    bool escaped, char ch, char repeat, const char* regex, const char* str);
-GTEST_API_ bool MatchRegexAnywhere(const char* regex, const char* str);
-
-#endif  // GTEST_USES_SIMPLE_RE
-
-// Parses the command line for Google Test flags, without initializing
-// other parts of Google Test.
-GTEST_API_ void ParseGoogleTestFlagsOnly(int* argc, char** argv);
-GTEST_API_ void ParseGoogleTestFlagsOnly(int* argc, wchar_t** argv);
-
-#if GTEST_HAS_DEATH_TEST
-
-// Returns the message describing the last system error, regardless of the
-// platform.
-GTEST_API_ std::string GetLastErrnoDescription();
-
-// Attempts to parse a string into a positive integer pointed to by the
-// number parameter.  Returns true if that is possible.
-// GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we can use
-// it here.
-template <typename Integer>
-bool ParseNaturalNumber(const ::std::string& str, Integer* number) {
-  // Fail fast if the given string does not begin with a digit;
-  // this bypasses strtoXXX's "optional leading whitespace and plus
-  // or minus sign" semantics, which are undesirable here.
-  if (str.empty() || !IsDigit(str[0])) {
-    return false;
-  }
-  errno = 0;
-
-  char* end;
-  // BiggestConvertible is the largest integer type that system-provided
-  // string-to-number conversion routines can return.
-  using BiggestConvertible = unsigned long long;  // NOLINT
-
-  const BiggestConvertible parsed = strtoull(str.c_str(), &end, 10);  // NOLINT
-  const bool parse_success = *end == '\0' && errno == 0;
-
-  GTEST_CHECK_(sizeof(Integer) <= sizeof(parsed));
-
-  const Integer result = static_cast<Integer>(parsed);
-  if (parse_success && static_cast<BiggestConvertible>(result) == parsed) {
-    *number = result;
-    return true;
-  }
-  return false;
-}
-#endif  // GTEST_HAS_DEATH_TEST
-
-// TestResult contains some private methods that should be hidden from
-// Google Test user but are required for testing. This class allow our tests
-// to access them.
-//
-// This class is supplied only for the purpose of testing Google Test's own
-// constructs. Do not use it in user tests, either directly or indirectly.
-class TestResultAccessor {
- public:
-  static void RecordProperty(TestResult* test_result,
-                             const std::string& xml_element,
-                             const TestProperty& property) {
-    test_result->RecordProperty(xml_element, property);
-  }
-
-  static void ClearTestPartResults(TestResult* test_result) {
-    test_result->ClearTestPartResults();
-  }
-
-  static const std::vector<testing::TestPartResult>& test_part_results(
-      const TestResult& test_result) {
-    return test_result.test_part_results();
-  }
-};
-
-#if GTEST_CAN_STREAM_RESULTS_
-
-// Streams test results to the given port on the given host machine.
-class StreamingListener : public EmptyTestEventListener {
- public:
-  // Abstract base class for writing strings to a socket.
-  class AbstractSocketWriter {
-   public:
-    virtual ~AbstractSocketWriter() {}
-
-    // Sends a string to the socket.
-    virtual void Send(const std::string& message) = 0;
-
-    // Closes the socket.
-    virtual void CloseConnection() {}
-
-    // Sends a string and a newline to the socket.
-    void SendLn(const std::string& message) { Send(message + "\n"); }
-  };
-
-  // Concrete class for actually writing strings to a socket.
-  class SocketWriter : public AbstractSocketWriter {
-   public:
-    SocketWriter(const std::string& host, const std::string& port)
-        : sockfd_(-1), host_name_(host), port_num_(port) {
-      MakeConnection();
-    }
-
-    ~SocketWriter() override {
-      if (sockfd_ != -1)
-        CloseConnection();
-    }
-
-    // Sends a string to the socket.
-    void Send(const std::string& message) override {
-      GTEST_CHECK_(sockfd_ != -1)
-          << "Send() can be called only when there is a connection.";
-
-      const auto len = static_cast<size_t>(message.length());
-      if (write(sockfd_, message.c_str(), len) != static_cast<ssize_t>(len)) {
-        GTEST_LOG_(WARNING)
-            << "stream_result_to: failed to stream to "
-            << host_name_ << ":" << port_num_;
-      }
-    }
-
-   private:
-    // Creates a client socket and connects to the server.
-    void MakeConnection();
-
-    // Closes the socket.
-    void CloseConnection() override {
-      GTEST_CHECK_(sockfd_ != -1)
-          << "CloseConnection() can be called only when there is a connection.";
-
-      close(sockfd_);
-      sockfd_ = -1;
-    }
-
-    int sockfd_;  // socket file descriptor
-    const std::string host_name_;
-    const std::string port_num_;
-
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(SocketWriter);
-  };  // class SocketWriter
-
-  // Escapes '=', '&', '%', and '\n' characters in str as "%xx".
-  static std::string UrlEncode(const char* str);
-
-  StreamingListener(const std::string& host, const std::string& port)
-      : socket_writer_(new SocketWriter(host, port)) {
-    Start();
-  }
-
-  explicit StreamingListener(AbstractSocketWriter* socket_writer)
-      : socket_writer_(socket_writer) { Start(); }
-
-  void OnTestProgramStart(const UnitTest& /* unit_test */) override {
-    SendLn("event=TestProgramStart");
-  }
-
-  void OnTestProgramEnd(const UnitTest& unit_test) override {
-    // Note that Google Test current only report elapsed time for each
-    // test iteration, not for the entire test program.
-    SendLn("event=TestProgramEnd&passed=" + FormatBool(unit_test.Passed()));
-
-    // Notify the streaming server to stop.
-    socket_writer_->CloseConnection();
-  }
-
-  void OnTestIterationStart(const UnitTest& /* unit_test */,
-                            int iteration) override {
-    SendLn("event=TestIterationStart&iteration=" +
-           StreamableToString(iteration));
-  }
-
-  void OnTestIterationEnd(const UnitTest& unit_test,
-                          int /* iteration */) override {
-    SendLn("event=TestIterationEnd&passed=" +
-           FormatBool(unit_test.Passed()) + "&elapsed_time=" +
-           StreamableToString(unit_test.elapsed_time()) + "ms");
-  }
-
-  // Note that "event=TestCaseStart" is a wire format and has to remain
-  // "case" for compatibility
-  void OnTestCaseStart(const TestCase& test_case) override {
-    SendLn(std::string("event=TestCaseStart&name=") + test_case.name());
-  }
-
-  // Note that "event=TestCaseEnd" is a wire format and has to remain
-  // "case" for compatibility
-  void OnTestCaseEnd(const TestCase& test_case) override {
-    SendLn("event=TestCaseEnd&passed=" + FormatBool(test_case.Passed()) +
-           "&elapsed_time=" + StreamableToString(test_case.elapsed_time()) +
-           "ms");
-  }
-
-  void OnTestStart(const TestInfo& test_info) override {
-    SendLn(std::string("event=TestStart&name=") + test_info.name());
-  }
-
-  void OnTestEnd(const TestInfo& test_info) override {
-    SendLn("event=TestEnd&passed=" +
-           FormatBool((test_info.result())->Passed()) +
-           "&elapsed_time=" +
-           StreamableToString((test_info.result())->elapsed_time()) + "ms");
-  }
-
-  void OnTestPartResult(const TestPartResult& test_part_result) override {
-    const char* file_name = test_part_result.file_name();
-    if (file_name == nullptr) file_name = "";
-    SendLn("event=TestPartResult&file=" + UrlEncode(file_name) +
-           "&line=" + StreamableToString(test_part_result.line_number()) +
-           "&message=" + UrlEncode(test_part_result.message()));
-  }
-
- private:
-  // Sends the given message and a newline to the socket.
-  void SendLn(const std::string& message) { socket_writer_->SendLn(message); }
-
-  // Called at the start of streaming to notify the receiver what
-  // protocol we are using.
-  void Start() { SendLn("gtest_streaming_protocol_version=1.0"); }
-
-  std::string FormatBool(bool value) { return value ? "1" : "0"; }
-
-  const std::unique_ptr<AbstractSocketWriter> socket_writer_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(StreamingListener);
-};  // class StreamingListener
-
-#endif  // GTEST_CAN_STREAM_RESULTS_
-
-}  // namespace internal
-}  // namespace testing
-
-GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
-
-#endif  // GOOGLETEST_SRC_GTEST_INTERNAL_INL_H_
-
-#if GTEST_OS_WINDOWS
-# define vsnprintf _vsnprintf
-#endif  // GTEST_OS_WINDOWS
-
-#if GTEST_OS_MAC
-#ifndef GTEST_OS_IOS
-#include <crt_externs.h>
-#endif
-#endif
-
-#if GTEST_HAS_ABSL
-#include "absl/debugging/failure_signal_handler.h"
-#include "absl/debugging/stacktrace.h"
-#include "absl/debugging/symbolize.h"
-#include "absl/strings/str_cat.h"
-#endif  // GTEST_HAS_ABSL
-
-namespace testing {
-
-using internal::CountIf;
-using internal::ForEach;
-using internal::GetElementOr;
-using internal::Shuffle;
-
-// Constants.
-
-// A test whose test suite name or test name matches this filter is
-// disabled and not run.
-static const char kDisableTestFilter[] = "DISABLED_*:*/DISABLED_*";
-
-// A test suite whose name matches this filter is considered a death
-// test suite and will be run before test suites whose name doesn't
-// match this filter.
-static const char kDeathTestSuiteFilter[] = "*DeathTest:*DeathTest/*";
-
-// A test filter that matches everything.
-static const char kUniversalFilter[] = "*";
-
-// The default output format.
-static const char kDefaultOutputFormat[] = "xml";
-// The default output file.
-static const char kDefaultOutputFile[] = "test_detail";
-
-// The environment variable name for the test shard index.
-static const char kTestShardIndex[] = "GTEST_SHARD_INDEX";
-// The environment variable name for the total number of test shards.
-static const char kTestTotalShards[] = "GTEST_TOTAL_SHARDS";
-// The environment variable name for the test shard status file.
-static const char kTestShardStatusFile[] = "GTEST_SHARD_STATUS_FILE";
-
-namespace internal {
-
-// The text used in failure messages to indicate the start of the
-// stack trace.
-const char kStackTraceMarker[] = "\nStack trace:\n";
-
-// g_help_flag is true if and only if the --help flag or an equivalent form
-// is specified on the command line.
-bool g_help_flag = false;
-
-// Utilty function to Open File for Writing
-static FILE* OpenFileForWriting(const std::string& output_file) {
-  FILE* fileout = nullptr;
-  FilePath output_file_path(output_file);
-  FilePath output_dir(output_file_path.RemoveFileName());
-
-  if (output_dir.CreateDirectoriesRecursively()) {
-    fileout = posix::FOpen(output_file.c_str(), "w");
-  }
-  if (fileout == nullptr) {
-    GTEST_LOG_(FATAL) << "Unable to open file \"" << output_file << "\"";
-  }
-  return fileout;
-}
-
-}  // namespace internal
-
-// Bazel passes in the argument to '--test_filter' via the TESTBRIDGE_TEST_ONLY
-// environment variable.
-static const char* GetDefaultFilter() {
-  const char* const testbridge_test_only =
-      internal::posix::GetEnv("TESTBRIDGE_TEST_ONLY");
-  if (testbridge_test_only != nullptr) {
-    return testbridge_test_only;
-  }
-  return kUniversalFilter;
-}
-
-// Bazel passes in the argument to '--test_runner_fail_fast' via the
-// TESTBRIDGE_TEST_RUNNER_FAIL_FAST environment variable.
-static bool GetDefaultFailFast() {
-  const char* const testbridge_test_runner_fail_fast =
-      internal::posix::GetEnv("TESTBRIDGE_TEST_RUNNER_FAIL_FAST");
-  if (testbridge_test_runner_fail_fast != nullptr) {
-    return strcmp(testbridge_test_runner_fail_fast, "1") == 0;
-  }
-  return false;
-}
-
-GTEST_DEFINE_bool_(
-    fail_fast, internal::BoolFromGTestEnv("fail_fast", GetDefaultFailFast()),
-    "True if and only if a test failure should stop further test execution.");
-
-GTEST_DEFINE_bool_(
-    also_run_disabled_tests,
-    internal::BoolFromGTestEnv("also_run_disabled_tests", false),
-    "Run disabled tests too, in addition to the tests normally being run.");
-
-GTEST_DEFINE_bool_(
-    break_on_failure, internal::BoolFromGTestEnv("break_on_failure", false),
-    "True if and only if a failed assertion should be a debugger "
-    "break-point.");
-
-GTEST_DEFINE_bool_(catch_exceptions,
-                   internal::BoolFromGTestEnv("catch_exceptions", true),
-                   "True if and only if " GTEST_NAME_
-                   " should catch exceptions and treat them as test failures.");
-
-GTEST_DEFINE_string_(
-    color,
-    internal::StringFromGTestEnv("color", "auto"),
-    "Whether to use colors in the output.  Valid values: yes, no, "
-    "and auto.  'auto' means to use colors if the output is "
-    "being sent to a terminal and the TERM environment variable "
-    "is set to a terminal type that supports colors.");
-
-GTEST_DEFINE_string_(
-    filter,
-    internal::StringFromGTestEnv("filter", GetDefaultFilter()),
-    "A colon-separated list of glob (not regex) patterns "
-    "for filtering the tests to run, optionally followed by a "
-    "'-' and a : separated list of negative patterns (tests to "
-    "exclude).  A test is run if it matches one of the positive "
-    "patterns and does not match any of the negative patterns.");
-
-GTEST_DEFINE_bool_(
-    install_failure_signal_handler,
-    internal::BoolFromGTestEnv("install_failure_signal_handler", false),
-    "If true and supported on the current platform, " GTEST_NAME_ " should "
-    "install a signal handler that dumps debugging information when fatal "
-    "signals are raised.");
-
-GTEST_DEFINE_bool_(list_tests, false,
-                   "List all tests without running them.");
-
-// The net priority order after flag processing is thus:
-//   --gtest_output command line flag
-//   GTEST_OUTPUT environment variable
-//   XML_OUTPUT_FILE environment variable
-//   ''
-GTEST_DEFINE_string_(
-    output,
-    internal::StringFromGTestEnv("output",
-      internal::OutputFlagAlsoCheckEnvVar().c_str()),
-    "A format (defaults to \"xml\" but can be specified to be \"json\"), "
-    "optionally followed by a colon and an output file name or directory. "
-    "A directory is indicated by a trailing pathname separator. "
-    "Examples: \"xml:filename.xml\", \"xml::directoryname/\". "
-    "If a directory is specified, output files will be created "
-    "within that directory, with file-names based on the test "
-    "executable's name and, if necessary, made unique by adding "
-    "digits.");
-
-GTEST_DEFINE_bool_(
-    brief, internal::BoolFromGTestEnv("brief", false),
-    "True if only test failures should be displayed in text output.");
-
-GTEST_DEFINE_bool_(print_time, internal::BoolFromGTestEnv("print_time", true),
-                   "True if and only if " GTEST_NAME_
-                   " should display elapsed time in text output.");
-
-GTEST_DEFINE_bool_(print_utf8, internal::BoolFromGTestEnv("print_utf8", true),
-                   "True if and only if " GTEST_NAME_
-                   " prints UTF8 characters as text.");
-
-GTEST_DEFINE_int32_(
-    random_seed,
-    internal::Int32FromGTestEnv("random_seed", 0),
-    "Random number seed to use when shuffling test orders.  Must be in range "
-    "[1, 99999], or 0 to use a seed based on the current time.");
-
-GTEST_DEFINE_int32_(
-    repeat,
-    internal::Int32FromGTestEnv("repeat", 1),
-    "How many times to repeat each test.  Specify a negative number "
-    "for repeating forever.  Useful for shaking out flaky tests.");
-
-GTEST_DEFINE_bool_(show_internal_stack_frames, false,
-                   "True if and only if " GTEST_NAME_
-                   " should include internal stack frames when "
-                   "printing test failure stack traces.");
-
-GTEST_DEFINE_bool_(shuffle, internal::BoolFromGTestEnv("shuffle", false),
-                   "True if and only if " GTEST_NAME_
-                   " should randomize tests' order on every run.");
-
-GTEST_DEFINE_int32_(
-    stack_trace_depth,
-    internal::Int32FromGTestEnv("stack_trace_depth", kMaxStackTraceDepth),
-    "The maximum number of stack frames to print when an "
-    "assertion fails.  The valid range is 0 through 100, inclusive.");
-
-GTEST_DEFINE_string_(
-    stream_result_to,
-    internal::StringFromGTestEnv("stream_result_to", ""),
-    "This flag specifies the host name and the port number on which to stream "
-    "test results. Example: \"localhost:555\". The flag is effective only on "
-    "Linux.");
-
-GTEST_DEFINE_bool_(
-    throw_on_failure,
-    internal::BoolFromGTestEnv("throw_on_failure", false),
-    "When this flag is specified, a failed assertion will throw an exception "
-    "if exceptions are enabled or exit the program with a non-zero code "
-    "otherwise. For use with an external test framework.");
-
-#if GTEST_USE_OWN_FLAGFILE_FLAG_
-GTEST_DEFINE_string_(
-    flagfile,
-    internal::StringFromGTestEnv("flagfile", ""),
-    "This flag specifies the flagfile to read command-line flags from.");
-#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
-
-namespace internal {
-
-// Generates a random number from [0, range), using a Linear
-// Congruential Generator (LCG).  Crashes if 'range' is 0 or greater
-// than kMaxRange.
-uint32_t Random::Generate(uint32_t range) {
-  // These constants are the same as are used in glibc's rand(3).
-  // Use wider types than necessary to prevent unsigned overflow diagnostics.
-  state_ = static_cast<uint32_t>(1103515245ULL*state_ + 12345U) % kMaxRange;
-
-  GTEST_CHECK_(range > 0)
-      << "Cannot generate a number in the range [0, 0).";
-  GTEST_CHECK_(range <= kMaxRange)
-      << "Generation of a number in [0, " << range << ") was requested, "
-      << "but this can only generate numbers in [0, " << kMaxRange << ").";
-
-  // Converting via modulus introduces a bit of downward bias, but
-  // it's simple, and a linear congruential generator isn't too good
-  // to begin with.
-  return state_ % range;
-}
-
-// GTestIsInitialized() returns true if and only if the user has initialized
-// Google Test.  Useful for catching the user mistake of not initializing
-// Google Test before calling RUN_ALL_TESTS().
-static bool GTestIsInitialized() { return GetArgvs().size() > 0; }
-
-// Iterates over a vector of TestSuites, keeping a running sum of the
-// results of calling a given int-returning method on each.
-// Returns the sum.
-static int SumOverTestSuiteList(const std::vector<TestSuite*>& case_list,
-                                int (TestSuite::*method)() const) {
-  int sum = 0;
-  for (size_t i = 0; i < case_list.size(); i++) {
-    sum += (case_list[i]->*method)();
-  }
-  return sum;
-}
-
-// Returns true if and only if the test suite passed.
-static bool TestSuitePassed(const TestSuite* test_suite) {
-  return test_suite->should_run() && test_suite->Passed();
-}
-
-// Returns true if and only if the test suite failed.
-static bool TestSuiteFailed(const TestSuite* test_suite) {
-  return test_suite->should_run() && test_suite->Failed();
-}
-
-// Returns true if and only if test_suite contains at least one test that
-// should run.
-static bool ShouldRunTestSuite(const TestSuite* test_suite) {
-  return test_suite->should_run();
-}
-
-// AssertHelper constructor.
-AssertHelper::AssertHelper(TestPartResult::Type type,
-                           const char* file,
-                           int line,
-                           const char* message)
-    : data_(new AssertHelperData(type, file, line, message)) {
-}
-
-AssertHelper::~AssertHelper() {
-  delete data_;
-}
-
-// Message assignment, for assertion streaming support.
-void AssertHelper::operator=(const Message& message) const {
-  UnitTest::GetInstance()->
-    AddTestPartResult(data_->type, data_->file, data_->line,
-                      AppendUserMessage(data_->message, message),
-                      UnitTest::GetInstance()->impl()
-                      ->CurrentOsStackTraceExceptTop(1)
-                      // Skips the stack frame for this function itself.
-                      );  // NOLINT
-}
-
-namespace {
-
-// When TEST_P is found without a matching INSTANTIATE_TEST_SUITE_P
-// to creates test cases for it, a synthetic test case is
-// inserted to report ether an error or a log message.
-//
-// This configuration bit will likely be removed at some point.
-constexpr bool kErrorOnUninstantiatedParameterizedTest = true;
-constexpr bool kErrorOnUninstantiatedTypeParameterizedTest = true;
-
-// A test that fails at a given file/line location with a given message.
-class FailureTest : public Test {
- public:
-  explicit FailureTest(const CodeLocation& loc, std::string error_message,
-                       bool as_error)
-      : loc_(loc),
-        error_message_(std::move(error_message)),
-        as_error_(as_error) {}
-
-  void TestBody() override {
-    if (as_error_) {
-      AssertHelper(TestPartResult::kNonFatalFailure, loc_.file.c_str(),
-                   loc_.line, "") = Message() << error_message_;
-    } else {
-      std::cout << error_message_ << std::endl;
-    }
-  }
-
- private:
-  const CodeLocation loc_;
-  const std::string error_message_;
-  const bool as_error_;
-};
-
-
-}  // namespace
-
-std::set<std::string>* GetIgnoredParameterizedTestSuites() {
-  return UnitTest::GetInstance()->impl()->ignored_parameterized_test_suites();
-}
-
-// Add a given test_suit to the list of them allow to go un-instantiated.
-MarkAsIgnored::MarkAsIgnored(const char* test_suite) {
-  GetIgnoredParameterizedTestSuites()->insert(test_suite);
-}
-
-// If this parameterized test suite has no instantiations (and that
-// has not been marked as okay), emit a test case reporting that.
-void InsertSyntheticTestCase(const std::string& name, CodeLocation location,
-                             bool has_test_p) {
-  const auto& ignored = *GetIgnoredParameterizedTestSuites();
-  if (ignored.find(name) != ignored.end()) return;
-
-  const char kMissingInstantiation[] =  //
-      " is defined via TEST_P, but never instantiated. None of the test cases "
-      "will run. Either no INSTANTIATE_TEST_SUITE_P is provided or the only "
-      "ones provided expand to nothing."
-      "\n\n"
-      "Ideally, TEST_P definitions should only ever be included as part of "
-      "binaries that intend to use them. (As opposed to, for example, being "
-      "placed in a library that may be linked in to get other utilities.)";
-
-  const char kMissingTestCase[] =  //
-      " is instantiated via INSTANTIATE_TEST_SUITE_P, but no tests are "
-      "defined via TEST_P . No test cases will run."
-      "\n\n"
-      "Ideally, INSTANTIATE_TEST_SUITE_P should only ever be invoked from "
-      "code that always depend on code that provides TEST_P. Failing to do "
-      "so is often an indication of dead code, e.g. the last TEST_P was "
-      "removed but the rest got left behind.";
-
-  std::string message =
-      "Parameterized test suite " + name +
-      (has_test_p ? kMissingInstantiation : kMissingTestCase) +
-      "\n\n"
-      "To suppress this error for this test suite, insert the following line "
-      "(in a non-header) in the namespace it is defined in:"
-      "\n\n"
-      "GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(" + name + ");";
-
-  std::string full_name = "UninstantiatedParameterizedTestSuite<" + name + ">";
-  RegisterTest(  //
-      "GoogleTestVerification", full_name.c_str(),
-      nullptr,  // No type parameter.
-      nullptr,  // No value parameter.
-      location.file.c_str(), location.line, [message, location] {
-        return new FailureTest(location, message,
-                               kErrorOnUninstantiatedParameterizedTest);
-      });
-}
-
-void RegisterTypeParameterizedTestSuite(const char* test_suite_name,
-                                        CodeLocation code_location) {
-  GetUnitTestImpl()->type_parameterized_test_registry().RegisterTestSuite(
-      test_suite_name, code_location);
-}
-
-void RegisterTypeParameterizedTestSuiteInstantiation(const char* case_name) {
-  GetUnitTestImpl()
-      ->type_parameterized_test_registry()
-      .RegisterInstantiation(case_name);
-}
-
-void TypeParameterizedTestSuiteRegistry::RegisterTestSuite(
-    const char* test_suite_name, CodeLocation code_location) {
-  suites_.emplace(std::string(test_suite_name),
-                 TypeParameterizedTestSuiteInfo(code_location));
-}
-
-void TypeParameterizedTestSuiteRegistry::RegisterInstantiation(
-        const char* test_suite_name) {
-  auto it = suites_.find(std::string(test_suite_name));
-  if (it != suites_.end()) {
-    it->second.instantiated = true;
-  } else {
-    GTEST_LOG_(ERROR) << "Unknown type parameterized test suit '"
-                      << test_suite_name << "'";
-  }
-}
-
-void TypeParameterizedTestSuiteRegistry::CheckForInstantiations() {
-  const auto& ignored = *GetIgnoredParameterizedTestSuites();
-  for (const auto& testcase : suites_) {
-    if (testcase.second.instantiated) continue;
-    if (ignored.find(testcase.first) != ignored.end()) continue;
-
-    std::string message =
-        "Type parameterized test suite " + testcase.first +
-        " is defined via REGISTER_TYPED_TEST_SUITE_P, but never instantiated "
-        "via INSTANTIATE_TYPED_TEST_SUITE_P. None of the test cases will run."
-        "\n\n"
-        "Ideally, TYPED_TEST_P definitions should only ever be included as "
-        "part of binaries that intend to use them. (As opposed to, for "
-        "example, being placed in a library that may be linked in to get other "
-        "utilities.)"
-        "\n\n"
-        "To suppress this error for this test suite, insert the following line "
-        "(in a non-header) in the namespace it is defined in:"
-        "\n\n"
-        "GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(" +
-        testcase.first + ");";
-
-    std::string full_name =
-        "UninstantiatedTypeParameterizedTestSuite<" + testcase.first + ">";
-    RegisterTest(  //
-        "GoogleTestVerification", full_name.c_str(),
-        nullptr,  // No type parameter.
-        nullptr,  // No value parameter.
-        testcase.second.code_location.file.c_str(),
-        testcase.second.code_location.line, [message, testcase] {
-          return new FailureTest(testcase.second.code_location, message,
-                                 kErrorOnUninstantiatedTypeParameterizedTest);
-        });
-  }
-}
-
-// A copy of all command line arguments.  Set by InitGoogleTest().
-static ::std::vector<std::string> g_argvs;
-
-::std::vector<std::string> GetArgvs() {
-#if defined(GTEST_CUSTOM_GET_ARGVS_)
-  // GTEST_CUSTOM_GET_ARGVS_() may return a container of std::string or
-  // ::string. This code converts it to the appropriate type.
-  const auto& custom = GTEST_CUSTOM_GET_ARGVS_();
-  return ::std::vector<std::string>(custom.begin(), custom.end());
-#else   // defined(GTEST_CUSTOM_GET_ARGVS_)
-  return g_argvs;
-#endif  // defined(GTEST_CUSTOM_GET_ARGVS_)
-}
-
-// Returns the current application's name, removing directory path if that
-// is present.
-FilePath GetCurrentExecutableName() {
-  FilePath result;
-
-#if GTEST_OS_WINDOWS || GTEST_OS_OS2
-  result.Set(FilePath(GetArgvs()[0]).RemoveExtension("exe"));
-#else
-  result.Set(FilePath(GetArgvs()[0]));
-#endif  // GTEST_OS_WINDOWS
-
-  return result.RemoveDirectoryName();
-}
-
-// Functions for processing the gtest_output flag.
-
-// Returns the output format, or "" for normal printed output.
-std::string UnitTestOptions::GetOutputFormat() {
-  const char* const gtest_output_flag = GTEST_FLAG(output).c_str();
-  const char* const colon = strchr(gtest_output_flag, ':');
-  return (colon == nullptr)
-             ? std::string(gtest_output_flag)
-             : std::string(gtest_output_flag,
-                           static_cast<size_t>(colon - gtest_output_flag));
-}
-
-// Returns the name of the requested output file, or the default if none
-// was explicitly specified.
-std::string UnitTestOptions::GetAbsolutePathToOutputFile() {
-  const char* const gtest_output_flag = GTEST_FLAG(output).c_str();
-
-  std::string format = GetOutputFormat();
-  if (format.empty())
-    format = std::string(kDefaultOutputFormat);
-
-  const char* const colon = strchr(gtest_output_flag, ':');
-  if (colon == nullptr)
-    return internal::FilePath::MakeFileName(
-        internal::FilePath(
-            UnitTest::GetInstance()->original_working_dir()),
-        internal::FilePath(kDefaultOutputFile), 0,
-        format.c_str()).string();
-
-  internal::FilePath output_name(colon + 1);
-  if (!output_name.IsAbsolutePath())
-    output_name = internal::FilePath::ConcatPaths(
-        internal::FilePath(UnitTest::GetInstance()->original_working_dir()),
-        internal::FilePath(colon + 1));
-
-  if (!output_name.IsDirectory())
-    return output_name.string();
-
-  internal::FilePath result(internal::FilePath::GenerateUniqueFileName(
-      output_name, internal::GetCurrentExecutableName(),
-      GetOutputFormat().c_str()));
-  return result.string();
-}
-
-// Returns true if and only if the wildcard pattern matches the string. Each
-// pattern consists of regular characters, single-character wildcards (?), and
-// multi-character wildcards (*).
-//
-// This function implements a linear-time string globbing algorithm based on
-// https://research.swtch.com/glob.
-static bool PatternMatchesString(const std::string& name_str,
-                                 const char* pattern, const char* pattern_end) {
-  const char* name = name_str.c_str();
-  const char* const name_begin = name;
-  const char* const name_end = name + name_str.size();
-
-  const char* pattern_next = pattern;
-  const char* name_next = name;
-
-  while (pattern < pattern_end || name < name_end) {
-    if (pattern < pattern_end) {
-      switch (*pattern) {
-        default:  // Match an ordinary character.
-          if (name < name_end && *name == *pattern) {
-            ++pattern;
-            ++name;
-            continue;
-          }
-          break;
-        case '?':  // Match any single character.
-          if (name < name_end) {
-            ++pattern;
-            ++name;
-            continue;
-          }
-          break;
-        case '*':
-          // Match zero or more characters. Start by skipping over the wildcard
-          // and matching zero characters from name. If that fails, restart and
-          // match one more character than the last attempt.
-          pattern_next = pattern;
-          name_next = name + 1;
-          ++pattern;
-          continue;
-      }
-    }
-    // Failed to match a character. Restart if possible.
-    if (name_begin < name_next && name_next <= name_end) {
-      pattern = pattern_next;
-      name = name_next;
-      continue;
-    }
-    return false;
-  }
-  return true;
-}
-
-bool UnitTestOptions::MatchesFilter(const std::string& name_str,
-                                    const char* filter) {
-  // The filter is a list of patterns separated by colons (:).
-  const char* pattern = filter;
-  while (true) {
-    // Find the bounds of this pattern.
-    const char* const next_sep = strchr(pattern, ':');
-    const char* const pattern_end =
-        next_sep != nullptr ? next_sep : pattern + strlen(pattern);
-
-    // Check if this pattern matches name_str.
-    if (PatternMatchesString(name_str, pattern, pattern_end)) {
-      return true;
-    }
-
-    // Give up on this pattern. However, if we found a pattern separator (:),
-    // advance to the next pattern (skipping over the separator) and restart.
-    if (next_sep == nullptr) {
-      return false;
-    }
-    pattern = next_sep + 1;
-  }
-  return true;
-}
-
-// Returns true if and only if the user-specified filter matches the test
-// suite name and the test name.
-bool UnitTestOptions::FilterMatchesTest(const std::string& test_suite_name,
-                                        const std::string& test_name) {
-  const std::string& full_name = test_suite_name + "." + test_name.c_str();
-
-  // Split --gtest_filter at '-', if there is one, to separate into
-  // positive filter and negative filter portions
-  const char* const p = GTEST_FLAG(filter).c_str();
-  const char* const dash = strchr(p, '-');
-  std::string positive;
-  std::string negative;
-  if (dash == nullptr) {
-    positive = GTEST_FLAG(filter).c_str();  // Whole string is a positive filter
-    negative = "";
-  } else {
-    positive = std::string(p, dash);   // Everything up to the dash
-    negative = std::string(dash + 1);  // Everything after the dash
-    if (positive.empty()) {
-      // Treat '-test1' as the same as '*-test1'
-      positive = kUniversalFilter;
-    }
-  }
-
-  // A filter is a colon-separated list of patterns.  It matches a
-  // test if any pattern in it matches the test.
-  return (MatchesFilter(full_name, positive.c_str()) &&
-          !MatchesFilter(full_name, negative.c_str()));
-}
-
-#if GTEST_HAS_SEH
-// Returns EXCEPTION_EXECUTE_HANDLER if Google Test should handle the
-// given SEH exception, or EXCEPTION_CONTINUE_SEARCH otherwise.
-// This function is useful as an __except condition.
-int UnitTestOptions::GTestShouldProcessSEH(DWORD exception_code) {
-  // Google Test should handle a SEH exception if:
-  //   1. the user wants it to, AND
-  //   2. this is not a breakpoint exception, AND
-  //   3. this is not a C++ exception (VC++ implements them via SEH,
-  //      apparently).
-  //
-  // SEH exception code for C++ exceptions.
-  // (see http://support.microsoft.com/kb/185294 for more information).
-  const DWORD kCxxExceptionCode = 0xe06d7363;
-
-  bool should_handle = true;
-
-  if (!GTEST_FLAG(catch_exceptions))
-    should_handle = false;
-  else if (exception_code == EXCEPTION_BREAKPOINT)
-    should_handle = false;
-  else if (exception_code == kCxxExceptionCode)
-    should_handle = false;
-
-  return should_handle ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH;
-}
-#endif  // GTEST_HAS_SEH
-
-}  // namespace internal
-
-// The c'tor sets this object as the test part result reporter used by
-// Google Test.  The 'result' parameter specifies where to report the
-// results. Intercepts only failures from the current thread.
-ScopedFakeTestPartResultReporter::ScopedFakeTestPartResultReporter(
-    TestPartResultArray* result)
-    : intercept_mode_(INTERCEPT_ONLY_CURRENT_THREAD),
-      result_(result) {
-  Init();
-}
-
-// The c'tor sets this object as the test part result reporter used by
-// Google Test.  The 'result' parameter specifies where to report the
-// results.
-ScopedFakeTestPartResultReporter::ScopedFakeTestPartResultReporter(
-    InterceptMode intercept_mode, TestPartResultArray* result)
-    : intercept_mode_(intercept_mode),
-      result_(result) {
-  Init();
-}
-
-void ScopedFakeTestPartResultReporter::Init() {
-  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
-  if (intercept_mode_ == INTERCEPT_ALL_THREADS) {
-    old_reporter_ = impl->GetGlobalTestPartResultReporter();
-    impl->SetGlobalTestPartResultReporter(this);
-  } else {
-    old_reporter_ = impl->GetTestPartResultReporterForCurrentThread();
-    impl->SetTestPartResultReporterForCurrentThread(this);
-  }
-}
-
-// The d'tor restores the test part result reporter used by Google Test
-// before.
-ScopedFakeTestPartResultReporter::~ScopedFakeTestPartResultReporter() {
-  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
-  if (intercept_mode_ == INTERCEPT_ALL_THREADS) {
-    impl->SetGlobalTestPartResultReporter(old_reporter_);
-  } else {
-    impl->SetTestPartResultReporterForCurrentThread(old_reporter_);
-  }
-}
-
-// Increments the test part result count and remembers the result.
-// This method is from the TestPartResultReporterInterface interface.
-void ScopedFakeTestPartResultReporter::ReportTestPartResult(
-    const TestPartResult& result) {
-  result_->Append(result);
-}
-
-namespace internal {
-
-// Returns the type ID of ::testing::Test.  We should always call this
-// instead of GetTypeId< ::testing::Test>() to get the type ID of
-// testing::Test.  This is to work around a suspected linker bug when
-// using Google Test as a framework on Mac OS X.  The bug causes
-// GetTypeId< ::testing::Test>() to return different values depending
-// on whether the call is from the Google Test framework itself or
-// from user test code.  GetTestTypeId() is guaranteed to always
-// return the same value, as it always calls GetTypeId<>() from the
-// gtest.cc, which is within the Google Test framework.
-TypeId GetTestTypeId() {
-  return GetTypeId<Test>();
-}
-
-// The value of GetTestTypeId() as seen from within the Google Test
-// library.  This is solely for testing GetTestTypeId().
-extern const TypeId kTestTypeIdInGoogleTest = GetTestTypeId();
-
-// This predicate-formatter checks that 'results' contains a test part
-// failure of the given type and that the failure message contains the
-// given substring.
-static AssertionResult HasOneFailure(const char* /* results_expr */,
-                                     const char* /* type_expr */,
-                                     const char* /* substr_expr */,
-                                     const TestPartResultArray& results,
-                                     TestPartResult::Type type,
-                                     const std::string& substr) {
-  const std::string expected(type == TestPartResult::kFatalFailure ?
-                        "1 fatal failure" :
-                        "1 non-fatal failure");
-  Message msg;
-  if (results.size() != 1) {
-    msg << "Expected: " << expected << "\n"
-        << "  Actual: " << results.size() << " failures";
-    for (int i = 0; i < results.size(); i++) {
-      msg << "\n" << results.GetTestPartResult(i);
-    }
-    return AssertionFailure() << msg;
-  }
-
-  const TestPartResult& r = results.GetTestPartResult(0);
-  if (r.type() != type) {
-    return AssertionFailure() << "Expected: " << expected << "\n"
-                              << "  Actual:\n"
-                              << r;
-  }
-
-  if (strstr(r.message(), substr.c_str()) == nullptr) {
-    return AssertionFailure() << "Expected: " << expected << " containing \""
-                              << substr << "\"\n"
-                              << "  Actual:\n"
-                              << r;
-  }
-
-  return AssertionSuccess();
-}
-
-// The constructor of SingleFailureChecker remembers where to look up
-// test part results, what type of failure we expect, and what
-// substring the failure message should contain.
-SingleFailureChecker::SingleFailureChecker(const TestPartResultArray* results,
-                                           TestPartResult::Type type,
-                                           const std::string& substr)
-    : results_(results), type_(type), substr_(substr) {}
-
-// The destructor of SingleFailureChecker verifies that the given
-// TestPartResultArray contains exactly one failure that has the given
-// type and contains the given substring.  If that's not the case, a
-// non-fatal failure will be generated.
-SingleFailureChecker::~SingleFailureChecker() {
-  EXPECT_PRED_FORMAT3(HasOneFailure, *results_, type_, substr_);
-}
-
-DefaultGlobalTestPartResultReporter::DefaultGlobalTestPartResultReporter(
-    UnitTestImpl* unit_test) : unit_test_(unit_test) {}
-
-void DefaultGlobalTestPartResultReporter::ReportTestPartResult(
-    const TestPartResult& result) {
-  unit_test_->current_test_result()->AddTestPartResult(result);
-  unit_test_->listeners()->repeater()->OnTestPartResult(result);
-}
-
-DefaultPerThreadTestPartResultReporter::DefaultPerThreadTestPartResultReporter(
-    UnitTestImpl* unit_test) : unit_test_(unit_test) {}
-
-void DefaultPerThreadTestPartResultReporter::ReportTestPartResult(
-    const TestPartResult& result) {
-  unit_test_->GetGlobalTestPartResultReporter()->ReportTestPartResult(result);
-}
-
-// Returns the global test part result reporter.
-TestPartResultReporterInterface*
-UnitTestImpl::GetGlobalTestPartResultReporter() {
-  internal::MutexLock lock(&global_test_part_result_reporter_mutex_);
-  return global_test_part_result_repoter_;
-}
-
-// Sets the global test part result reporter.
-void UnitTestImpl::SetGlobalTestPartResultReporter(
-    TestPartResultReporterInterface* reporter) {
-  internal::MutexLock lock(&global_test_part_result_reporter_mutex_);
-  global_test_part_result_repoter_ = reporter;
-}
-
-// Returns the test part result reporter for the current thread.
-TestPartResultReporterInterface*
-UnitTestImpl::GetTestPartResultReporterForCurrentThread() {
-  return per_thread_test_part_result_reporter_.get();
-}
-
-// Sets the test part result reporter for the current thread.
-void UnitTestImpl::SetTestPartResultReporterForCurrentThread(
-    TestPartResultReporterInterface* reporter) {
-  per_thread_test_part_result_reporter_.set(reporter);
-}
-
-// Gets the number of successful test suites.
-int UnitTestImpl::successful_test_suite_count() const {
-  return CountIf(test_suites_, TestSuitePassed);
-}
-
-// Gets the number of failed test suites.
-int UnitTestImpl::failed_test_suite_count() const {
-  return CountIf(test_suites_, TestSuiteFailed);
-}
-
-// Gets the number of all test suites.
-int UnitTestImpl::total_test_suite_count() const {
-  return static_cast<int>(test_suites_.size());
-}
-
-// Gets the number of all test suites that contain at least one test
-// that should run.
-int UnitTestImpl::test_suite_to_run_count() const {
-  return CountIf(test_suites_, ShouldRunTestSuite);
-}
-
-// Gets the number of successful tests.
-int UnitTestImpl::successful_test_count() const {
-  return SumOverTestSuiteList(test_suites_, &TestSuite::successful_test_count);
-}
-
-// Gets the number of skipped tests.
-int UnitTestImpl::skipped_test_count() const {
-  return SumOverTestSuiteList(test_suites_, &TestSuite::skipped_test_count);
-}
-
-// Gets the number of failed tests.
-int UnitTestImpl::failed_test_count() const {
-  return SumOverTestSuiteList(test_suites_, &TestSuite::failed_test_count);
-}
-
-// Gets the number of disabled tests that will be reported in the XML report.
-int UnitTestImpl::reportable_disabled_test_count() const {
-  return SumOverTestSuiteList(test_suites_,
-                              &TestSuite::reportable_disabled_test_count);
-}
-
-// Gets the number of disabled tests.
-int UnitTestImpl::disabled_test_count() const {
-  return SumOverTestSuiteList(test_suites_, &TestSuite::disabled_test_count);
-}
-
-// Gets the number of tests to be printed in the XML report.
-int UnitTestImpl::reportable_test_count() const {
-  return SumOverTestSuiteList(test_suites_, &TestSuite::reportable_test_count);
-}
-
-// Gets the number of all tests.
-int UnitTestImpl::total_test_count() const {
-  return SumOverTestSuiteList(test_suites_, &TestSuite::total_test_count);
-}
-
-// Gets the number of tests that should run.
-int UnitTestImpl::test_to_run_count() const {
-  return SumOverTestSuiteList(test_suites_, &TestSuite::test_to_run_count);
-}
-
-// Returns the current OS stack trace as an std::string.
-//
-// The maximum number of stack frames to be included is specified by
-// the gtest_stack_trace_depth flag.  The skip_count parameter
-// specifies the number of top frames to be skipped, which doesn't
-// count against the number of frames to be included.
-//
-// For example, if Foo() calls Bar(), which in turn calls
-// CurrentOsStackTraceExceptTop(1), Foo() will be included in the
-// trace but Bar() and CurrentOsStackTraceExceptTop() won't.
-std::string UnitTestImpl::CurrentOsStackTraceExceptTop(int skip_count) {
-  return os_stack_trace_getter()->CurrentStackTrace(
-      static_cast<int>(GTEST_FLAG(stack_trace_depth)),
-      skip_count + 1
-      // Skips the user-specified number of frames plus this function
-      // itself.
-      );  // NOLINT
-}
-
-// A helper class for measuring elapsed times.
-class Timer {
- public:
-  Timer() : start_(std::chrono::steady_clock::now()) {}
-
-  // Return time elapsed in milliseconds since the timer was created.
-  TimeInMillis Elapsed() {
-    return std::chrono::duration_cast<std::chrono::milliseconds>(
-               std::chrono::steady_clock::now() - start_)
-        .count();
-  }
-
- private:
-  std::chrono::steady_clock::time_point start_;
-};
-
-// Returns a timestamp as milliseconds since the epoch. Note this time may jump
-// around subject to adjustments by the system, to measure elapsed time use
-// Timer instead.
-TimeInMillis GetTimeInMillis() {
-  return std::chrono::duration_cast<std::chrono::milliseconds>(
-             std::chrono::system_clock::now() -
-             std::chrono::system_clock::from_time_t(0))
-      .count();
-}
-
-// Utilities
-
-// class String.
-
-#if GTEST_OS_WINDOWS_MOBILE
-// Creates a UTF-16 wide string from the given ANSI string, allocating
-// memory using new. The caller is responsible for deleting the return
-// value using delete[]. Returns the wide string, or NULL if the
-// input is NULL.
-LPCWSTR String::AnsiToUtf16(const char* ansi) {
-  if (!ansi) return nullptr;
-  const int length = strlen(ansi);
-  const int unicode_length =
-      MultiByteToWideChar(CP_ACP, 0, ansi, length, nullptr, 0);
-  WCHAR* unicode = new WCHAR[unicode_length + 1];
-  MultiByteToWideChar(CP_ACP, 0, ansi, length,
-                      unicode, unicode_length);
-  unicode[unicode_length] = 0;
-  return unicode;
-}
-
-// Creates an ANSI string from the given wide string, allocating
-// memory using new. The caller is responsible for deleting the return
-// value using delete[]. Returns the ANSI string, or NULL if the
-// input is NULL.
-const char* String::Utf16ToAnsi(LPCWSTR utf16_str)  {
-  if (!utf16_str) return nullptr;
-  const int ansi_length = WideCharToMultiByte(CP_ACP, 0, utf16_str, -1, nullptr,
-                                              0, nullptr, nullptr);
-  char* ansi = new char[ansi_length + 1];
-  WideCharToMultiByte(CP_ACP, 0, utf16_str, -1, ansi, ansi_length, nullptr,
-                      nullptr);
-  ansi[ansi_length] = 0;
-  return ansi;
-}
-
-#endif  // GTEST_OS_WINDOWS_MOBILE
-
-// Compares two C strings.  Returns true if and only if they have the same
-// content.
-//
-// Unlike strcmp(), this function can handle NULL argument(s).  A NULL
-// C string is considered different to any non-NULL C string,
-// including the empty string.
-bool String::CStringEquals(const char * lhs, const char * rhs) {
-  if (lhs == nullptr) return rhs == nullptr;
-
-  if (rhs == nullptr) return false;
-
-  return strcmp(lhs, rhs) == 0;
-}
-
-#if GTEST_HAS_STD_WSTRING
-
-// Converts an array of wide chars to a narrow string using the UTF-8
-// encoding, and streams the result to the given Message object.
-static void StreamWideCharsToMessage(const wchar_t* wstr, size_t length,
-                                     Message* msg) {
-  for (size_t i = 0; i != length; ) {  // NOLINT
-    if (wstr[i] != L'\0') {
-      *msg << WideStringToUtf8(wstr + i, static_cast<int>(length - i));
-      while (i != length && wstr[i] != L'\0')
-        i++;
-    } else {
-      *msg << '\0';
-      i++;
-    }
-  }
-}
-
-#endif  // GTEST_HAS_STD_WSTRING
-
-void SplitString(const ::std::string& str, char delimiter,
-                 ::std::vector< ::std::string>* dest) {
-  ::std::vector< ::std::string> parsed;
-  ::std::string::size_type pos = 0;
-  while (::testing::internal::AlwaysTrue()) {
-    const ::std::string::size_type colon = str.find(delimiter, pos);
-    if (colon == ::std::string::npos) {
-      parsed.push_back(str.substr(pos));
-      break;
-    } else {
-      parsed.push_back(str.substr(pos, colon - pos));
-      pos = colon + 1;
-    }
-  }
-  dest->swap(parsed);
-}
-
-}  // namespace internal
-
-// Constructs an empty Message.
-// We allocate the stringstream separately because otherwise each use of
-// ASSERT/EXPECT in a procedure adds over 200 bytes to the procedure's
-// stack frame leading to huge stack frames in some cases; gcc does not reuse
-// the stack space.
-Message::Message() : ss_(new ::std::stringstream) {
-  // By default, we want there to be enough precision when printing
-  // a double to a Message.
-  *ss_ << std::setprecision(std::numeric_limits<double>::digits10 + 2);
-}
-
-// These two overloads allow streaming a wide C string to a Message
-// using the UTF-8 encoding.
-Message& Message::operator <<(const wchar_t* wide_c_str) {
-  return *this << internal::String::ShowWideCString(wide_c_str);
-}
-Message& Message::operator <<(wchar_t* wide_c_str) {
-  return *this << internal::String::ShowWideCString(wide_c_str);
-}
-
-#if GTEST_HAS_STD_WSTRING
-// Converts the given wide string to a narrow string using the UTF-8
-// encoding, and streams the result to this Message object.
-Message& Message::operator <<(const ::std::wstring& wstr) {
-  internal::StreamWideCharsToMessage(wstr.c_str(), wstr.length(), this);
-  return *this;
-}
-#endif  // GTEST_HAS_STD_WSTRING
-
-// Gets the text streamed to this object so far as an std::string.
-// Each '\0' character in the buffer is replaced with "\\0".
-std::string Message::GetString() const {
-  return internal::StringStreamToString(ss_.get());
-}
-
-// AssertionResult constructors.
-// Used in EXPECT_TRUE/FALSE(assertion_result).
-AssertionResult::AssertionResult(const AssertionResult& other)
-    : success_(other.success_),
-      message_(other.message_.get() != nullptr
-                   ? new ::std::string(*other.message_)
-                   : static_cast< ::std::string*>(nullptr)) {}
-
-// Swaps two AssertionResults.
-void AssertionResult::swap(AssertionResult& other) {
-  using std::swap;
-  swap(success_, other.success_);
-  swap(message_, other.message_);
-}
-
-// Returns the assertion's negation. Used with EXPECT/ASSERT_FALSE.
-AssertionResult AssertionResult::operator!() const {
-  AssertionResult negation(!success_);
-  if (message_.get() != nullptr) negation << *message_;
-  return negation;
-}
-
-// Makes a successful assertion result.
-AssertionResult AssertionSuccess() {
-  return AssertionResult(true);
-}
-
-// Makes a failed assertion result.
-AssertionResult AssertionFailure() {
-  return AssertionResult(false);
-}
-
-// Makes a failed assertion result with the given failure message.
-// Deprecated; use AssertionFailure() << message.
-AssertionResult AssertionFailure(const Message& message) {
-  return AssertionFailure() << message;
-}
-
-namespace internal {
-
-namespace edit_distance {
-std::vector<EditType> CalculateOptimalEdits(const std::vector<size_t>& left,
-                                            const std::vector<size_t>& right) {
-  std::vector<std::vector<double> > costs(
-      left.size() + 1, std::vector<double>(right.size() + 1));
-  std::vector<std::vector<EditType> > best_move(
-      left.size() + 1, std::vector<EditType>(right.size() + 1));
-
-  // Populate for empty right.
-  for (size_t l_i = 0; l_i < costs.size(); ++l_i) {
-    costs[l_i][0] = static_cast<double>(l_i);
-    best_move[l_i][0] = kRemove;
-  }
-  // Populate for empty left.
-  for (size_t r_i = 1; r_i < costs[0].size(); ++r_i) {
-    costs[0][r_i] = static_cast<double>(r_i);
-    best_move[0][r_i] = kAdd;
-  }
-
-  for (size_t l_i = 0; l_i < left.size(); ++l_i) {
-    for (size_t r_i = 0; r_i < right.size(); ++r_i) {
-      if (left[l_i] == right[r_i]) {
-        // Found a match. Consume it.
-        costs[l_i + 1][r_i + 1] = costs[l_i][r_i];
-        best_move[l_i + 1][r_i + 1] = kMatch;
-        continue;
-      }
-
-      const double add = costs[l_i + 1][r_i];
-      const double remove = costs[l_i][r_i + 1];
-      const double replace = costs[l_i][r_i];
-      if (add < remove && add < replace) {
-        costs[l_i + 1][r_i + 1] = add + 1;
-        best_move[l_i + 1][r_i + 1] = kAdd;
-      } else if (remove < add && remove < replace) {
-        costs[l_i + 1][r_i + 1] = remove + 1;
-        best_move[l_i + 1][r_i + 1] = kRemove;
-      } else {
-        // We make replace a little more expensive than add/remove to lower
-        // their priority.
-        costs[l_i + 1][r_i + 1] = replace + 1.00001;
-        best_move[l_i + 1][r_i + 1] = kReplace;
-      }
-    }
-  }
-
-  // Reconstruct the best path. We do it in reverse order.
-  std::vector<EditType> best_path;
-  for (size_t l_i = left.size(), r_i = right.size(); l_i > 0 || r_i > 0;) {
-    EditType move = best_move[l_i][r_i];
-    best_path.push_back(move);
-    l_i -= move != kAdd;
-    r_i -= move != kRemove;
-  }
-  std::reverse(best_path.begin(), best_path.end());
-  return best_path;
-}
-
-namespace {
-
-// Helper class to convert string into ids with deduplication.
-class InternalStrings {
- public:
-  size_t GetId(const std::string& str) {
-    IdMap::iterator it = ids_.find(str);
-    if (it != ids_.end()) return it->second;
-    size_t id = ids_.size();
-    return ids_[str] = id;
-  }
-
- private:
-  typedef std::map<std::string, size_t> IdMap;
-  IdMap ids_;
-};
-
-}  // namespace
-
-std::vector<EditType> CalculateOptimalEdits(
-    const std::vector<std::string>& left,
-    const std::vector<std::string>& right) {
-  std::vector<size_t> left_ids, right_ids;
-  {
-    InternalStrings intern_table;
-    for (size_t i = 0; i < left.size(); ++i) {
-      left_ids.push_back(intern_table.GetId(left[i]));
-    }
-    for (size_t i = 0; i < right.size(); ++i) {
-      right_ids.push_back(intern_table.GetId(right[i]));
-    }
-  }
-  return CalculateOptimalEdits(left_ids, right_ids);
-}
-
-namespace {
-
-// Helper class that holds the state for one hunk and prints it out to the
-// stream.
-// It reorders adds/removes when possible to group all removes before all
-// adds. It also adds the hunk header before printint into the stream.
-class Hunk {
- public:
-  Hunk(size_t left_start, size_t right_start)
-      : left_start_(left_start),
-        right_start_(right_start),
-        adds_(),
-        removes_(),
-        common_() {}
-
-  void PushLine(char edit, const char* line) {
-    switch (edit) {
-      case ' ':
-        ++common_;
-        FlushEdits();
-        hunk_.push_back(std::make_pair(' ', line));
-        break;
-      case '-':
-        ++removes_;
-        hunk_removes_.push_back(std::make_pair('-', line));
-        break;
-      case '+':
-        ++adds_;
-        hunk_adds_.push_back(std::make_pair('+', line));
-        break;
-    }
-  }
-
-  void PrintTo(std::ostream* os) {
-    PrintHeader(os);
-    FlushEdits();
-    for (std::list<std::pair<char, const char*> >::const_iterator it =
-             hunk_.begin();
-         it != hunk_.end(); ++it) {
-      *os << it->first << it->second << "\n";
-    }
-  }
-
-  bool has_edits() const { return adds_ || removes_; }
-
- private:
-  void FlushEdits() {
-    hunk_.splice(hunk_.end(), hunk_removes_);
-    hunk_.splice(hunk_.end(), hunk_adds_);
-  }
-
-  // Print a unified diff header for one hunk.
-  // The format is
-  //   "@@ -<left_start>,<left_length> +<right_start>,<right_length> @@"
-  // where the left/right parts are omitted if unnecessary.
-  void PrintHeader(std::ostream* ss) const {
-    *ss << "@@ ";
-    if (removes_) {
-      *ss << "-" << left_start_ << "," << (removes_ + common_);
-    }
-    if (removes_ && adds_) {
-      *ss << " ";
-    }
-    if (adds_) {
-      *ss << "+" << right_start_ << "," << (adds_ + common_);
-    }
-    *ss << " @@\n";
-  }
-
-  size_t left_start_, right_start_;
-  size_t adds_, removes_, common_;
-  std::list<std::pair<char, const char*> > hunk_, hunk_adds_, hunk_removes_;
-};
-
-}  // namespace
-
-// Create a list of diff hunks in Unified diff format.
-// Each hunk has a header generated by PrintHeader above plus a body with
-// lines prefixed with ' ' for no change, '-' for deletion and '+' for
-// addition.
-// 'context' represents the desired unchanged prefix/suffix around the diff.
-// If two hunks are close enough that their contexts overlap, then they are
-// joined into one hunk.
-std::string CreateUnifiedDiff(const std::vector<std::string>& left,
-                              const std::vector<std::string>& right,
-                              size_t context) {
-  const std::vector<EditType> edits = CalculateOptimalEdits(left, right);
-
-  size_t l_i = 0, r_i = 0, edit_i = 0;
-  std::stringstream ss;
-  while (edit_i < edits.size()) {
-    // Find first edit.
-    while (edit_i < edits.size() && edits[edit_i] == kMatch) {
-      ++l_i;
-      ++r_i;
-      ++edit_i;
-    }
-
-    // Find the first line to include in the hunk.
-    const size_t prefix_context = std::min(l_i, context);
-    Hunk hunk(l_i - prefix_context + 1, r_i - prefix_context + 1);
-    for (size_t i = prefix_context; i > 0; --i) {
-      hunk.PushLine(' ', left[l_i - i].c_str());
-    }
-
-    // Iterate the edits until we found enough suffix for the hunk or the input
-    // is over.
-    size_t n_suffix = 0;
-    for (; edit_i < edits.size(); ++edit_i) {
-      if (n_suffix >= context) {
-        // Continue only if the next hunk is very close.
-        auto it = edits.begin() + static_cast<int>(edit_i);
-        while (it != edits.end() && *it == kMatch) ++it;
-        if (it == edits.end() ||
-            static_cast<size_t>(it - edits.begin()) - edit_i >= context) {
-          // There is no next edit or it is too far away.
-          break;
-        }
-      }
-
-      EditType edit = edits[edit_i];
-      // Reset count when a non match is found.
-      n_suffix = edit == kMatch ? n_suffix + 1 : 0;
-
-      if (edit == kMatch || edit == kRemove || edit == kReplace) {
-        hunk.PushLine(edit == kMatch ? ' ' : '-', left[l_i].c_str());
-      }
-      if (edit == kAdd || edit == kReplace) {
-        hunk.PushLine('+', right[r_i].c_str());
-      }
-
-      // Advance indices, depending on edit type.
-      l_i += edit != kAdd;
-      r_i += edit != kRemove;
-    }
-
-    if (!hunk.has_edits()) {
-      // We are done. We don't want this hunk.
-      break;
-    }
-
-    hunk.PrintTo(&ss);
-  }
-  return ss.str();
-}
-
-}  // namespace edit_distance
-
-namespace {
-
-// The string representation of the values received in EqFailure() are already
-// escaped. Split them on escaped '\n' boundaries. Leave all other escaped
-// characters the same.
-std::vector<std::string> SplitEscapedString(const std::string& str) {
-  std::vector<std::string> lines;
-  size_t start = 0, end = str.size();
-  if (end > 2 && str[0] == '"' && str[end - 1] == '"') {
-    ++start;
-    --end;
-  }
-  bool escaped = false;
-  for (size_t i = start; i + 1 < end; ++i) {
-    if (escaped) {
-      escaped = false;
-      if (str[i] == 'n') {
-        lines.push_back(str.substr(start, i - start - 1));
-        start = i + 1;
-      }
-    } else {
-      escaped = str[i] == '\\';
-    }
-  }
-  lines.push_back(str.substr(start, end - start));
-  return lines;
-}
-
-}  // namespace
-
-// Constructs and returns the message for an equality assertion
-// (e.g. ASSERT_EQ, EXPECT_STREQ, etc) failure.
-//
-// The first four parameters are the expressions used in the assertion
-// and their values, as strings.  For example, for ASSERT_EQ(foo, bar)
-// where foo is 5 and bar is 6, we have:
-//
-//   lhs_expression: "foo"
-//   rhs_expression: "bar"
-//   lhs_value:      "5"
-//   rhs_value:      "6"
-//
-// The ignoring_case parameter is true if and only if the assertion is a
-// *_STRCASEEQ*.  When it's true, the string "Ignoring case" will
-// be inserted into the message.
-AssertionResult EqFailure(const char* lhs_expression,
-                          const char* rhs_expression,
-                          const std::string& lhs_value,
-                          const std::string& rhs_value,
-                          bool ignoring_case) {
-  Message msg;
-  msg << "Expected equality of these values:";
-  msg << "\n  " << lhs_expression;
-  if (lhs_value != lhs_expression) {
-    msg << "\n    Which is: " << lhs_value;
-  }
-  msg << "\n  " << rhs_expression;
-  if (rhs_value != rhs_expression) {
-    msg << "\n    Which is: " << rhs_value;
-  }
-
-  if (ignoring_case) {
-    msg << "\nIgnoring case";
-  }
-
-  if (!lhs_value.empty() && !rhs_value.empty()) {
-    const std::vector<std::string> lhs_lines =
-        SplitEscapedString(lhs_value);
-    const std::vector<std::string> rhs_lines =
-        SplitEscapedString(rhs_value);
-    if (lhs_lines.size() > 1 || rhs_lines.size() > 1) {
-      msg << "\nWith diff:\n"
-          << edit_distance::CreateUnifiedDiff(lhs_lines, rhs_lines);
-    }
-  }
-
-  return AssertionFailure() << msg;
-}
-
-// Constructs a failure message for Boolean assertions such as EXPECT_TRUE.
-std::string GetBoolAssertionFailureMessage(
-    const AssertionResult& assertion_result,
-    const char* expression_text,
-    const char* actual_predicate_value,
-    const char* expected_predicate_value) {
-  const char* actual_message = assertion_result.message();
-  Message msg;
-  msg << "Value of: " << expression_text
-      << "\n  Actual: " << actual_predicate_value;
-  if (actual_message[0] != '\0')
-    msg << " (" << actual_message << ")";
-  msg << "\nExpected: " << expected_predicate_value;
-  return msg.GetString();
-}
-
-// Helper function for implementing ASSERT_NEAR.
-AssertionResult DoubleNearPredFormat(const char* expr1,
-                                     const char* expr2,
-                                     const char* abs_error_expr,
-                                     double val1,
-                                     double val2,
-                                     double abs_error) {
-  const double diff = fabs(val1 - val2);
-  if (diff <= abs_error) return AssertionSuccess();
-
-  // Find the value which is closest to zero.
-  const double min_abs = std::min(fabs(val1), fabs(val2));
-  // Find the distance to the next double from that value.
-  const double epsilon =
-      nextafter(min_abs, std::numeric_limits<double>::infinity()) - min_abs;
-  // Detect the case where abs_error is so small that EXPECT_NEAR is
-  // effectively the same as EXPECT_EQUAL, and give an informative error
-  // message so that the situation can be more easily understood without
-  // requiring exotic floating-point knowledge.
-  // Don't do an epsilon check if abs_error is zero because that implies
-  // that an equality check was actually intended.
-  if (!(std::isnan)(val1) && !(std::isnan)(val2) && abs_error > 0 &&
-      abs_error < epsilon) {
-    return AssertionFailure()
-           << "The difference between " << expr1 << " and " << expr2 << " is "
-           << diff << ", where\n"
-           << expr1 << " evaluates to " << val1 << ",\n"
-           << expr2 << " evaluates to " << val2 << ".\nThe abs_error parameter "
-           << abs_error_expr << " evaluates to " << abs_error
-           << " which is smaller than the minimum distance between doubles for "
-              "numbers of this magnitude which is "
-           << epsilon
-           << ", thus making this EXPECT_NEAR check equivalent to "
-              "EXPECT_EQUAL. Consider using EXPECT_DOUBLE_EQ instead.";
-  }
-  return AssertionFailure()
-      << "The difference between " << expr1 << " and " << expr2
-      << " is " << diff << ", which exceeds " << abs_error_expr << ", where\n"
-      << expr1 << " evaluates to " << val1 << ",\n"
-      << expr2 << " evaluates to " << val2 << ", and\n"
-      << abs_error_expr << " evaluates to " << abs_error << ".";
-}
-
-
-// Helper template for implementing FloatLE() and DoubleLE().
-template <typename RawType>
-AssertionResult FloatingPointLE(const char* expr1,
-                                const char* expr2,
-                                RawType val1,
-                                RawType val2) {
-  // Returns success if val1 is less than val2,
-  if (val1 < val2) {
-    return AssertionSuccess();
-  }
-
-  // or if val1 is almost equal to val2.
-  const FloatingPoint<RawType> lhs(val1), rhs(val2);
-  if (lhs.AlmostEquals(rhs)) {
-    return AssertionSuccess();
-  }
-
-  // Note that the above two checks will both fail if either val1 or
-  // val2 is NaN, as the IEEE floating-point standard requires that
-  // any predicate involving a NaN must return false.
-
-  ::std::stringstream val1_ss;
-  val1_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
-          << val1;
-
-  ::std::stringstream val2_ss;
-  val2_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
-          << val2;
-
-  return AssertionFailure()
-      << "Expected: (" << expr1 << ") <= (" << expr2 << ")\n"
-      << "  Actual: " << StringStreamToString(&val1_ss) << " vs "
-      << StringStreamToString(&val2_ss);
-}
-
-}  // namespace internal
-
-// Asserts that val1 is less than, or almost equal to, val2.  Fails
-// otherwise.  In particular, it fails if either val1 or val2 is NaN.
-AssertionResult FloatLE(const char* expr1, const char* expr2,
-                        float val1, float val2) {
-  return internal::FloatingPointLE<float>(expr1, expr2, val1, val2);
-}
-
-// Asserts that val1 is less than, or almost equal to, val2.  Fails
-// otherwise.  In particular, it fails if either val1 or val2 is NaN.
-AssertionResult DoubleLE(const char* expr1, const char* expr2,
-                         double val1, double val2) {
-  return internal::FloatingPointLE<double>(expr1, expr2, val1, val2);
-}
-
-namespace internal {
-
-// The helper function for {ASSERT|EXPECT}_STREQ.
-AssertionResult CmpHelperSTREQ(const char* lhs_expression,
-                               const char* rhs_expression,
-                               const char* lhs,
-                               const char* rhs) {
-  if (String::CStringEquals(lhs, rhs)) {
-    return AssertionSuccess();
-  }
-
-  return EqFailure(lhs_expression,
-                   rhs_expression,
-                   PrintToString(lhs),
-                   PrintToString(rhs),
-                   false);
-}
-
-// The helper function for {ASSERT|EXPECT}_STRCASEEQ.
-AssertionResult CmpHelperSTRCASEEQ(const char* lhs_expression,
-                                   const char* rhs_expression,
-                                   const char* lhs,
-                                   const char* rhs) {
-  if (String::CaseInsensitiveCStringEquals(lhs, rhs)) {
-    return AssertionSuccess();
-  }
-
-  return EqFailure(lhs_expression,
-                   rhs_expression,
-                   PrintToString(lhs),
-                   PrintToString(rhs),
-                   true);
-}
-
-// The helper function for {ASSERT|EXPECT}_STRNE.
-AssertionResult CmpHelperSTRNE(const char* s1_expression,
-                               const char* s2_expression,
-                               const char* s1,
-                               const char* s2) {
-  if (!String::CStringEquals(s1, s2)) {
-    return AssertionSuccess();
-  } else {
-    return AssertionFailure() << "Expected: (" << s1_expression << ") != ("
-                              << s2_expression << "), actual: \""
-                              << s1 << "\" vs \"" << s2 << "\"";
-  }
-}
-
-// The helper function for {ASSERT|EXPECT}_STRCASENE.
-AssertionResult CmpHelperSTRCASENE(const char* s1_expression,
-                                   const char* s2_expression,
-                                   const char* s1,
-                                   const char* s2) {
-  if (!String::CaseInsensitiveCStringEquals(s1, s2)) {
-    return AssertionSuccess();
-  } else {
-    return AssertionFailure()
-        << "Expected: (" << s1_expression << ") != ("
-        << s2_expression << ") (ignoring case), actual: \""
-        << s1 << "\" vs \"" << s2 << "\"";
-  }
-}
-
-}  // namespace internal
-
-namespace {
-
-// Helper functions for implementing IsSubString() and IsNotSubstring().
-
-// This group of overloaded functions return true if and only if needle
-// is a substring of haystack.  NULL is considered a substring of
-// itself only.
-
-bool IsSubstringPred(const char* needle, const char* haystack) {
-  if (needle == nullptr || haystack == nullptr) return needle == haystack;
-
-  return strstr(haystack, needle) != nullptr;
-}
-
-bool IsSubstringPred(const wchar_t* needle, const wchar_t* haystack) {
-  if (needle == nullptr || haystack == nullptr) return needle == haystack;
-
-  return wcsstr(haystack, needle) != nullptr;
-}
-
-// StringType here can be either ::std::string or ::std::wstring.
-template <typename StringType>
-bool IsSubstringPred(const StringType& needle,
-                     const StringType& haystack) {
-  return haystack.find(needle) != StringType::npos;
-}
-
-// This function implements either IsSubstring() or IsNotSubstring(),
-// depending on the value of the expected_to_be_substring parameter.
-// StringType here can be const char*, const wchar_t*, ::std::string,
-// or ::std::wstring.
-template <typename StringType>
-AssertionResult IsSubstringImpl(
-    bool expected_to_be_substring,
-    const char* needle_expr, const char* haystack_expr,
-    const StringType& needle, const StringType& haystack) {
-  if (IsSubstringPred(needle, haystack) == expected_to_be_substring)
-    return AssertionSuccess();
-
-  const bool is_wide_string = sizeof(needle[0]) > 1;
-  const char* const begin_string_quote = is_wide_string ? "L\"" : "\"";
-  return AssertionFailure()
-      << "Value of: " << needle_expr << "\n"
-      << "  Actual: " << begin_string_quote << needle << "\"\n"
-      << "Expected: " << (expected_to_be_substring ? "" : "not ")
-      << "a substring of " << haystack_expr << "\n"
-      << "Which is: " << begin_string_quote << haystack << "\"";
-}
-
-}  // namespace
-
-// IsSubstring() and IsNotSubstring() check whether needle is a
-// substring of haystack (NULL is considered a substring of itself
-// only), and return an appropriate error message when they fail.
-
-AssertionResult IsSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const char* needle, const char* haystack) {
-  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
-}
-
-AssertionResult IsSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const wchar_t* needle, const wchar_t* haystack) {
-  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
-}
-
-AssertionResult IsNotSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const char* needle, const char* haystack) {
-  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
-}
-
-AssertionResult IsNotSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const wchar_t* needle, const wchar_t* haystack) {
-  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
-}
-
-AssertionResult IsSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const ::std::string& needle, const ::std::string& haystack) {
-  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
-}
-
-AssertionResult IsNotSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const ::std::string& needle, const ::std::string& haystack) {
-  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
-}
-
-#if GTEST_HAS_STD_WSTRING
-AssertionResult IsSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const ::std::wstring& needle, const ::std::wstring& haystack) {
-  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
-}
-
-AssertionResult IsNotSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const ::std::wstring& needle, const ::std::wstring& haystack) {
-  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
-}
-#endif  // GTEST_HAS_STD_WSTRING
-
-namespace internal {
-
-#if GTEST_OS_WINDOWS
-
-namespace {
-
-// Helper function for IsHRESULT{SuccessFailure} predicates
-AssertionResult HRESULTFailureHelper(const char* expr,
-                                     const char* expected,
-                                     long hr) {  // NOLINT
-# if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_TV_TITLE
-
-  // Windows CE doesn't support FormatMessage.
-  const char error_text[] = "";
-
-# else
-
-  // Looks up the human-readable system message for the HRESULT code
-  // and since we're not passing any params to FormatMessage, we don't
-  // want inserts expanded.
-  const DWORD kFlags = FORMAT_MESSAGE_FROM_SYSTEM |
-                       FORMAT_MESSAGE_IGNORE_INSERTS;
-  const DWORD kBufSize = 4096;
-  // Gets the system's human readable message string for this HRESULT.
-  char error_text[kBufSize] = { '\0' };
-  DWORD message_length = ::FormatMessageA(kFlags,
-                                          0,   // no source, we're asking system
-                                          static_cast<DWORD>(hr),  // the error
-                                          0,   // no line width restrictions
-                                          error_text,  // output buffer
-                                          kBufSize,    // buf size
-                                          nullptr);  // no arguments for inserts
-  // Trims tailing white space (FormatMessage leaves a trailing CR-LF)
-  for (; message_length && IsSpace(error_text[message_length - 1]);
-          --message_length) {
-    error_text[message_length - 1] = '\0';
-  }
-
-# endif  // GTEST_OS_WINDOWS_MOBILE
-
-  const std::string error_hex("0x" + String::FormatHexInt(hr));
-  return ::testing::AssertionFailure()
-      << "Expected: " << expr << " " << expected << ".\n"
-      << "  Actual: " << error_hex << " " << error_text << "\n";
-}
-
-}  // namespace
-
-AssertionResult IsHRESULTSuccess(const char* expr, long hr) {  // NOLINT
-  if (SUCCEEDED(hr)) {
-    return AssertionSuccess();
-  }
-  return HRESULTFailureHelper(expr, "succeeds", hr);
-}
-
-AssertionResult IsHRESULTFailure(const char* expr, long hr) {  // NOLINT
-  if (FAILED(hr)) {
-    return AssertionSuccess();
-  }
-  return HRESULTFailureHelper(expr, "fails", hr);
-}
-
-#endif  // GTEST_OS_WINDOWS
-
-// Utility functions for encoding Unicode text (wide strings) in
-// UTF-8.
-
-// A Unicode code-point can have up to 21 bits, and is encoded in UTF-8
-// like this:
-//
-// Code-point length   Encoding
-//   0 -  7 bits       0xxxxxxx
-//   8 - 11 bits       110xxxxx 10xxxxxx
-//  12 - 16 bits       1110xxxx 10xxxxxx 10xxxxxx
-//  17 - 21 bits       11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
-
-// The maximum code-point a one-byte UTF-8 sequence can represent.
-constexpr uint32_t kMaxCodePoint1 = (static_cast<uint32_t>(1) <<  7) - 1;
-
-// The maximum code-point a two-byte UTF-8 sequence can represent.
-constexpr uint32_t kMaxCodePoint2 = (static_cast<uint32_t>(1) << (5 + 6)) - 1;
-
-// The maximum code-point a three-byte UTF-8 sequence can represent.
-constexpr uint32_t kMaxCodePoint3 = (static_cast<uint32_t>(1) << (4 + 2*6)) - 1;
-
-// The maximum code-point a four-byte UTF-8 sequence can represent.
-constexpr uint32_t kMaxCodePoint4 = (static_cast<uint32_t>(1) << (3 + 3*6)) - 1;
-
-// Chops off the n lowest bits from a bit pattern.  Returns the n
-// lowest bits.  As a side effect, the original bit pattern will be
-// shifted to the right by n bits.
-inline uint32_t ChopLowBits(uint32_t* bits, int n) {
-  const uint32_t low_bits = *bits & ((static_cast<uint32_t>(1) << n) - 1);
-  *bits >>= n;
-  return low_bits;
-}
-
-// Converts a Unicode code point to a narrow string in UTF-8 encoding.
-// code_point parameter is of type uint32_t because wchar_t may not be
-// wide enough to contain a code point.
-// If the code_point is not a valid Unicode code point
-// (i.e. outside of Unicode range U+0 to U+10FFFF) it will be converted
-// to "(Invalid Unicode 0xXXXXXXXX)".
-std::string CodePointToUtf8(uint32_t code_point) {
-  if (code_point > kMaxCodePoint4) {
-    return "(Invalid Unicode 0x" + String::FormatHexUInt32(code_point) + ")";
-  }
-
-  char str[5];  // Big enough for the largest valid code point.
-  if (code_point <= kMaxCodePoint1) {
-    str[1] = '\0';
-    str[0] = static_cast<char>(code_point);                          // 0xxxxxxx
-  } else if (code_point <= kMaxCodePoint2) {
-    str[2] = '\0';
-    str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
-    str[0] = static_cast<char>(0xC0 | code_point);                   // 110xxxxx
-  } else if (code_point <= kMaxCodePoint3) {
-    str[3] = '\0';
-    str[2] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
-    str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
-    str[0] = static_cast<char>(0xE0 | code_point);                   // 1110xxxx
-  } else {  // code_point <= kMaxCodePoint4
-    str[4] = '\0';
-    str[3] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
-    str[2] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
-    str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
-    str[0] = static_cast<char>(0xF0 | code_point);                   // 11110xxx
-  }
-  return str;
-}
-
-// The following two functions only make sense if the system
-// uses UTF-16 for wide string encoding. All supported systems
-// with 16 bit wchar_t (Windows, Cygwin) do use UTF-16.
-
-// Determines if the arguments constitute UTF-16 surrogate pair
-// and thus should be combined into a single Unicode code point
-// using CreateCodePointFromUtf16SurrogatePair.
-inline bool IsUtf16SurrogatePair(wchar_t first, wchar_t second) {
-  return sizeof(wchar_t) == 2 &&
-      (first & 0xFC00) == 0xD800 && (second & 0xFC00) == 0xDC00;
-}
-
-// Creates a Unicode code point from UTF16 surrogate pair.
-inline uint32_t CreateCodePointFromUtf16SurrogatePair(wchar_t first,
-                                                      wchar_t second) {
-  const auto first_u = static_cast<uint32_t>(first);
-  const auto second_u = static_cast<uint32_t>(second);
-  const uint32_t mask = (1 << 10) - 1;
-  return (sizeof(wchar_t) == 2)
-             ? (((first_u & mask) << 10) | (second_u & mask)) + 0x10000
-             :
-             // This function should not be called when the condition is
-             // false, but we provide a sensible default in case it is.
-             first_u;
-}
-
-// Converts a wide string to a narrow string in UTF-8 encoding.
-// The wide string is assumed to have the following encoding:
-//   UTF-16 if sizeof(wchar_t) == 2 (on Windows, Cygwin)
-//   UTF-32 if sizeof(wchar_t) == 4 (on Linux)
-// Parameter str points to a null-terminated wide string.
-// Parameter num_chars may additionally limit the number
-// of wchar_t characters processed. -1 is used when the entire string
-// should be processed.
-// If the string contains code points that are not valid Unicode code points
-// (i.e. outside of Unicode range U+0 to U+10FFFF) they will be output
-// as '(Invalid Unicode 0xXXXXXXXX)'. If the string is in UTF16 encoding
-// and contains invalid UTF-16 surrogate pairs, values in those pairs
-// will be encoded as individual Unicode characters from Basic Normal Plane.
-std::string WideStringToUtf8(const wchar_t* str, int num_chars) {
-  if (num_chars == -1)
-    num_chars = static_cast<int>(wcslen(str));
-
-  ::std::stringstream stream;
-  for (int i = 0; i < num_chars; ++i) {
-    uint32_t unicode_code_point;
-
-    if (str[i] == L'\0') {
-      break;
-    } else if (i + 1 < num_chars && IsUtf16SurrogatePair(str[i], str[i + 1])) {
-      unicode_code_point = CreateCodePointFromUtf16SurrogatePair(str[i],
-                                                                 str[i + 1]);
-      i++;
-    } else {
-      unicode_code_point = static_cast<uint32_t>(str[i]);
-    }
-
-    stream << CodePointToUtf8(unicode_code_point);
-  }
-  return StringStreamToString(&stream);
-}
-
-// Converts a wide C string to an std::string using the UTF-8 encoding.
-// NULL will be converted to "(null)".
-std::string String::ShowWideCString(const wchar_t * wide_c_str) {
-  if (wide_c_str == nullptr) return "(null)";
-
-  return internal::WideStringToUtf8(wide_c_str, -1);
-}
-
-// Compares two wide C strings.  Returns true if and only if they have the
-// same content.
-//
-// Unlike wcscmp(), this function can handle NULL argument(s).  A NULL
-// C string is considered different to any non-NULL C string,
-// including the empty string.
-bool String::WideCStringEquals(const wchar_t * lhs, const wchar_t * rhs) {
-  if (lhs == nullptr) return rhs == nullptr;
-
-  if (rhs == nullptr) return false;
-
-  return wcscmp(lhs, rhs) == 0;
-}
-
-// Helper function for *_STREQ on wide strings.
-AssertionResult CmpHelperSTREQ(const char* lhs_expression,
-                               const char* rhs_expression,
-                               const wchar_t* lhs,
-                               const wchar_t* rhs) {
-  if (String::WideCStringEquals(lhs, rhs)) {
-    return AssertionSuccess();
-  }
-
-  return EqFailure(lhs_expression,
-                   rhs_expression,
-                   PrintToString(lhs),
-                   PrintToString(rhs),
-                   false);
-}
-
-// Helper function for *_STRNE on wide strings.
-AssertionResult CmpHelperSTRNE(const char* s1_expression,
-                               const char* s2_expression,
-                               const wchar_t* s1,
-                               const wchar_t* s2) {
-  if (!String::WideCStringEquals(s1, s2)) {
-    return AssertionSuccess();
-  }
-
-  return AssertionFailure() << "Expected: (" << s1_expression << ") != ("
-                            << s2_expression << "), actual: "
-                            << PrintToString(s1)
-                            << " vs " << PrintToString(s2);
-}
-
-// Compares two C strings, ignoring case.  Returns true if and only if they have
-// the same content.
-//
-// Unlike strcasecmp(), this function can handle NULL argument(s).  A
-// NULL C string is considered different to any non-NULL C string,
-// including the empty string.
-bool String::CaseInsensitiveCStringEquals(const char * lhs, const char * rhs) {
-  if (lhs == nullptr) return rhs == nullptr;
-  if (rhs == nullptr) return false;
-  return posix::StrCaseCmp(lhs, rhs) == 0;
-}
-
-// Compares two wide C strings, ignoring case.  Returns true if and only if they
-// have the same content.
-//
-// Unlike wcscasecmp(), this function can handle NULL argument(s).
-// A NULL C string is considered different to any non-NULL wide C string,
-// including the empty string.
-// NB: The implementations on different platforms slightly differ.
-// On windows, this method uses _wcsicmp which compares according to LC_CTYPE
-// environment variable. On GNU platform this method uses wcscasecmp
-// which compares according to LC_CTYPE category of the current locale.
-// On MacOS X, it uses towlower, which also uses LC_CTYPE category of the
-// current locale.
-bool String::CaseInsensitiveWideCStringEquals(const wchar_t* lhs,
-                                              const wchar_t* rhs) {
-  if (lhs == nullptr) return rhs == nullptr;
-
-  if (rhs == nullptr) return false;
-
-#if GTEST_OS_WINDOWS
-  return _wcsicmp(lhs, rhs) == 0;
-#elif GTEST_OS_LINUX && !GTEST_OS_LINUX_ANDROID
-  return wcscasecmp(lhs, rhs) == 0;
-#else
-  // Android, Mac OS X and Cygwin don't define wcscasecmp.
-  // Other unknown OSes may not define it either.
-  wint_t left, right;
-  do {
-    left = towlower(static_cast<wint_t>(*lhs++));
-    right = towlower(static_cast<wint_t>(*rhs++));
-  } while (left && left == right);
-  return left == right;
-#endif  // OS selector
-}
-
-// Returns true if and only if str ends with the given suffix, ignoring case.
-// Any string is considered to end with an empty suffix.
-bool String::EndsWithCaseInsensitive(
-    const std::string& str, const std::string& suffix) {
-  const size_t str_len = str.length();
-  const size_t suffix_len = suffix.length();
-  return (str_len >= suffix_len) &&
-         CaseInsensitiveCStringEquals(str.c_str() + str_len - suffix_len,
-                                      suffix.c_str());
-}
-
-// Formats an int value as "%02d".
-std::string String::FormatIntWidth2(int value) {
-  return FormatIntWidthN(value, 2);
-}
-
-// Formats an int value to given width with leading zeros.
-std::string String::FormatIntWidthN(int value, int width) {
-  std::stringstream ss;
-  ss << std::setfill('0') << std::setw(width) << value;
-  return ss.str();
-}
-
-// Formats an int value as "%X".
-std::string String::FormatHexUInt32(uint32_t value) {
-  std::stringstream ss;
-  ss << std::hex << std::uppercase << value;
-  return ss.str();
-}
-
-// Formats an int value as "%X".
-std::string String::FormatHexInt(int value) {
-  return FormatHexUInt32(static_cast<uint32_t>(value));
-}
-
-// Formats a byte as "%02X".
-std::string String::FormatByte(unsigned char value) {
-  std::stringstream ss;
-  ss << std::setfill('0') << std::setw(2) << std::hex << std::uppercase
-     << static_cast<unsigned int>(value);
-  return ss.str();
-}
-
-// Converts the buffer in a stringstream to an std::string, converting NUL
-// bytes to "\\0" along the way.
-std::string StringStreamToString(::std::stringstream* ss) {
-  const ::std::string& str = ss->str();
-  const char* const start = str.c_str();
-  const char* const end = start + str.length();
-
-  std::string result;
-  result.reserve(static_cast<size_t>(2 * (end - start)));
-  for (const char* ch = start; ch != end; ++ch) {
-    if (*ch == '\0') {
-      result += "\\0";  // Replaces NUL with "\\0";
-    } else {
-      result += *ch;
-    }
-  }
-
-  return result;
-}
-
-// Appends the user-supplied message to the Google-Test-generated message.
-std::string AppendUserMessage(const std::string& gtest_msg,
-                              const Message& user_msg) {
-  // Appends the user message if it's non-empty.
-  const std::string user_msg_string = user_msg.GetString();
-  if (user_msg_string.empty()) {
-    return gtest_msg;
-  }
-  if (gtest_msg.empty()) {
-    return user_msg_string;
-  }
-  return gtest_msg + "\n" + user_msg_string;
-}
-
-}  // namespace internal
-
-// class TestResult
-
-// Creates an empty TestResult.
-TestResult::TestResult()
-    : death_test_count_(0), start_timestamp_(0), elapsed_time_(0) {}
-
-// D'tor.
-TestResult::~TestResult() {
-}
-
-// Returns the i-th test part result among all the results. i can
-// range from 0 to total_part_count() - 1. If i is not in that range,
-// aborts the program.
-const TestPartResult& TestResult::GetTestPartResult(int i) const {
-  if (i < 0 || i >= total_part_count())
-    internal::posix::Abort();
-  return test_part_results_.at(static_cast<size_t>(i));
-}
-
-// Returns the i-th test property. i can range from 0 to
-// test_property_count() - 1. If i is not in that range, aborts the
-// program.
-const TestProperty& TestResult::GetTestProperty(int i) const {
-  if (i < 0 || i >= test_property_count())
-    internal::posix::Abort();
-  return test_properties_.at(static_cast<size_t>(i));
-}
-
-// Clears the test part results.
-void TestResult::ClearTestPartResults() {
-  test_part_results_.clear();
-}
-
-// Adds a test part result to the list.
-void TestResult::AddTestPartResult(const TestPartResult& test_part_result) {
-  test_part_results_.push_back(test_part_result);
-}
-
-// Adds a test property to the list. If a property with the same key as the
-// supplied property is already represented, the value of this test_property
-// replaces the old value for that key.
-void TestResult::RecordProperty(const std::string& xml_element,
-                                const TestProperty& test_property) {
-  if (!ValidateTestProperty(xml_element, test_property)) {
-    return;
-  }
-  internal::MutexLock lock(&test_properties_mutex_);
-  const std::vector<TestProperty>::iterator property_with_matching_key =
-      std::find_if(test_properties_.begin(), test_properties_.end(),
-                   internal::TestPropertyKeyIs(test_property.key()));
-  if (property_with_matching_key == test_properties_.end()) {
-    test_properties_.push_back(test_property);
-    return;
-  }
-  property_with_matching_key->SetValue(test_property.value());
-}
-
-// The list of reserved attributes used in the <testsuites> element of XML
-// output.
-static const char* const kReservedTestSuitesAttributes[] = {
-  "disabled",
-  "errors",
-  "failures",
-  "name",
-  "random_seed",
-  "tests",
-  "time",
-  "timestamp"
-};
-
-// The list of reserved attributes used in the <testsuite> element of XML
-// output.
-static const char* const kReservedTestSuiteAttributes[] = {
-    "disabled", "errors", "failures",  "name",
-    "tests",    "time",   "timestamp", "skipped"};
-
-// The list of reserved attributes used in the <testcase> element of XML output.
-static const char* const kReservedTestCaseAttributes[] = {
-    "classname",   "name", "status", "time",  "type_param",
-    "value_param", "file", "line"};
-
-// Use a slightly different set for allowed output to ensure existing tests can
-// still RecordProperty("result") or "RecordProperty(timestamp")
-static const char* const kReservedOutputTestCaseAttributes[] = {
-    "classname",   "name", "status", "time",   "type_param",
-    "value_param", "file", "line",   "result", "timestamp"};
-
-template <size_t kSize>
-std::vector<std::string> ArrayAsVector(const char* const (&array)[kSize]) {
-  return std::vector<std::string>(array, array + kSize);
-}
-
-static std::vector<std::string> GetReservedAttributesForElement(
-    const std::string& xml_element) {
-  if (xml_element == "testsuites") {
-    return ArrayAsVector(kReservedTestSuitesAttributes);
-  } else if (xml_element == "testsuite") {
-    return ArrayAsVector(kReservedTestSuiteAttributes);
-  } else if (xml_element == "testcase") {
-    return ArrayAsVector(kReservedTestCaseAttributes);
-  } else {
-    GTEST_CHECK_(false) << "Unrecognized xml_element provided: " << xml_element;
-  }
-  // This code is unreachable but some compilers may not realizes that.
-  return std::vector<std::string>();
-}
-
-// TODO(jdesprez): Merge the two getReserved attributes once skip is improved
-static std::vector<std::string> GetReservedOutputAttributesForElement(
-    const std::string& xml_element) {
-  if (xml_element == "testsuites") {
-    return ArrayAsVector(kReservedTestSuitesAttributes);
-  } else if (xml_element == "testsuite") {
-    return ArrayAsVector(kReservedTestSuiteAttributes);
-  } else if (xml_element == "testcase") {
-    return ArrayAsVector(kReservedOutputTestCaseAttributes);
-  } else {
-    GTEST_CHECK_(false) << "Unrecognized xml_element provided: " << xml_element;
-  }
-  // This code is unreachable but some compilers may not realizes that.
-  return std::vector<std::string>();
-}
-
-static std::string FormatWordList(const std::vector<std::string>& words) {
-  Message word_list;
-  for (size_t i = 0; i < words.size(); ++i) {
-    if (i > 0 && words.size() > 2) {
-      word_list << ", ";
-    }
-    if (i == words.size() - 1) {
-      word_list << "and ";
-    }
-    word_list << "'" << words[i] << "'";
-  }
-  return word_list.GetString();
-}
-
-static bool ValidateTestPropertyName(
-    const std::string& property_name,
-    const std::vector<std::string>& reserved_names) {
-  if (std::find(reserved_names.begin(), reserved_names.end(), property_name) !=
-          reserved_names.end()) {
-    ADD_FAILURE() << "Reserved key used in RecordProperty(): " << property_name
-                  << " (" << FormatWordList(reserved_names)
-                  << " are reserved by " << GTEST_NAME_ << ")";
-    return false;
-  }
-  return true;
-}
-
-// Adds a failure if the key is a reserved attribute of the element named
-// xml_element.  Returns true if the property is valid.
-bool TestResult::ValidateTestProperty(const std::string& xml_element,
-                                      const TestProperty& test_property) {
-  return ValidateTestPropertyName(test_property.key(),
-                                  GetReservedAttributesForElement(xml_element));
-}
-
-// Clears the object.
-void TestResult::Clear() {
-  test_part_results_.clear();
-  test_properties_.clear();
-  death_test_count_ = 0;
-  elapsed_time_ = 0;
-}
-
-// Returns true off the test part was skipped.
-static bool TestPartSkipped(const TestPartResult& result) {
-  return result.skipped();
-}
-
-// Returns true if and only if the test was skipped.
-bool TestResult::Skipped() const {
-  return !Failed() && CountIf(test_part_results_, TestPartSkipped) > 0;
-}
-
-// Returns true if and only if the test failed.
-bool TestResult::Failed() const {
-  for (int i = 0; i < total_part_count(); ++i) {
-    if (GetTestPartResult(i).failed())
-      return true;
-  }
-  return false;
-}
-
-// Returns true if and only if the test part fatally failed.
-static bool TestPartFatallyFailed(const TestPartResult& result) {
-  return result.fatally_failed();
-}
-
-// Returns true if and only if the test fatally failed.
-bool TestResult::HasFatalFailure() const {
-  return CountIf(test_part_results_, TestPartFatallyFailed) > 0;
-}
-
-// Returns true if and only if the test part non-fatally failed.
-static bool TestPartNonfatallyFailed(const TestPartResult& result) {
-  return result.nonfatally_failed();
-}
-
-// Returns true if and only if the test has a non-fatal failure.
-bool TestResult::HasNonfatalFailure() const {
-  return CountIf(test_part_results_, TestPartNonfatallyFailed) > 0;
-}
-
-// Gets the number of all test parts.  This is the sum of the number
-// of successful test parts and the number of failed test parts.
-int TestResult::total_part_count() const {
-  return static_cast<int>(test_part_results_.size());
-}
-
-// Returns the number of the test properties.
-int TestResult::test_property_count() const {
-  return static_cast<int>(test_properties_.size());
-}
-
-// class Test
-
-// Creates a Test object.
-
-// The c'tor saves the states of all flags.
-Test::Test()
-    : gtest_flag_saver_(new GTEST_FLAG_SAVER_) {
-}
-
-// The d'tor restores the states of all flags.  The actual work is
-// done by the d'tor of the gtest_flag_saver_ field, and thus not
-// visible here.
-Test::~Test() {
-}
-
-// Sets up the test fixture.
-//
-// A sub-class may override this.
-void Test::SetUp() {
-}
-
-// Tears down the test fixture.
-//
-// A sub-class may override this.
-void Test::TearDown() {
-}
-
-// Allows user supplied key value pairs to be recorded for later output.
-void Test::RecordProperty(const std::string& key, const std::string& value) {
-  UnitTest::GetInstance()->RecordProperty(key, value);
-}
-
-// Allows user supplied key value pairs to be recorded for later output.
-void Test::RecordProperty(const std::string& key, int value) {
-  Message value_message;
-  value_message << value;
-  RecordProperty(key, value_message.GetString().c_str());
-}
-
-namespace internal {
-
-void ReportFailureInUnknownLocation(TestPartResult::Type result_type,
-                                    const std::string& message) {
-  // This function is a friend of UnitTest and as such has access to
-  // AddTestPartResult.
-  UnitTest::GetInstance()->AddTestPartResult(
-      result_type,
-      nullptr,  // No info about the source file where the exception occurred.
-      -1,       // We have no info on which line caused the exception.
-      message,
-      "");  // No stack trace, either.
-}
-
-}  // namespace internal
-
-// Google Test requires all tests in the same test suite to use the same test
-// fixture class.  This function checks if the current test has the
-// same fixture class as the first test in the current test suite.  If
-// yes, it returns true; otherwise it generates a Google Test failure and
-// returns false.
-bool Test::HasSameFixtureClass() {
-  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
-  const TestSuite* const test_suite = impl->current_test_suite();
-
-  // Info about the first test in the current test suite.
-  const TestInfo* const first_test_info = test_suite->test_info_list()[0];
-  const internal::TypeId first_fixture_id = first_test_info->fixture_class_id_;
-  const char* const first_test_name = first_test_info->name();
-
-  // Info about the current test.
-  const TestInfo* const this_test_info = impl->current_test_info();
-  const internal::TypeId this_fixture_id = this_test_info->fixture_class_id_;
-  const char* const this_test_name = this_test_info->name();
-
-  if (this_fixture_id != first_fixture_id) {
-    // Is the first test defined using TEST?
-    const bool first_is_TEST = first_fixture_id == internal::GetTestTypeId();
-    // Is this test defined using TEST?
-    const bool this_is_TEST = this_fixture_id == internal::GetTestTypeId();
-
-    if (first_is_TEST || this_is_TEST) {
-      // Both TEST and TEST_F appear in same test suite, which is incorrect.
-      // Tell the user how to fix this.
-
-      // Gets the name of the TEST and the name of the TEST_F.  Note
-      // that first_is_TEST and this_is_TEST cannot both be true, as
-      // the fixture IDs are different for the two tests.
-      const char* const TEST_name =
-          first_is_TEST ? first_test_name : this_test_name;
-      const char* const TEST_F_name =
-          first_is_TEST ? this_test_name : first_test_name;
-
-      ADD_FAILURE()
-          << "All tests in the same test suite must use the same test fixture\n"
-          << "class, so mixing TEST_F and TEST in the same test suite is\n"
-          << "illegal.  In test suite " << this_test_info->test_suite_name()
-          << ",\n"
-          << "test " << TEST_F_name << " is defined using TEST_F but\n"
-          << "test " << TEST_name << " is defined using TEST.  You probably\n"
-          << "want to change the TEST to TEST_F or move it to another test\n"
-          << "case.";
-    } else {
-      // Two fixture classes with the same name appear in two different
-      // namespaces, which is not allowed. Tell the user how to fix this.
-      ADD_FAILURE()
-          << "All tests in the same test suite must use the same test fixture\n"
-          << "class.  However, in test suite "
-          << this_test_info->test_suite_name() << ",\n"
-          << "you defined test " << first_test_name << " and test "
-          << this_test_name << "\n"
-          << "using two different test fixture classes.  This can happen if\n"
-          << "the two classes are from different namespaces or translation\n"
-          << "units and have the same name.  You should probably rename one\n"
-          << "of the classes to put the tests into different test suites.";
-    }
-    return false;
-  }
-
-  return true;
-}
-
-#if GTEST_HAS_SEH
-
-// Adds an "exception thrown" fatal failure to the current test.  This
-// function returns its result via an output parameter pointer because VC++
-// prohibits creation of objects with destructors on stack in functions
-// using __try (see error C2712).
-static std::string* FormatSehExceptionMessage(DWORD exception_code,
-                                              const char* location) {
-  Message message;
-  message << "SEH exception with code 0x" << std::setbase(16) <<
-    exception_code << std::setbase(10) << " thrown in " << location << ".";
-
-  return new std::string(message.GetString());
-}
-
-#endif  // GTEST_HAS_SEH
-
-namespace internal {
-
-#if GTEST_HAS_EXCEPTIONS
-
-// Adds an "exception thrown" fatal failure to the current test.
-static std::string FormatCxxExceptionMessage(const char* description,
-                                             const char* location) {
-  Message message;
-  if (description != nullptr) {
-    message << "C++ exception with description \"" << description << "\"";
-  } else {
-    message << "Unknown C++ exception";
-  }
-  message << " thrown in " << location << ".";
-
-  return message.GetString();
-}
-
-static std::string PrintTestPartResultToString(
-    const TestPartResult& test_part_result);
-
-GoogleTestFailureException::GoogleTestFailureException(
-    const TestPartResult& failure)
-    : ::std::runtime_error(PrintTestPartResultToString(failure).c_str()) {}
-
-#endif  // GTEST_HAS_EXCEPTIONS
-
-// We put these helper functions in the internal namespace as IBM's xlC
-// compiler rejects the code if they were declared static.
-
-// Runs the given method and handles SEH exceptions it throws, when
-// SEH is supported; returns the 0-value for type Result in case of an
-// SEH exception.  (Microsoft compilers cannot handle SEH and C++
-// exceptions in the same function.  Therefore, we provide a separate
-// wrapper function for handling SEH exceptions.)
-template <class T, typename Result>
-Result HandleSehExceptionsInMethodIfSupported(
-    T* object, Result (T::*method)(), const char* location) {
-#if GTEST_HAS_SEH
-  __try {
-    return (object->*method)();
-  } __except (internal::UnitTestOptions::GTestShouldProcessSEH(  // NOLINT
-      GetExceptionCode())) {
-    // We create the exception message on the heap because VC++ prohibits
-    // creation of objects with destructors on stack in functions using __try
-    // (see error C2712).
-    std::string* exception_message = FormatSehExceptionMessage(
-        GetExceptionCode(), location);
-    internal::ReportFailureInUnknownLocation(TestPartResult::kFatalFailure,
-                                             *exception_message);
-    delete exception_message;
-    return static_cast<Result>(0);
-  }
-#else
-  (void)location;
-  return (object->*method)();
-#endif  // GTEST_HAS_SEH
-}
-
-// Runs the given method and catches and reports C++ and/or SEH-style
-// exceptions, if they are supported; returns the 0-value for type
-// Result in case of an SEH exception.
-template <class T, typename Result>
-Result HandleExceptionsInMethodIfSupported(
-    T* object, Result (T::*method)(), const char* location) {
-  // NOTE: The user code can affect the way in which Google Test handles
-  // exceptions by setting GTEST_FLAG(catch_exceptions), but only before
-  // RUN_ALL_TESTS() starts. It is technically possible to check the flag
-  // after the exception is caught and either report or re-throw the
-  // exception based on the flag's value:
-  //
-  // try {
-  //   // Perform the test method.
-  // } catch (...) {
-  //   if (GTEST_FLAG(catch_exceptions))
-  //     // Report the exception as failure.
-  //   else
-  //     throw;  // Re-throws the original exception.
-  // }
-  //
-  // However, the purpose of this flag is to allow the program to drop into
-  // the debugger when the exception is thrown. On most platforms, once the
-  // control enters the catch block, the exception origin information is
-  // lost and the debugger will stop the program at the point of the
-  // re-throw in this function -- instead of at the point of the original
-  // throw statement in the code under test.  For this reason, we perform
-  // the check early, sacrificing the ability to affect Google Test's
-  // exception handling in the method where the exception is thrown.
-  if (internal::GetUnitTestImpl()->catch_exceptions()) {
-#if GTEST_HAS_EXCEPTIONS
-    try {
-      return HandleSehExceptionsInMethodIfSupported(object, method, location);
-    } catch (const AssertionException&) {  // NOLINT
-      // This failure was reported already.
-    } catch (const internal::GoogleTestFailureException&) {  // NOLINT
-      // This exception type can only be thrown by a failed Google
-      // Test assertion with the intention of letting another testing
-      // framework catch it.  Therefore we just re-throw it.
-      throw;
-    } catch (const std::exception& e) {  // NOLINT
-      internal::ReportFailureInUnknownLocation(
-          TestPartResult::kFatalFailure,
-          FormatCxxExceptionMessage(e.what(), location));
-    } catch (...) {  // NOLINT
-      internal::ReportFailureInUnknownLocation(
-          TestPartResult::kFatalFailure,
-          FormatCxxExceptionMessage(nullptr, location));
-    }
-    return static_cast<Result>(0);
-#else
-    return HandleSehExceptionsInMethodIfSupported(object, method, location);
-#endif  // GTEST_HAS_EXCEPTIONS
-  } else {
-    return (object->*method)();
-  }
-}
-
-}  // namespace internal
-
-// Runs the test and updates the test result.
-void Test::Run() {
-  if (!HasSameFixtureClass()) return;
-
-  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
-  impl->os_stack_trace_getter()->UponLeavingGTest();
-  internal::HandleExceptionsInMethodIfSupported(this, &Test::SetUp, "SetUp()");
-  // We will run the test only if SetUp() was successful and didn't call
-  // GTEST_SKIP().
-  if (!HasFatalFailure() && !IsSkipped()) {
-    impl->os_stack_trace_getter()->UponLeavingGTest();
-    internal::HandleExceptionsInMethodIfSupported(
-        this, &Test::TestBody, "the test body");
-  }
-
-  // However, we want to clean up as much as possible.  Hence we will
-  // always call TearDown(), even if SetUp() or the test body has
-  // failed.
-  impl->os_stack_trace_getter()->UponLeavingGTest();
-  internal::HandleExceptionsInMethodIfSupported(
-      this, &Test::TearDown, "TearDown()");
-}
-
-// Returns true if and only if the current test has a fatal failure.
-bool Test::HasFatalFailure() {
-  return internal::GetUnitTestImpl()->current_test_result()->HasFatalFailure();
-}
-
-// Returns true if and only if the current test has a non-fatal failure.
-bool Test::HasNonfatalFailure() {
-  return internal::GetUnitTestImpl()->current_test_result()->
-      HasNonfatalFailure();
-}
-
-// Returns true if and only if the current test was skipped.
-bool Test::IsSkipped() {
-  return internal::GetUnitTestImpl()->current_test_result()->Skipped();
-}
-
-// class TestInfo
-
-// Constructs a TestInfo object. It assumes ownership of the test factory
-// object.
-TestInfo::TestInfo(const std::string& a_test_suite_name,
-                   const std::string& a_name, const char* a_type_param,
-                   const char* a_value_param,
-                   internal::CodeLocation a_code_location,
-                   internal::TypeId fixture_class_id,
-                   internal::TestFactoryBase* factory)
-    : test_suite_name_(a_test_suite_name),
-      name_(a_name),
-      type_param_(a_type_param ? new std::string(a_type_param) : nullptr),
-      value_param_(a_value_param ? new std::string(a_value_param) : nullptr),
-      location_(a_code_location),
-      fixture_class_id_(fixture_class_id),
-      should_run_(false),
-      is_disabled_(false),
-      matches_filter_(false),
-      is_in_another_shard_(false),
-      factory_(factory),
-      result_() {}
-
-// Destructs a TestInfo object.
-TestInfo::~TestInfo() { delete factory_; }
-
-namespace internal {
-
-// Creates a new TestInfo object and registers it with Google Test;
-// returns the created object.
-//
-// Arguments:
-//
-//   test_suite_name:  name of the test suite
-//   name:             name of the test
-//   type_param:       the name of the test's type parameter, or NULL if
-//                     this is not a typed or a type-parameterized test.
-//   value_param:      text representation of the test's value parameter,
-//                     or NULL if this is not a value-parameterized test.
-//   code_location:    code location where the test is defined
-//   fixture_class_id: ID of the test fixture class
-//   set_up_tc:        pointer to the function that sets up the test suite
-//   tear_down_tc:     pointer to the function that tears down the test suite
-//   factory:          pointer to the factory that creates a test object.
-//                     The newly created TestInfo instance will assume
-//                     ownership of the factory object.
-TestInfo* MakeAndRegisterTestInfo(
-    const char* test_suite_name, const char* name, const char* type_param,
-    const char* value_param, CodeLocation code_location,
-    TypeId fixture_class_id, SetUpTestSuiteFunc set_up_tc,
-    TearDownTestSuiteFunc tear_down_tc, TestFactoryBase* factory) {
-  TestInfo* const test_info =
-      new TestInfo(test_suite_name, name, type_param, value_param,
-                   code_location, fixture_class_id, factory);
-  GetUnitTestImpl()->AddTestInfo(set_up_tc, tear_down_tc, test_info);
-  return test_info;
-}
-
-void ReportInvalidTestSuiteType(const char* test_suite_name,
-                                CodeLocation code_location) {
-  Message errors;
-  errors
-      << "Attempted redefinition of test suite " << test_suite_name << ".\n"
-      << "All tests in the same test suite must use the same test fixture\n"
-      << "class.  However, in test suite " << test_suite_name << ", you tried\n"
-      << "to define a test using a fixture class different from the one\n"
-      << "used earlier. This can happen if the two fixture classes are\n"
-      << "from different namespaces and have the same name. You should\n"
-      << "probably rename one of the classes to put the tests into different\n"
-      << "test suites.";
-
-  GTEST_LOG_(ERROR) << FormatFileLocation(code_location.file.c_str(),
-                                          code_location.line)
-                    << " " << errors.GetString();
-}
-}  // namespace internal
-
-namespace {
-
-// A predicate that checks the test name of a TestInfo against a known
-// value.
-//
-// This is used for implementation of the TestSuite class only.  We put
-// it in the anonymous namespace to prevent polluting the outer
-// namespace.
-//
-// TestNameIs is copyable.
-class TestNameIs {
- public:
-  // Constructor.
-  //
-  // TestNameIs has NO default constructor.
-  explicit TestNameIs(const char* name)
-      : name_(name) {}
-
-  // Returns true if and only if the test name of test_info matches name_.
-  bool operator()(const TestInfo * test_info) const {
-    return test_info && test_info->name() == name_;
-  }
-
- private:
-  std::string name_;
-};
-
-}  // namespace
-
-namespace internal {
-
-// This method expands all parameterized tests registered with macros TEST_P
-// and INSTANTIATE_TEST_SUITE_P into regular tests and registers those.
-// This will be done just once during the program runtime.
-void UnitTestImpl::RegisterParameterizedTests() {
-  if (!parameterized_tests_registered_) {
-    parameterized_test_registry_.RegisterTests();
-    type_parameterized_test_registry_.CheckForInstantiations();
-    parameterized_tests_registered_ = true;
-  }
-}
-
-}  // namespace internal
-
-// Creates the test object, runs it, records its result, and then
-// deletes it.
-void TestInfo::Run() {
-  if (!should_run_) return;
-
-  // Tells UnitTest where to store test result.
-  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
-  impl->set_current_test_info(this);
-
-  TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
-
-  // Notifies the unit test event listeners that a test is about to start.
-  repeater->OnTestStart(*this);
-
-  result_.set_start_timestamp(internal::GetTimeInMillis());
-  internal::Timer timer;
-
-  impl->os_stack_trace_getter()->UponLeavingGTest();
-
-  // Creates the test object.
-  Test* const test = internal::HandleExceptionsInMethodIfSupported(
-      factory_, &internal::TestFactoryBase::CreateTest,
-      "the test fixture's constructor");
-
-  // Runs the test if the constructor didn't generate a fatal failure or invoke
-  // GTEST_SKIP().
-  // Note that the object will not be null
-  if (!Test::HasFatalFailure() && !Test::IsSkipped()) {
-    // This doesn't throw as all user code that can throw are wrapped into
-    // exception handling code.
-    test->Run();
-  }
-
-  if (test != nullptr) {
-    // Deletes the test object.
-    impl->os_stack_trace_getter()->UponLeavingGTest();
-    internal::HandleExceptionsInMethodIfSupported(
-        test, &Test::DeleteSelf_, "the test fixture's destructor");
-  }
-
-  result_.set_elapsed_time(timer.Elapsed());
-
-  // Notifies the unit test event listener that a test has just finished.
-  repeater->OnTestEnd(*this);
-
-  // Tells UnitTest to stop associating assertion results to this
-  // test.
-  impl->set_current_test_info(nullptr);
-}
-
-// Skip and records a skipped test result for this object.
-void TestInfo::Skip() {
-  if (!should_run_) return;
-
-  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
-  impl->set_current_test_info(this);
-
-  TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
-
-  // Notifies the unit test event listeners that a test is about to start.
-  repeater->OnTestStart(*this);
-
-  const TestPartResult test_part_result =
-      TestPartResult(TestPartResult::kSkip, this->file(), this->line(), "");
-  impl->GetTestPartResultReporterForCurrentThread()->ReportTestPartResult(
-      test_part_result);
-
-  // Notifies the unit test event listener that a test has just finished.
-  repeater->OnTestEnd(*this);
-  impl->set_current_test_info(nullptr);
-}
-
-// class TestSuite
-
-// Gets the number of successful tests in this test suite.
-int TestSuite::successful_test_count() const {
-  return CountIf(test_info_list_, TestPassed);
-}
-
-// Gets the number of successful tests in this test suite.
-int TestSuite::skipped_test_count() const {
-  return CountIf(test_info_list_, TestSkipped);
-}
-
-// Gets the number of failed tests in this test suite.
-int TestSuite::failed_test_count() const {
-  return CountIf(test_info_list_, TestFailed);
-}
-
-// Gets the number of disabled tests that will be reported in the XML report.
-int TestSuite::reportable_disabled_test_count() const {
-  return CountIf(test_info_list_, TestReportableDisabled);
-}
-
-// Gets the number of disabled tests in this test suite.
-int TestSuite::disabled_test_count() const {
-  return CountIf(test_info_list_, TestDisabled);
-}
-
-// Gets the number of tests to be printed in the XML report.
-int TestSuite::reportable_test_count() const {
-  return CountIf(test_info_list_, TestReportable);
-}
-
-// Get the number of tests in this test suite that should run.
-int TestSuite::test_to_run_count() const {
-  return CountIf(test_info_list_, ShouldRunTest);
-}
-
-// Gets the number of all tests.
-int TestSuite::total_test_count() const {
-  return static_cast<int>(test_info_list_.size());
-}
-
-// Creates a TestSuite with the given name.
-//
-// Arguments:
-//
-//   a_name:       name of the test suite
-//   a_type_param: the name of the test suite's type parameter, or NULL if
-//                 this is not a typed or a type-parameterized test suite.
-//   set_up_tc:    pointer to the function that sets up the test suite
-//   tear_down_tc: pointer to the function that tears down the test suite
-TestSuite::TestSuite(const char* a_name, const char* a_type_param,
-                     internal::SetUpTestSuiteFunc set_up_tc,
-                     internal::TearDownTestSuiteFunc tear_down_tc)
-    : name_(a_name),
-      type_param_(a_type_param ? new std::string(a_type_param) : nullptr),
-      set_up_tc_(set_up_tc),
-      tear_down_tc_(tear_down_tc),
-      should_run_(false),
-      start_timestamp_(0),
-      elapsed_time_(0) {}
-
-// Destructor of TestSuite.
-TestSuite::~TestSuite() {
-  // Deletes every Test in the collection.
-  ForEach(test_info_list_, internal::Delete<TestInfo>);
-}
-
-// Returns the i-th test among all the tests. i can range from 0 to
-// total_test_count() - 1. If i is not in that range, returns NULL.
-const TestInfo* TestSuite::GetTestInfo(int i) const {
-  const int index = GetElementOr(test_indices_, i, -1);
-  return index < 0 ? nullptr : test_info_list_[static_cast<size_t>(index)];
-}
-
-// Returns the i-th test among all the tests. i can range from 0 to
-// total_test_count() - 1. If i is not in that range, returns NULL.
-TestInfo* TestSuite::GetMutableTestInfo(int i) {
-  const int index = GetElementOr(test_indices_, i, -1);
-  return index < 0 ? nullptr : test_info_list_[static_cast<size_t>(index)];
-}
-
-// Adds a test to this test suite.  Will delete the test upon
-// destruction of the TestSuite object.
-void TestSuite::AddTestInfo(TestInfo* test_info) {
-  test_info_list_.push_back(test_info);
-  test_indices_.push_back(static_cast<int>(test_indices_.size()));
-}
-
-// Runs every test in this TestSuite.
-void TestSuite::Run() {
-  if (!should_run_) return;
-
-  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
-  impl->set_current_test_suite(this);
-
-  TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
-
-  // Call both legacy and the new API
-  repeater->OnTestSuiteStart(*this);
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  repeater->OnTestCaseStart(*this);
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  impl->os_stack_trace_getter()->UponLeavingGTest();
-  internal::HandleExceptionsInMethodIfSupported(
-      this, &TestSuite::RunSetUpTestSuite, "SetUpTestSuite()");
-
-  start_timestamp_ = internal::GetTimeInMillis();
-  internal::Timer timer;
-  for (int i = 0; i < total_test_count(); i++) {
-    GetMutableTestInfo(i)->Run();
-    if (GTEST_FLAG(fail_fast) && GetMutableTestInfo(i)->result()->Failed()) {
-      for (int j = i + 1; j < total_test_count(); j++) {
-        GetMutableTestInfo(j)->Skip();
-      }
-      break;
-    }
-  }
-  elapsed_time_ = timer.Elapsed();
-
-  impl->os_stack_trace_getter()->UponLeavingGTest();
-  internal::HandleExceptionsInMethodIfSupported(
-      this, &TestSuite::RunTearDownTestSuite, "TearDownTestSuite()");
-
-  // Call both legacy and the new API
-  repeater->OnTestSuiteEnd(*this);
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  repeater->OnTestCaseEnd(*this);
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  impl->set_current_test_suite(nullptr);
-}
-
-// Skips all tests under this TestSuite.
-void TestSuite::Skip() {
-  if (!should_run_) return;
-
-  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
-  impl->set_current_test_suite(this);
-
-  TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
-
-  // Call both legacy and the new API
-  repeater->OnTestSuiteStart(*this);
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  repeater->OnTestCaseStart(*this);
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  for (int i = 0; i < total_test_count(); i++) {
-    GetMutableTestInfo(i)->Skip();
-  }
-
-  // Call both legacy and the new API
-  repeater->OnTestSuiteEnd(*this);
-  // Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  repeater->OnTestCaseEnd(*this);
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  impl->set_current_test_suite(nullptr);
-}
-
-// Clears the results of all tests in this test suite.
-void TestSuite::ClearResult() {
-  ad_hoc_test_result_.Clear();
-  ForEach(test_info_list_, TestInfo::ClearTestResult);
-}
-
-// Shuffles the tests in this test suite.
-void TestSuite::ShuffleTests(internal::Random* random) {
-  Shuffle(random, &test_indices_);
-}
-
-// Restores the test order to before the first shuffle.
-void TestSuite::UnshuffleTests() {
-  for (size_t i = 0; i < test_indices_.size(); i++) {
-    test_indices_[i] = static_cast<int>(i);
-  }
-}
-
-// Formats a countable noun.  Depending on its quantity, either the
-// singular form or the plural form is used. e.g.
-//
-// FormatCountableNoun(1, "formula", "formuli") returns "1 formula".
-// FormatCountableNoun(5, "book", "books") returns "5 books".
-static std::string FormatCountableNoun(int count,
-                                       const char * singular_form,
-                                       const char * plural_form) {
-  return internal::StreamableToString(count) + " " +
-      (count == 1 ? singular_form : plural_form);
-}
-
-// Formats the count of tests.
-static std::string FormatTestCount(int test_count) {
-  return FormatCountableNoun(test_count, "test", "tests");
-}
-
-// Formats the count of test suites.
-static std::string FormatTestSuiteCount(int test_suite_count) {
-  return FormatCountableNoun(test_suite_count, "test suite", "test suites");
-}
-
-// Converts a TestPartResult::Type enum to human-friendly string
-// representation.  Both kNonFatalFailure and kFatalFailure are translated
-// to "Failure", as the user usually doesn't care about the difference
-// between the two when viewing the test result.
-static const char * TestPartResultTypeToString(TestPartResult::Type type) {
-  switch (type) {
-    case TestPartResult::kSkip:
-      return "Skipped\n";
-    case TestPartResult::kSuccess:
-      return "Success";
-
-    case TestPartResult::kNonFatalFailure:
-    case TestPartResult::kFatalFailure:
-#ifdef _MSC_VER
-      return "error: ";
-#else
-      return "Failure\n";
-#endif
-    default:
-      return "Unknown result type";
-  }
-}
-
-namespace internal {
-namespace {
-enum class GTestColor { kDefault, kRed, kGreen, kYellow };
-}  // namespace
-
-// Prints a TestPartResult to an std::string.
-static std::string PrintTestPartResultToString(
-    const TestPartResult& test_part_result) {
-  return (Message()
-          << internal::FormatFileLocation(test_part_result.file_name(),
-                                          test_part_result.line_number())
-          << " " << TestPartResultTypeToString(test_part_result.type())
-          << test_part_result.message()).GetString();
-}
-
-// Prints a TestPartResult.
-static void PrintTestPartResult(const TestPartResult& test_part_result) {
-  const std::string& result =
-      PrintTestPartResultToString(test_part_result);
-  printf("%s\n", result.c_str());
-  fflush(stdout);
-  // If the test program runs in Visual Studio or a debugger, the
-  // following statements add the test part result message to the Output
-  // window such that the user can double-click on it to jump to the
-  // corresponding source code location; otherwise they do nothing.
-#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
-  // We don't call OutputDebugString*() on Windows Mobile, as printing
-  // to stdout is done by OutputDebugString() there already - we don't
-  // want the same message printed twice.
-  ::OutputDebugStringA(result.c_str());
-  ::OutputDebugStringA("\n");
-#endif
-}
-
-// class PrettyUnitTestResultPrinter
-#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE && \
-    !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT && !GTEST_OS_WINDOWS_MINGW
-
-// Returns the character attribute for the given color.
-static WORD GetColorAttribute(GTestColor color) {
-  switch (color) {
-    case GTestColor::kRed:
-      return FOREGROUND_RED;
-    case GTestColor::kGreen:
-      return FOREGROUND_GREEN;
-    case GTestColor::kYellow:
-      return FOREGROUND_RED | FOREGROUND_GREEN;
-    default:           return 0;
-  }
-}
-
-static int GetBitOffset(WORD color_mask) {
-  if (color_mask == 0) return 0;
-
-  int bitOffset = 0;
-  while ((color_mask & 1) == 0) {
-    color_mask >>= 1;
-    ++bitOffset;
-  }
-  return bitOffset;
-}
-
-static WORD GetNewColor(GTestColor color, WORD old_color_attrs) {
-  // Let's reuse the BG
-  static const WORD background_mask = BACKGROUND_BLUE | BACKGROUND_GREEN |
-                                      BACKGROUND_RED | BACKGROUND_INTENSITY;
-  static const WORD foreground_mask = FOREGROUND_BLUE | FOREGROUND_GREEN |
-                                      FOREGROUND_RED | FOREGROUND_INTENSITY;
-  const WORD existing_bg = old_color_attrs & background_mask;
-
-  WORD new_color =
-      GetColorAttribute(color) | existing_bg | FOREGROUND_INTENSITY;
-  static const int bg_bitOffset = GetBitOffset(background_mask);
-  static const int fg_bitOffset = GetBitOffset(foreground_mask);
-
-  if (((new_color & background_mask) >> bg_bitOffset) ==
-      ((new_color & foreground_mask) >> fg_bitOffset)) {
-    new_color ^= FOREGROUND_INTENSITY;  // invert intensity
-  }
-  return new_color;
-}
-
-#else
-
-// Returns the ANSI color code for the given color. GTestColor::kDefault is
-// an invalid input.
-static const char* GetAnsiColorCode(GTestColor color) {
-  switch (color) {
-    case GTestColor::kRed:
-      return "1";
-    case GTestColor::kGreen:
-      return "2";
-    case GTestColor::kYellow:
-      return "3";
-    default:
-      return nullptr;
-  }
-}
-
-#endif  // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
-
-// Returns true if and only if Google Test should use colors in the output.
-bool ShouldUseColor(bool stdout_is_tty) {
-  const char* const gtest_color = GTEST_FLAG(color).c_str();
-
-  if (String::CaseInsensitiveCStringEquals(gtest_color, "auto")) {
-#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
-    // On Windows the TERM variable is usually not set, but the
-    // console there does support colors.
-    return stdout_is_tty;
-#else
-    // On non-Windows platforms, we rely on the TERM variable.
-    const char* const term = posix::GetEnv("TERM");
-    const bool term_supports_color =
-        String::CStringEquals(term, "xterm") ||
-        String::CStringEquals(term, "xterm-color") ||
-        String::CStringEquals(term, "xterm-256color") ||
-        String::CStringEquals(term, "screen") ||
-        String::CStringEquals(term, "screen-256color") ||
-        String::CStringEquals(term, "tmux") ||
-        String::CStringEquals(term, "tmux-256color") ||
-        String::CStringEquals(term, "rxvt-unicode") ||
-        String::CStringEquals(term, "rxvt-unicode-256color") ||
-        String::CStringEquals(term, "linux") ||
-        String::CStringEquals(term, "cygwin");
-    return stdout_is_tty && term_supports_color;
-#endif  // GTEST_OS_WINDOWS
-  }
-
-  return String::CaseInsensitiveCStringEquals(gtest_color, "yes") ||
-      String::CaseInsensitiveCStringEquals(gtest_color, "true") ||
-      String::CaseInsensitiveCStringEquals(gtest_color, "t") ||
-      String::CStringEquals(gtest_color, "1");
-  // We take "yes", "true", "t", and "1" as meaning "yes".  If the
-  // value is neither one of these nor "auto", we treat it as "no" to
-  // be conservative.
-}
-
-// Helpers for printing colored strings to stdout. Note that on Windows, we
-// cannot simply emit special characters and have the terminal change colors.
-// This routine must actually emit the characters rather than return a string
-// that would be colored when printed, as can be done on Linux.
-
-GTEST_ATTRIBUTE_PRINTF_(2, 3)
-static void ColoredPrintf(GTestColor color, const char *fmt, ...) {
-  va_list args;
-  va_start(args, fmt);
-
-#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_ZOS || GTEST_OS_IOS || \
-    GTEST_OS_WINDOWS_PHONE || GTEST_OS_WINDOWS_RT || defined(ESP_PLATFORM)
-  const bool use_color = AlwaysFalse();
-#else
-  static const bool in_color_mode =
-      ShouldUseColor(posix::IsATTY(posix::FileNo(stdout)) != 0);
-  const bool use_color = in_color_mode && (color != GTestColor::kDefault);
-#endif  // GTEST_OS_WINDOWS_MOBILE || GTEST_OS_ZOS
-
-  if (!use_color) {
-    vprintf(fmt, args);
-    va_end(args);
-    return;
-  }
-
-#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE && \
-    !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT && !GTEST_OS_WINDOWS_MINGW
-  const HANDLE stdout_handle = GetStdHandle(STD_OUTPUT_HANDLE);
-
-  // Gets the current text color.
-  CONSOLE_SCREEN_BUFFER_INFO buffer_info;
-  GetConsoleScreenBufferInfo(stdout_handle, &buffer_info);
-  const WORD old_color_attrs = buffer_info.wAttributes;
-  const WORD new_color = GetNewColor(color, old_color_attrs);
-
-  // We need to flush the stream buffers into the console before each
-  // SetConsoleTextAttribute call lest it affect the text that is already
-  // printed but has not yet reached the console.
-  fflush(stdout);
-  SetConsoleTextAttribute(stdout_handle, new_color);
-
-  vprintf(fmt, args);
-
-  fflush(stdout);
-  // Restores the text color.
-  SetConsoleTextAttribute(stdout_handle, old_color_attrs);
-#else
-  printf("\033[0;3%sm", GetAnsiColorCode(color));
-  vprintf(fmt, args);
-  printf("\033[m");  // Resets the terminal to default.
-#endif  // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
-  va_end(args);
-}
-
-// Text printed in Google Test's text output and --gtest_list_tests
-// output to label the type parameter and value parameter for a test.
-static const char kTypeParamLabel[] = "TypeParam";
-static const char kValueParamLabel[] = "GetParam()";
-
-static void PrintFullTestCommentIfPresent(const TestInfo& test_info) {
-  const char* const type_param = test_info.type_param();
-  const char* const value_param = test_info.value_param();
-
-  if (type_param != nullptr || value_param != nullptr) {
-    printf(", where ");
-    if (type_param != nullptr) {
-      printf("%s = %s", kTypeParamLabel, type_param);
-      if (value_param != nullptr) printf(" and ");
-    }
-    if (value_param != nullptr) {
-      printf("%s = %s", kValueParamLabel, value_param);
-    }
-  }
-}
-
-// This class implements the TestEventListener interface.
-//
-// Class PrettyUnitTestResultPrinter is copyable.
-class PrettyUnitTestResultPrinter : public TestEventListener {
- public:
-  PrettyUnitTestResultPrinter() {}
-  static void PrintTestName(const char* test_suite, const char* test) {
-    printf("%s.%s", test_suite, test);
-  }
-
-  // The following methods override what's in the TestEventListener class.
-  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {}
-  void OnTestIterationStart(const UnitTest& unit_test, int iteration) override;
-  void OnEnvironmentsSetUpStart(const UnitTest& unit_test) override;
-  void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {}
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  void OnTestCaseStart(const TestCase& test_case) override;
-#else
-  void OnTestSuiteStart(const TestSuite& test_suite) override;
-#endif  // OnTestCaseStart
-
-  void OnTestStart(const TestInfo& test_info) override;
-
-  void OnTestPartResult(const TestPartResult& result) override;
-  void OnTestEnd(const TestInfo& test_info) override;
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  void OnTestCaseEnd(const TestCase& test_case) override;
-#else
-  void OnTestSuiteEnd(const TestSuite& test_suite) override;
-#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  void OnEnvironmentsTearDownStart(const UnitTest& unit_test) override;
-  void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {}
-  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
-  void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {}
-
- private:
-  static void PrintFailedTests(const UnitTest& unit_test);
-  static void PrintFailedTestSuites(const UnitTest& unit_test);
-  static void PrintSkippedTests(const UnitTest& unit_test);
-};
-
-  // Fired before each iteration of tests starts.
-void PrettyUnitTestResultPrinter::OnTestIterationStart(
-    const UnitTest& unit_test, int iteration) {
-  if (GTEST_FLAG(repeat) != 1)
-    printf("\nRepeating all tests (iteration %d) . . .\n\n", iteration + 1);
-
-  const char* const filter = GTEST_FLAG(filter).c_str();
-
-  // Prints the filter if it's not *.  This reminds the user that some
-  // tests may be skipped.
-  if (!String::CStringEquals(filter, kUniversalFilter)) {
-    ColoredPrintf(GTestColor::kYellow, "Note: %s filter = %s\n", GTEST_NAME_,
-                  filter);
-  }
-
-  if (internal::ShouldShard(kTestTotalShards, kTestShardIndex, false)) {
-    const int32_t shard_index = Int32FromEnvOrDie(kTestShardIndex, -1);
-    ColoredPrintf(GTestColor::kYellow, "Note: This is test shard %d of %s.\n",
-                  static_cast<int>(shard_index) + 1,
-                  internal::posix::GetEnv(kTestTotalShards));
-  }
-
-  if (GTEST_FLAG(shuffle)) {
-    ColoredPrintf(GTestColor::kYellow,
-                  "Note: Randomizing tests' orders with a seed of %d .\n",
-                  unit_test.random_seed());
-  }
-
-  ColoredPrintf(GTestColor::kGreen, "[==========] ");
-  printf("Running %s from %s.\n",
-         FormatTestCount(unit_test.test_to_run_count()).c_str(),
-         FormatTestSuiteCount(unit_test.test_suite_to_run_count()).c_str());
-  fflush(stdout);
-}
-
-void PrettyUnitTestResultPrinter::OnEnvironmentsSetUpStart(
-    const UnitTest& /*unit_test*/) {
-  ColoredPrintf(GTestColor::kGreen, "[----------] ");
-  printf("Global test environment set-up.\n");
-  fflush(stdout);
-}
-
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-void PrettyUnitTestResultPrinter::OnTestCaseStart(const TestCase& test_case) {
-  const std::string counts =
-      FormatCountableNoun(test_case.test_to_run_count(), "test", "tests");
-  ColoredPrintf(GTestColor::kGreen, "[----------] ");
-  printf("%s from %s", counts.c_str(), test_case.name());
-  if (test_case.type_param() == nullptr) {
-    printf("\n");
-  } else {
-    printf(", where %s = %s\n", kTypeParamLabel, test_case.type_param());
-  }
-  fflush(stdout);
-}
-#else
-void PrettyUnitTestResultPrinter::OnTestSuiteStart(
-    const TestSuite& test_suite) {
-  const std::string counts =
-      FormatCountableNoun(test_suite.test_to_run_count(), "test", "tests");
-  ColoredPrintf(GTestColor::kGreen, "[----------] ");
-  printf("%s from %s", counts.c_str(), test_suite.name());
-  if (test_suite.type_param() == nullptr) {
-    printf("\n");
-  } else {
-    printf(", where %s = %s\n", kTypeParamLabel, test_suite.type_param());
-  }
-  fflush(stdout);
-}
-#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-void PrettyUnitTestResultPrinter::OnTestStart(const TestInfo& test_info) {
-  ColoredPrintf(GTestColor::kGreen, "[ RUN      ] ");
-  PrintTestName(test_info.test_suite_name(), test_info.name());
-  printf("\n");
-  fflush(stdout);
-}
-
-// Called after an assertion failure.
-void PrettyUnitTestResultPrinter::OnTestPartResult(
-    const TestPartResult& result) {
-  switch (result.type()) {
-    // If the test part succeeded, we don't need to do anything.
-    case TestPartResult::kSuccess:
-      return;
-    default:
-      // Print failure message from the assertion
-      // (e.g. expected this and got that).
-      PrintTestPartResult(result);
-      fflush(stdout);
-  }
-}
-
-void PrettyUnitTestResultPrinter::OnTestEnd(const TestInfo& test_info) {
-  if (test_info.result()->Passed()) {
-    ColoredPrintf(GTestColor::kGreen, "[       OK ] ");
-  } else if (test_info.result()->Skipped()) {
-    ColoredPrintf(GTestColor::kGreen, "[  SKIPPED ] ");
-  } else {
-    ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
-  }
-  PrintTestName(test_info.test_suite_name(), test_info.name());
-  if (test_info.result()->Failed())
-    PrintFullTestCommentIfPresent(test_info);
-
-  if (GTEST_FLAG(print_time)) {
-    printf(" (%s ms)\n", internal::StreamableToString(
-           test_info.result()->elapsed_time()).c_str());
-  } else {
-    printf("\n");
-  }
-  fflush(stdout);
-}
-
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-void PrettyUnitTestResultPrinter::OnTestCaseEnd(const TestCase& test_case) {
-  if (!GTEST_FLAG(print_time)) return;
-
-  const std::string counts =
-      FormatCountableNoun(test_case.test_to_run_count(), "test", "tests");
-  ColoredPrintf(GTestColor::kGreen, "[----------] ");
-  printf("%s from %s (%s ms total)\n\n", counts.c_str(), test_case.name(),
-         internal::StreamableToString(test_case.elapsed_time()).c_str());
-  fflush(stdout);
-}
-#else
-void PrettyUnitTestResultPrinter::OnTestSuiteEnd(const TestSuite& test_suite) {
-  if (!GTEST_FLAG(print_time)) return;
-
-  const std::string counts =
-      FormatCountableNoun(test_suite.test_to_run_count(), "test", "tests");
-  ColoredPrintf(GTestColor::kGreen, "[----------] ");
-  printf("%s from %s (%s ms total)\n\n", counts.c_str(), test_suite.name(),
-         internal::StreamableToString(test_suite.elapsed_time()).c_str());
-  fflush(stdout);
-}
-#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-void PrettyUnitTestResultPrinter::OnEnvironmentsTearDownStart(
-    const UnitTest& /*unit_test*/) {
-  ColoredPrintf(GTestColor::kGreen, "[----------] ");
-  printf("Global test environment tear-down\n");
-  fflush(stdout);
-}
-
-// Internal helper for printing the list of failed tests.
-void PrettyUnitTestResultPrinter::PrintFailedTests(const UnitTest& unit_test) {
-  const int failed_test_count = unit_test.failed_test_count();
-  ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
-  printf("%s, listed below:\n", FormatTestCount(failed_test_count).c_str());
-
-  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
-    const TestSuite& test_suite = *unit_test.GetTestSuite(i);
-    if (!test_suite.should_run() || (test_suite.failed_test_count() == 0)) {
-      continue;
-    }
-    for (int j = 0; j < test_suite.total_test_count(); ++j) {
-      const TestInfo& test_info = *test_suite.GetTestInfo(j);
-      if (!test_info.should_run() || !test_info.result()->Failed()) {
-        continue;
-      }
-      ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
-      printf("%s.%s", test_suite.name(), test_info.name());
-      PrintFullTestCommentIfPresent(test_info);
-      printf("\n");
-    }
-  }
-  printf("\n%2d FAILED %s\n", failed_test_count,
-         failed_test_count == 1 ? "TEST" : "TESTS");
-}
-
-// Internal helper for printing the list of test suite failures not covered by
-// PrintFailedTests.
-void PrettyUnitTestResultPrinter::PrintFailedTestSuites(
-    const UnitTest& unit_test) {
-  int suite_failure_count = 0;
-  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
-    const TestSuite& test_suite = *unit_test.GetTestSuite(i);
-    if (!test_suite.should_run()) {
-      continue;
-    }
-    if (test_suite.ad_hoc_test_result().Failed()) {
-      ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
-      printf("%s: SetUpTestSuite or TearDownTestSuite\n", test_suite.name());
-      ++suite_failure_count;
-    }
-  }
-  if (suite_failure_count > 0) {
-    printf("\n%2d FAILED TEST %s\n", suite_failure_count,
-           suite_failure_count == 1 ? "SUITE" : "SUITES");
-  }
-}
-
-// Internal helper for printing the list of skipped tests.
-void PrettyUnitTestResultPrinter::PrintSkippedTests(const UnitTest& unit_test) {
-  const int skipped_test_count = unit_test.skipped_test_count();
-  if (skipped_test_count == 0) {
-    return;
-  }
-
-  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
-    const TestSuite& test_suite = *unit_test.GetTestSuite(i);
-    if (!test_suite.should_run() || (test_suite.skipped_test_count() == 0)) {
-      continue;
-    }
-    for (int j = 0; j < test_suite.total_test_count(); ++j) {
-      const TestInfo& test_info = *test_suite.GetTestInfo(j);
-      if (!test_info.should_run() || !test_info.result()->Skipped()) {
-        continue;
-      }
-      ColoredPrintf(GTestColor::kGreen, "[  SKIPPED ] ");
-      printf("%s.%s", test_suite.name(), test_info.name());
-      printf("\n");
-    }
-  }
-}
-
-void PrettyUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
-                                                     int /*iteration*/) {
-  ColoredPrintf(GTestColor::kGreen, "[==========] ");
-  printf("%s from %s ran.",
-         FormatTestCount(unit_test.test_to_run_count()).c_str(),
-         FormatTestSuiteCount(unit_test.test_suite_to_run_count()).c_str());
-  if (GTEST_FLAG(print_time)) {
-    printf(" (%s ms total)",
-           internal::StreamableToString(unit_test.elapsed_time()).c_str());
-  }
-  printf("\n");
-  ColoredPrintf(GTestColor::kGreen, "[  PASSED  ] ");
-  printf("%s.\n", FormatTestCount(unit_test.successful_test_count()).c_str());
-
-  const int skipped_test_count = unit_test.skipped_test_count();
-  if (skipped_test_count > 0) {
-    ColoredPrintf(GTestColor::kGreen, "[  SKIPPED ] ");
-    printf("%s, listed below:\n", FormatTestCount(skipped_test_count).c_str());
-    PrintSkippedTests(unit_test);
-  }
-
-  if (!unit_test.Passed()) {
-    PrintFailedTests(unit_test);
-    PrintFailedTestSuites(unit_test);
-  }
-
-  int num_disabled = unit_test.reportable_disabled_test_count();
-  if (num_disabled && !GTEST_FLAG(also_run_disabled_tests)) {
-    if (unit_test.Passed()) {
-      printf("\n");  // Add a spacer if no FAILURE banner is displayed.
-    }
-    ColoredPrintf(GTestColor::kYellow, "  YOU HAVE %d DISABLED %s\n\n",
-                  num_disabled, num_disabled == 1 ? "TEST" : "TESTS");
-  }
-  // Ensure that Google Test output is printed before, e.g., heapchecker output.
-  fflush(stdout);
-}
-
-// End PrettyUnitTestResultPrinter
-
-// This class implements the TestEventListener interface.
-//
-// Class BriefUnitTestResultPrinter is copyable.
-class BriefUnitTestResultPrinter : public TestEventListener {
- public:
-  BriefUnitTestResultPrinter() {}
-  static void PrintTestName(const char* test_suite, const char* test) {
-    printf("%s.%s", test_suite, test);
-  }
-
-  // The following methods override what's in the TestEventListener class.
-  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {}
-  void OnTestIterationStart(const UnitTest& /*unit_test*/,
-                            int /*iteration*/) override {}
-  void OnEnvironmentsSetUpStart(const UnitTest& /*unit_test*/) override {}
-  void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {}
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  void OnTestCaseStart(const TestCase& /*test_case*/) override {}
-#else
-  void OnTestSuiteStart(const TestSuite& /*test_suite*/) override {}
-#endif  // OnTestCaseStart
-
-  void OnTestStart(const TestInfo& /*test_info*/) override {}
-
-  void OnTestPartResult(const TestPartResult& result) override;
-  void OnTestEnd(const TestInfo& test_info) override;
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  void OnTestCaseEnd(const TestCase& /*test_case*/) override {}
-#else
-  void OnTestSuiteEnd(const TestSuite& /*test_suite*/) override {}
-#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  void OnEnvironmentsTearDownStart(const UnitTest& /*unit_test*/) override {}
-  void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {}
-  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
-  void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {}
-};
-
-// Called after an assertion failure.
-void BriefUnitTestResultPrinter::OnTestPartResult(
-    const TestPartResult& result) {
-  switch (result.type()) {
-    // If the test part succeeded, we don't need to do anything.
-    case TestPartResult::kSuccess:
-      return;
-    default:
-      // Print failure message from the assertion
-      // (e.g. expected this and got that).
-      PrintTestPartResult(result);
-      fflush(stdout);
-  }
-}
-
-void BriefUnitTestResultPrinter::OnTestEnd(const TestInfo& test_info) {
-  if (test_info.result()->Failed()) {
-    ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
-    PrintTestName(test_info.test_suite_name(), test_info.name());
-    PrintFullTestCommentIfPresent(test_info);
-
-    if (GTEST_FLAG(print_time)) {
-      printf(" (%s ms)\n",
-             internal::StreamableToString(test_info.result()->elapsed_time())
-                 .c_str());
-    } else {
-      printf("\n");
-    }
-    fflush(stdout);
-  }
-}
-
-void BriefUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
-                                                    int /*iteration*/) {
-  ColoredPrintf(GTestColor::kGreen, "[==========] ");
-  printf("%s from %s ran.",
-         FormatTestCount(unit_test.test_to_run_count()).c_str(),
-         FormatTestSuiteCount(unit_test.test_suite_to_run_count()).c_str());
-  if (GTEST_FLAG(print_time)) {
-    printf(" (%s ms total)",
-           internal::StreamableToString(unit_test.elapsed_time()).c_str());
-  }
-  printf("\n");
-  ColoredPrintf(GTestColor::kGreen, "[  PASSED  ] ");
-  printf("%s.\n", FormatTestCount(unit_test.successful_test_count()).c_str());
-
-  const int skipped_test_count = unit_test.skipped_test_count();
-  if (skipped_test_count > 0) {
-    ColoredPrintf(GTestColor::kGreen, "[  SKIPPED ] ");
-    printf("%s.\n", FormatTestCount(skipped_test_count).c_str());
-  }
-
-  int num_disabled = unit_test.reportable_disabled_test_count();
-  if (num_disabled && !GTEST_FLAG(also_run_disabled_tests)) {
-    if (unit_test.Passed()) {
-      printf("\n");  // Add a spacer if no FAILURE banner is displayed.
-    }
-    ColoredPrintf(GTestColor::kYellow, "  YOU HAVE %d DISABLED %s\n\n",
-                  num_disabled, num_disabled == 1 ? "TEST" : "TESTS");
-  }
-  // Ensure that Google Test output is printed before, e.g., heapchecker output.
-  fflush(stdout);
-}
-
-// End BriefUnitTestResultPrinter
-
-// class TestEventRepeater
-//
-// This class forwards events to other event listeners.
-class TestEventRepeater : public TestEventListener {
- public:
-  TestEventRepeater() : forwarding_enabled_(true) {}
-  ~TestEventRepeater() override;
-  void Append(TestEventListener *listener);
-  TestEventListener* Release(TestEventListener* listener);
-
-  // Controls whether events will be forwarded to listeners_. Set to false
-  // in death test child processes.
-  bool forwarding_enabled() const { return forwarding_enabled_; }
-  void set_forwarding_enabled(bool enable) { forwarding_enabled_ = enable; }
-
-  void OnTestProgramStart(const UnitTest& unit_test) override;
-  void OnTestIterationStart(const UnitTest& unit_test, int iteration) override;
-  void OnEnvironmentsSetUpStart(const UnitTest& unit_test) override;
-  void OnEnvironmentsSetUpEnd(const UnitTest& unit_test) override;
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  void OnTestCaseStart(const TestSuite& parameter) override;
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  void OnTestSuiteStart(const TestSuite& parameter) override;
-  void OnTestStart(const TestInfo& test_info) override;
-  void OnTestPartResult(const TestPartResult& result) override;
-  void OnTestEnd(const TestInfo& test_info) override;
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  void OnTestCaseEnd(const TestCase& parameter) override;
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  void OnTestSuiteEnd(const TestSuite& parameter) override;
-  void OnEnvironmentsTearDownStart(const UnitTest& unit_test) override;
-  void OnEnvironmentsTearDownEnd(const UnitTest& unit_test) override;
-  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
-  void OnTestProgramEnd(const UnitTest& unit_test) override;
-
- private:
-  // Controls whether events will be forwarded to listeners_. Set to false
-  // in death test child processes.
-  bool forwarding_enabled_;
-  // The list of listeners that receive events.
-  std::vector<TestEventListener*> listeners_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestEventRepeater);
-};
-
-TestEventRepeater::~TestEventRepeater() {
-  ForEach(listeners_, Delete<TestEventListener>);
-}
-
-void TestEventRepeater::Append(TestEventListener *listener) {
-  listeners_.push_back(listener);
-}
-
-TestEventListener* TestEventRepeater::Release(TestEventListener *listener) {
-  for (size_t i = 0; i < listeners_.size(); ++i) {
-    if (listeners_[i] == listener) {
-      listeners_.erase(listeners_.begin() + static_cast<int>(i));
-      return listener;
-    }
-  }
-
-  return nullptr;
-}
-
-// Since most methods are very similar, use macros to reduce boilerplate.
-// This defines a member that forwards the call to all listeners.
-#define GTEST_REPEATER_METHOD_(Name, Type) \
-void TestEventRepeater::Name(const Type& parameter) { \
-  if (forwarding_enabled_) { \
-    for (size_t i = 0; i < listeners_.size(); i++) { \
-      listeners_[i]->Name(parameter); \
-    } \
-  } \
-}
-// This defines a member that forwards the call to all listeners in reverse
-// order.
-#define GTEST_REVERSE_REPEATER_METHOD_(Name, Type)      \
-  void TestEventRepeater::Name(const Type& parameter) { \
-    if (forwarding_enabled_) {                          \
-      for (size_t i = listeners_.size(); i != 0; i--) { \
-        listeners_[i - 1]->Name(parameter);             \
-      }                                                 \
-    }                                                   \
-  }
-
-GTEST_REPEATER_METHOD_(OnTestProgramStart, UnitTest)
-GTEST_REPEATER_METHOD_(OnEnvironmentsSetUpStart, UnitTest)
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-GTEST_REPEATER_METHOD_(OnTestCaseStart, TestSuite)
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-GTEST_REPEATER_METHOD_(OnTestSuiteStart, TestSuite)
-GTEST_REPEATER_METHOD_(OnTestStart, TestInfo)
-GTEST_REPEATER_METHOD_(OnTestPartResult, TestPartResult)
-GTEST_REPEATER_METHOD_(OnEnvironmentsTearDownStart, UnitTest)
-GTEST_REVERSE_REPEATER_METHOD_(OnEnvironmentsSetUpEnd, UnitTest)
-GTEST_REVERSE_REPEATER_METHOD_(OnEnvironmentsTearDownEnd, UnitTest)
-GTEST_REVERSE_REPEATER_METHOD_(OnTestEnd, TestInfo)
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-GTEST_REVERSE_REPEATER_METHOD_(OnTestCaseEnd, TestSuite)
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-GTEST_REVERSE_REPEATER_METHOD_(OnTestSuiteEnd, TestSuite)
-GTEST_REVERSE_REPEATER_METHOD_(OnTestProgramEnd, UnitTest)
-
-#undef GTEST_REPEATER_METHOD_
-#undef GTEST_REVERSE_REPEATER_METHOD_
-
-void TestEventRepeater::OnTestIterationStart(const UnitTest& unit_test,
-                                             int iteration) {
-  if (forwarding_enabled_) {
-    for (size_t i = 0; i < listeners_.size(); i++) {
-      listeners_[i]->OnTestIterationStart(unit_test, iteration);
-    }
-  }
-}
-
-void TestEventRepeater::OnTestIterationEnd(const UnitTest& unit_test,
-                                           int iteration) {
-  if (forwarding_enabled_) {
-    for (size_t i = listeners_.size(); i > 0; i--) {
-      listeners_[i - 1]->OnTestIterationEnd(unit_test, iteration);
-    }
-  }
-}
-
-// End TestEventRepeater
-
-// This class generates an XML output file.
-class XmlUnitTestResultPrinter : public EmptyTestEventListener {
- public:
-  explicit XmlUnitTestResultPrinter(const char* output_file);
-
-  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
-  void ListTestsMatchingFilter(const std::vector<TestSuite*>& test_suites);
-
-  // Prints an XML summary of all unit tests.
-  static void PrintXmlTestsList(std::ostream* stream,
-                                const std::vector<TestSuite*>& test_suites);
-
- private:
-  // Is c a whitespace character that is normalized to a space character
-  // when it appears in an XML attribute value?
-  static bool IsNormalizableWhitespace(char c) {
-    return c == 0x9 || c == 0xA || c == 0xD;
-  }
-
-  // May c appear in a well-formed XML document?
-  static bool IsValidXmlCharacter(char c) {
-    return IsNormalizableWhitespace(c) || c >= 0x20;
-  }
-
-  // Returns an XML-escaped copy of the input string str.  If
-  // is_attribute is true, the text is meant to appear as an attribute
-  // value, and normalizable whitespace is preserved by replacing it
-  // with character references.
-  static std::string EscapeXml(const std::string& str, bool is_attribute);
-
-  // Returns the given string with all characters invalid in XML removed.
-  static std::string RemoveInvalidXmlCharacters(const std::string& str);
-
-  // Convenience wrapper around EscapeXml when str is an attribute value.
-  static std::string EscapeXmlAttribute(const std::string& str) {
-    return EscapeXml(str, true);
-  }
-
-  // Convenience wrapper around EscapeXml when str is not an attribute value.
-  static std::string EscapeXmlText(const char* str) {
-    return EscapeXml(str, false);
-  }
-
-  // Verifies that the given attribute belongs to the given element and
-  // streams the attribute as XML.
-  static void OutputXmlAttribute(std::ostream* stream,
-                                 const std::string& element_name,
-                                 const std::string& name,
-                                 const std::string& value);
-
-  // Streams an XML CDATA section, escaping invalid CDATA sequences as needed.
-  static void OutputXmlCDataSection(::std::ostream* stream, const char* data);
-
-  // Streams a test suite XML stanza containing the given test result.
-  //
-  // Requires: result.Failed()
-  static void OutputXmlTestSuiteForTestResult(::std::ostream* stream,
-                                              const TestResult& result);
-
-  // Streams an XML representation of a TestResult object.
-  static void OutputXmlTestResult(::std::ostream* stream,
-                                  const TestResult& result);
-
-  // Streams an XML representation of a TestInfo object.
-  static void OutputXmlTestInfo(::std::ostream* stream,
-                                const char* test_suite_name,
-                                const TestInfo& test_info);
-
-  // Prints an XML representation of a TestSuite object
-  static void PrintXmlTestSuite(::std::ostream* stream,
-                                const TestSuite& test_suite);
-
-  // Prints an XML summary of unit_test to output stream out.
-  static void PrintXmlUnitTest(::std::ostream* stream,
-                               const UnitTest& unit_test);
-
-  // Produces a string representing the test properties in a result as space
-  // delimited XML attributes based on the property key="value" pairs.
-  // When the std::string is not empty, it includes a space at the beginning,
-  // to delimit this attribute from prior attributes.
-  static std::string TestPropertiesAsXmlAttributes(const TestResult& result);
-
-  // Streams an XML representation of the test properties of a TestResult
-  // object.
-  static void OutputXmlTestProperties(std::ostream* stream,
-                                      const TestResult& result);
-
-  // The output file.
-  const std::string output_file_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(XmlUnitTestResultPrinter);
-};
-
-// Creates a new XmlUnitTestResultPrinter.
-XmlUnitTestResultPrinter::XmlUnitTestResultPrinter(const char* output_file)
-    : output_file_(output_file) {
-  if (output_file_.empty()) {
-    GTEST_LOG_(FATAL) << "XML output file may not be null";
-  }
-}
-
-// Called after the unit test ends.
-void XmlUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
-                                                  int /*iteration*/) {
-  FILE* xmlout = OpenFileForWriting(output_file_);
-  std::stringstream stream;
-  PrintXmlUnitTest(&stream, unit_test);
-  fprintf(xmlout, "%s", StringStreamToString(&stream).c_str());
-  fclose(xmlout);
-}
-
-void XmlUnitTestResultPrinter::ListTestsMatchingFilter(
-    const std::vector<TestSuite*>& test_suites) {
-  FILE* xmlout = OpenFileForWriting(output_file_);
-  std::stringstream stream;
-  PrintXmlTestsList(&stream, test_suites);
-  fprintf(xmlout, "%s", StringStreamToString(&stream).c_str());
-  fclose(xmlout);
-}
-
-// Returns an XML-escaped copy of the input string str.  If is_attribute
-// is true, the text is meant to appear as an attribute value, and
-// normalizable whitespace is preserved by replacing it with character
-// references.
-//
-// Invalid XML characters in str, if any, are stripped from the output.
-// It is expected that most, if not all, of the text processed by this
-// module will consist of ordinary English text.
-// If this module is ever modified to produce version 1.1 XML output,
-// most invalid characters can be retained using character references.
-std::string XmlUnitTestResultPrinter::EscapeXml(
-    const std::string& str, bool is_attribute) {
-  Message m;
-
-  for (size_t i = 0; i < str.size(); ++i) {
-    const char ch = str[i];
-    switch (ch) {
-      case '<':
-        m << "&lt;";
-        break;
-      case '>':
-        m << "&gt;";
-        break;
-      case '&':
-        m << "&amp;";
-        break;
-      case '\'':
-        if (is_attribute)
-          m << "&apos;";
-        else
-          m << '\'';
-        break;
-      case '"':
-        if (is_attribute)
-          m << "&quot;";
-        else
-          m << '"';
-        break;
-      default:
-        if (IsValidXmlCharacter(ch)) {
-          if (is_attribute && IsNormalizableWhitespace(ch))
-            m << "&#x" << String::FormatByte(static_cast<unsigned char>(ch))
-              << ";";
-          else
-            m << ch;
-        }
-        break;
-    }
-  }
-
-  return m.GetString();
-}
-
-// Returns the given string with all characters invalid in XML removed.
-// Currently invalid characters are dropped from the string. An
-// alternative is to replace them with certain characters such as . or ?.
-std::string XmlUnitTestResultPrinter::RemoveInvalidXmlCharacters(
-    const std::string& str) {
-  std::string output;
-  output.reserve(str.size());
-  for (std::string::const_iterator it = str.begin(); it != str.end(); ++it)
-    if (IsValidXmlCharacter(*it))
-      output.push_back(*it);
-
-  return output;
-}
-
-// The following routines generate an XML representation of a UnitTest
-// object.
-// GOOGLETEST_CM0009 DO NOT DELETE
-//
-// This is how Google Test concepts map to the DTD:
-//
-// <testsuites name="AllTests">        <-- corresponds to a UnitTest object
-//   <testsuite name="testcase-name">  <-- corresponds to a TestSuite object
-//     <testcase name="test-name">     <-- corresponds to a TestInfo object
-//       <failure message="...">...</failure>
-//       <failure message="...">...</failure>
-//       <failure message="...">...</failure>
-//                                     <-- individual assertion failures
-//     </testcase>
-//   </testsuite>
-// </testsuites>
-
-// Formats the given time in milliseconds as seconds.
-std::string FormatTimeInMillisAsSeconds(TimeInMillis ms) {
-  ::std::stringstream ss;
-  ss << (static_cast<double>(ms) * 1e-3);
-  return ss.str();
-}
-
-static bool PortableLocaltime(time_t seconds, struct tm* out) {
-#if defined(_MSC_VER)
-  return localtime_s(out, &seconds) == 0;
-#elif defined(__MINGW32__) || defined(__MINGW64__)
-  // MINGW <time.h> provides neither localtime_r nor localtime_s, but uses
-  // Windows' localtime(), which has a thread-local tm buffer.
-  struct tm* tm_ptr = localtime(&seconds);  // NOLINT
-  if (tm_ptr == nullptr) return false;
-  *out = *tm_ptr;
-  return true;
-#elif defined(__STDC_LIB_EXT1__)
-  // Uses localtime_s when available as localtime_r is only available from
-  // C23 standard.
-  return localtime_s(&seconds, out) != nullptr;
-#else
-  return localtime_r(&seconds, out) != nullptr;
-#endif
-}
-
-// Converts the given epoch time in milliseconds to a date string in the ISO
-// 8601 format, without the timezone information.
-std::string FormatEpochTimeInMillisAsIso8601(TimeInMillis ms) {
-  struct tm time_struct;
-  if (!PortableLocaltime(static_cast<time_t>(ms / 1000), &time_struct))
-    return "";
-  // YYYY-MM-DDThh:mm:ss.sss
-  return StreamableToString(time_struct.tm_year + 1900) + "-" +
-      String::FormatIntWidth2(time_struct.tm_mon + 1) + "-" +
-      String::FormatIntWidth2(time_struct.tm_mday) + "T" +
-      String::FormatIntWidth2(time_struct.tm_hour) + ":" +
-      String::FormatIntWidth2(time_struct.tm_min) + ":" +
-      String::FormatIntWidth2(time_struct.tm_sec) + "." +
-      String::FormatIntWidthN(static_cast<int>(ms % 1000), 3);
-}
-
-// Streams an XML CDATA section, escaping invalid CDATA sequences as needed.
-void XmlUnitTestResultPrinter::OutputXmlCDataSection(::std::ostream* stream,
-                                                     const char* data) {
-  const char* segment = data;
-  *stream << "<![CDATA[";
-  for (;;) {
-    const char* const next_segment = strstr(segment, "]]>");
-    if (next_segment != nullptr) {
-      stream->write(
-          segment, static_cast<std::streamsize>(next_segment - segment));
-      *stream << "]]>]]&gt;<![CDATA[";
-      segment = next_segment + strlen("]]>");
-    } else {
-      *stream << segment;
-      break;
-    }
-  }
-  *stream << "]]>";
-}
-
-void XmlUnitTestResultPrinter::OutputXmlAttribute(
-    std::ostream* stream,
-    const std::string& element_name,
-    const std::string& name,
-    const std::string& value) {
-  const std::vector<std::string>& allowed_names =
-      GetReservedOutputAttributesForElement(element_name);
-
-  GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
-                   allowed_names.end())
-      << "Attribute " << name << " is not allowed for element <" << element_name
-      << ">.";
-
-  *stream << " " << name << "=\"" << EscapeXmlAttribute(value) << "\"";
-}
-
-// Streams a test suite XML stanza containing the given test result.
-void XmlUnitTestResultPrinter::OutputXmlTestSuiteForTestResult(
-    ::std::ostream* stream, const TestResult& result) {
-  // Output the boilerplate for a minimal test suite with one test.
-  *stream << "  <testsuite";
-  OutputXmlAttribute(stream, "testsuite", "name", "NonTestSuiteFailure");
-  OutputXmlAttribute(stream, "testsuite", "tests", "1");
-  OutputXmlAttribute(stream, "testsuite", "failures", "1");
-  OutputXmlAttribute(stream, "testsuite", "disabled", "0");
-  OutputXmlAttribute(stream, "testsuite", "skipped", "0");
-  OutputXmlAttribute(stream, "testsuite", "errors", "0");
-  OutputXmlAttribute(stream, "testsuite", "time",
-                     FormatTimeInMillisAsSeconds(result.elapsed_time()));
-  OutputXmlAttribute(
-      stream, "testsuite", "timestamp",
-      FormatEpochTimeInMillisAsIso8601(result.start_timestamp()));
-  *stream << ">";
-
-  // Output the boilerplate for a minimal test case with a single test.
-  *stream << "    <testcase";
-  OutputXmlAttribute(stream, "testcase", "name", "");
-  OutputXmlAttribute(stream, "testcase", "status", "run");
-  OutputXmlAttribute(stream, "testcase", "result", "completed");
-  OutputXmlAttribute(stream, "testcase", "classname", "");
-  OutputXmlAttribute(stream, "testcase", "time",
-                     FormatTimeInMillisAsSeconds(result.elapsed_time()));
-  OutputXmlAttribute(
-      stream, "testcase", "timestamp",
-      FormatEpochTimeInMillisAsIso8601(result.start_timestamp()));
-
-  // Output the actual test result.
-  OutputXmlTestResult(stream, result);
-
-  // Complete the test suite.
-  *stream << "  </testsuite>\n";
-}
-
-// Prints an XML representation of a TestInfo object.
-void XmlUnitTestResultPrinter::OutputXmlTestInfo(::std::ostream* stream,
-                                                 const char* test_suite_name,
-                                                 const TestInfo& test_info) {
-  const TestResult& result = *test_info.result();
-  const std::string kTestsuite = "testcase";
-
-  if (test_info.is_in_another_shard()) {
-    return;
-  }
-
-  *stream << "    <testcase";
-  OutputXmlAttribute(stream, kTestsuite, "name", test_info.name());
-
-  if (test_info.value_param() != nullptr) {
-    OutputXmlAttribute(stream, kTestsuite, "value_param",
-                       test_info.value_param());
-  }
-  if (test_info.type_param() != nullptr) {
-    OutputXmlAttribute(stream, kTestsuite, "type_param",
-                       test_info.type_param());
-  }
-  if (GTEST_FLAG(list_tests)) {
-    OutputXmlAttribute(stream, kTestsuite, "file", test_info.file());
-    OutputXmlAttribute(stream, kTestsuite, "line",
-                       StreamableToString(test_info.line()));
-    *stream << " />\n";
-    return;
-  }
-
-  OutputXmlAttribute(stream, kTestsuite, "status",
-                     test_info.should_run() ? "run" : "notrun");
-  OutputXmlAttribute(stream, kTestsuite, "result",
-                     test_info.should_run()
-                         ? (result.Skipped() ? "skipped" : "completed")
-                         : "suppressed");
-  OutputXmlAttribute(stream, kTestsuite, "time",
-                     FormatTimeInMillisAsSeconds(result.elapsed_time()));
-  OutputXmlAttribute(
-      stream, kTestsuite, "timestamp",
-      FormatEpochTimeInMillisAsIso8601(result.start_timestamp()));
-  OutputXmlAttribute(stream, kTestsuite, "classname", test_suite_name);
-
-  OutputXmlTestResult(stream, result);
-}
-
-void XmlUnitTestResultPrinter::OutputXmlTestResult(::std::ostream* stream,
-                                                   const TestResult& result) {
-  int failures = 0;
-  int skips = 0;
-  for (int i = 0; i < result.total_part_count(); ++i) {
-    const TestPartResult& part = result.GetTestPartResult(i);
-    if (part.failed()) {
-      if (++failures == 1 && skips == 0) {
-        *stream << ">\n";
-      }
-      const std::string location =
-          internal::FormatCompilerIndependentFileLocation(part.file_name(),
-                                                          part.line_number());
-      const std::string summary = location + "\n" + part.summary();
-      *stream << "      <failure message=\""
-              << EscapeXmlAttribute(summary)
-              << "\" type=\"\">";
-      const std::string detail = location + "\n" + part.message();
-      OutputXmlCDataSection(stream, RemoveInvalidXmlCharacters(detail).c_str());
-      *stream << "</failure>\n";
-    } else if (part.skipped()) {
-      if (++skips == 1 && failures == 0) {
-        *stream << ">\n";
-      }
-      const std::string location =
-          internal::FormatCompilerIndependentFileLocation(part.file_name(),
-                                                          part.line_number());
-      const std::string summary = location + "\n" + part.summary();
-      *stream << "      <skipped message=\""
-              << EscapeXmlAttribute(summary.c_str()) << "\">";
-      const std::string detail = location + "\n" + part.message();
-      OutputXmlCDataSection(stream, RemoveInvalidXmlCharacters(detail).c_str());
-      *stream << "</skipped>\n";
-    }
-  }
-
-  if (failures == 0 && skips == 0 && result.test_property_count() == 0) {
-    *stream << " />\n";
-  } else {
-    if (failures == 0 && skips == 0) {
-      *stream << ">\n";
-    }
-    OutputXmlTestProperties(stream, result);
-    *stream << "    </testcase>\n";
-  }
-}
-
-// Prints an XML representation of a TestSuite object
-void XmlUnitTestResultPrinter::PrintXmlTestSuite(std::ostream* stream,
-                                                 const TestSuite& test_suite) {
-  const std::string kTestsuite = "testsuite";
-  *stream << "  <" << kTestsuite;
-  OutputXmlAttribute(stream, kTestsuite, "name", test_suite.name());
-  OutputXmlAttribute(stream, kTestsuite, "tests",
-                     StreamableToString(test_suite.reportable_test_count()));
-  if (!GTEST_FLAG(list_tests)) {
-    OutputXmlAttribute(stream, kTestsuite, "failures",
-                       StreamableToString(test_suite.failed_test_count()));
-    OutputXmlAttribute(
-        stream, kTestsuite, "disabled",
-        StreamableToString(test_suite.reportable_disabled_test_count()));
-    OutputXmlAttribute(stream, kTestsuite, "skipped",
-                       StreamableToString(test_suite.skipped_test_count()));
-
-    OutputXmlAttribute(stream, kTestsuite, "errors", "0");
-
-    OutputXmlAttribute(stream, kTestsuite, "time",
-                       FormatTimeInMillisAsSeconds(test_suite.elapsed_time()));
-    OutputXmlAttribute(
-        stream, kTestsuite, "timestamp",
-        FormatEpochTimeInMillisAsIso8601(test_suite.start_timestamp()));
-    *stream << TestPropertiesAsXmlAttributes(test_suite.ad_hoc_test_result());
-  }
-  *stream << ">\n";
-  for (int i = 0; i < test_suite.total_test_count(); ++i) {
-    if (test_suite.GetTestInfo(i)->is_reportable())
-      OutputXmlTestInfo(stream, test_suite.name(), *test_suite.GetTestInfo(i));
-  }
-  *stream << "  </" << kTestsuite << ">\n";
-}
-
-// Prints an XML summary of unit_test to output stream out.
-void XmlUnitTestResultPrinter::PrintXmlUnitTest(std::ostream* stream,
-                                                const UnitTest& unit_test) {
-  const std::string kTestsuites = "testsuites";
-
-  *stream << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
-  *stream << "<" << kTestsuites;
-
-  OutputXmlAttribute(stream, kTestsuites, "tests",
-                     StreamableToString(unit_test.reportable_test_count()));
-  OutputXmlAttribute(stream, kTestsuites, "failures",
-                     StreamableToString(unit_test.failed_test_count()));
-  OutputXmlAttribute(
-      stream, kTestsuites, "disabled",
-      StreamableToString(unit_test.reportable_disabled_test_count()));
-  OutputXmlAttribute(stream, kTestsuites, "errors", "0");
-  OutputXmlAttribute(stream, kTestsuites, "time",
-                     FormatTimeInMillisAsSeconds(unit_test.elapsed_time()));
-  OutputXmlAttribute(
-      stream, kTestsuites, "timestamp",
-      FormatEpochTimeInMillisAsIso8601(unit_test.start_timestamp()));
-
-  if (GTEST_FLAG(shuffle)) {
-    OutputXmlAttribute(stream, kTestsuites, "random_seed",
-                       StreamableToString(unit_test.random_seed()));
-  }
-  *stream << TestPropertiesAsXmlAttributes(unit_test.ad_hoc_test_result());
-
-  OutputXmlAttribute(stream, kTestsuites, "name", "AllTests");
-  *stream << ">\n";
-
-  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
-    if (unit_test.GetTestSuite(i)->reportable_test_count() > 0)
-      PrintXmlTestSuite(stream, *unit_test.GetTestSuite(i));
-  }
-
-  // If there was a test failure outside of one of the test suites (like in a
-  // test environment) include that in the output.
-  if (unit_test.ad_hoc_test_result().Failed()) {
-    OutputXmlTestSuiteForTestResult(stream, unit_test.ad_hoc_test_result());
-  }
-
-  *stream << "</" << kTestsuites << ">\n";
-}
-
-void XmlUnitTestResultPrinter::PrintXmlTestsList(
-    std::ostream* stream, const std::vector<TestSuite*>& test_suites) {
-  const std::string kTestsuites = "testsuites";
-
-  *stream << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
-  *stream << "<" << kTestsuites;
-
-  int total_tests = 0;
-  for (auto test_suite : test_suites) {
-    total_tests += test_suite->total_test_count();
-  }
-  OutputXmlAttribute(stream, kTestsuites, "tests",
-                     StreamableToString(total_tests));
-  OutputXmlAttribute(stream, kTestsuites, "name", "AllTests");
-  *stream << ">\n";
-
-  for (auto test_suite : test_suites) {
-    PrintXmlTestSuite(stream, *test_suite);
-  }
-  *stream << "</" << kTestsuites << ">\n";
-}
-
-// Produces a string representing the test properties in a result as space
-// delimited XML attributes based on the property key="value" pairs.
-std::string XmlUnitTestResultPrinter::TestPropertiesAsXmlAttributes(
-    const TestResult& result) {
-  Message attributes;
-  for (int i = 0; i < result.test_property_count(); ++i) {
-    const TestProperty& property = result.GetTestProperty(i);
-    attributes << " " << property.key() << "="
-        << "\"" << EscapeXmlAttribute(property.value()) << "\"";
-  }
-  return attributes.GetString();
-}
-
-void XmlUnitTestResultPrinter::OutputXmlTestProperties(
-    std::ostream* stream, const TestResult& result) {
-  const std::string kProperties = "properties";
-  const std::string kProperty = "property";
-
-  if (result.test_property_count() <= 0) {
-    return;
-  }
-
-  *stream << "<" << kProperties << ">\n";
-  for (int i = 0; i < result.test_property_count(); ++i) {
-    const TestProperty& property = result.GetTestProperty(i);
-    *stream << "<" << kProperty;
-    *stream << " name=\"" << EscapeXmlAttribute(property.key()) << "\"";
-    *stream << " value=\"" << EscapeXmlAttribute(property.value()) << "\"";
-    *stream << "/>\n";
-  }
-  *stream << "</" << kProperties << ">\n";
-}
-
-// End XmlUnitTestResultPrinter
-
-// This class generates an JSON output file.
-class JsonUnitTestResultPrinter : public EmptyTestEventListener {
- public:
-  explicit JsonUnitTestResultPrinter(const char* output_file);
-
-  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
-
-  // Prints an JSON summary of all unit tests.
-  static void PrintJsonTestList(::std::ostream* stream,
-                                const std::vector<TestSuite*>& test_suites);
-
- private:
-  // Returns an JSON-escaped copy of the input string str.
-  static std::string EscapeJson(const std::string& str);
-
-  //// Verifies that the given attribute belongs to the given element and
-  //// streams the attribute as JSON.
-  static void OutputJsonKey(std::ostream* stream,
-                            const std::string& element_name,
-                            const std::string& name,
-                            const std::string& value,
-                            const std::string& indent,
-                            bool comma = true);
-  static void OutputJsonKey(std::ostream* stream,
-                            const std::string& element_name,
-                            const std::string& name,
-                            int value,
-                            const std::string& indent,
-                            bool comma = true);
-
-  // Streams a test suite JSON stanza containing the given test result.
-  //
-  // Requires: result.Failed()
-  static void OutputJsonTestSuiteForTestResult(::std::ostream* stream,
-                                               const TestResult& result);
-
-  // Streams a JSON representation of a TestResult object.
-  static void OutputJsonTestResult(::std::ostream* stream,
-                                   const TestResult& result);
-
-  // Streams a JSON representation of a TestInfo object.
-  static void OutputJsonTestInfo(::std::ostream* stream,
-                                 const char* test_suite_name,
-                                 const TestInfo& test_info);
-
-  // Prints a JSON representation of a TestSuite object
-  static void PrintJsonTestSuite(::std::ostream* stream,
-                                 const TestSuite& test_suite);
-
-  // Prints a JSON summary of unit_test to output stream out.
-  static void PrintJsonUnitTest(::std::ostream* stream,
-                                const UnitTest& unit_test);
-
-  // Produces a string representing the test properties in a result as
-  // a JSON dictionary.
-  static std::string TestPropertiesAsJson(const TestResult& result,
-                                          const std::string& indent);
-
-  // The output file.
-  const std::string output_file_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(JsonUnitTestResultPrinter);
-};
-
-// Creates a new JsonUnitTestResultPrinter.
-JsonUnitTestResultPrinter::JsonUnitTestResultPrinter(const char* output_file)
-    : output_file_(output_file) {
-  if (output_file_.empty()) {
-    GTEST_LOG_(FATAL) << "JSON output file may not be null";
-  }
-}
-
-void JsonUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
-                                                  int /*iteration*/) {
-  FILE* jsonout = OpenFileForWriting(output_file_);
-  std::stringstream stream;
-  PrintJsonUnitTest(&stream, unit_test);
-  fprintf(jsonout, "%s", StringStreamToString(&stream).c_str());
-  fclose(jsonout);
-}
-
-// Returns an JSON-escaped copy of the input string str.
-std::string JsonUnitTestResultPrinter::EscapeJson(const std::string& str) {
-  Message m;
-
-  for (size_t i = 0; i < str.size(); ++i) {
-    const char ch = str[i];
-    switch (ch) {
-      case '\\':
-      case '"':
-      case '/':
-        m << '\\' << ch;
-        break;
-      case '\b':
-        m << "\\b";
-        break;
-      case '\t':
-        m << "\\t";
-        break;
-      case '\n':
-        m << "\\n";
-        break;
-      case '\f':
-        m << "\\f";
-        break;
-      case '\r':
-        m << "\\r";
-        break;
-      default:
-        if (ch < ' ') {
-          m << "\\u00" << String::FormatByte(static_cast<unsigned char>(ch));
-        } else {
-          m << ch;
-        }
-        break;
-    }
-  }
-
-  return m.GetString();
-}
-
-// The following routines generate an JSON representation of a UnitTest
-// object.
-
-// Formats the given time in milliseconds as seconds.
-static std::string FormatTimeInMillisAsDuration(TimeInMillis ms) {
-  ::std::stringstream ss;
-  ss << (static_cast<double>(ms) * 1e-3) << "s";
-  return ss.str();
-}
-
-// Converts the given epoch time in milliseconds to a date string in the
-// RFC3339 format, without the timezone information.
-static std::string FormatEpochTimeInMillisAsRFC3339(TimeInMillis ms) {
-  struct tm time_struct;
-  if (!PortableLocaltime(static_cast<time_t>(ms / 1000), &time_struct))
-    return "";
-  // YYYY-MM-DDThh:mm:ss
-  return StreamableToString(time_struct.tm_year + 1900) + "-" +
-      String::FormatIntWidth2(time_struct.tm_mon + 1) + "-" +
-      String::FormatIntWidth2(time_struct.tm_mday) + "T" +
-      String::FormatIntWidth2(time_struct.tm_hour) + ":" +
-      String::FormatIntWidth2(time_struct.tm_min) + ":" +
-      String::FormatIntWidth2(time_struct.tm_sec) + "Z";
-}
-
-static inline std::string Indent(size_t width) {
-  return std::string(width, ' ');
-}
-
-void JsonUnitTestResultPrinter::OutputJsonKey(
-    std::ostream* stream,
-    const std::string& element_name,
-    const std::string& name,
-    const std::string& value,
-    const std::string& indent,
-    bool comma) {
-  const std::vector<std::string>& allowed_names =
-      GetReservedOutputAttributesForElement(element_name);
-
-  GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
-                   allowed_names.end())
-      << "Key \"" << name << "\" is not allowed for value \"" << element_name
-      << "\".";
-
-  *stream << indent << "\"" << name << "\": \"" << EscapeJson(value) << "\"";
-  if (comma)
-    *stream << ",\n";
-}
-
-void JsonUnitTestResultPrinter::OutputJsonKey(
-    std::ostream* stream,
-    const std::string& element_name,
-    const std::string& name,
-    int value,
-    const std::string& indent,
-    bool comma) {
-  const std::vector<std::string>& allowed_names =
-      GetReservedOutputAttributesForElement(element_name);
-
-  GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
-                   allowed_names.end())
-      << "Key \"" << name << "\" is not allowed for value \"" << element_name
-      << "\".";
-
-  *stream << indent << "\"" << name << "\": " << StreamableToString(value);
-  if (comma)
-    *stream << ",\n";
-}
-
-// Streams a test suite JSON stanza containing the given test result.
-void JsonUnitTestResultPrinter::OutputJsonTestSuiteForTestResult(
-    ::std::ostream* stream, const TestResult& result) {
-  // Output the boilerplate for a new test suite.
-  *stream << Indent(4) << "{\n";
-  OutputJsonKey(stream, "testsuite", "name", "NonTestSuiteFailure", Indent(6));
-  OutputJsonKey(stream, "testsuite", "tests", 1, Indent(6));
-  if (!GTEST_FLAG(list_tests)) {
-    OutputJsonKey(stream, "testsuite", "failures", 1, Indent(6));
-    OutputJsonKey(stream, "testsuite", "disabled", 0, Indent(6));
-    OutputJsonKey(stream, "testsuite", "skipped", 0, Indent(6));
-    OutputJsonKey(stream, "testsuite", "errors", 0, Indent(6));
-    OutputJsonKey(stream, "testsuite", "time",
-                  FormatTimeInMillisAsDuration(result.elapsed_time()),
-                  Indent(6));
-    OutputJsonKey(stream, "testsuite", "timestamp",
-                  FormatEpochTimeInMillisAsRFC3339(result.start_timestamp()),
-                  Indent(6));
-  }
-  *stream << Indent(6) << "\"testsuite\": [\n";
-
-  // Output the boilerplate for a new test case.
-  *stream << Indent(8) << "{\n";
-  OutputJsonKey(stream, "testcase", "name", "", Indent(10));
-  OutputJsonKey(stream, "testcase", "status", "RUN", Indent(10));
-  OutputJsonKey(stream, "testcase", "result", "COMPLETED", Indent(10));
-  OutputJsonKey(stream, "testcase", "timestamp",
-                FormatEpochTimeInMillisAsRFC3339(result.start_timestamp()),
-                Indent(10));
-  OutputJsonKey(stream, "testcase", "time",
-                FormatTimeInMillisAsDuration(result.elapsed_time()),
-                Indent(10));
-  OutputJsonKey(stream, "testcase", "classname", "", Indent(10), false);
-  *stream << TestPropertiesAsJson(result, Indent(10));
-
-  // Output the actual test result.
-  OutputJsonTestResult(stream, result);
-
-  // Finish the test suite.
-  *stream << "\n" << Indent(6) << "]\n" << Indent(4) << "}";
-}
-
-// Prints a JSON representation of a TestInfo object.
-void JsonUnitTestResultPrinter::OutputJsonTestInfo(::std::ostream* stream,
-                                                   const char* test_suite_name,
-                                                   const TestInfo& test_info) {
-  const TestResult& result = *test_info.result();
-  const std::string kTestsuite = "testcase";
-  const std::string kIndent = Indent(10);
-
-  *stream << Indent(8) << "{\n";
-  OutputJsonKey(stream, kTestsuite, "name", test_info.name(), kIndent);
-
-  if (test_info.value_param() != nullptr) {
-    OutputJsonKey(stream, kTestsuite, "value_param", test_info.value_param(),
-                  kIndent);
-  }
-  if (test_info.type_param() != nullptr) {
-    OutputJsonKey(stream, kTestsuite, "type_param", test_info.type_param(),
-                  kIndent);
-  }
-  if (GTEST_FLAG(list_tests)) {
-    OutputJsonKey(stream, kTestsuite, "file", test_info.file(), kIndent);
-    OutputJsonKey(stream, kTestsuite, "line", test_info.line(), kIndent, false);
-    *stream << "\n" << Indent(8) << "}";
-    return;
-  }
-
-  OutputJsonKey(stream, kTestsuite, "status",
-                test_info.should_run() ? "RUN" : "NOTRUN", kIndent);
-  OutputJsonKey(stream, kTestsuite, "result",
-                test_info.should_run()
-                    ? (result.Skipped() ? "SKIPPED" : "COMPLETED")
-                    : "SUPPRESSED",
-                kIndent);
-  OutputJsonKey(stream, kTestsuite, "timestamp",
-                FormatEpochTimeInMillisAsRFC3339(result.start_timestamp()),
-                kIndent);
-  OutputJsonKey(stream, kTestsuite, "time",
-                FormatTimeInMillisAsDuration(result.elapsed_time()), kIndent);
-  OutputJsonKey(stream, kTestsuite, "classname", test_suite_name, kIndent,
-                false);
-  *stream << TestPropertiesAsJson(result, kIndent);
-
-  OutputJsonTestResult(stream, result);
-}
-
-void JsonUnitTestResultPrinter::OutputJsonTestResult(::std::ostream* stream,
-                                                     const TestResult& result) {
-  const std::string kIndent = Indent(10);
-
-  int failures = 0;
-  for (int i = 0; i < result.total_part_count(); ++i) {
-    const TestPartResult& part = result.GetTestPartResult(i);
-    if (part.failed()) {
-      *stream << ",\n";
-      if (++failures == 1) {
-        *stream << kIndent << "\"" << "failures" << "\": [\n";
-      }
-      const std::string location =
-          internal::FormatCompilerIndependentFileLocation(part.file_name(),
-                                                          part.line_number());
-      const std::string message = EscapeJson(location + "\n" + part.message());
-      *stream << kIndent << "  {\n"
-              << kIndent << "    \"failure\": \"" << message << "\",\n"
-              << kIndent << "    \"type\": \"\"\n"
-              << kIndent << "  }";
-    }
-  }
-
-  if (failures > 0)
-    *stream << "\n" << kIndent << "]";
-  *stream << "\n" << Indent(8) << "}";
-}
-
-// Prints an JSON representation of a TestSuite object
-void JsonUnitTestResultPrinter::PrintJsonTestSuite(
-    std::ostream* stream, const TestSuite& test_suite) {
-  const std::string kTestsuite = "testsuite";
-  const std::string kIndent = Indent(6);
-
-  *stream << Indent(4) << "{\n";
-  OutputJsonKey(stream, kTestsuite, "name", test_suite.name(), kIndent);
-  OutputJsonKey(stream, kTestsuite, "tests", test_suite.reportable_test_count(),
-                kIndent);
-  if (!GTEST_FLAG(list_tests)) {
-    OutputJsonKey(stream, kTestsuite, "failures",
-                  test_suite.failed_test_count(), kIndent);
-    OutputJsonKey(stream, kTestsuite, "disabled",
-                  test_suite.reportable_disabled_test_count(), kIndent);
-    OutputJsonKey(stream, kTestsuite, "errors", 0, kIndent);
-    OutputJsonKey(
-        stream, kTestsuite, "timestamp",
-        FormatEpochTimeInMillisAsRFC3339(test_suite.start_timestamp()),
-        kIndent);
-    OutputJsonKey(stream, kTestsuite, "time",
-                  FormatTimeInMillisAsDuration(test_suite.elapsed_time()),
-                  kIndent, false);
-    *stream << TestPropertiesAsJson(test_suite.ad_hoc_test_result(), kIndent)
-            << ",\n";
-  }
-
-  *stream << kIndent << "\"" << kTestsuite << "\": [\n";
-
-  bool comma = false;
-  for (int i = 0; i < test_suite.total_test_count(); ++i) {
-    if (test_suite.GetTestInfo(i)->is_reportable()) {
-      if (comma) {
-        *stream << ",\n";
-      } else {
-        comma = true;
-      }
-      OutputJsonTestInfo(stream, test_suite.name(), *test_suite.GetTestInfo(i));
-    }
-  }
-  *stream << "\n" << kIndent << "]\n" << Indent(4) << "}";
-}
-
-// Prints a JSON summary of unit_test to output stream out.
-void JsonUnitTestResultPrinter::PrintJsonUnitTest(std::ostream* stream,
-                                                  const UnitTest& unit_test) {
-  const std::string kTestsuites = "testsuites";
-  const std::string kIndent = Indent(2);
-  *stream << "{\n";
-
-  OutputJsonKey(stream, kTestsuites, "tests", unit_test.reportable_test_count(),
-                kIndent);
-  OutputJsonKey(stream, kTestsuites, "failures", unit_test.failed_test_count(),
-                kIndent);
-  OutputJsonKey(stream, kTestsuites, "disabled",
-                unit_test.reportable_disabled_test_count(), kIndent);
-  OutputJsonKey(stream, kTestsuites, "errors", 0, kIndent);
-  if (GTEST_FLAG(shuffle)) {
-    OutputJsonKey(stream, kTestsuites, "random_seed", unit_test.random_seed(),
-                  kIndent);
-  }
-  OutputJsonKey(stream, kTestsuites, "timestamp",
-                FormatEpochTimeInMillisAsRFC3339(unit_test.start_timestamp()),
-                kIndent);
-  OutputJsonKey(stream, kTestsuites, "time",
-                FormatTimeInMillisAsDuration(unit_test.elapsed_time()), kIndent,
-                false);
-
-  *stream << TestPropertiesAsJson(unit_test.ad_hoc_test_result(), kIndent)
-          << ",\n";
-
-  OutputJsonKey(stream, kTestsuites, "name", "AllTests", kIndent);
-  *stream << kIndent << "\"" << kTestsuites << "\": [\n";
-
-  bool comma = false;
-  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
-    if (unit_test.GetTestSuite(i)->reportable_test_count() > 0) {
-      if (comma) {
-        *stream << ",\n";
-      } else {
-        comma = true;
-      }
-      PrintJsonTestSuite(stream, *unit_test.GetTestSuite(i));
-    }
-  }
-
-  // If there was a test failure outside of one of the test suites (like in a
-  // test environment) include that in the output.
-  if (unit_test.ad_hoc_test_result().Failed()) {
-    OutputJsonTestSuiteForTestResult(stream, unit_test.ad_hoc_test_result());
-  }
-
-  *stream << "\n" << kIndent << "]\n" << "}\n";
-}
-
-void JsonUnitTestResultPrinter::PrintJsonTestList(
-    std::ostream* stream, const std::vector<TestSuite*>& test_suites) {
-  const std::string kTestsuites = "testsuites";
-  const std::string kIndent = Indent(2);
-  *stream << "{\n";
-  int total_tests = 0;
-  for (auto test_suite : test_suites) {
-    total_tests += test_suite->total_test_count();
-  }
-  OutputJsonKey(stream, kTestsuites, "tests", total_tests, kIndent);
-
-  OutputJsonKey(stream, kTestsuites, "name", "AllTests", kIndent);
-  *stream << kIndent << "\"" << kTestsuites << "\": [\n";
-
-  for (size_t i = 0; i < test_suites.size(); ++i) {
-    if (i != 0) {
-      *stream << ",\n";
-    }
-    PrintJsonTestSuite(stream, *test_suites[i]);
-  }
-
-  *stream << "\n"
-          << kIndent << "]\n"
-          << "}\n";
-}
-// Produces a string representing the test properties in a result as
-// a JSON dictionary.
-std::string JsonUnitTestResultPrinter::TestPropertiesAsJson(
-    const TestResult& result, const std::string& indent) {
-  Message attributes;
-  for (int i = 0; i < result.test_property_count(); ++i) {
-    const TestProperty& property = result.GetTestProperty(i);
-    attributes << ",\n" << indent << "\"" << property.key() << "\": "
-               << "\"" << EscapeJson(property.value()) << "\"";
-  }
-  return attributes.GetString();
-}
-
-// End JsonUnitTestResultPrinter
-
-#if GTEST_CAN_STREAM_RESULTS_
-
-// Checks if str contains '=', '&', '%' or '\n' characters. If yes,
-// replaces them by "%xx" where xx is their hexadecimal value. For
-// example, replaces "=" with "%3D".  This algorithm is O(strlen(str))
-// in both time and space -- important as the input str may contain an
-// arbitrarily long test failure message and stack trace.
-std::string StreamingListener::UrlEncode(const char* str) {
-  std::string result;
-  result.reserve(strlen(str) + 1);
-  for (char ch = *str; ch != '\0'; ch = *++str) {
-    switch (ch) {
-      case '%':
-      case '=':
-      case '&':
-      case '\n':
-        result.append("%" + String::FormatByte(static_cast<unsigned char>(ch)));
-        break;
-      default:
-        result.push_back(ch);
-        break;
-    }
-  }
-  return result;
-}
-
-void StreamingListener::SocketWriter::MakeConnection() {
-  GTEST_CHECK_(sockfd_ == -1)
-      << "MakeConnection() can't be called when there is already a connection.";
-
-  addrinfo hints;
-  memset(&hints, 0, sizeof(hints));
-  hints.ai_family = AF_UNSPEC;    // To allow both IPv4 and IPv6 addresses.
-  hints.ai_socktype = SOCK_STREAM;
-  addrinfo* servinfo = nullptr;
-
-  // Use the getaddrinfo() to get a linked list of IP addresses for
-  // the given host name.
-  const int error_num = getaddrinfo(
-      host_name_.c_str(), port_num_.c_str(), &hints, &servinfo);
-  if (error_num != 0) {
-    GTEST_LOG_(WARNING) << "stream_result_to: getaddrinfo() failed: "
-                        << gai_strerror(error_num);
-  }
-
-  // Loop through all the results and connect to the first we can.
-  for (addrinfo* cur_addr = servinfo; sockfd_ == -1 && cur_addr != nullptr;
-       cur_addr = cur_addr->ai_next) {
-    sockfd_ = socket(
-        cur_addr->ai_family, cur_addr->ai_socktype, cur_addr->ai_protocol);
-    if (sockfd_ != -1) {
-      // Connect the client socket to the server socket.
-      if (connect(sockfd_, cur_addr->ai_addr, cur_addr->ai_addrlen) == -1) {
-        close(sockfd_);
-        sockfd_ = -1;
-      }
-    }
-  }
-
-  freeaddrinfo(servinfo);  // all done with this structure
-
-  if (sockfd_ == -1) {
-    GTEST_LOG_(WARNING) << "stream_result_to: failed to connect to "
-                        << host_name_ << ":" << port_num_;
-  }
-}
-
-// End of class Streaming Listener
-#endif  // GTEST_CAN_STREAM_RESULTS__
-
-// class OsStackTraceGetter
-
-const char* const OsStackTraceGetterInterface::kElidedFramesMarker =
-    "... " GTEST_NAME_ " internal frames ...";
-
-std::string OsStackTraceGetter::CurrentStackTrace(int max_depth, int skip_count)
-    GTEST_LOCK_EXCLUDED_(mutex_) {
-#if GTEST_HAS_ABSL
-  std::string result;
-
-  if (max_depth <= 0) {
-    return result;
-  }
-
-  max_depth = std::min(max_depth, kMaxStackTraceDepth);
-
-  std::vector<void*> raw_stack(max_depth);
-  // Skips the frames requested by the caller, plus this function.
-  const int raw_stack_size =
-      absl::GetStackTrace(&raw_stack[0], max_depth, skip_count + 1);
-
-  void* caller_frame = nullptr;
-  {
-    MutexLock lock(&mutex_);
-    caller_frame = caller_frame_;
-  }
-
-  for (int i = 0; i < raw_stack_size; ++i) {
-    if (raw_stack[i] == caller_frame &&
-        !GTEST_FLAG(show_internal_stack_frames)) {
-      // Add a marker to the trace and stop adding frames.
-      absl::StrAppend(&result, kElidedFramesMarker, "\n");
-      break;
-    }
-
-    char tmp[1024];
-    const char* symbol = "(unknown)";
-    if (absl::Symbolize(raw_stack[i], tmp, sizeof(tmp))) {
-      symbol = tmp;
-    }
-
-    char line[1024];
-    snprintf(line, sizeof(line), "  %p: %s\n", raw_stack[i], symbol);
-    result += line;
-  }
-
-  return result;
-
-#else  // !GTEST_HAS_ABSL
-  static_cast<void>(max_depth);
-  static_cast<void>(skip_count);
-  return "";
-#endif  // GTEST_HAS_ABSL
-}
-
-void OsStackTraceGetter::UponLeavingGTest() GTEST_LOCK_EXCLUDED_(mutex_) {
-#if GTEST_HAS_ABSL
-  void* caller_frame = nullptr;
-  if (absl::GetStackTrace(&caller_frame, 1, 3) <= 0) {
-    caller_frame = nullptr;
-  }
-
-  MutexLock lock(&mutex_);
-  caller_frame_ = caller_frame;
-#endif  // GTEST_HAS_ABSL
-}
-
-// A helper class that creates the premature-exit file in its
-// constructor and deletes the file in its destructor.
-class ScopedPrematureExitFile {
- public:
-  explicit ScopedPrematureExitFile(const char* premature_exit_filepath)
-      : premature_exit_filepath_(premature_exit_filepath ?
-                                 premature_exit_filepath : "") {
-    // If a path to the premature-exit file is specified...
-    if (!premature_exit_filepath_.empty()) {
-      // create the file with a single "0" character in it.  I/O
-      // errors are ignored as there's nothing better we can do and we
-      // don't want to fail the test because of this.
-      FILE* pfile = posix::FOpen(premature_exit_filepath, "w");
-      fwrite("0", 1, 1, pfile);
-      fclose(pfile);
-    }
-  }
-
-  ~ScopedPrematureExitFile() {
-#if !defined GTEST_OS_ESP8266
-    if (!premature_exit_filepath_.empty()) {
-      int retval = remove(premature_exit_filepath_.c_str());
-      if (retval) {
-        GTEST_LOG_(ERROR) << "Failed to remove premature exit filepath \""
-                          << premature_exit_filepath_ << "\" with error "
-                          << retval;
-      }
-    }
-#endif
-  }
-
- private:
-  const std::string premature_exit_filepath_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ScopedPrematureExitFile);
-};
-
-}  // namespace internal
-
-// class TestEventListeners
-
-TestEventListeners::TestEventListeners()
-    : repeater_(new internal::TestEventRepeater()),
-      default_result_printer_(nullptr),
-      default_xml_generator_(nullptr) {}
-
-TestEventListeners::~TestEventListeners() { delete repeater_; }
-
-// Returns the standard listener responsible for the default console
-// output.  Can be removed from the listeners list to shut down default
-// console output.  Note that removing this object from the listener list
-// with Release transfers its ownership to the user.
-void TestEventListeners::Append(TestEventListener* listener) {
-  repeater_->Append(listener);
-}
-
-// Removes the given event listener from the list and returns it.  It then
-// becomes the caller's responsibility to delete the listener. Returns
-// NULL if the listener is not found in the list.
-TestEventListener* TestEventListeners::Release(TestEventListener* listener) {
-  if (listener == default_result_printer_)
-    default_result_printer_ = nullptr;
-  else if (listener == default_xml_generator_)
-    default_xml_generator_ = nullptr;
-  return repeater_->Release(listener);
-}
-
-// Returns repeater that broadcasts the TestEventListener events to all
-// subscribers.
-TestEventListener* TestEventListeners::repeater() { return repeater_; }
-
-// Sets the default_result_printer attribute to the provided listener.
-// The listener is also added to the listener list and previous
-// default_result_printer is removed from it and deleted. The listener can
-// also be NULL in which case it will not be added to the list. Does
-// nothing if the previous and the current listener objects are the same.
-void TestEventListeners::SetDefaultResultPrinter(TestEventListener* listener) {
-  if (default_result_printer_ != listener) {
-    // It is an error to pass this method a listener that is already in the
-    // list.
-    delete Release(default_result_printer_);
-    default_result_printer_ = listener;
-    if (listener != nullptr) Append(listener);
-  }
-}
-
-// Sets the default_xml_generator attribute to the provided listener.  The
-// listener is also added to the listener list and previous
-// default_xml_generator is removed from it and deleted. The listener can
-// also be NULL in which case it will not be added to the list. Does
-// nothing if the previous and the current listener objects are the same.
-void TestEventListeners::SetDefaultXmlGenerator(TestEventListener* listener) {
-  if (default_xml_generator_ != listener) {
-    // It is an error to pass this method a listener that is already in the
-    // list.
-    delete Release(default_xml_generator_);
-    default_xml_generator_ = listener;
-    if (listener != nullptr) Append(listener);
-  }
-}
-
-// Controls whether events will be forwarded by the repeater to the
-// listeners in the list.
-bool TestEventListeners::EventForwardingEnabled() const {
-  return repeater_->forwarding_enabled();
-}
-
-void TestEventListeners::SuppressEventForwarding() {
-  repeater_->set_forwarding_enabled(false);
-}
-
-// class UnitTest
-
-// Gets the singleton UnitTest object.  The first time this method is
-// called, a UnitTest object is constructed and returned.  Consecutive
-// calls will return the same object.
-//
-// We don't protect this under mutex_ as a user is not supposed to
-// call this before main() starts, from which point on the return
-// value will never change.
-UnitTest* UnitTest::GetInstance() {
-  // CodeGear C++Builder insists on a public destructor for the
-  // default implementation.  Use this implementation to keep good OO
-  // design with private destructor.
-
-#if defined(__BORLANDC__)
-  static UnitTest* const instance = new UnitTest;
-  return instance;
-#else
-  static UnitTest instance;
-  return &instance;
-#endif  // defined(__BORLANDC__)
-}
-
-// Gets the number of successful test suites.
-int UnitTest::successful_test_suite_count() const {
-  return impl()->successful_test_suite_count();
-}
-
-// Gets the number of failed test suites.
-int UnitTest::failed_test_suite_count() const {
-  return impl()->failed_test_suite_count();
-}
-
-// Gets the number of all test suites.
-int UnitTest::total_test_suite_count() const {
-  return impl()->total_test_suite_count();
-}
-
-// Gets the number of all test suites that contain at least one test
-// that should run.
-int UnitTest::test_suite_to_run_count() const {
-  return impl()->test_suite_to_run_count();
-}
-
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-int UnitTest::successful_test_case_count() const {
-  return impl()->successful_test_suite_count();
-}
-int UnitTest::failed_test_case_count() const {
-  return impl()->failed_test_suite_count();
-}
-int UnitTest::total_test_case_count() const {
-  return impl()->total_test_suite_count();
-}
-int UnitTest::test_case_to_run_count() const {
-  return impl()->test_suite_to_run_count();
-}
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-// Gets the number of successful tests.
-int UnitTest::successful_test_count() const {
-  return impl()->successful_test_count();
-}
-
-// Gets the number of skipped tests.
-int UnitTest::skipped_test_count() const {
-  return impl()->skipped_test_count();
-}
-
-// Gets the number of failed tests.
-int UnitTest::failed_test_count() const { return impl()->failed_test_count(); }
-
-// Gets the number of disabled tests that will be reported in the XML report.
-int UnitTest::reportable_disabled_test_count() const {
-  return impl()->reportable_disabled_test_count();
-}
-
-// Gets the number of disabled tests.
-int UnitTest::disabled_test_count() const {
-  return impl()->disabled_test_count();
-}
-
-// Gets the number of tests to be printed in the XML report.
-int UnitTest::reportable_test_count() const {
-  return impl()->reportable_test_count();
-}
-
-// Gets the number of all tests.
-int UnitTest::total_test_count() const { return impl()->total_test_count(); }
-
-// Gets the number of tests that should run.
-int UnitTest::test_to_run_count() const { return impl()->test_to_run_count(); }
-
-// Gets the time of the test program start, in ms from the start of the
-// UNIX epoch.
-internal::TimeInMillis UnitTest::start_timestamp() const {
-    return impl()->start_timestamp();
-}
-
-// Gets the elapsed time, in milliseconds.
-internal::TimeInMillis UnitTest::elapsed_time() const {
-  return impl()->elapsed_time();
-}
-
-// Returns true if and only if the unit test passed (i.e. all test suites
-// passed).
-bool UnitTest::Passed() const { return impl()->Passed(); }
-
-// Returns true if and only if the unit test failed (i.e. some test suite
-// failed or something outside of all tests failed).
-bool UnitTest::Failed() const { return impl()->Failed(); }
-
-// Gets the i-th test suite among all the test suites. i can range from 0 to
-// total_test_suite_count() - 1. If i is not in that range, returns NULL.
-const TestSuite* UnitTest::GetTestSuite(int i) const {
-  return impl()->GetTestSuite(i);
-}
-
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-const TestCase* UnitTest::GetTestCase(int i) const {
-  return impl()->GetTestCase(i);
-}
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-// Returns the TestResult containing information on test failures and
-// properties logged outside of individual test suites.
-const TestResult& UnitTest::ad_hoc_test_result() const {
-  return *impl()->ad_hoc_test_result();
-}
-
-// Gets the i-th test suite among all the test suites. i can range from 0 to
-// total_test_suite_count() - 1. If i is not in that range, returns NULL.
-TestSuite* UnitTest::GetMutableTestSuite(int i) {
-  return impl()->GetMutableSuiteCase(i);
-}
-
-// Returns the list of event listeners that can be used to track events
-// inside Google Test.
-TestEventListeners& UnitTest::listeners() {
-  return *impl()->listeners();
-}
-
-// Registers and returns a global test environment.  When a test
-// program is run, all global test environments will be set-up in the
-// order they were registered.  After all tests in the program have
-// finished, all global test environments will be torn-down in the
-// *reverse* order they were registered.
-//
-// The UnitTest object takes ownership of the given environment.
-//
-// We don't protect this under mutex_, as we only support calling it
-// from the main thread.
-Environment* UnitTest::AddEnvironment(Environment* env) {
-  if (env == nullptr) {
-    return nullptr;
-  }
-
-  impl_->environments().push_back(env);
-  return env;
-}
-
-// Adds a TestPartResult to the current TestResult object.  All Google Test
-// assertion macros (e.g. ASSERT_TRUE, EXPECT_EQ, etc) eventually call
-// this to report their results.  The user code should use the
-// assertion macros instead of calling this directly.
-void UnitTest::AddTestPartResult(
-    TestPartResult::Type result_type,
-    const char* file_name,
-    int line_number,
-    const std::string& message,
-    const std::string& os_stack_trace) GTEST_LOCK_EXCLUDED_(mutex_) {
-  Message msg;
-  msg << message;
-
-  internal::MutexLock lock(&mutex_);
-  if (impl_->gtest_trace_stack().size() > 0) {
-    msg << "\n" << GTEST_NAME_ << " trace:";
-
-    for (size_t i = impl_->gtest_trace_stack().size(); i > 0; --i) {
-      const internal::TraceInfo& trace = impl_->gtest_trace_stack()[i - 1];
-      msg << "\n" << internal::FormatFileLocation(trace.file, trace.line)
-          << " " << trace.message;
-    }
-  }
-
-  if (os_stack_trace.c_str() != nullptr && !os_stack_trace.empty()) {
-    msg << internal::kStackTraceMarker << os_stack_trace;
-  }
-
-  const TestPartResult result = TestPartResult(
-      result_type, file_name, line_number, msg.GetString().c_str());
-  impl_->GetTestPartResultReporterForCurrentThread()->
-      ReportTestPartResult(result);
-
-  if (result_type != TestPartResult::kSuccess &&
-      result_type != TestPartResult::kSkip) {
-    // gtest_break_on_failure takes precedence over
-    // gtest_throw_on_failure.  This allows a user to set the latter
-    // in the code (perhaps in order to use Google Test assertions
-    // with another testing framework) and specify the former on the
-    // command line for debugging.
-    if (GTEST_FLAG(break_on_failure)) {
-#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
-      // Using DebugBreak on Windows allows gtest to still break into a debugger
-      // when a failure happens and both the --gtest_break_on_failure and
-      // the --gtest_catch_exceptions flags are specified.
-      DebugBreak();
-#elif (!defined(__native_client__)) &&            \
-    ((defined(__clang__) || defined(__GNUC__)) && \
-     (defined(__x86_64__) || defined(__i386__)))
-      // with clang/gcc we can achieve the same effect on x86 by invoking int3
-      asm("int3");
-#else
-      // Dereference nullptr through a volatile pointer to prevent the compiler
-      // from removing. We use this rather than abort() or __builtin_trap() for
-      // portability: some debuggers don't correctly trap abort().
-      *static_cast<volatile int*>(nullptr) = 1;
-#endif  // GTEST_OS_WINDOWS
-    } else if (GTEST_FLAG(throw_on_failure)) {
-#if GTEST_HAS_EXCEPTIONS
-      throw internal::GoogleTestFailureException(result);
-#else
-      // We cannot call abort() as it generates a pop-up in debug mode
-      // that cannot be suppressed in VC 7.1 or below.
-      exit(1);
-#endif
-    }
-  }
-}
-
-// Adds a TestProperty to the current TestResult object when invoked from
-// inside a test, to current TestSuite's ad_hoc_test_result_ when invoked
-// from SetUpTestSuite or TearDownTestSuite, or to the global property set
-// when invoked elsewhere.  If the result already contains a property with
-// the same key, the value will be updated.
-void UnitTest::RecordProperty(const std::string& key,
-                              const std::string& value) {
-  impl_->RecordProperty(TestProperty(key, value));
-}
-
-// Runs all tests in this UnitTest object and prints the result.
-// Returns 0 if successful, or 1 otherwise.
-//
-// We don't protect this under mutex_, as we only support calling it
-// from the main thread.
-int UnitTest::Run() {
-  const bool in_death_test_child_process =
-      internal::GTEST_FLAG(internal_run_death_test).length() > 0;
-
-  // Google Test implements this protocol for catching that a test
-  // program exits before returning control to Google Test:
-  //
-  //   1. Upon start, Google Test creates a file whose absolute path
-  //      is specified by the environment variable
-  //      TEST_PREMATURE_EXIT_FILE.
-  //   2. When Google Test has finished its work, it deletes the file.
-  //
-  // This allows a test runner to set TEST_PREMATURE_EXIT_FILE before
-  // running a Google-Test-based test program and check the existence
-  // of the file at the end of the test execution to see if it has
-  // exited prematurely.
-
-  // If we are in the child process of a death test, don't
-  // create/delete the premature exit file, as doing so is unnecessary
-  // and will confuse the parent process.  Otherwise, create/delete
-  // the file upon entering/leaving this function.  If the program
-  // somehow exits before this function has a chance to return, the
-  // premature-exit file will be left undeleted, causing a test runner
-  // that understands the premature-exit-file protocol to report the
-  // test as having failed.
-  const internal::ScopedPrematureExitFile premature_exit_file(
-      in_death_test_child_process
-          ? nullptr
-          : internal::posix::GetEnv("TEST_PREMATURE_EXIT_FILE"));
-
-  // Captures the value of GTEST_FLAG(catch_exceptions).  This value will be
-  // used for the duration of the program.
-  impl()->set_catch_exceptions(GTEST_FLAG(catch_exceptions));
-
-#if GTEST_OS_WINDOWS
-  // Either the user wants Google Test to catch exceptions thrown by the
-  // tests or this is executing in the context of death test child
-  // process. In either case the user does not want to see pop-up dialogs
-  // about crashes - they are expected.
-  if (impl()->catch_exceptions() || in_death_test_child_process) {
-# if !GTEST_OS_WINDOWS_MOBILE && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
-    // SetErrorMode doesn't exist on CE.
-    SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOALIGNMENTFAULTEXCEPT |
-                 SEM_NOGPFAULTERRORBOX | SEM_NOOPENFILEERRORBOX);
-# endif  // !GTEST_OS_WINDOWS_MOBILE
-
-# if (defined(_MSC_VER) || GTEST_OS_WINDOWS_MINGW) && !GTEST_OS_WINDOWS_MOBILE
-    // Death test children can be terminated with _abort().  On Windows,
-    // _abort() can show a dialog with a warning message.  This forces the
-    // abort message to go to stderr instead.
-    _set_error_mode(_OUT_TO_STDERR);
-# endif
-
-# if defined(_MSC_VER) && !GTEST_OS_WINDOWS_MOBILE
-    // In the debug version, Visual Studio pops up a separate dialog
-    // offering a choice to debug the aborted program. We need to suppress
-    // this dialog or it will pop up for every EXPECT/ASSERT_DEATH statement
-    // executed. Google Test will notify the user of any unexpected
-    // failure via stderr.
-    if (!GTEST_FLAG(break_on_failure))
-      _set_abort_behavior(
-          0x0,                                    // Clear the following flags:
-          _WRITE_ABORT_MSG | _CALL_REPORTFAULT);  // pop-up window, core dump.
-
-    // In debug mode, the Windows CRT can crash with an assertion over invalid
-    // input (e.g. passing an invalid file descriptor).  The default handling
-    // for these assertions is to pop up a dialog and wait for user input.
-    // Instead ask the CRT to dump such assertions to stderr non-interactively.
-    if (!IsDebuggerPresent()) {
-      (void)_CrtSetReportMode(_CRT_ASSERT,
-                              _CRTDBG_MODE_FILE | _CRTDBG_MODE_DEBUG);
-      (void)_CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
-    }
-# endif
-  }
-#endif  // GTEST_OS_WINDOWS
-
-  return internal::HandleExceptionsInMethodIfSupported(
-      impl(),
-      &internal::UnitTestImpl::RunAllTests,
-      "auxiliary test code (environments or event listeners)") ? 0 : 1;
-}
-
-// Returns the working directory when the first TEST() or TEST_F() was
-// executed.
-const char* UnitTest::original_working_dir() const {
-  return impl_->original_working_dir_.c_str();
-}
-
-// Returns the TestSuite object for the test that's currently running,
-// or NULL if no test is running.
-const TestSuite* UnitTest::current_test_suite() const
-    GTEST_LOCK_EXCLUDED_(mutex_) {
-  internal::MutexLock lock(&mutex_);
-  return impl_->current_test_suite();
-}
-
-// Legacy API is still available but deprecated
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-const TestCase* UnitTest::current_test_case() const
-    GTEST_LOCK_EXCLUDED_(mutex_) {
-  internal::MutexLock lock(&mutex_);
-  return impl_->current_test_suite();
-}
-#endif
-
-// Returns the TestInfo object for the test that's currently running,
-// or NULL if no test is running.
-const TestInfo* UnitTest::current_test_info() const
-    GTEST_LOCK_EXCLUDED_(mutex_) {
-  internal::MutexLock lock(&mutex_);
-  return impl_->current_test_info();
-}
-
-// Returns the random seed used at the start of the current test run.
-int UnitTest::random_seed() const { return impl_->random_seed(); }
-
-// Returns ParameterizedTestSuiteRegistry object used to keep track of
-// value-parameterized tests and instantiate and register them.
-internal::ParameterizedTestSuiteRegistry&
-UnitTest::parameterized_test_registry() GTEST_LOCK_EXCLUDED_(mutex_) {
-  return impl_->parameterized_test_registry();
-}
-
-// Creates an empty UnitTest.
-UnitTest::UnitTest() {
-  impl_ = new internal::UnitTestImpl(this);
-}
-
-// Destructor of UnitTest.
-UnitTest::~UnitTest() {
-  delete impl_;
-}
-
-// Pushes a trace defined by SCOPED_TRACE() on to the per-thread
-// Google Test trace stack.
-void UnitTest::PushGTestTrace(const internal::TraceInfo& trace)
-    GTEST_LOCK_EXCLUDED_(mutex_) {
-  internal::MutexLock lock(&mutex_);
-  impl_->gtest_trace_stack().push_back(trace);
-}
-
-// Pops a trace from the per-thread Google Test trace stack.
-void UnitTest::PopGTestTrace()
-    GTEST_LOCK_EXCLUDED_(mutex_) {
-  internal::MutexLock lock(&mutex_);
-  impl_->gtest_trace_stack().pop_back();
-}
-
-namespace internal {
-
-UnitTestImpl::UnitTestImpl(UnitTest* parent)
-    : parent_(parent),
-      GTEST_DISABLE_MSC_WARNINGS_PUSH_(4355 /* using this in initializer */)
-          default_global_test_part_result_reporter_(this),
-      default_per_thread_test_part_result_reporter_(this),
-      GTEST_DISABLE_MSC_WARNINGS_POP_() global_test_part_result_repoter_(
-          &default_global_test_part_result_reporter_),
-      per_thread_test_part_result_reporter_(
-          &default_per_thread_test_part_result_reporter_),
-      parameterized_test_registry_(),
-      parameterized_tests_registered_(false),
-      last_death_test_suite_(-1),
-      current_test_suite_(nullptr),
-      current_test_info_(nullptr),
-      ad_hoc_test_result_(),
-      os_stack_trace_getter_(nullptr),
-      post_flag_parse_init_performed_(false),
-      random_seed_(0),  // Will be overridden by the flag before first use.
-      random_(0),       // Will be reseeded before first use.
-      start_timestamp_(0),
-      elapsed_time_(0),
-#if GTEST_HAS_DEATH_TEST
-      death_test_factory_(new DefaultDeathTestFactory),
-#endif
-      // Will be overridden by the flag before first use.
-      catch_exceptions_(false) {
-  listeners()->SetDefaultResultPrinter(new PrettyUnitTestResultPrinter);
-}
-
-UnitTestImpl::~UnitTestImpl() {
-  // Deletes every TestSuite.
-  ForEach(test_suites_, internal::Delete<TestSuite>);
-
-  // Deletes every Environment.
-  ForEach(environments_, internal::Delete<Environment>);
-
-  delete os_stack_trace_getter_;
-}
-
-// Adds a TestProperty to the current TestResult object when invoked in a
-// context of a test, to current test suite's ad_hoc_test_result when invoke
-// from SetUpTestSuite/TearDownTestSuite, or to the global property set
-// otherwise.  If the result already contains a property with the same key,
-// the value will be updated.
-void UnitTestImpl::RecordProperty(const TestProperty& test_property) {
-  std::string xml_element;
-  TestResult* test_result;  // TestResult appropriate for property recording.
-
-  if (current_test_info_ != nullptr) {
-    xml_element = "testcase";
-    test_result = &(current_test_info_->result_);
-  } else if (current_test_suite_ != nullptr) {
-    xml_element = "testsuite";
-    test_result = &(current_test_suite_->ad_hoc_test_result_);
-  } else {
-    xml_element = "testsuites";
-    test_result = &ad_hoc_test_result_;
-  }
-  test_result->RecordProperty(xml_element, test_property);
-}
-
-#if GTEST_HAS_DEATH_TEST
-// Disables event forwarding if the control is currently in a death test
-// subprocess. Must not be called before InitGoogleTest.
-void UnitTestImpl::SuppressTestEventsIfInSubprocess() {
-  if (internal_run_death_test_flag_.get() != nullptr)
-    listeners()->SuppressEventForwarding();
-}
-#endif  // GTEST_HAS_DEATH_TEST
-
-// Initializes event listeners performing XML output as specified by
-// UnitTestOptions. Must not be called before InitGoogleTest.
-void UnitTestImpl::ConfigureXmlOutput() {
-  const std::string& output_format = UnitTestOptions::GetOutputFormat();
-  if (output_format == "xml") {
-    listeners()->SetDefaultXmlGenerator(new XmlUnitTestResultPrinter(
-        UnitTestOptions::GetAbsolutePathToOutputFile().c_str()));
-  } else if (output_format == "json") {
-    listeners()->SetDefaultXmlGenerator(new JsonUnitTestResultPrinter(
-        UnitTestOptions::GetAbsolutePathToOutputFile().c_str()));
-  } else if (output_format != "") {
-    GTEST_LOG_(WARNING) << "WARNING: unrecognized output format \""
-                        << output_format << "\" ignored.";
-  }
-}
-
-#if GTEST_CAN_STREAM_RESULTS_
-// Initializes event listeners for streaming test results in string form.
-// Must not be called before InitGoogleTest.
-void UnitTestImpl::ConfigureStreamingOutput() {
-  const std::string& target = GTEST_FLAG(stream_result_to);
-  if (!target.empty()) {
-    const size_t pos = target.find(':');
-    if (pos != std::string::npos) {
-      listeners()->Append(new StreamingListener(target.substr(0, pos),
-                                                target.substr(pos+1)));
-    } else {
-      GTEST_LOG_(WARNING) << "unrecognized streaming target \"" << target
-                          << "\" ignored.";
-    }
-  }
-}
-#endif  // GTEST_CAN_STREAM_RESULTS_
-
-// Performs initialization dependent upon flag values obtained in
-// ParseGoogleTestFlagsOnly.  Is called from InitGoogleTest after the call to
-// ParseGoogleTestFlagsOnly.  In case a user neglects to call InitGoogleTest
-// this function is also called from RunAllTests.  Since this function can be
-// called more than once, it has to be idempotent.
-void UnitTestImpl::PostFlagParsingInit() {
-  // Ensures that this function does not execute more than once.
-  if (!post_flag_parse_init_performed_) {
-    post_flag_parse_init_performed_ = true;
-
-#if defined(GTEST_CUSTOM_TEST_EVENT_LISTENER_)
-    // Register to send notifications about key process state changes.
-    listeners()->Append(new GTEST_CUSTOM_TEST_EVENT_LISTENER_());
-#endif  // defined(GTEST_CUSTOM_TEST_EVENT_LISTENER_)
-
-#if GTEST_HAS_DEATH_TEST
-    InitDeathTestSubprocessControlInfo();
-    SuppressTestEventsIfInSubprocess();
-#endif  // GTEST_HAS_DEATH_TEST
-
-    // Registers parameterized tests. This makes parameterized tests
-    // available to the UnitTest reflection API without running
-    // RUN_ALL_TESTS.
-    RegisterParameterizedTests();
-
-    // Configures listeners for XML output. This makes it possible for users
-    // to shut down the default XML output before invoking RUN_ALL_TESTS.
-    ConfigureXmlOutput();
-
-    if (GTEST_FLAG(brief)) {
-      listeners()->SetDefaultResultPrinter(new BriefUnitTestResultPrinter);
-    }
-
-#if GTEST_CAN_STREAM_RESULTS_
-    // Configures listeners for streaming test results to the specified server.
-    ConfigureStreamingOutput();
-#endif  // GTEST_CAN_STREAM_RESULTS_
-
-#if GTEST_HAS_ABSL
-    if (GTEST_FLAG(install_failure_signal_handler)) {
-      absl::FailureSignalHandlerOptions options;
-      absl::InstallFailureSignalHandler(options);
-    }
-#endif  // GTEST_HAS_ABSL
-  }
-}
-
-// A predicate that checks the name of a TestSuite against a known
-// value.
-//
-// This is used for implementation of the UnitTest class only.  We put
-// it in the anonymous namespace to prevent polluting the outer
-// namespace.
-//
-// TestSuiteNameIs is copyable.
-class TestSuiteNameIs {
- public:
-  // Constructor.
-  explicit TestSuiteNameIs(const std::string& name) : name_(name) {}
-
-  // Returns true if and only if the name of test_suite matches name_.
-  bool operator()(const TestSuite* test_suite) const {
-    return test_suite != nullptr &&
-           strcmp(test_suite->name(), name_.c_str()) == 0;
-  }
-
- private:
-  std::string name_;
-};
-
-// Finds and returns a TestSuite with the given name.  If one doesn't
-// exist, creates one and returns it.  It's the CALLER'S
-// RESPONSIBILITY to ensure that this function is only called WHEN THE
-// TESTS ARE NOT SHUFFLED.
-//
-// Arguments:
-//
-//   test_suite_name: name of the test suite
-//   type_param:      the name of the test suite's type parameter, or NULL if
-//                    this is not a typed or a type-parameterized test suite.
-//   set_up_tc:       pointer to the function that sets up the test suite
-//   tear_down_tc:    pointer to the function that tears down the test suite
-TestSuite* UnitTestImpl::GetTestSuite(
-    const char* test_suite_name, const char* type_param,
-    internal::SetUpTestSuiteFunc set_up_tc,
-    internal::TearDownTestSuiteFunc tear_down_tc) {
-  // Can we find a TestSuite with the given name?
-  const auto test_suite =
-      std::find_if(test_suites_.rbegin(), test_suites_.rend(),
-                   TestSuiteNameIs(test_suite_name));
-
-  if (test_suite != test_suites_.rend()) return *test_suite;
-
-  // No.  Let's create one.
-  auto* const new_test_suite =
-      new TestSuite(test_suite_name, type_param, set_up_tc, tear_down_tc);
-
-  // Is this a death test suite?
-  if (internal::UnitTestOptions::MatchesFilter(test_suite_name,
-                                               kDeathTestSuiteFilter)) {
-    // Yes.  Inserts the test suite after the last death test suite
-    // defined so far.  This only works when the test suites haven't
-    // been shuffled.  Otherwise we may end up running a death test
-    // after a non-death test.
-    ++last_death_test_suite_;
-    test_suites_.insert(test_suites_.begin() + last_death_test_suite_,
-                        new_test_suite);
-  } else {
-    // No.  Appends to the end of the list.
-    test_suites_.push_back(new_test_suite);
-  }
-
-  test_suite_indices_.push_back(static_cast<int>(test_suite_indices_.size()));
-  return new_test_suite;
-}
-
-// Helpers for setting up / tearing down the given environment.  They
-// are for use in the ForEach() function.
-static void SetUpEnvironment(Environment* env) { env->SetUp(); }
-static void TearDownEnvironment(Environment* env) { env->TearDown(); }
-
-// Runs all tests in this UnitTest object, prints the result, and
-// returns true if all tests are successful.  If any exception is
-// thrown during a test, the test is considered to be failed, but the
-// rest of the tests will still be run.
-//
-// When parameterized tests are enabled, it expands and registers
-// parameterized tests first in RegisterParameterizedTests().
-// All other functions called from RunAllTests() may safely assume that
-// parameterized tests are ready to be counted and run.
-bool UnitTestImpl::RunAllTests() {
-  // True if and only if Google Test is initialized before RUN_ALL_TESTS() is
-  // called.
-  const bool gtest_is_initialized_before_run_all_tests = GTestIsInitialized();
-
-  // Do not run any test if the --help flag was specified.
-  if (g_help_flag)
-    return true;
-
-  // Repeats the call to the post-flag parsing initialization in case the
-  // user didn't call InitGoogleTest.
-  PostFlagParsingInit();
-
-  // Even if sharding is not on, test runners may want to use the
-  // GTEST_SHARD_STATUS_FILE to query whether the test supports the sharding
-  // protocol.
-  internal::WriteToShardStatusFileIfNeeded();
-
-  // True if and only if we are in a subprocess for running a thread-safe-style
-  // death test.
-  bool in_subprocess_for_death_test = false;
-
-#if GTEST_HAS_DEATH_TEST
-  in_subprocess_for_death_test =
-      (internal_run_death_test_flag_.get() != nullptr);
-# if defined(GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_)
-  if (in_subprocess_for_death_test) {
-    GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_();
-  }
-# endif  // defined(GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_)
-#endif  // GTEST_HAS_DEATH_TEST
-
-  const bool should_shard = ShouldShard(kTestTotalShards, kTestShardIndex,
-                                        in_subprocess_for_death_test);
-
-  // Compares the full test names with the filter to decide which
-  // tests to run.
-  const bool has_tests_to_run = FilterTests(should_shard
-                                              ? HONOR_SHARDING_PROTOCOL
-                                              : IGNORE_SHARDING_PROTOCOL) > 0;
-
-  // Lists the tests and exits if the --gtest_list_tests flag was specified.
-  if (GTEST_FLAG(list_tests)) {
-    // This must be called *after* FilterTests() has been called.
-    ListTestsMatchingFilter();
-    return true;
-  }
-
-  random_seed_ = GTEST_FLAG(shuffle) ?
-      GetRandomSeedFromFlag(GTEST_FLAG(random_seed)) : 0;
-
-  // True if and only if at least one test has failed.
-  bool failed = false;
-
-  TestEventListener* repeater = listeners()->repeater();
-
-  start_timestamp_ = GetTimeInMillis();
-  repeater->OnTestProgramStart(*parent_);
-
-  // How many times to repeat the tests?  We don't want to repeat them
-  // when we are inside the subprocess of a death test.
-  const int repeat = in_subprocess_for_death_test ? 1 : GTEST_FLAG(repeat);
-  // Repeats forever if the repeat count is negative.
-  const bool gtest_repeat_forever = repeat < 0;
-  for (int i = 0; gtest_repeat_forever || i != repeat; i++) {
-    // We want to preserve failures generated by ad-hoc test
-    // assertions executed before RUN_ALL_TESTS().
-    ClearNonAdHocTestResult();
-
-    Timer timer;
-
-    // Shuffles test suites and tests if requested.
-    if (has_tests_to_run && GTEST_FLAG(shuffle)) {
-      random()->Reseed(static_cast<uint32_t>(random_seed_));
-      // This should be done before calling OnTestIterationStart(),
-      // such that a test event listener can see the actual test order
-      // in the event.
-      ShuffleTests();
-    }
-
-    // Tells the unit test event listeners that the tests are about to start.
-    repeater->OnTestIterationStart(*parent_, i);
-
-    // Runs each test suite if there is at least one test to run.
-    if (has_tests_to_run) {
-      // Sets up all environments beforehand.
-      repeater->OnEnvironmentsSetUpStart(*parent_);
-      ForEach(environments_, SetUpEnvironment);
-      repeater->OnEnvironmentsSetUpEnd(*parent_);
-
-      // Runs the tests only if there was no fatal failure or skip triggered
-      // during global set-up.
-      if (Test::IsSkipped()) {
-        // Emit diagnostics when global set-up calls skip, as it will not be
-        // emitted by default.
-        TestResult& test_result =
-            *internal::GetUnitTestImpl()->current_test_result();
-        for (int j = 0; j < test_result.total_part_count(); ++j) {
-          const TestPartResult& test_part_result =
-              test_result.GetTestPartResult(j);
-          if (test_part_result.type() == TestPartResult::kSkip) {
-            const std::string& result = test_part_result.message();
-            printf("%s\n", result.c_str());
-          }
-        }
-        fflush(stdout);
-      } else if (!Test::HasFatalFailure()) {
-        for (int test_index = 0; test_index < total_test_suite_count();
-             test_index++) {
-          GetMutableSuiteCase(test_index)->Run();
-          if (GTEST_FLAG(fail_fast) &&
-              GetMutableSuiteCase(test_index)->Failed()) {
-            for (int j = test_index + 1; j < total_test_suite_count(); j++) {
-              GetMutableSuiteCase(j)->Skip();
-            }
-            break;
-          }
-        }
-      } else if (Test::HasFatalFailure()) {
-        // If there was a fatal failure during the global setup then we know we
-        // aren't going to run any tests. Explicitly mark all of the tests as
-        // skipped to make this obvious in the output.
-        for (int test_index = 0; test_index < total_test_suite_count();
-             test_index++) {
-          GetMutableSuiteCase(test_index)->Skip();
-        }
-      }
-
-      // Tears down all environments in reverse order afterwards.
-      repeater->OnEnvironmentsTearDownStart(*parent_);
-      std::for_each(environments_.rbegin(), environments_.rend(),
-                    TearDownEnvironment);
-      repeater->OnEnvironmentsTearDownEnd(*parent_);
-    }
-
-    elapsed_time_ = timer.Elapsed();
-
-    // Tells the unit test event listener that the tests have just finished.
-    repeater->OnTestIterationEnd(*parent_, i);
-
-    // Gets the result and clears it.
-    if (!Passed()) {
-      failed = true;
-    }
-
-    // Restores the original test order after the iteration.  This
-    // allows the user to quickly repro a failure that happens in the
-    // N-th iteration without repeating the first (N - 1) iterations.
-    // This is not enclosed in "if (GTEST_FLAG(shuffle)) { ... }", in
-    // case the user somehow changes the value of the flag somewhere
-    // (it's always safe to unshuffle the tests).
-    UnshuffleTests();
-
-    if (GTEST_FLAG(shuffle)) {
-      // Picks a new random seed for each iteration.
-      random_seed_ = GetNextRandomSeed(random_seed_);
-    }
-  }
-
-  repeater->OnTestProgramEnd(*parent_);
-
-  if (!gtest_is_initialized_before_run_all_tests) {
-    ColoredPrintf(
-        GTestColor::kRed,
-        "\nIMPORTANT NOTICE - DO NOT IGNORE:\n"
-        "This test program did NOT call " GTEST_INIT_GOOGLE_TEST_NAME_
-        "() before calling RUN_ALL_TESTS(). This is INVALID. Soon " GTEST_NAME_
-        " will start to enforce the valid usage. "
-        "Please fix it ASAP, or IT WILL START TO FAIL.\n");  // NOLINT
-#if GTEST_FOR_GOOGLE_
-    ColoredPrintf(GTestColor::kRed,
-                  "For more details, see http://wiki/Main/ValidGUnitMain.\n");
-#endif  // GTEST_FOR_GOOGLE_
-  }
-
-  return !failed;
-}
-
-// Reads the GTEST_SHARD_STATUS_FILE environment variable, and creates the file
-// if the variable is present. If a file already exists at this location, this
-// function will write over it. If the variable is present, but the file cannot
-// be created, prints an error and exits.
-void WriteToShardStatusFileIfNeeded() {
-  const char* const test_shard_file = posix::GetEnv(kTestShardStatusFile);
-  if (test_shard_file != nullptr) {
-    FILE* const file = posix::FOpen(test_shard_file, "w");
-    if (file == nullptr) {
-      ColoredPrintf(GTestColor::kRed,
-                    "Could not write to the test shard status file \"%s\" "
-                    "specified by the %s environment variable.\n",
-                    test_shard_file, kTestShardStatusFile);
-      fflush(stdout);
-      exit(EXIT_FAILURE);
-    }
-    fclose(file);
-  }
-}
-
-// Checks whether sharding is enabled by examining the relevant
-// environment variable values. If the variables are present,
-// but inconsistent (i.e., shard_index >= total_shards), prints
-// an error and exits. If in_subprocess_for_death_test, sharding is
-// disabled because it must only be applied to the original test
-// process. Otherwise, we could filter out death tests we intended to execute.
-bool ShouldShard(const char* total_shards_env,
-                 const char* shard_index_env,
-                 bool in_subprocess_for_death_test) {
-  if (in_subprocess_for_death_test) {
-    return false;
-  }
-
-  const int32_t total_shards = Int32FromEnvOrDie(total_shards_env, -1);
-  const int32_t shard_index = Int32FromEnvOrDie(shard_index_env, -1);
-
-  if (total_shards == -1 && shard_index == -1) {
-    return false;
-  } else if (total_shards == -1 && shard_index != -1) {
-    const Message msg = Message()
-      << "Invalid environment variables: you have "
-      << kTestShardIndex << " = " << shard_index
-      << ", but have left " << kTestTotalShards << " unset.\n";
-    ColoredPrintf(GTestColor::kRed, "%s", msg.GetString().c_str());
-    fflush(stdout);
-    exit(EXIT_FAILURE);
-  } else if (total_shards != -1 && shard_index == -1) {
-    const Message msg = Message()
-      << "Invalid environment variables: you have "
-      << kTestTotalShards << " = " << total_shards
-      << ", but have left " << kTestShardIndex << " unset.\n";
-    ColoredPrintf(GTestColor::kRed, "%s", msg.GetString().c_str());
-    fflush(stdout);
-    exit(EXIT_FAILURE);
-  } else if (shard_index < 0 || shard_index >= total_shards) {
-    const Message msg = Message()
-      << "Invalid environment variables: we require 0 <= "
-      << kTestShardIndex << " < " << kTestTotalShards
-      << ", but you have " << kTestShardIndex << "=" << shard_index
-      << ", " << kTestTotalShards << "=" << total_shards << ".\n";
-    ColoredPrintf(GTestColor::kRed, "%s", msg.GetString().c_str());
-    fflush(stdout);
-    exit(EXIT_FAILURE);
-  }
-
-  return total_shards > 1;
-}
-
-// Parses the environment variable var as an Int32. If it is unset,
-// returns default_val. If it is not an Int32, prints an error
-// and aborts.
-int32_t Int32FromEnvOrDie(const char* var, int32_t default_val) {
-  const char* str_val = posix::GetEnv(var);
-  if (str_val == nullptr) {
-    return default_val;
-  }
-
-  int32_t result;
-  if (!ParseInt32(Message() << "The value of environment variable " << var,
-                  str_val, &result)) {
-    exit(EXIT_FAILURE);
-  }
-  return result;
-}
-
-// Given the total number of shards, the shard index, and the test id,
-// returns true if and only if the test should be run on this shard. The test id
-// is some arbitrary but unique non-negative integer assigned to each test
-// method. Assumes that 0 <= shard_index < total_shards.
-bool ShouldRunTestOnShard(int total_shards, int shard_index, int test_id) {
-  return (test_id % total_shards) == shard_index;
-}
-
-// Compares the name of each test with the user-specified filter to
-// decide whether the test should be run, then records the result in
-// each TestSuite and TestInfo object.
-// If shard_tests == true, further filters tests based on sharding
-// variables in the environment - see
-// https://github.com/google/googletest/blob/master/googletest/docs/advanced.md
-// . Returns the number of tests that should run.
-int UnitTestImpl::FilterTests(ReactionToSharding shard_tests) {
-  const int32_t total_shards = shard_tests == HONOR_SHARDING_PROTOCOL ?
-      Int32FromEnvOrDie(kTestTotalShards, -1) : -1;
-  const int32_t shard_index = shard_tests == HONOR_SHARDING_PROTOCOL ?
-      Int32FromEnvOrDie(kTestShardIndex, -1) : -1;
-
-  // num_runnable_tests are the number of tests that will
-  // run across all shards (i.e., match filter and are not disabled).
-  // num_selected_tests are the number of tests to be run on
-  // this shard.
-  int num_runnable_tests = 0;
-  int num_selected_tests = 0;
-  for (auto* test_suite : test_suites_) {
-    const std::string& test_suite_name = test_suite->name();
-    test_suite->set_should_run(false);
-
-    for (size_t j = 0; j < test_suite->test_info_list().size(); j++) {
-      TestInfo* const test_info = test_suite->test_info_list()[j];
-      const std::string test_name(test_info->name());
-      // A test is disabled if test suite name or test name matches
-      // kDisableTestFilter.
-      const bool is_disabled = internal::UnitTestOptions::MatchesFilter(
-                                   test_suite_name, kDisableTestFilter) ||
-                               internal::UnitTestOptions::MatchesFilter(
-                                   test_name, kDisableTestFilter);
-      test_info->is_disabled_ = is_disabled;
-
-      const bool matches_filter = internal::UnitTestOptions::FilterMatchesTest(
-          test_suite_name, test_name);
-      test_info->matches_filter_ = matches_filter;
-
-      const bool is_runnable =
-          (GTEST_FLAG(also_run_disabled_tests) || !is_disabled) &&
-          matches_filter;
-
-      const bool is_in_another_shard =
-          shard_tests != IGNORE_SHARDING_PROTOCOL &&
-          !ShouldRunTestOnShard(total_shards, shard_index, num_runnable_tests);
-      test_info->is_in_another_shard_ = is_in_another_shard;
-      const bool is_selected = is_runnable && !is_in_another_shard;
-
-      num_runnable_tests += is_runnable;
-      num_selected_tests += is_selected;
-
-      test_info->should_run_ = is_selected;
-      test_suite->set_should_run(test_suite->should_run() || is_selected);
-    }
-  }
-  return num_selected_tests;
-}
-
-// Prints the given C-string on a single line by replacing all '\n'
-// characters with string "\\n".  If the output takes more than
-// max_length characters, only prints the first max_length characters
-// and "...".
-static void PrintOnOneLine(const char* str, int max_length) {
-  if (str != nullptr) {
-    for (int i = 0; *str != '\0'; ++str) {
-      if (i >= max_length) {
-        printf("...");
-        break;
-      }
-      if (*str == '\n') {
-        printf("\\n");
-        i += 2;
-      } else {
-        printf("%c", *str);
-        ++i;
-      }
-    }
-  }
-}
-
-// Prints the names of the tests matching the user-specified filter flag.
-void UnitTestImpl::ListTestsMatchingFilter() {
-  // Print at most this many characters for each type/value parameter.
-  const int kMaxParamLength = 250;
-
-  for (auto* test_suite : test_suites_) {
-    bool printed_test_suite_name = false;
-
-    for (size_t j = 0; j < test_suite->test_info_list().size(); j++) {
-      const TestInfo* const test_info = test_suite->test_info_list()[j];
-      if (test_info->matches_filter_) {
-        if (!printed_test_suite_name) {
-          printed_test_suite_name = true;
-          printf("%s.", test_suite->name());
-          if (test_suite->type_param() != nullptr) {
-            printf("  # %s = ", kTypeParamLabel);
-            // We print the type parameter on a single line to make
-            // the output easy to parse by a program.
-            PrintOnOneLine(test_suite->type_param(), kMaxParamLength);
-          }
-          printf("\n");
-        }
-        printf("  %s", test_info->name());
-        if (test_info->value_param() != nullptr) {
-          printf("  # %s = ", kValueParamLabel);
-          // We print the value parameter on a single line to make the
-          // output easy to parse by a program.
-          PrintOnOneLine(test_info->value_param(), kMaxParamLength);
-        }
-        printf("\n");
-      }
-    }
-  }
-  fflush(stdout);
-  const std::string& output_format = UnitTestOptions::GetOutputFormat();
-  if (output_format == "xml" || output_format == "json") {
-    FILE* fileout = OpenFileForWriting(
-        UnitTestOptions::GetAbsolutePathToOutputFile().c_str());
-    std::stringstream stream;
-    if (output_format == "xml") {
-      XmlUnitTestResultPrinter(
-          UnitTestOptions::GetAbsolutePathToOutputFile().c_str())
-          .PrintXmlTestsList(&stream, test_suites_);
-    } else if (output_format == "json") {
-      JsonUnitTestResultPrinter(
-          UnitTestOptions::GetAbsolutePathToOutputFile().c_str())
-          .PrintJsonTestList(&stream, test_suites_);
-    }
-    fprintf(fileout, "%s", StringStreamToString(&stream).c_str());
-    fclose(fileout);
-  }
-}
-
-// Sets the OS stack trace getter.
-//
-// Does nothing if the input and the current OS stack trace getter are
-// the same; otherwise, deletes the old getter and makes the input the
-// current getter.
-void UnitTestImpl::set_os_stack_trace_getter(
-    OsStackTraceGetterInterface* getter) {
-  if (os_stack_trace_getter_ != getter) {
-    delete os_stack_trace_getter_;
-    os_stack_trace_getter_ = getter;
-  }
-}
-
-// Returns the current OS stack trace getter if it is not NULL;
-// otherwise, creates an OsStackTraceGetter, makes it the current
-// getter, and returns it.
-OsStackTraceGetterInterface* UnitTestImpl::os_stack_trace_getter() {
-  if (os_stack_trace_getter_ == nullptr) {
-#ifdef GTEST_OS_STACK_TRACE_GETTER_
-    os_stack_trace_getter_ = new GTEST_OS_STACK_TRACE_GETTER_;
-#else
-    os_stack_trace_getter_ = new OsStackTraceGetter;
-#endif  // GTEST_OS_STACK_TRACE_GETTER_
-  }
-
-  return os_stack_trace_getter_;
-}
-
-// Returns the most specific TestResult currently running.
-TestResult* UnitTestImpl::current_test_result() {
-  if (current_test_info_ != nullptr) {
-    return &current_test_info_->result_;
-  }
-  if (current_test_suite_ != nullptr) {
-    return &current_test_suite_->ad_hoc_test_result_;
-  }
-  return &ad_hoc_test_result_;
-}
-
-// Shuffles all test suites, and the tests within each test suite,
-// making sure that death tests are still run first.
-void UnitTestImpl::ShuffleTests() {
-  // Shuffles the death test suites.
-  ShuffleRange(random(), 0, last_death_test_suite_ + 1, &test_suite_indices_);
-
-  // Shuffles the non-death test suites.
-  ShuffleRange(random(), last_death_test_suite_ + 1,
-               static_cast<int>(test_suites_.size()), &test_suite_indices_);
-
-  // Shuffles the tests inside each test suite.
-  for (auto& test_suite : test_suites_) {
-    test_suite->ShuffleTests(random());
-  }
-}
-
-// Restores the test suites and tests to their order before the first shuffle.
-void UnitTestImpl::UnshuffleTests() {
-  for (size_t i = 0; i < test_suites_.size(); i++) {
-    // Unshuffles the tests in each test suite.
-    test_suites_[i]->UnshuffleTests();
-    // Resets the index of each test suite.
-    test_suite_indices_[i] = static_cast<int>(i);
-  }
-}
-
-// Returns the current OS stack trace as an std::string.
-//
-// The maximum number of stack frames to be included is specified by
-// the gtest_stack_trace_depth flag.  The skip_count parameter
-// specifies the number of top frames to be skipped, which doesn't
-// count against the number of frames to be included.
-//
-// For example, if Foo() calls Bar(), which in turn calls
-// GetCurrentOsStackTraceExceptTop(..., 1), Foo() will be included in
-// the trace but Bar() and GetCurrentOsStackTraceExceptTop() won't.
-std::string GetCurrentOsStackTraceExceptTop(UnitTest* /*unit_test*/,
-                                            int skip_count) {
-  // We pass skip_count + 1 to skip this wrapper function in addition
-  // to what the user really wants to skip.
-  return GetUnitTestImpl()->CurrentOsStackTraceExceptTop(skip_count + 1);
-}
-
-// Used by the GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_ macro to
-// suppress unreachable code warnings.
-namespace {
-class ClassUniqueToAlwaysTrue {};
-}
-
-bool IsTrue(bool condition) { return condition; }
-
-bool AlwaysTrue() {
-#if GTEST_HAS_EXCEPTIONS
-  // This condition is always false so AlwaysTrue() never actually throws,
-  // but it makes the compiler think that it may throw.
-  if (IsTrue(false))
-    throw ClassUniqueToAlwaysTrue();
-#endif  // GTEST_HAS_EXCEPTIONS
-  return true;
-}
-
-// If *pstr starts with the given prefix, modifies *pstr to be right
-// past the prefix and returns true; otherwise leaves *pstr unchanged
-// and returns false.  None of pstr, *pstr, and prefix can be NULL.
-bool SkipPrefix(const char* prefix, const char** pstr) {
-  const size_t prefix_len = strlen(prefix);
-  if (strncmp(*pstr, prefix, prefix_len) == 0) {
-    *pstr += prefix_len;
-    return true;
-  }
-  return false;
-}
-
-// Parses a string as a command line flag.  The string should have
-// the format "--flag=value".  When def_optional is true, the "=value"
-// part can be omitted.
-//
-// Returns the value of the flag, or NULL if the parsing failed.
-static const char* ParseFlagValue(const char* str, const char* flag,
-                                  bool def_optional) {
-  // str and flag must not be NULL.
-  if (str == nullptr || flag == nullptr) return nullptr;
-
-  // The flag must start with "--" followed by GTEST_FLAG_PREFIX_.
-  const std::string flag_str = std::string("--") + GTEST_FLAG_PREFIX_ + flag;
-  const size_t flag_len = flag_str.length();
-  if (strncmp(str, flag_str.c_str(), flag_len) != 0) return nullptr;
-
-  // Skips the flag name.
-  const char* flag_end = str + flag_len;
-
-  // When def_optional is true, it's OK to not have a "=value" part.
-  if (def_optional && (flag_end[0] == '\0')) {
-    return flag_end;
-  }
-
-  // If def_optional is true and there are more characters after the
-  // flag name, or if def_optional is false, there must be a '=' after
-  // the flag name.
-  if (flag_end[0] != '=') return nullptr;
-
-  // Returns the string after "=".
-  return flag_end + 1;
-}
-
-// Parses a string for a bool flag, in the form of either
-// "--flag=value" or "--flag".
-//
-// In the former case, the value is taken as true as long as it does
-// not start with '0', 'f', or 'F'.
-//
-// In the latter case, the value is taken as true.
-//
-// On success, stores the value of the flag in *value, and returns
-// true.  On failure, returns false without changing *value.
-static bool ParseBoolFlag(const char* str, const char* flag, bool* value) {
-  // Gets the value of the flag as a string.
-  const char* const value_str = ParseFlagValue(str, flag, true);
-
-  // Aborts if the parsing failed.
-  if (value_str == nullptr) return false;
-
-  // Converts the string value to a bool.
-  *value = !(*value_str == '0' || *value_str == 'f' || *value_str == 'F');
-  return true;
-}
-
-// Parses a string for an int32_t flag, in the form of "--flag=value".
-//
-// On success, stores the value of the flag in *value, and returns
-// true.  On failure, returns false without changing *value.
-bool ParseInt32Flag(const char* str, const char* flag, int32_t* value) {
-  // Gets the value of the flag as a string.
-  const char* const value_str = ParseFlagValue(str, flag, false);
-
-  // Aborts if the parsing failed.
-  if (value_str == nullptr) return false;
-
-  // Sets *value to the value of the flag.
-  return ParseInt32(Message() << "The value of flag --" << flag,
-                    value_str, value);
-}
-
-// Parses a string for a string flag, in the form of "--flag=value".
-//
-// On success, stores the value of the flag in *value, and returns
-// true.  On failure, returns false without changing *value.
-template <typename String>
-static bool ParseStringFlag(const char* str, const char* flag, String* value) {
-  // Gets the value of the flag as a string.
-  const char* const value_str = ParseFlagValue(str, flag, false);
-
-  // Aborts if the parsing failed.
-  if (value_str == nullptr) return false;
-
-  // Sets *value to the value of the flag.
-  *value = value_str;
-  return true;
-}
-
-// Determines whether a string has a prefix that Google Test uses for its
-// flags, i.e., starts with GTEST_FLAG_PREFIX_ or GTEST_FLAG_PREFIX_DASH_.
-// If Google Test detects that a command line flag has its prefix but is not
-// recognized, it will print its help message. Flags starting with
-// GTEST_INTERNAL_PREFIX_ followed by "internal_" are considered Google Test
-// internal flags and do not trigger the help message.
-static bool HasGoogleTestFlagPrefix(const char* str) {
-  return (SkipPrefix("--", &str) ||
-          SkipPrefix("-", &str) ||
-          SkipPrefix("/", &str)) &&
-         !SkipPrefix(GTEST_FLAG_PREFIX_ "internal_", &str) &&
-         (SkipPrefix(GTEST_FLAG_PREFIX_, &str) ||
-          SkipPrefix(GTEST_FLAG_PREFIX_DASH_, &str));
-}
-
-// Prints a string containing code-encoded text.  The following escape
-// sequences can be used in the string to control the text color:
-//
-//   @@    prints a single '@' character.
-//   @R    changes the color to red.
-//   @G    changes the color to green.
-//   @Y    changes the color to yellow.
-//   @D    changes to the default terminal text color.
-//
-static void PrintColorEncoded(const char* str) {
-  GTestColor color = GTestColor::kDefault;  // The current color.
-
-  // Conceptually, we split the string into segments divided by escape
-  // sequences.  Then we print one segment at a time.  At the end of
-  // each iteration, the str pointer advances to the beginning of the
-  // next segment.
-  for (;;) {
-    const char* p = strchr(str, '@');
-    if (p == nullptr) {
-      ColoredPrintf(color, "%s", str);
-      return;
-    }
-
-    ColoredPrintf(color, "%s", std::string(str, p).c_str());
-
-    const char ch = p[1];
-    str = p + 2;
-    if (ch == '@') {
-      ColoredPrintf(color, "@");
-    } else if (ch == 'D') {
-      color = GTestColor::kDefault;
-    } else if (ch == 'R') {
-      color = GTestColor::kRed;
-    } else if (ch == 'G') {
-      color = GTestColor::kGreen;
-    } else if (ch == 'Y') {
-      color = GTestColor::kYellow;
-    } else {
-      --str;
-    }
-  }
-}
-
-static const char kColorEncodedHelpMessage[] =
-    "This program contains tests written using " GTEST_NAME_
-    ". You can use the\n"
-    "following command line flags to control its behavior:\n"
-    "\n"
-    "Test Selection:\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "list_tests@D\n"
-    "      List the names of all tests instead of running them. The name of\n"
-    "      TEST(Foo, Bar) is \"Foo.Bar\".\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "filter=@YPOSITIVE_PATTERNS"
-    "[@G-@YNEGATIVE_PATTERNS]@D\n"
-    "      Run only the tests whose name matches one of the positive patterns "
-    "but\n"
-    "      none of the negative patterns. '?' matches any single character; "
-    "'*'\n"
-    "      matches any substring; ':' separates two patterns.\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "also_run_disabled_tests@D\n"
-    "      Run all disabled tests too.\n"
-    "\n"
-    "Test Execution:\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "repeat=@Y[COUNT]@D\n"
-    "      Run the tests repeatedly; use a negative count to repeat forever.\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "shuffle@D\n"
-    "      Randomize tests' orders on every iteration.\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "random_seed=@Y[NUMBER]@D\n"
-    "      Random number seed to use for shuffling test orders (between 1 and\n"
-    "      99999, or 0 to use a seed based on the current time).\n"
-    "\n"
-    "Test Output:\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "color=@Y(@Gyes@Y|@Gno@Y|@Gauto@Y)@D\n"
-    "      Enable/disable colored output. The default is @Gauto@D.\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "brief=1@D\n"
-    "      Only print test failures.\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "print_time=0@D\n"
-    "      Don't print the elapsed time of each test.\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "output=@Y(@Gjson@Y|@Gxml@Y)[@G:@YDIRECTORY_PATH@G" GTEST_PATH_SEP_
-    "@Y|@G:@YFILE_PATH]@D\n"
-    "      Generate a JSON or XML report in the given directory or with the "
-    "given\n"
-    "      file name. @YFILE_PATH@D defaults to @Gtest_detail.xml@D.\n"
-# if GTEST_CAN_STREAM_RESULTS_
-    "  @G--" GTEST_FLAG_PREFIX_
-    "stream_result_to=@YHOST@G:@YPORT@D\n"
-    "      Stream test results to the given server.\n"
-# endif  // GTEST_CAN_STREAM_RESULTS_
-    "\n"
-    "Assertion Behavior:\n"
-# if GTEST_HAS_DEATH_TEST && !GTEST_OS_WINDOWS
-    "  @G--" GTEST_FLAG_PREFIX_
-    "death_test_style=@Y(@Gfast@Y|@Gthreadsafe@Y)@D\n"
-    "      Set the default death test style.\n"
-# endif  // GTEST_HAS_DEATH_TEST && !GTEST_OS_WINDOWS
-    "  @G--" GTEST_FLAG_PREFIX_
-    "break_on_failure@D\n"
-    "      Turn assertion failures into debugger break-points.\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "throw_on_failure@D\n"
-    "      Turn assertion failures into C++ exceptions for use by an external\n"
-    "      test framework.\n"
-    "  @G--" GTEST_FLAG_PREFIX_
-    "catch_exceptions=0@D\n"
-    "      Do not report exceptions as test failures. Instead, allow them\n"
-    "      to crash the program or throw a pop-up (on Windows).\n"
-    "\n"
-    "Except for @G--" GTEST_FLAG_PREFIX_
-    "list_tests@D, you can alternatively set "
-    "the corresponding\n"
-    "environment variable of a flag (all letters in upper-case). For example, "
-    "to\n"
-    "disable colored text output, you can either specify "
-    "@G--" GTEST_FLAG_PREFIX_
-    "color=no@D or set\n"
-    "the @G" GTEST_FLAG_PREFIX_UPPER_
-    "COLOR@D environment variable to @Gno@D.\n"
-    "\n"
-    "For more information, please read the " GTEST_NAME_
-    " documentation at\n"
-    "@G" GTEST_PROJECT_URL_ "@D. If you find a bug in " GTEST_NAME_
-    "\n"
-    "(not one in your own code or tests), please report it to\n"
-    "@G<" GTEST_DEV_EMAIL_ ">@D.\n";
-
-static bool ParseGoogleTestFlag(const char* const arg) {
-  return ParseBoolFlag(arg, kAlsoRunDisabledTestsFlag,
-                       &GTEST_FLAG(also_run_disabled_tests)) ||
-         ParseBoolFlag(arg, kBreakOnFailureFlag,
-                       &GTEST_FLAG(break_on_failure)) ||
-         ParseBoolFlag(arg, kCatchExceptionsFlag,
-                       &GTEST_FLAG(catch_exceptions)) ||
-         ParseStringFlag(arg, kColorFlag, &GTEST_FLAG(color)) ||
-         ParseStringFlag(arg, kDeathTestStyleFlag,
-                         &GTEST_FLAG(death_test_style)) ||
-         ParseBoolFlag(arg, kDeathTestUseFork,
-                       &GTEST_FLAG(death_test_use_fork)) ||
-         ParseBoolFlag(arg, kFailFast, &GTEST_FLAG(fail_fast)) ||
-         ParseStringFlag(arg, kFilterFlag, &GTEST_FLAG(filter)) ||
-         ParseStringFlag(arg, kInternalRunDeathTestFlag,
-                         &GTEST_FLAG(internal_run_death_test)) ||
-         ParseBoolFlag(arg, kListTestsFlag, &GTEST_FLAG(list_tests)) ||
-         ParseStringFlag(arg, kOutputFlag, &GTEST_FLAG(output)) ||
-         ParseBoolFlag(arg, kBriefFlag, &GTEST_FLAG(brief)) ||
-         ParseBoolFlag(arg, kPrintTimeFlag, &GTEST_FLAG(print_time)) ||
-         ParseBoolFlag(arg, kPrintUTF8Flag, &GTEST_FLAG(print_utf8)) ||
-         ParseInt32Flag(arg, kRandomSeedFlag, &GTEST_FLAG(random_seed)) ||
-         ParseInt32Flag(arg, kRepeatFlag, &GTEST_FLAG(repeat)) ||
-         ParseBoolFlag(arg, kShuffleFlag, &GTEST_FLAG(shuffle)) ||
-         ParseInt32Flag(arg, kStackTraceDepthFlag,
-                        &GTEST_FLAG(stack_trace_depth)) ||
-         ParseStringFlag(arg, kStreamResultToFlag,
-                         &GTEST_FLAG(stream_result_to)) ||
-         ParseBoolFlag(arg, kThrowOnFailureFlag, &GTEST_FLAG(throw_on_failure));
-}
-
-#if GTEST_USE_OWN_FLAGFILE_FLAG_
-static void LoadFlagsFromFile(const std::string& path) {
-  FILE* flagfile = posix::FOpen(path.c_str(), "r");
-  if (!flagfile) {
-    GTEST_LOG_(FATAL) << "Unable to open file \"" << GTEST_FLAG(flagfile)
-                      << "\"";
-  }
-  std::string contents(ReadEntireFile(flagfile));
-  posix::FClose(flagfile);
-  std::vector<std::string> lines;
-  SplitString(contents, '\n', &lines);
-  for (size_t i = 0; i < lines.size(); ++i) {
-    if (lines[i].empty())
-      continue;
-    if (!ParseGoogleTestFlag(lines[i].c_str()))
-      g_help_flag = true;
-  }
-}
-#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
-
-// Parses the command line for Google Test flags, without initializing
-// other parts of Google Test.  The type parameter CharType can be
-// instantiated to either char or wchar_t.
-template <typename CharType>
-void ParseGoogleTestFlagsOnlyImpl(int* argc, CharType** argv) {
-  for (int i = 1; i < *argc; i++) {
-    const std::string arg_string = StreamableToString(argv[i]);
-    const char* const arg = arg_string.c_str();
-
-    using internal::ParseBoolFlag;
-    using internal::ParseInt32Flag;
-    using internal::ParseStringFlag;
-
-    bool remove_flag = false;
-    if (ParseGoogleTestFlag(arg)) {
-      remove_flag = true;
-#if GTEST_USE_OWN_FLAGFILE_FLAG_
-    } else if (ParseStringFlag(arg, kFlagfileFlag, &GTEST_FLAG(flagfile))) {
-      LoadFlagsFromFile(GTEST_FLAG(flagfile));
-      remove_flag = true;
-#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
-    } else if (arg_string == "--help" || arg_string == "-h" ||
-               arg_string == "-?" || arg_string == "/?" ||
-               HasGoogleTestFlagPrefix(arg)) {
-      // Both help flag and unrecognized Google Test flags (excluding
-      // internal ones) trigger help display.
-      g_help_flag = true;
-    }
-
-    if (remove_flag) {
-      // Shift the remainder of the argv list left by one.  Note
-      // that argv has (*argc + 1) elements, the last one always being
-      // NULL.  The following loop moves the trailing NULL element as
-      // well.
-      for (int j = i; j != *argc; j++) {
-        argv[j] = argv[j + 1];
-      }
-
-      // Decrements the argument count.
-      (*argc)--;
-
-      // We also need to decrement the iterator as we just removed
-      // an element.
-      i--;
-    }
-  }
-
-  if (g_help_flag) {
-    // We print the help here instead of in RUN_ALL_TESTS(), as the
-    // latter may not be called at all if the user is using Google
-    // Test with another testing framework.
-    PrintColorEncoded(kColorEncodedHelpMessage);
-  }
-}
-
-// Parses the command line for Google Test flags, without initializing
-// other parts of Google Test.
-void ParseGoogleTestFlagsOnly(int* argc, char** argv) {
-  ParseGoogleTestFlagsOnlyImpl(argc, argv);
-
-  // Fix the value of *_NSGetArgc() on macOS, but if and only if
-  // *_NSGetArgv() == argv
-  // Only applicable to char** version of argv
-#if GTEST_OS_MAC
-#ifndef GTEST_OS_IOS
-  if (*_NSGetArgv() == argv) {
-    *_NSGetArgc() = *argc;
-  }
-#endif
-#endif
-}
-void ParseGoogleTestFlagsOnly(int* argc, wchar_t** argv) {
-  ParseGoogleTestFlagsOnlyImpl(argc, argv);
-}
-
-// The internal implementation of InitGoogleTest().
-//
-// The type parameter CharType can be instantiated to either char or
-// wchar_t.
-template <typename CharType>
-void InitGoogleTestImpl(int* argc, CharType** argv) {
-  // We don't want to run the initialization code twice.
-  if (GTestIsInitialized()) return;
-
-  if (*argc <= 0) return;
-
-  g_argvs.clear();
-  for (int i = 0; i != *argc; i++) {
-    g_argvs.push_back(StreamableToString(argv[i]));
-  }
-
-#if GTEST_HAS_ABSL
-  absl::InitializeSymbolizer(g_argvs[0].c_str());
-#endif  // GTEST_HAS_ABSL
-
-  ParseGoogleTestFlagsOnly(argc, argv);
-  GetUnitTestImpl()->PostFlagParsingInit();
-}
-
-}  // namespace internal
-
-// Initializes Google Test.  This must be called before calling
-// RUN_ALL_TESTS().  In particular, it parses a command line for the
-// flags that Google Test recognizes.  Whenever a Google Test flag is
-// seen, it is removed from argv, and *argc is decremented.
-//
-// No value is returned.  Instead, the Google Test flag variables are
-// updated.
-//
-// Calling the function for the second time has no user-visible effect.
-void InitGoogleTest(int* argc, char** argv) {
-#if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
-  GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(argc, argv);
-#else  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
-  internal::InitGoogleTestImpl(argc, argv);
-#endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
-}
-
-// This overloaded version can be used in Windows programs compiled in
-// UNICODE mode.
-void InitGoogleTest(int* argc, wchar_t** argv) {
-#if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
-  GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(argc, argv);
-#else  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
-  internal::InitGoogleTestImpl(argc, argv);
-#endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
-}
-
-// This overloaded version can be used on Arduino/embedded platforms where
-// there is no argc/argv.
-void InitGoogleTest() {
-  // Since Arduino doesn't have a command line, fake out the argc/argv arguments
-  int argc = 1;
-  const auto arg0 = "dummy";
-  char* argv0 = const_cast<char*>(arg0);
-  char** argv = &argv0;
-
-#if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
-  GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(&argc, argv);
-#else  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
-  internal::InitGoogleTestImpl(&argc, argv);
-#endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
-}
-
-std::string TempDir() {
-#if defined(GTEST_CUSTOM_TEMPDIR_FUNCTION_)
-  return GTEST_CUSTOM_TEMPDIR_FUNCTION_();
-#elif GTEST_OS_WINDOWS_MOBILE
-  return "\\temp\\";
-#elif GTEST_OS_WINDOWS
-  const char* temp_dir = internal::posix::GetEnv("TEMP");
-  if (temp_dir == nullptr || temp_dir[0] == '\0') {
-    return "\\temp\\";
-  } else if (temp_dir[strlen(temp_dir) - 1] == '\\') {
-    return temp_dir;
-  } else {
-    return std::string(temp_dir) + "\\";
-  }
-#elif GTEST_OS_LINUX_ANDROID
-  const char* temp_dir = internal::posix::GetEnv("TEST_TMPDIR");
-  if (temp_dir == nullptr || temp_dir[0] == '\0') {
-    return "/data/local/tmp/";
-  } else {
-    return temp_dir;
-  }
-#elif GTEST_OS_LINUX
-  const char* temp_dir = internal::posix::GetEnv("TEST_TMPDIR");
-  if (temp_dir == nullptr || temp_dir[0] == '\0') {
-    return "/tmp/";
-  } else {
-    return temp_dir;
-  }
-#else
-  return "/tmp/";
-#endif  // GTEST_OS_WINDOWS_MOBILE
-}
-
-// Class ScopedTrace
-
-// Pushes the given source file location and message onto a per-thread
-// trace stack maintained by Google Test.
-void ScopedTrace::PushTrace(const char* file, int line, std::string message) {
-  internal::TraceInfo trace;
-  trace.file = file;
-  trace.line = line;
-  trace.message.swap(message);
-
-  UnitTest::GetInstance()->PushGTestTrace(trace);
-}
-
-// Pops the info pushed by the c'tor.
-ScopedTrace::~ScopedTrace()
-    GTEST_LOCK_EXCLUDED_(&UnitTest::mutex_) {
-  UnitTest::GetInstance()->PopGTestTrace();
-}
-
-}  // namespace testing
-// Copyright 2005, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-//
-// This file implements death tests.
-
-
-#include <functional>
-#include <utility>
-
-
-#if GTEST_HAS_DEATH_TEST
-
-# if GTEST_OS_MAC
-#  include <crt_externs.h>
-# endif  // GTEST_OS_MAC
-
-# include <errno.h>
-# include <fcntl.h>
-# include <limits.h>
-
-# if GTEST_OS_LINUX
-#  include <signal.h>
-# endif  // GTEST_OS_LINUX
-
-# include <stdarg.h>
-
-# if GTEST_OS_WINDOWS
-#  include <windows.h>
-# else
-#  include <sys/mman.h>
-#  include <sys/wait.h>
-# endif  // GTEST_OS_WINDOWS
-
-# if GTEST_OS_QNX
-#  include <spawn.h>
-# endif  // GTEST_OS_QNX
-
-# if GTEST_OS_FUCHSIA
-#  include <lib/fdio/fd.h>
-#  include <lib/fdio/io.h>
-#  include <lib/fdio/spawn.h>
-#  include <lib/zx/channel.h>
-#  include <lib/zx/port.h>
-#  include <lib/zx/process.h>
-#  include <lib/zx/socket.h>
-#  include <zircon/processargs.h>
-#  include <zircon/syscalls.h>
-#  include <zircon/syscalls/policy.h>
-#  include <zircon/syscalls/port.h>
-# endif  // GTEST_OS_FUCHSIA
-
-#endif  // GTEST_HAS_DEATH_TEST
-
-
-namespace testing {
-
-// Constants.
-
-// The default death test style.
-//
-// This is defined in internal/gtest-port.h as "fast", but can be overridden by
-// a definition in internal/custom/gtest-port.h. The recommended value, which is
-// used internally at Google, is "threadsafe".
-static const char kDefaultDeathTestStyle[] = GTEST_DEFAULT_DEATH_TEST_STYLE;
-
-GTEST_DEFINE_string_(
-    death_test_style,
-    internal::StringFromGTestEnv("death_test_style", kDefaultDeathTestStyle),
-    "Indicates how to run a death test in a forked child process: "
-    "\"threadsafe\" (child process re-executes the test binary "
-    "from the beginning, running only the specific death test) or "
-    "\"fast\" (child process runs the death test immediately "
-    "after forking).");
-
-GTEST_DEFINE_bool_(
-    death_test_use_fork,
-    internal::BoolFromGTestEnv("death_test_use_fork", false),
-    "Instructs to use fork()/_exit() instead of clone() in death tests. "
-    "Ignored and always uses fork() on POSIX systems where clone() is not "
-    "implemented. Useful when running under valgrind or similar tools if "
-    "those do not support clone(). Valgrind 3.3.1 will just fail if "
-    "it sees an unsupported combination of clone() flags. "
-    "It is not recommended to use this flag w/o valgrind though it will "
-    "work in 99% of the cases. Once valgrind is fixed, this flag will "
-    "most likely be removed.");
-
-namespace internal {
-GTEST_DEFINE_string_(
-    internal_run_death_test, "",
-    "Indicates the file, line number, temporal index of "
-    "the single death test to run, and a file descriptor to "
-    "which a success code may be sent, all separated by "
-    "the '|' characters.  This flag is specified if and only if the "
-    "current process is a sub-process launched for running a thread-safe "
-    "death test.  FOR INTERNAL USE ONLY.");
-}  // namespace internal
-
-#if GTEST_HAS_DEATH_TEST
-
-namespace internal {
-
-// Valid only for fast death tests. Indicates the code is running in the
-// child process of a fast style death test.
-# if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
-static bool g_in_fast_death_test_child = false;
-# endif
-
-// Returns a Boolean value indicating whether the caller is currently
-// executing in the context of the death test child process.  Tools such as
-// Valgrind heap checkers may need this to modify their behavior in death
-// tests.  IMPORTANT: This is an internal utility.  Using it may break the
-// implementation of death tests.  User code MUST NOT use it.
-bool InDeathTestChild() {
-# if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
-
-  // On Windows and Fuchsia, death tests are thread-safe regardless of the value
-  // of the death_test_style flag.
-  return !GTEST_FLAG(internal_run_death_test).empty();
-
-# else
-
-  if (GTEST_FLAG(death_test_style) == "threadsafe")
-    return !GTEST_FLAG(internal_run_death_test).empty();
-  else
-    return g_in_fast_death_test_child;
-#endif
-}
-
-}  // namespace internal
-
-// ExitedWithCode constructor.
-ExitedWithCode::ExitedWithCode(int exit_code) : exit_code_(exit_code) {
-}
-
-// ExitedWithCode function-call operator.
-bool ExitedWithCode::operator()(int exit_status) const {
-# if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
-
-  return exit_status == exit_code_;
-
-# else
-
-  return WIFEXITED(exit_status) && WEXITSTATUS(exit_status) == exit_code_;
-
-# endif  // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
-}
-
-# if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
-// KilledBySignal constructor.
-KilledBySignal::KilledBySignal(int signum) : signum_(signum) {
-}
-
-// KilledBySignal function-call operator.
-bool KilledBySignal::operator()(int exit_status) const {
-#  if defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
-  {
-    bool result;
-    if (GTEST_KILLED_BY_SIGNAL_OVERRIDE_(signum_, exit_status, &result)) {
-      return result;
-    }
-  }
-#  endif  // defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
-  return WIFSIGNALED(exit_status) && WTERMSIG(exit_status) == signum_;
-}
-# endif  // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
-
-namespace internal {
-
-// Utilities needed for death tests.
-
-// Generates a textual description of a given exit code, in the format
-// specified by wait(2).
-static std::string ExitSummary(int exit_code) {
-  Message m;
-
-# if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
-
-  m << "Exited with exit status " << exit_code;
-
-# else
-
-  if (WIFEXITED(exit_code)) {
-    m << "Exited with exit status " << WEXITSTATUS(exit_code);
-  } else if (WIFSIGNALED(exit_code)) {
-    m << "Terminated by signal " << WTERMSIG(exit_code);
-  }
-#  ifdef WCOREDUMP
-  if (WCOREDUMP(exit_code)) {
-    m << " (core dumped)";
-  }
-#  endif
-# endif  // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
-
-  return m.GetString();
-}
-
-// Returns true if exit_status describes a process that was terminated
-// by a signal, or exited normally with a nonzero exit code.
-bool ExitedUnsuccessfully(int exit_status) {
-  return !ExitedWithCode(0)(exit_status);
-}
-
-# if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
-// Generates a textual failure message when a death test finds more than
-// one thread running, or cannot determine the number of threads, prior
-// to executing the given statement.  It is the responsibility of the
-// caller not to pass a thread_count of 1.
-static std::string DeathTestThreadWarning(size_t thread_count) {
-  Message msg;
-  msg << "Death tests use fork(), which is unsafe particularly"
-      << " in a threaded context. For this test, " << GTEST_NAME_ << " ";
-  if (thread_count == 0) {
-    msg << "couldn't detect the number of threads.";
-  } else {
-    msg << "detected " << thread_count << " threads.";
-  }
-  msg << " See "
-         "https://github.com/google/googletest/blob/master/docs/"
-         "advanced.md#death-tests-and-threads"
-      << " for more explanation and suggested solutions, especially if"
-      << " this is the last message you see before your test times out.";
-  return msg.GetString();
-}
-# endif  // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
-
-// Flag characters for reporting a death test that did not die.
-static const char kDeathTestLived = 'L';
-static const char kDeathTestReturned = 'R';
-static const char kDeathTestThrew = 'T';
-static const char kDeathTestInternalError = 'I';
-
-#if GTEST_OS_FUCHSIA
-
-// File descriptor used for the pipe in the child process.
-static const int kFuchsiaReadPipeFd = 3;
-
-#endif
-
-// An enumeration describing all of the possible ways that a death test can
-// conclude.  DIED means that the process died while executing the test
-// code; LIVED means that process lived beyond the end of the test code;
-// RETURNED means that the test statement attempted to execute a return
-// statement, which is not allowed; THREW means that the test statement
-// returned control by throwing an exception.  IN_PROGRESS means the test
-// has not yet concluded.
-enum DeathTestOutcome { IN_PROGRESS, DIED, LIVED, RETURNED, THREW };
-
-// Routine for aborting the program which is safe to call from an
-// exec-style death test child process, in which case the error
-// message is propagated back to the parent process.  Otherwise, the
-// message is simply printed to stderr.  In either case, the program
-// then exits with status 1.
-static void DeathTestAbort(const std::string& message) {
-  // On a POSIX system, this function may be called from a threadsafe-style
-  // death test child process, which operates on a very small stack.  Use
-  // the heap for any additional non-minuscule memory requirements.
-  const InternalRunDeathTestFlag* const flag =
-      GetUnitTestImpl()->internal_run_death_test_flag();
-  if (flag != nullptr) {
-    FILE* parent = posix::FDOpen(flag->write_fd(), "w");
-    fputc(kDeathTestInternalError, parent);
-    fprintf(parent, "%s", message.c_str());
-    fflush(parent);
-    _exit(1);
-  } else {
-    fprintf(stderr, "%s", message.c_str());
-    fflush(stderr);
-    posix::Abort();
-  }
-}
-
-// A replacement for CHECK that calls DeathTestAbort if the assertion
-// fails.
-# define GTEST_DEATH_TEST_CHECK_(expression) \
-  do { \
-    if (!::testing::internal::IsTrue(expression)) { \
-      DeathTestAbort( \
-          ::std::string("CHECK failed: File ") + __FILE__ +  ", line " \
-          + ::testing::internal::StreamableToString(__LINE__) + ": " \
-          + #expression); \
-    } \
-  } while (::testing::internal::AlwaysFalse())
-
-// This macro is similar to GTEST_DEATH_TEST_CHECK_, but it is meant for
-// evaluating any system call that fulfills two conditions: it must return
-// -1 on failure, and set errno to EINTR when it is interrupted and
-// should be tried again.  The macro expands to a loop that repeatedly
-// evaluates the expression as long as it evaluates to -1 and sets
-// errno to EINTR.  If the expression evaluates to -1 but errno is
-// something other than EINTR, DeathTestAbort is called.
-# define GTEST_DEATH_TEST_CHECK_SYSCALL_(expression) \
-  do { \
-    int gtest_retval; \
-    do { \
-      gtest_retval = (expression); \
-    } while (gtest_retval == -1 && errno == EINTR); \
-    if (gtest_retval == -1) { \
-      DeathTestAbort( \
-          ::std::string("CHECK failed: File ") + __FILE__ + ", line " \
-          + ::testing::internal::StreamableToString(__LINE__) + ": " \
-          + #expression + " != -1"); \
-    } \
-  } while (::testing::internal::AlwaysFalse())
-
-// Returns the message describing the last system error in errno.
-std::string GetLastErrnoDescription() {
-    return errno == 0 ? "" : posix::StrError(errno);
-}
-
-// This is called from a death test parent process to read a failure
-// message from the death test child process and log it with the FATAL
-// severity. On Windows, the message is read from a pipe handle. On other
-// platforms, it is read from a file descriptor.
-static void FailFromInternalError(int fd) {
-  Message error;
-  char buffer[256];
-  int num_read;
-
-  do {
-    while ((num_read = posix::Read(fd, buffer, 255)) > 0) {
-      buffer[num_read] = '\0';
-      error << buffer;
-    }
-  } while (num_read == -1 && errno == EINTR);
-
-  if (num_read == 0) {
-    GTEST_LOG_(FATAL) << error.GetString();
-  } else {
-    const int last_error = errno;
-    GTEST_LOG_(FATAL) << "Error while reading death test internal: "
-                      << GetLastErrnoDescription() << " [" << last_error << "]";
-  }
-}
-
-// Death test constructor.  Increments the running death test count
-// for the current test.
-DeathTest::DeathTest() {
-  TestInfo* const info = GetUnitTestImpl()->current_test_info();
-  if (info == nullptr) {
-    DeathTestAbort("Cannot run a death test outside of a TEST or "
-                   "TEST_F construct");
-  }
-}
-
-// Creates and returns a death test by dispatching to the current
-// death test factory.
-bool DeathTest::Create(const char* statement,
-                       Matcher<const std::string&> matcher, const char* file,
-                       int line, DeathTest** test) {
-  return GetUnitTestImpl()->death_test_factory()->Create(
-      statement, std::move(matcher), file, line, test);
-}
-
-const char* DeathTest::LastMessage() {
-  return last_death_test_message_.c_str();
-}
-
-void DeathTest::set_last_death_test_message(const std::string& message) {
-  last_death_test_message_ = message;
-}
-
-std::string DeathTest::last_death_test_message_;
-
-// Provides cross platform implementation for some death functionality.
-class DeathTestImpl : public DeathTest {
- protected:
-  DeathTestImpl(const char* a_statement, Matcher<const std::string&> matcher)
-      : statement_(a_statement),
-        matcher_(std::move(matcher)),
-        spawned_(false),
-        status_(-1),
-        outcome_(IN_PROGRESS),
-        read_fd_(-1),
-        write_fd_(-1) {}
-
-  // read_fd_ is expected to be closed and cleared by a derived class.
-  ~DeathTestImpl() override { GTEST_DEATH_TEST_CHECK_(read_fd_ == -1); }
-
-  void Abort(AbortReason reason) override;
-  bool Passed(bool status_ok) override;
-
-  const char* statement() const { return statement_; }
-  bool spawned() const { return spawned_; }
-  void set_spawned(bool is_spawned) { spawned_ = is_spawned; }
-  int status() const { return status_; }
-  void set_status(int a_status) { status_ = a_status; }
-  DeathTestOutcome outcome() const { return outcome_; }
-  void set_outcome(DeathTestOutcome an_outcome) { outcome_ = an_outcome; }
-  int read_fd() const { return read_fd_; }
-  void set_read_fd(int fd) { read_fd_ = fd; }
-  int write_fd() const { return write_fd_; }
-  void set_write_fd(int fd) { write_fd_ = fd; }
-
-  // Called in the parent process only. Reads the result code of the death
-  // test child process via a pipe, interprets it to set the outcome_
-  // member, and closes read_fd_.  Outputs diagnostics and terminates in
-  // case of unexpected codes.
-  void ReadAndInterpretStatusByte();
-
-  // Returns stderr output from the child process.
-  virtual std::string GetErrorLogs();
-
- private:
-  // The textual content of the code this object is testing.  This class
-  // doesn't own this string and should not attempt to delete it.
-  const char* const statement_;
-  // A matcher that's expected to match the stderr output by the child process.
-  Matcher<const std::string&> matcher_;
-  // True if the death test child process has been successfully spawned.
-  bool spawned_;
-  // The exit status of the child process.
-  int status_;
-  // How the death test concluded.
-  DeathTestOutcome outcome_;
-  // Descriptor to the read end of the pipe to the child process.  It is
-  // always -1 in the child process.  The child keeps its write end of the
-  // pipe in write_fd_.
-  int read_fd_;
-  // Descriptor to the child's write end of the pipe to the parent process.
-  // It is always -1 in the parent process.  The parent keeps its end of the
-  // pipe in read_fd_.
-  int write_fd_;
-};
-
-// Called in the parent process only. Reads the result code of the death
-// test child process via a pipe, interprets it to set the outcome_
-// member, and closes read_fd_.  Outputs diagnostics and terminates in
-// case of unexpected codes.
-void DeathTestImpl::ReadAndInterpretStatusByte() {
-  char flag;
-  int bytes_read;
-
-  // The read() here blocks until data is available (signifying the
-  // failure of the death test) or until the pipe is closed (signifying
-  // its success), so it's okay to call this in the parent before
-  // the child process has exited.
-  do {
-    bytes_read = posix::Read(read_fd(), &flag, 1);
-  } while (bytes_read == -1 && errno == EINTR);
-
-  if (bytes_read == 0) {
-    set_outcome(DIED);
-  } else if (bytes_read == 1) {
-    switch (flag) {
-      case kDeathTestReturned:
-        set_outcome(RETURNED);
-        break;
-      case kDeathTestThrew:
-        set_outcome(THREW);
-        break;
-      case kDeathTestLived:
-        set_outcome(LIVED);
-        break;
-      case kDeathTestInternalError:
-        FailFromInternalError(read_fd());  // Does not return.
-        break;
-      default:
-        GTEST_LOG_(FATAL) << "Death test child process reported "
-                          << "unexpected status byte ("
-                          << static_cast<unsigned int>(flag) << ")";
-    }
-  } else {
-    GTEST_LOG_(FATAL) << "Read from death test child process failed: "
-                      << GetLastErrnoDescription();
-  }
-  GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Close(read_fd()));
-  set_read_fd(-1);
-}
-
-std::string DeathTestImpl::GetErrorLogs() {
-  return GetCapturedStderr();
-}
-
-// Signals that the death test code which should have exited, didn't.
-// Should be called only in a death test child process.
-// Writes a status byte to the child's status file descriptor, then
-// calls _exit(1).
-void DeathTestImpl::Abort(AbortReason reason) {
-  // The parent process considers the death test to be a failure if
-  // it finds any data in our pipe.  So, here we write a single flag byte
-  // to the pipe, then exit.
-  const char status_ch =
-      reason == TEST_DID_NOT_DIE ? kDeathTestLived :
-      reason == TEST_THREW_EXCEPTION ? kDeathTestThrew : kDeathTestReturned;
-
-  GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Write(write_fd(), &status_ch, 1));
-  // We are leaking the descriptor here because on some platforms (i.e.,
-  // when built as Windows DLL), destructors of global objects will still
-  // run after calling _exit(). On such systems, write_fd_ will be
-  // indirectly closed from the destructor of UnitTestImpl, causing double
-  // close if it is also closed here. On debug configurations, double close
-  // may assert. As there are no in-process buffers to flush here, we are
-  // relying on the OS to close the descriptor after the process terminates
-  // when the destructors are not run.
-  _exit(1);  // Exits w/o any normal exit hooks (we were supposed to crash)
-}
-
-// Returns an indented copy of stderr output for a death test.
-// This makes distinguishing death test output lines from regular log lines
-// much easier.
-static ::std::string FormatDeathTestOutput(const ::std::string& output) {
-  ::std::string ret;
-  for (size_t at = 0; ; ) {
-    const size_t line_end = output.find('\n', at);
-    ret += "[  DEATH   ] ";
-    if (line_end == ::std::string::npos) {
-      ret += output.substr(at);
-      break;
-    }
-    ret += output.substr(at, line_end + 1 - at);
-    at = line_end + 1;
-  }
-  return ret;
-}
-
-// Assesses the success or failure of a death test, using both private
-// members which have previously been set, and one argument:
-//
-// Private data members:
-//   outcome:  An enumeration describing how the death test
-//             concluded: DIED, LIVED, THREW, or RETURNED.  The death test
-//             fails in the latter three cases.
-//   status:   The exit status of the child process. On *nix, it is in the
-//             in the format specified by wait(2). On Windows, this is the
-//             value supplied to the ExitProcess() API or a numeric code
-//             of the exception that terminated the program.
-//   matcher_: A matcher that's expected to match the stderr output by the child
-//             process.
-//
-// Argument:
-//   status_ok: true if exit_status is acceptable in the context of
-//              this particular death test, which fails if it is false
-//
-// Returns true if and only if all of the above conditions are met.  Otherwise,
-// the first failing condition, in the order given above, is the one that is
-// reported. Also sets the last death test message string.
-bool DeathTestImpl::Passed(bool status_ok) {
-  if (!spawned())
-    return false;
-
-  const std::string error_message = GetErrorLogs();
-
-  bool success = false;
-  Message buffer;
-
-  buffer << "Death test: " << statement() << "\n";
-  switch (outcome()) {
-    case LIVED:
-      buffer << "    Result: failed to die.\n"
-             << " Error msg:\n" << FormatDeathTestOutput(error_message);
-      break;
-    case THREW:
-      buffer << "    Result: threw an exception.\n"
-             << " Error msg:\n" << FormatDeathTestOutput(error_message);
-      break;
-    case RETURNED:
-      buffer << "    Result: illegal return in test statement.\n"
-             << " Error msg:\n" << FormatDeathTestOutput(error_message);
-      break;
-    case DIED:
-      if (status_ok) {
-        if (matcher_.Matches(error_message)) {
-          success = true;
-        } else {
-          std::ostringstream stream;
-          matcher_.DescribeTo(&stream);
-          buffer << "    Result: died but not with expected error.\n"
-                 << "  Expected: " << stream.str() << "\n"
-                 << "Actual msg:\n"
-                 << FormatDeathTestOutput(error_message);
-        }
-      } else {
-        buffer << "    Result: died but not with expected exit code:\n"
-               << "            " << ExitSummary(status()) << "\n"
-               << "Actual msg:\n" << FormatDeathTestOutput(error_message);
-      }
-      break;
-    case IN_PROGRESS:
-    default:
-      GTEST_LOG_(FATAL)
-          << "DeathTest::Passed somehow called before conclusion of test";
-  }
-
-  DeathTest::set_last_death_test_message(buffer.GetString());
-  return success;
-}
-
-# if GTEST_OS_WINDOWS
-// WindowsDeathTest implements death tests on Windows. Due to the
-// specifics of starting new processes on Windows, death tests there are
-// always threadsafe, and Google Test considers the
-// --gtest_death_test_style=fast setting to be equivalent to
-// --gtest_death_test_style=threadsafe there.
-//
-// A few implementation notes:  Like the Linux version, the Windows
-// implementation uses pipes for child-to-parent communication. But due to
-// the specifics of pipes on Windows, some extra steps are required:
-//
-// 1. The parent creates a communication pipe and stores handles to both
-//    ends of it.
-// 2. The parent starts the child and provides it with the information
-//    necessary to acquire the handle to the write end of the pipe.
-// 3. The child acquires the write end of the pipe and signals the parent
-//    using a Windows event.
-// 4. Now the parent can release the write end of the pipe on its side. If
-//    this is done before step 3, the object's reference count goes down to
-//    0 and it is destroyed, preventing the child from acquiring it. The
-//    parent now has to release it, or read operations on the read end of
-//    the pipe will not return when the child terminates.
-// 5. The parent reads child's output through the pipe (outcome code and
-//    any possible error messages) from the pipe, and its stderr and then
-//    determines whether to fail the test.
-//
-// Note: to distinguish Win32 API calls from the local method and function
-// calls, the former are explicitly resolved in the global namespace.
-//
-class WindowsDeathTest : public DeathTestImpl {
- public:
-  WindowsDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
-                   const char* file, int line)
-      : DeathTestImpl(a_statement, std::move(matcher)),
-        file_(file),
-        line_(line) {}
-
-  // All of these virtual functions are inherited from DeathTest.
-  virtual int Wait();
-  virtual TestRole AssumeRole();
-
- private:
-  // The name of the file in which the death test is located.
-  const char* const file_;
-  // The line number on which the death test is located.
-  const int line_;
-  // Handle to the write end of the pipe to the child process.
-  AutoHandle write_handle_;
-  // Child process handle.
-  AutoHandle child_handle_;
-  // Event the child process uses to signal the parent that it has
-  // acquired the handle to the write end of the pipe. After seeing this
-  // event the parent can release its own handles to make sure its
-  // ReadFile() calls return when the child terminates.
-  AutoHandle event_handle_;
-};
-
-// Waits for the child in a death test to exit, returning its exit
-// status, or 0 if no child process exists.  As a side effect, sets the
-// outcome data member.
-int WindowsDeathTest::Wait() {
-  if (!spawned())
-    return 0;
-
-  // Wait until the child either signals that it has acquired the write end
-  // of the pipe or it dies.
-  const HANDLE wait_handles[2] = { child_handle_.Get(), event_handle_.Get() };
-  switch (::WaitForMultipleObjects(2,
-                                   wait_handles,
-                                   FALSE,  // Waits for any of the handles.
-                                   INFINITE)) {
-    case WAIT_OBJECT_0:
-    case WAIT_OBJECT_0 + 1:
-      break;
-    default:
-      GTEST_DEATH_TEST_CHECK_(false);  // Should not get here.
-  }
-
-  // The child has acquired the write end of the pipe or exited.
-  // We release the handle on our side and continue.
-  write_handle_.Reset();
-  event_handle_.Reset();
-
-  ReadAndInterpretStatusByte();
-
-  // Waits for the child process to exit if it haven't already. This
-  // returns immediately if the child has already exited, regardless of
-  // whether previous calls to WaitForMultipleObjects synchronized on this
-  // handle or not.
-  GTEST_DEATH_TEST_CHECK_(
-      WAIT_OBJECT_0 == ::WaitForSingleObject(child_handle_.Get(),
-                                             INFINITE));
-  DWORD status_code;
-  GTEST_DEATH_TEST_CHECK_(
-      ::GetExitCodeProcess(child_handle_.Get(), &status_code) != FALSE);
-  child_handle_.Reset();
-  set_status(static_cast<int>(status_code));
-  return status();
-}
-
-// The AssumeRole process for a Windows death test.  It creates a child
-// process with the same executable as the current process to run the
-// death test.  The child process is given the --gtest_filter and
-// --gtest_internal_run_death_test flags such that it knows to run the
-// current death test only.
-DeathTest::TestRole WindowsDeathTest::AssumeRole() {
-  const UnitTestImpl* const impl = GetUnitTestImpl();
-  const InternalRunDeathTestFlag* const flag =
-      impl->internal_run_death_test_flag();
-  const TestInfo* const info = impl->current_test_info();
-  const int death_test_index = info->result()->death_test_count();
-
-  if (flag != nullptr) {
-    // ParseInternalRunDeathTestFlag() has performed all the necessary
-    // processing.
-    set_write_fd(flag->write_fd());
-    return EXECUTE_TEST;
-  }
-
-  // WindowsDeathTest uses an anonymous pipe to communicate results of
-  // a death test.
-  SECURITY_ATTRIBUTES handles_are_inheritable = {sizeof(SECURITY_ATTRIBUTES),
-                                                 nullptr, TRUE};
-  HANDLE read_handle, write_handle;
-  GTEST_DEATH_TEST_CHECK_(
-      ::CreatePipe(&read_handle, &write_handle, &handles_are_inheritable,
-                   0)  // Default buffer size.
-      != FALSE);
-  set_read_fd(::_open_osfhandle(reinterpret_cast<intptr_t>(read_handle),
-                                O_RDONLY));
-  write_handle_.Reset(write_handle);
-  event_handle_.Reset(::CreateEvent(
-      &handles_are_inheritable,
-      TRUE,       // The event will automatically reset to non-signaled state.
-      FALSE,      // The initial state is non-signalled.
-      nullptr));  // The even is unnamed.
-  GTEST_DEATH_TEST_CHECK_(event_handle_.Get() != nullptr);
-  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
-                                  kFilterFlag + "=" + info->test_suite_name() +
-                                  "." + info->name();
-  const std::string internal_flag =
-      std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag +
-      "=" + file_ + "|" + StreamableToString(line_) + "|" +
-      StreamableToString(death_test_index) + "|" +
-      StreamableToString(static_cast<unsigned int>(::GetCurrentProcessId())) +
-      // size_t has the same width as pointers on both 32-bit and 64-bit
-      // Windows platforms.
-      // See http://msdn.microsoft.com/en-us/library/tcxf1dw6.aspx.
-      "|" + StreamableToString(reinterpret_cast<size_t>(write_handle)) +
-      "|" + StreamableToString(reinterpret_cast<size_t>(event_handle_.Get()));
-
-  char executable_path[_MAX_PATH + 1];  // NOLINT
-  GTEST_DEATH_TEST_CHECK_(_MAX_PATH + 1 != ::GetModuleFileNameA(nullptr,
-                                                                executable_path,
-                                                                _MAX_PATH));
-
-  std::string command_line =
-      std::string(::GetCommandLineA()) + " " + filter_flag + " \"" +
-      internal_flag + "\"";
-
-  DeathTest::set_last_death_test_message("");
-
-  CaptureStderr();
-  // Flush the log buffers since the log streams are shared with the child.
-  FlushInfoLog();
-
-  // The child process will share the standard handles with the parent.
-  STARTUPINFOA startup_info;
-  memset(&startup_info, 0, sizeof(STARTUPINFO));
-  startup_info.dwFlags = STARTF_USESTDHANDLES;
-  startup_info.hStdInput = ::GetStdHandle(STD_INPUT_HANDLE);
-  startup_info.hStdOutput = ::GetStdHandle(STD_OUTPUT_HANDLE);
-  startup_info.hStdError = ::GetStdHandle(STD_ERROR_HANDLE);
-
-  PROCESS_INFORMATION process_info;
-  GTEST_DEATH_TEST_CHECK_(
-      ::CreateProcessA(
-          executable_path, const_cast<char*>(command_line.c_str()),
-          nullptr,  // Retuned process handle is not inheritable.
-          nullptr,  // Retuned thread handle is not inheritable.
-          TRUE,  // Child inherits all inheritable handles (for write_handle_).
-          0x0,   // Default creation flags.
-          nullptr,  // Inherit the parent's environment.
-          UnitTest::GetInstance()->original_working_dir(), &startup_info,
-          &process_info) != FALSE);
-  child_handle_.Reset(process_info.hProcess);
-  ::CloseHandle(process_info.hThread);
-  set_spawned(true);
-  return OVERSEE_TEST;
-}
-
-# elif GTEST_OS_FUCHSIA
-
-class FuchsiaDeathTest : public DeathTestImpl {
- public:
-  FuchsiaDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
-                   const char* file, int line)
-      : DeathTestImpl(a_statement, std::move(matcher)),
-        file_(file),
-        line_(line) {}
-
-  // All of these virtual functions are inherited from DeathTest.
-  int Wait() override;
-  TestRole AssumeRole() override;
-  std::string GetErrorLogs() override;
-
- private:
-  // The name of the file in which the death test is located.
-  const char* const file_;
-  // The line number on which the death test is located.
-  const int line_;
-  // The stderr data captured by the child process.
-  std::string captured_stderr_;
-
-  zx::process child_process_;
-  zx::channel exception_channel_;
-  zx::socket stderr_socket_;
-};
-
-// Utility class for accumulating command-line arguments.
-class Arguments {
- public:
-  Arguments() { args_.push_back(nullptr); }
-
-  ~Arguments() {
-    for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
-         ++i) {
-      free(*i);
-    }
-  }
-  void AddArgument(const char* argument) {
-    args_.insert(args_.end() - 1, posix::StrDup(argument));
-  }
-
-  template <typename Str>
-  void AddArguments(const ::std::vector<Str>& arguments) {
-    for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
-         i != arguments.end();
-         ++i) {
-      args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
-    }
-  }
-  char* const* Argv() {
-    return &args_[0];
-  }
-
-  int size() {
-    return static_cast<int>(args_.size()) - 1;
-  }
-
- private:
-  std::vector<char*> args_;
-};
-
-// Waits for the child in a death test to exit, returning its exit
-// status, or 0 if no child process exists.  As a side effect, sets the
-// outcome data member.
-int FuchsiaDeathTest::Wait() {
-  const int kProcessKey = 0;
-  const int kSocketKey = 1;
-  const int kExceptionKey = 2;
-
-  if (!spawned())
-    return 0;
-
-  // Create a port to wait for socket/task/exception events.
-  zx_status_t status_zx;
-  zx::port port;
-  status_zx = zx::port::create(0, &port);
-  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
-
-  // Register to wait for the child process to terminate.
-  status_zx = child_process_.wait_async(
-      port, kProcessKey, ZX_PROCESS_TERMINATED, 0);
-  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
-
-  // Register to wait for the socket to be readable or closed.
-  status_zx = stderr_socket_.wait_async(
-      port, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED, 0);
-  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
-
-  // Register to wait for an exception.
-  status_zx = exception_channel_.wait_async(
-      port, kExceptionKey, ZX_CHANNEL_READABLE, 0);
-  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
-
-  bool process_terminated = false;
-  bool socket_closed = false;
-  do {
-    zx_port_packet_t packet = {};
-    status_zx = port.wait(zx::time::infinite(), &packet);
-    GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
-
-    if (packet.key == kExceptionKey) {
-      // Process encountered an exception. Kill it directly rather than
-      // letting other handlers process the event. We will get a kProcessKey
-      // event when the process actually terminates.
-      status_zx = child_process_.kill();
-      GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
-    } else if (packet.key == kProcessKey) {
-      // Process terminated.
-      GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
-      GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_PROCESS_TERMINATED);
-      process_terminated = true;
-    } else if (packet.key == kSocketKey) {
-      GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
-      if (packet.signal.observed & ZX_SOCKET_READABLE) {
-        // Read data from the socket.
-        constexpr size_t kBufferSize = 1024;
-        do {
-          size_t old_length = captured_stderr_.length();
-          size_t bytes_read = 0;
-          captured_stderr_.resize(old_length + kBufferSize);
-          status_zx = stderr_socket_.read(
-              0, &captured_stderr_.front() + old_length, kBufferSize,
-              &bytes_read);
-          captured_stderr_.resize(old_length + bytes_read);
-        } while (status_zx == ZX_OK);
-        if (status_zx == ZX_ERR_PEER_CLOSED) {
-          socket_closed = true;
-        } else {
-          GTEST_DEATH_TEST_CHECK_(status_zx == ZX_ERR_SHOULD_WAIT);
-          status_zx = stderr_socket_.wait_async(
-              port, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED, 0);
-          GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
-        }
-      } else {
-        GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_SOCKET_PEER_CLOSED);
-        socket_closed = true;
-      }
-    }
-  } while (!process_terminated && !socket_closed);
-
-  ReadAndInterpretStatusByte();
-
-  zx_info_process_t buffer;
-  status_zx = child_process_.get_info(ZX_INFO_PROCESS, &buffer, sizeof(buffer),
-                                      nullptr, nullptr);
-  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
-
-  GTEST_DEATH_TEST_CHECK_(buffer.flags & ZX_INFO_PROCESS_FLAG_EXITED);
-  set_status(static_cast<int>(buffer.return_code));
-  return status();
-}
-
-// The AssumeRole process for a Fuchsia death test.  It creates a child
-// process with the same executable as the current process to run the
-// death test.  The child process is given the --gtest_filter and
-// --gtest_internal_run_death_test flags such that it knows to run the
-// current death test only.
-DeathTest::TestRole FuchsiaDeathTest::AssumeRole() {
-  const UnitTestImpl* const impl = GetUnitTestImpl();
-  const InternalRunDeathTestFlag* const flag =
-      impl->internal_run_death_test_flag();
-  const TestInfo* const info = impl->current_test_info();
-  const int death_test_index = info->result()->death_test_count();
-
-  if (flag != nullptr) {
-    // ParseInternalRunDeathTestFlag() has performed all the necessary
-    // processing.
-    set_write_fd(kFuchsiaReadPipeFd);
-    return EXECUTE_TEST;
-  }
-
-  // Flush the log buffers since the log streams are shared with the child.
-  FlushInfoLog();
-
-  // Build the child process command line.
-  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
-                                  kFilterFlag + "=" + info->test_suite_name() +
-                                  "." + info->name();
-  const std::string internal_flag =
-      std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag + "="
-      + file_ + "|"
-      + StreamableToString(line_) + "|"
-      + StreamableToString(death_test_index);
-  Arguments args;
-  args.AddArguments(GetInjectableArgvs());
-  args.AddArgument(filter_flag.c_str());
-  args.AddArgument(internal_flag.c_str());
-
-  // Build the pipe for communication with the child.
-  zx_status_t status;
-  zx_handle_t child_pipe_handle;
-  int child_pipe_fd;
-  status = fdio_pipe_half(&child_pipe_fd, &child_pipe_handle);
-  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
-  set_read_fd(child_pipe_fd);
-
-  // Set the pipe handle for the child.
-  fdio_spawn_action_t spawn_actions[2] = {};
-  fdio_spawn_action_t* add_handle_action = &spawn_actions[0];
-  add_handle_action->action = FDIO_SPAWN_ACTION_ADD_HANDLE;
-  add_handle_action->h.id = PA_HND(PA_FD, kFuchsiaReadPipeFd);
-  add_handle_action->h.handle = child_pipe_handle;
-
-  // Create a socket pair will be used to receive the child process' stderr.
-  zx::socket stderr_producer_socket;
-  status =
-      zx::socket::create(0, &stderr_producer_socket, &stderr_socket_);
-  GTEST_DEATH_TEST_CHECK_(status >= 0);
-  int stderr_producer_fd = -1;
-  status =
-      fdio_fd_create(stderr_producer_socket.release(), &stderr_producer_fd);
-  GTEST_DEATH_TEST_CHECK_(status >= 0);
-
-  // Make the stderr socket nonblocking.
-  GTEST_DEATH_TEST_CHECK_(fcntl(stderr_producer_fd, F_SETFL, 0) == 0);
-
-  fdio_spawn_action_t* add_stderr_action = &spawn_actions[1];
-  add_stderr_action->action = FDIO_SPAWN_ACTION_CLONE_FD;
-  add_stderr_action->fd.local_fd = stderr_producer_fd;
-  add_stderr_action->fd.target_fd = STDERR_FILENO;
-
-  // Create a child job.
-  zx_handle_t child_job = ZX_HANDLE_INVALID;
-  status = zx_job_create(zx_job_default(), 0, & child_job);
-  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
-  zx_policy_basic_t policy;
-  policy.condition = ZX_POL_NEW_ANY;
-  policy.policy = ZX_POL_ACTION_ALLOW;
-  status = zx_job_set_policy(
-      child_job, ZX_JOB_POL_RELATIVE, ZX_JOB_POL_BASIC, &policy, 1);
-  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
-
-  // Create an exception channel attached to the |child_job|, to allow
-  // us to suppress the system default exception handler from firing.
-  status =
-      zx_task_create_exception_channel(
-          child_job, 0, exception_channel_.reset_and_get_address());
-  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
-
-  // Spawn the child process.
-  status = fdio_spawn_etc(
-      child_job, FDIO_SPAWN_CLONE_ALL, args.Argv()[0], args.Argv(), nullptr,
-      2, spawn_actions, child_process_.reset_and_get_address(), nullptr);
-  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
-
-  set_spawned(true);
-  return OVERSEE_TEST;
-}
-
-std::string FuchsiaDeathTest::GetErrorLogs() {
-  return captured_stderr_;
-}
-
-#else  // We are neither on Windows, nor on Fuchsia.
-
-// ForkingDeathTest provides implementations for most of the abstract
-// methods of the DeathTest interface.  Only the AssumeRole method is
-// left undefined.
-class ForkingDeathTest : public DeathTestImpl {
- public:
-  ForkingDeathTest(const char* statement, Matcher<const std::string&> matcher);
-
-  // All of these virtual functions are inherited from DeathTest.
-  int Wait() override;
-
- protected:
-  void set_child_pid(pid_t child_pid) { child_pid_ = child_pid; }
-
- private:
-  // PID of child process during death test; 0 in the child process itself.
-  pid_t child_pid_;
-};
-
-// Constructs a ForkingDeathTest.
-ForkingDeathTest::ForkingDeathTest(const char* a_statement,
-                                   Matcher<const std::string&> matcher)
-    : DeathTestImpl(a_statement, std::move(matcher)), child_pid_(-1) {}
-
-// Waits for the child in a death test to exit, returning its exit
-// status, or 0 if no child process exists.  As a side effect, sets the
-// outcome data member.
-int ForkingDeathTest::Wait() {
-  if (!spawned())
-    return 0;
-
-  ReadAndInterpretStatusByte();
-
-  int status_value;
-  GTEST_DEATH_TEST_CHECK_SYSCALL_(waitpid(child_pid_, &status_value, 0));
-  set_status(status_value);
-  return status_value;
-}
-
-// A concrete death test class that forks, then immediately runs the test
-// in the child process.
-class NoExecDeathTest : public ForkingDeathTest {
- public:
-  NoExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher)
-      : ForkingDeathTest(a_statement, std::move(matcher)) {}
-  TestRole AssumeRole() override;
-};
-
-// The AssumeRole process for a fork-and-run death test.  It implements a
-// straightforward fork, with a simple pipe to transmit the status byte.
-DeathTest::TestRole NoExecDeathTest::AssumeRole() {
-  const size_t thread_count = GetThreadCount();
-  if (thread_count != 1) {
-    GTEST_LOG_(WARNING) << DeathTestThreadWarning(thread_count);
-  }
-
-  int pipe_fd[2];
-  GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
-
-  DeathTest::set_last_death_test_message("");
-  CaptureStderr();
-  // When we fork the process below, the log file buffers are copied, but the
-  // file descriptors are shared.  We flush all log files here so that closing
-  // the file descriptors in the child process doesn't throw off the
-  // synchronization between descriptors and buffers in the parent process.
-  // This is as close to the fork as possible to avoid a race condition in case
-  // there are multiple threads running before the death test, and another
-  // thread writes to the log file.
-  FlushInfoLog();
-
-  const pid_t child_pid = fork();
-  GTEST_DEATH_TEST_CHECK_(child_pid != -1);
-  set_child_pid(child_pid);
-  if (child_pid == 0) {
-    GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[0]));
-    set_write_fd(pipe_fd[1]);
-    // Redirects all logging to stderr in the child process to prevent
-    // concurrent writes to the log files.  We capture stderr in the parent
-    // process and append the child process' output to a log.
-    LogToStderr();
-    // Event forwarding to the listeners of event listener API mush be shut
-    // down in death test subprocesses.
-    GetUnitTestImpl()->listeners()->SuppressEventForwarding();
-    g_in_fast_death_test_child = true;
-    return EXECUTE_TEST;
-  } else {
-    GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
-    set_read_fd(pipe_fd[0]);
-    set_spawned(true);
-    return OVERSEE_TEST;
-  }
-}
-
-// A concrete death test class that forks and re-executes the main
-// program from the beginning, with command-line flags set that cause
-// only this specific death test to be run.
-class ExecDeathTest : public ForkingDeathTest {
- public:
-  ExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
-                const char* file, int line)
-      : ForkingDeathTest(a_statement, std::move(matcher)),
-        file_(file),
-        line_(line) {}
-  TestRole AssumeRole() override;
-
- private:
-  static ::std::vector<std::string> GetArgvsForDeathTestChildProcess() {
-    ::std::vector<std::string> args = GetInjectableArgvs();
-#  if defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
-    ::std::vector<std::string> extra_args =
-        GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_();
-    args.insert(args.end(), extra_args.begin(), extra_args.end());
-#  endif  // defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
-    return args;
-  }
-  // The name of the file in which the death test is located.
-  const char* const file_;
-  // The line number on which the death test is located.
-  const int line_;
-};
-
-// Utility class for accumulating command-line arguments.
-class Arguments {
- public:
-  Arguments() { args_.push_back(nullptr); }
-
-  ~Arguments() {
-    for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
-         ++i) {
-      free(*i);
-    }
-  }
-  void AddArgument(const char* argument) {
-    args_.insert(args_.end() - 1, posix::StrDup(argument));
-  }
-
-  template <typename Str>
-  void AddArguments(const ::std::vector<Str>& arguments) {
-    for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
-         i != arguments.end();
-         ++i) {
-      args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
-    }
-  }
-  char* const* Argv() {
-    return &args_[0];
-  }
-
- private:
-  std::vector<char*> args_;
-};
-
-// A struct that encompasses the arguments to the child process of a
-// threadsafe-style death test process.
-struct ExecDeathTestArgs {
-  char* const* argv;  // Command-line arguments for the child's call to exec
-  int close_fd;       // File descriptor to close; the read end of a pipe
-};
-
-#  if GTEST_OS_QNX
-extern "C" char** environ;
-#  else  // GTEST_OS_QNX
-// The main function for a threadsafe-style death test child process.
-// This function is called in a clone()-ed process and thus must avoid
-// any potentially unsafe operations like malloc or libc functions.
-static int ExecDeathTestChildMain(void* child_arg) {
-  ExecDeathTestArgs* const args = static_cast<ExecDeathTestArgs*>(child_arg);
-  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(args->close_fd));
-
-  // We need to execute the test program in the same environment where
-  // it was originally invoked.  Therefore we change to the original
-  // working directory first.
-  const char* const original_dir =
-      UnitTest::GetInstance()->original_working_dir();
-  // We can safely call chdir() as it's a direct system call.
-  if (chdir(original_dir) != 0) {
-    DeathTestAbort(std::string("chdir(\"") + original_dir + "\") failed: " +
-                   GetLastErrnoDescription());
-    return EXIT_FAILURE;
-  }
-
-  // We can safely call execv() as it's almost a direct system call. We
-  // cannot use execvp() as it's a libc function and thus potentially
-  // unsafe.  Since execv() doesn't search the PATH, the user must
-  // invoke the test program via a valid path that contains at least
-  // one path separator.
-  execv(args->argv[0], args->argv);
-  DeathTestAbort(std::string("execv(") + args->argv[0] + ", ...) in " +
-                 original_dir + " failed: " +
-                 GetLastErrnoDescription());
-  return EXIT_FAILURE;
-}
-#  endif  // GTEST_OS_QNX
-
-#  if GTEST_HAS_CLONE
-// Two utility routines that together determine the direction the stack
-// grows.
-// This could be accomplished more elegantly by a single recursive
-// function, but we want to guard against the unlikely possibility of
-// a smart compiler optimizing the recursion away.
-//
-// GTEST_NO_INLINE_ is required to prevent GCC 4.6 from inlining
-// StackLowerThanAddress into StackGrowsDown, which then doesn't give
-// correct answer.
-static void StackLowerThanAddress(const void* ptr,
-                                  bool* result) GTEST_NO_INLINE_;
-// Make sure sanitizers do not tamper with the stack here.
-// Ideally, we want to use `__builtin_frame_address` instead of a local variable
-// address with sanitizer disabled, but it does not work when the
-// compiler optimizes the stack frame out, which happens on PowerPC targets.
-// HWAddressSanitizer add a random tag to the MSB of the local variable address,
-// making comparison result unpredictable.
-GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
-GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
-static void StackLowerThanAddress(const void* ptr, bool* result) {
-  int dummy = 0;
-  *result = std::less<const void*>()(&dummy, ptr);
-}
-
-// Make sure AddressSanitizer does not tamper with the stack here.
-GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
-GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
-static bool StackGrowsDown() {
-  int dummy = 0;
-  bool result;
-  StackLowerThanAddress(&dummy, &result);
-  return result;
-}
-#  endif  // GTEST_HAS_CLONE
-
-// Spawns a child process with the same executable as the current process in
-// a thread-safe manner and instructs it to run the death test.  The
-// implementation uses fork(2) + exec.  On systems where clone(2) is
-// available, it is used instead, being slightly more thread-safe.  On QNX,
-// fork supports only single-threaded environments, so this function uses
-// spawn(2) there instead.  The function dies with an error message if
-// anything goes wrong.
-static pid_t ExecDeathTestSpawnChild(char* const* argv, int close_fd) {
-  ExecDeathTestArgs args = { argv, close_fd };
-  pid_t child_pid = -1;
-
-#  if GTEST_OS_QNX
-  // Obtains the current directory and sets it to be closed in the child
-  // process.
-  const int cwd_fd = open(".", O_RDONLY);
-  GTEST_DEATH_TEST_CHECK_(cwd_fd != -1);
-  GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(cwd_fd, F_SETFD, FD_CLOEXEC));
-  // We need to execute the test program in the same environment where
-  // it was originally invoked.  Therefore we change to the original
-  // working directory first.
-  const char* const original_dir =
-      UnitTest::GetInstance()->original_working_dir();
-  // We can safely call chdir() as it's a direct system call.
-  if (chdir(original_dir) != 0) {
-    DeathTestAbort(std::string("chdir(\"") + original_dir + "\") failed: " +
-                   GetLastErrnoDescription());
-    return EXIT_FAILURE;
-  }
-
-  int fd_flags;
-  // Set close_fd to be closed after spawn.
-  GTEST_DEATH_TEST_CHECK_SYSCALL_(fd_flags = fcntl(close_fd, F_GETFD));
-  GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(close_fd, F_SETFD,
-                                        fd_flags | FD_CLOEXEC));
-  struct inheritance inherit = {0};
-  // spawn is a system call.
-  child_pid = spawn(args.argv[0], 0, nullptr, &inherit, args.argv, environ);
-  // Restores the current working directory.
-  GTEST_DEATH_TEST_CHECK_(fchdir(cwd_fd) != -1);
-  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(cwd_fd));
-
-#  else   // GTEST_OS_QNX
-#   if GTEST_OS_LINUX
-  // When a SIGPROF signal is received while fork() or clone() are executing,
-  // the process may hang. To avoid this, we ignore SIGPROF here and re-enable
-  // it after the call to fork()/clone() is complete.
-  struct sigaction saved_sigprof_action;
-  struct sigaction ignore_sigprof_action;
-  memset(&ignore_sigprof_action, 0, sizeof(ignore_sigprof_action));
-  sigemptyset(&ignore_sigprof_action.sa_mask);
-  ignore_sigprof_action.sa_handler = SIG_IGN;
-  GTEST_DEATH_TEST_CHECK_SYSCALL_(sigaction(
-      SIGPROF, &ignore_sigprof_action, &saved_sigprof_action));
-#   endif  // GTEST_OS_LINUX
-
-#   if GTEST_HAS_CLONE
-  const bool use_fork = GTEST_FLAG(death_test_use_fork);
-
-  if (!use_fork) {
-    static const bool stack_grows_down = StackGrowsDown();
-    const auto stack_size = static_cast<size_t>(getpagesize() * 2);
-    // MMAP_ANONYMOUS is not defined on Mac, so we use MAP_ANON instead.
-    void* const stack = mmap(nullptr, stack_size, PROT_READ | PROT_WRITE,
-                             MAP_ANON | MAP_PRIVATE, -1, 0);
-    GTEST_DEATH_TEST_CHECK_(stack != MAP_FAILED);
-
-    // Maximum stack alignment in bytes:  For a downward-growing stack, this
-    // amount is subtracted from size of the stack space to get an address
-    // that is within the stack space and is aligned on all systems we care
-    // about.  As far as I know there is no ABI with stack alignment greater
-    // than 64.  We assume stack and stack_size already have alignment of
-    // kMaxStackAlignment.
-    const size_t kMaxStackAlignment = 64;
-    void* const stack_top =
-        static_cast<char*>(stack) +
-            (stack_grows_down ? stack_size - kMaxStackAlignment : 0);
-    GTEST_DEATH_TEST_CHECK_(
-        static_cast<size_t>(stack_size) > kMaxStackAlignment &&
-        reinterpret_cast<uintptr_t>(stack_top) % kMaxStackAlignment == 0);
-
-    child_pid = clone(&ExecDeathTestChildMain, stack_top, SIGCHLD, &args);
-
-    GTEST_DEATH_TEST_CHECK_(munmap(stack, stack_size) != -1);
-  }
-#   else
-  const bool use_fork = true;
-#   endif  // GTEST_HAS_CLONE
-
-  if (use_fork && (child_pid = fork()) == 0) {
-      ExecDeathTestChildMain(&args);
-      _exit(0);
-  }
-#  endif  // GTEST_OS_QNX
-#  if GTEST_OS_LINUX
-  GTEST_DEATH_TEST_CHECK_SYSCALL_(
-      sigaction(SIGPROF, &saved_sigprof_action, nullptr));
-#  endif  // GTEST_OS_LINUX
-
-  GTEST_DEATH_TEST_CHECK_(child_pid != -1);
-  return child_pid;
-}
-
-// The AssumeRole process for a fork-and-exec death test.  It re-executes the
-// main program from the beginning, setting the --gtest_filter
-// and --gtest_internal_run_death_test flags to cause only the current
-// death test to be re-run.
-DeathTest::TestRole ExecDeathTest::AssumeRole() {
-  const UnitTestImpl* const impl = GetUnitTestImpl();
-  const InternalRunDeathTestFlag* const flag =
-      impl->internal_run_death_test_flag();
-  const TestInfo* const info = impl->current_test_info();
-  const int death_test_index = info->result()->death_test_count();
-
-  if (flag != nullptr) {
-    set_write_fd(flag->write_fd());
-    return EXECUTE_TEST;
-  }
-
-  int pipe_fd[2];
-  GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
-  // Clear the close-on-exec flag on the write end of the pipe, lest
-  // it be closed when the child process does an exec:
-  GTEST_DEATH_TEST_CHECK_(fcntl(pipe_fd[1], F_SETFD, 0) != -1);
-
-  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
-                                  kFilterFlag + "=" + info->test_suite_name() +
-                                  "." + info->name();
-  const std::string internal_flag =
-      std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag + "="
-      + file_ + "|" + StreamableToString(line_) + "|"
-      + StreamableToString(death_test_index) + "|"
-      + StreamableToString(pipe_fd[1]);
-  Arguments args;
-  args.AddArguments(GetArgvsForDeathTestChildProcess());
-  args.AddArgument(filter_flag.c_str());
-  args.AddArgument(internal_flag.c_str());
-
-  DeathTest::set_last_death_test_message("");
-
-  CaptureStderr();
-  // See the comment in NoExecDeathTest::AssumeRole for why the next line
-  // is necessary.
-  FlushInfoLog();
-
-  const pid_t child_pid = ExecDeathTestSpawnChild(args.Argv(), pipe_fd[0]);
-  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
-  set_child_pid(child_pid);
-  set_read_fd(pipe_fd[0]);
-  set_spawned(true);
-  return OVERSEE_TEST;
-}
-
-# endif  // !GTEST_OS_WINDOWS
-
-// Creates a concrete DeathTest-derived class that depends on the
-// --gtest_death_test_style flag, and sets the pointer pointed to
-// by the "test" argument to its address.  If the test should be
-// skipped, sets that pointer to NULL.  Returns true, unless the
-// flag is set to an invalid value.
-bool DefaultDeathTestFactory::Create(const char* statement,
-                                     Matcher<const std::string&> matcher,
-                                     const char* file, int line,
-                                     DeathTest** test) {
-  UnitTestImpl* const impl = GetUnitTestImpl();
-  const InternalRunDeathTestFlag* const flag =
-      impl->internal_run_death_test_flag();
-  const int death_test_index = impl->current_test_info()
-      ->increment_death_test_count();
-
-  if (flag != nullptr) {
-    if (death_test_index > flag->index()) {
-      DeathTest::set_last_death_test_message(
-          "Death test count (" + StreamableToString(death_test_index)
-          + ") somehow exceeded expected maximum ("
-          + StreamableToString(flag->index()) + ")");
-      return false;
-    }
-
-    if (!(flag->file() == file && flag->line() == line &&
-          flag->index() == death_test_index)) {
-      *test = nullptr;
-      return true;
-    }
-  }
-
-# if GTEST_OS_WINDOWS
-
-  if (GTEST_FLAG(death_test_style) == "threadsafe" ||
-      GTEST_FLAG(death_test_style) == "fast") {
-    *test = new WindowsDeathTest(statement, std::move(matcher), file, line);
-  }
-
-# elif GTEST_OS_FUCHSIA
-
-  if (GTEST_FLAG(death_test_style) == "threadsafe" ||
-      GTEST_FLAG(death_test_style) == "fast") {
-    *test = new FuchsiaDeathTest(statement, std::move(matcher), file, line);
-  }
-
-# else
-
-  if (GTEST_FLAG(death_test_style) == "threadsafe") {
-    *test = new ExecDeathTest(statement, std::move(matcher), file, line);
-  } else if (GTEST_FLAG(death_test_style) == "fast") {
-    *test = new NoExecDeathTest(statement, std::move(matcher));
-  }
-
-# endif  // GTEST_OS_WINDOWS
-
-  else {  // NOLINT - this is more readable than unbalanced brackets inside #if.
-    DeathTest::set_last_death_test_message(
-        "Unknown death test style \"" + GTEST_FLAG(death_test_style)
-        + "\" encountered");
-    return false;
-  }
-
-  return true;
-}
-
-# if GTEST_OS_WINDOWS
-// Recreates the pipe and event handles from the provided parameters,
-// signals the event, and returns a file descriptor wrapped around the pipe
-// handle. This function is called in the child process only.
-static int GetStatusFileDescriptor(unsigned int parent_process_id,
-                            size_t write_handle_as_size_t,
-                            size_t event_handle_as_size_t) {
-  AutoHandle parent_process_handle(::OpenProcess(PROCESS_DUP_HANDLE,
-                                                   FALSE,  // Non-inheritable.
-                                                   parent_process_id));
-  if (parent_process_handle.Get() == INVALID_HANDLE_VALUE) {
-    DeathTestAbort("Unable to open parent process " +
-                   StreamableToString(parent_process_id));
-  }
-
-  GTEST_CHECK_(sizeof(HANDLE) <= sizeof(size_t));
-
-  const HANDLE write_handle =
-      reinterpret_cast<HANDLE>(write_handle_as_size_t);
-  HANDLE dup_write_handle;
-
-  // The newly initialized handle is accessible only in the parent
-  // process. To obtain one accessible within the child, we need to use
-  // DuplicateHandle.
-  if (!::DuplicateHandle(parent_process_handle.Get(), write_handle,
-                         ::GetCurrentProcess(), &dup_write_handle,
-                         0x0,    // Requested privileges ignored since
-                                 // DUPLICATE_SAME_ACCESS is used.
-                         FALSE,  // Request non-inheritable handler.
-                         DUPLICATE_SAME_ACCESS)) {
-    DeathTestAbort("Unable to duplicate the pipe handle " +
-                   StreamableToString(write_handle_as_size_t) +
-                   " from the parent process " +
-                   StreamableToString(parent_process_id));
-  }
-
-  const HANDLE event_handle = reinterpret_cast<HANDLE>(event_handle_as_size_t);
-  HANDLE dup_event_handle;
-
-  if (!::DuplicateHandle(parent_process_handle.Get(), event_handle,
-                         ::GetCurrentProcess(), &dup_event_handle,
-                         0x0,
-                         FALSE,
-                         DUPLICATE_SAME_ACCESS)) {
-    DeathTestAbort("Unable to duplicate the event handle " +
-                   StreamableToString(event_handle_as_size_t) +
-                   " from the parent process " +
-                   StreamableToString(parent_process_id));
-  }
-
-  const int write_fd =
-      ::_open_osfhandle(reinterpret_cast<intptr_t>(dup_write_handle), O_APPEND);
-  if (write_fd == -1) {
-    DeathTestAbort("Unable to convert pipe handle " +
-                   StreamableToString(write_handle_as_size_t) +
-                   " to a file descriptor");
-  }
-
-  // Signals the parent that the write end of the pipe has been acquired
-  // so the parent can release its own write end.
-  ::SetEvent(dup_event_handle);
-
-  return write_fd;
-}
-# endif  // GTEST_OS_WINDOWS
-
-// Returns a newly created InternalRunDeathTestFlag object with fields
-// initialized from the GTEST_FLAG(internal_run_death_test) flag if
-// the flag is specified; otherwise returns NULL.
-InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag() {
-  if (GTEST_FLAG(internal_run_death_test) == "") return nullptr;
-
-  // GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we
-  // can use it here.
-  int line = -1;
-  int index = -1;
-  ::std::vector< ::std::string> fields;
-  SplitString(GTEST_FLAG(internal_run_death_test).c_str(), '|', &fields);
-  int write_fd = -1;
-
-# if GTEST_OS_WINDOWS
-
-  unsigned int parent_process_id = 0;
-  size_t write_handle_as_size_t = 0;
-  size_t event_handle_as_size_t = 0;
-
-  if (fields.size() != 6
-      || !ParseNaturalNumber(fields[1], &line)
-      || !ParseNaturalNumber(fields[2], &index)
-      || !ParseNaturalNumber(fields[3], &parent_process_id)
-      || !ParseNaturalNumber(fields[4], &write_handle_as_size_t)
-      || !ParseNaturalNumber(fields[5], &event_handle_as_size_t)) {
-    DeathTestAbort("Bad --gtest_internal_run_death_test flag: " +
-                   GTEST_FLAG(internal_run_death_test));
-  }
-  write_fd = GetStatusFileDescriptor(parent_process_id,
-                                     write_handle_as_size_t,
-                                     event_handle_as_size_t);
-
-# elif GTEST_OS_FUCHSIA
-
-  if (fields.size() != 3
-      || !ParseNaturalNumber(fields[1], &line)
-      || !ParseNaturalNumber(fields[2], &index)) {
-    DeathTestAbort("Bad --gtest_internal_run_death_test flag: "
-        + GTEST_FLAG(internal_run_death_test));
-  }
-
-# else
-
-  if (fields.size() != 4
-      || !ParseNaturalNumber(fields[1], &line)
-      || !ParseNaturalNumber(fields[2], &index)
-      || !ParseNaturalNumber(fields[3], &write_fd)) {
-    DeathTestAbort("Bad --gtest_internal_run_death_test flag: "
-        + GTEST_FLAG(internal_run_death_test));
-  }
-
-# endif  // GTEST_OS_WINDOWS
-
-  return new InternalRunDeathTestFlag(fields[0], line, index, write_fd);
-}
-
-}  // namespace internal
-
-#endif  // GTEST_HAS_DEATH_TEST
-
-}  // namespace testing
-// Copyright 2008, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-#include <stdlib.h>
-
-#if GTEST_OS_WINDOWS_MOBILE
-# include <windows.h>
-#elif GTEST_OS_WINDOWS
-# include <direct.h>
-# include <io.h>
-#else
-# include <limits.h>
-# include <climits>  // Some Linux distributions define PATH_MAX here.
-#endif  // GTEST_OS_WINDOWS_MOBILE
-
-
-#if GTEST_OS_WINDOWS
-# define GTEST_PATH_MAX_ _MAX_PATH
-#elif defined(PATH_MAX)
-# define GTEST_PATH_MAX_ PATH_MAX
-#elif defined(_XOPEN_PATH_MAX)
-# define GTEST_PATH_MAX_ _XOPEN_PATH_MAX
-#else
-# define GTEST_PATH_MAX_ _POSIX_PATH_MAX
-#endif  // GTEST_OS_WINDOWS
-
-namespace testing {
-namespace internal {
-
-#if GTEST_OS_WINDOWS
-// On Windows, '\\' is the standard path separator, but many tools and the
-// Windows API also accept '/' as an alternate path separator. Unless otherwise
-// noted, a file path can contain either kind of path separators, or a mixture
-// of them.
-const char kPathSeparator = '\\';
-const char kAlternatePathSeparator = '/';
-const char kAlternatePathSeparatorString[] = "/";
-# if GTEST_OS_WINDOWS_MOBILE
-// Windows CE doesn't have a current directory. You should not use
-// the current directory in tests on Windows CE, but this at least
-// provides a reasonable fallback.
-const char kCurrentDirectoryString[] = "\\";
-// Windows CE doesn't define INVALID_FILE_ATTRIBUTES
-const DWORD kInvalidFileAttributes = 0xffffffff;
-# else
-const char kCurrentDirectoryString[] = ".\\";
-# endif  // GTEST_OS_WINDOWS_MOBILE
-#else
-const char kPathSeparator = '/';
-const char kCurrentDirectoryString[] = "./";
-#endif  // GTEST_OS_WINDOWS
-
-// Returns whether the given character is a valid path separator.
-static bool IsPathSeparator(char c) {
-#if GTEST_HAS_ALT_PATH_SEP_
-  return (c == kPathSeparator) || (c == kAlternatePathSeparator);
-#else
-  return c == kPathSeparator;
-#endif
-}
-
-// Returns the current working directory, or "" if unsuccessful.
-FilePath FilePath::GetCurrentDir() {
-#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_PHONE ||         \
-    GTEST_OS_WINDOWS_RT || GTEST_OS_ESP8266 || GTEST_OS_ESP32 || \
-    GTEST_OS_XTENSA
-  // These platforms do not have a current directory, so we just return
-  // something reasonable.
-  return FilePath(kCurrentDirectoryString);
-#elif GTEST_OS_WINDOWS
-  char cwd[GTEST_PATH_MAX_ + 1] = { '\0' };
-  return FilePath(_getcwd(cwd, sizeof(cwd)) == nullptr ? "" : cwd);
-#else
-  char cwd[GTEST_PATH_MAX_ + 1] = { '\0' };
-  char* result = getcwd(cwd, sizeof(cwd));
-# if GTEST_OS_NACL
-  // getcwd will likely fail in NaCl due to the sandbox, so return something
-  // reasonable. The user may have provided a shim implementation for getcwd,
-  // however, so fallback only when failure is detected.
-  return FilePath(result == nullptr ? kCurrentDirectoryString : cwd);
-# endif  // GTEST_OS_NACL
-  return FilePath(result == nullptr ? "" : cwd);
-#endif  // GTEST_OS_WINDOWS_MOBILE
-}
-
-// Returns a copy of the FilePath with the case-insensitive extension removed.
-// Example: FilePath("dir/file.exe").RemoveExtension("EXE") returns
-// FilePath("dir/file"). If a case-insensitive extension is not
-// found, returns a copy of the original FilePath.
-FilePath FilePath::RemoveExtension(const char* extension) const {
-  const std::string dot_extension = std::string(".") + extension;
-  if (String::EndsWithCaseInsensitive(pathname_, dot_extension)) {
-    return FilePath(pathname_.substr(
-        0, pathname_.length() - dot_extension.length()));
-  }
-  return *this;
-}
-
-// Returns a pointer to the last occurrence of a valid path separator in
-// the FilePath. On Windows, for example, both '/' and '\' are valid path
-// separators. Returns NULL if no path separator was found.
-const char* FilePath::FindLastPathSeparator() const {
-  const char* const last_sep = strrchr(c_str(), kPathSeparator);
-#if GTEST_HAS_ALT_PATH_SEP_
-  const char* const last_alt_sep = strrchr(c_str(), kAlternatePathSeparator);
-  // Comparing two pointers of which only one is NULL is undefined.
-  if (last_alt_sep != nullptr &&
-      (last_sep == nullptr || last_alt_sep > last_sep)) {
-    return last_alt_sep;
-  }
-#endif
-  return last_sep;
-}
-
-// Returns a copy of the FilePath with the directory part removed.
-// Example: FilePath("path/to/file").RemoveDirectoryName() returns
-// FilePath("file"). If there is no directory part ("just_a_file"), it returns
-// the FilePath unmodified. If there is no file part ("just_a_dir/") it
-// returns an empty FilePath ("").
-// On Windows platform, '\' is the path separator, otherwise it is '/'.
-FilePath FilePath::RemoveDirectoryName() const {
-  const char* const last_sep = FindLastPathSeparator();
-  return last_sep ? FilePath(last_sep + 1) : *this;
-}
-
-// RemoveFileName returns the directory path with the filename removed.
-// Example: FilePath("path/to/file").RemoveFileName() returns "path/to/".
-// If the FilePath is "a_file" or "/a_file", RemoveFileName returns
-// FilePath("./") or, on Windows, FilePath(".\\"). If the filepath does
-// not have a file, like "just/a/dir/", it returns the FilePath unmodified.
-// On Windows platform, '\' is the path separator, otherwise it is '/'.
-FilePath FilePath::RemoveFileName() const {
-  const char* const last_sep = FindLastPathSeparator();
-  std::string dir;
-  if (last_sep) {
-    dir = std::string(c_str(), static_cast<size_t>(last_sep + 1 - c_str()));
-  } else {
-    dir = kCurrentDirectoryString;
-  }
-  return FilePath(dir);
-}
-
-// Helper functions for naming files in a directory for xml output.
-
-// Given directory = "dir", base_name = "test", number = 0,
-// extension = "xml", returns "dir/test.xml". If number is greater
-// than zero (e.g., 12), returns "dir/test_12.xml".
-// On Windows platform, uses \ as the separator rather than /.
-FilePath FilePath::MakeFileName(const FilePath& directory,
-                                const FilePath& base_name,
-                                int number,
-                                const char* extension) {
-  std::string file;
-  if (number == 0) {
-    file = base_name.string() + "." + extension;
-  } else {
-    file = base_name.string() + "_" + StreamableToString(number)
-        + "." + extension;
-  }
-  return ConcatPaths(directory, FilePath(file));
-}
-
-// Given directory = "dir", relative_path = "test.xml", returns "dir/test.xml".
-// On Windows, uses \ as the separator rather than /.
-FilePath FilePath::ConcatPaths(const FilePath& directory,
-                               const FilePath& relative_path) {
-  if (directory.IsEmpty())
-    return relative_path;
-  const FilePath dir(directory.RemoveTrailingPathSeparator());
-  return FilePath(dir.string() + kPathSeparator + relative_path.string());
-}
-
-// Returns true if pathname describes something findable in the file-system,
-// either a file, directory, or whatever.
-bool FilePath::FileOrDirectoryExists() const {
-#if GTEST_OS_WINDOWS_MOBILE
-  LPCWSTR unicode = String::AnsiToUtf16(pathname_.c_str());
-  const DWORD attributes = GetFileAttributes(unicode);
-  delete [] unicode;
-  return attributes != kInvalidFileAttributes;
-#else
-  posix::StatStruct file_stat{};
-  return posix::Stat(pathname_.c_str(), &file_stat) == 0;
-#endif  // GTEST_OS_WINDOWS_MOBILE
-}
-
-// Returns true if pathname describes a directory in the file-system
-// that exists.
-bool FilePath::DirectoryExists() const {
-  bool result = false;
-#if GTEST_OS_WINDOWS
-  // Don't strip off trailing separator if path is a root directory on
-  // Windows (like "C:\\").
-  const FilePath& path(IsRootDirectory() ? *this :
-                                           RemoveTrailingPathSeparator());
-#else
-  const FilePath& path(*this);
-#endif
-
-#if GTEST_OS_WINDOWS_MOBILE
-  LPCWSTR unicode = String::AnsiToUtf16(path.c_str());
-  const DWORD attributes = GetFileAttributes(unicode);
-  delete [] unicode;
-  if ((attributes != kInvalidFileAttributes) &&
-      (attributes & FILE_ATTRIBUTE_DIRECTORY)) {
-    result = true;
-  }
-#else
-  posix::StatStruct file_stat{};
-  result = posix::Stat(path.c_str(), &file_stat) == 0 &&
-      posix::IsDir(file_stat);
-#endif  // GTEST_OS_WINDOWS_MOBILE
-
-  return result;
-}
-
-// Returns true if pathname describes a root directory. (Windows has one
-// root directory per disk drive.)
-bool FilePath::IsRootDirectory() const {
-#if GTEST_OS_WINDOWS
-  return pathname_.length() == 3 && IsAbsolutePath();
-#else
-  return pathname_.length() == 1 && IsPathSeparator(pathname_.c_str()[0]);
-#endif
-}
-
-// Returns true if pathname describes an absolute path.
-bool FilePath::IsAbsolutePath() const {
-  const char* const name = pathname_.c_str();
-#if GTEST_OS_WINDOWS
-  return pathname_.length() >= 3 &&
-     ((name[0] >= 'a' && name[0] <= 'z') ||
-      (name[0] >= 'A' && name[0] <= 'Z')) &&
-     name[1] == ':' &&
-     IsPathSeparator(name[2]);
-#else
-  return IsPathSeparator(name[0]);
-#endif
-}
-
-// Returns a pathname for a file that does not currently exist. The pathname
-// will be directory/base_name.extension or
-// directory/base_name_<number>.extension if directory/base_name.extension
-// already exists. The number will be incremented until a pathname is found
-// that does not already exist.
-// Examples: 'dir/foo_test.xml' or 'dir/foo_test_1.xml'.
-// There could be a race condition if two or more processes are calling this
-// function at the same time -- they could both pick the same filename.
-FilePath FilePath::GenerateUniqueFileName(const FilePath& directory,
-                                          const FilePath& base_name,
-                                          const char* extension) {
-  FilePath full_pathname;
-  int number = 0;
-  do {
-    full_pathname.Set(MakeFileName(directory, base_name, number++, extension));
-  } while (full_pathname.FileOrDirectoryExists());
-  return full_pathname;
-}
-
-// Returns true if FilePath ends with a path separator, which indicates that
-// it is intended to represent a directory. Returns false otherwise.
-// This does NOT check that a directory (or file) actually exists.
-bool FilePath::IsDirectory() const {
-  return !pathname_.empty() &&
-         IsPathSeparator(pathname_.c_str()[pathname_.length() - 1]);
-}
-
-// Create directories so that path exists. Returns true if successful or if
-// the directories already exist; returns false if unable to create directories
-// for any reason.
-bool FilePath::CreateDirectoriesRecursively() const {
-  if (!this->IsDirectory()) {
-    return false;
-  }
-
-  if (pathname_.length() == 0 || this->DirectoryExists()) {
-    return true;
-  }
-
-  const FilePath parent(this->RemoveTrailingPathSeparator().RemoveFileName());
-  return parent.CreateDirectoriesRecursively() && this->CreateFolder();
-}
-
-// Create the directory so that path exists. Returns true if successful or
-// if the directory already exists; returns false if unable to create the
-// directory for any reason, including if the parent directory does not
-// exist. Not named "CreateDirectory" because that's a macro on Windows.
-bool FilePath::CreateFolder() const {
-#if GTEST_OS_WINDOWS_MOBILE
-  FilePath removed_sep(this->RemoveTrailingPathSeparator());
-  LPCWSTR unicode = String::AnsiToUtf16(removed_sep.c_str());
-  int result = CreateDirectory(unicode, nullptr) ? 0 : -1;
-  delete [] unicode;
-#elif GTEST_OS_WINDOWS
-  int result = _mkdir(pathname_.c_str());
-#elif GTEST_OS_ESP8266 || GTEST_OS_XTENSA
-  // do nothing
-  int result = 0;
-#else
-  int result = mkdir(pathname_.c_str(), 0777);
-#endif  // GTEST_OS_WINDOWS_MOBILE
-
-  if (result == -1) {
-    return this->DirectoryExists();  // An error is OK if the directory exists.
-  }
-  return true;  // No error.
-}
-
-// If input name has a trailing separator character, remove it and return the
-// name, otherwise return the name string unmodified.
-// On Windows platform, uses \ as the separator, other platforms use /.
-FilePath FilePath::RemoveTrailingPathSeparator() const {
-  return IsDirectory()
-      ? FilePath(pathname_.substr(0, pathname_.length() - 1))
-      : *this;
-}
-
-// Removes any redundant separators that might be in the pathname.
-// For example, "bar///foo" becomes "bar/foo". Does not eliminate other
-// redundancies that might be in a pathname involving "." or "..".
-void FilePath::Normalize() {
-  auto out = pathname_.begin();
-
-  for (const char character : pathname_) {
-    if (!IsPathSeparator(character)) {
-      *(out++) = character;
-    } else if (out == pathname_.begin() || *std::prev(out) != kPathSeparator) {
-      *(out++) = kPathSeparator;
-    } else {
-      continue;
-    }
-  }
-
-  pathname_.erase(out, pathname_.end());
-}
-
-}  // namespace internal
-}  // namespace testing
-// Copyright 2007, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// The Google C++ Testing and Mocking Framework (Google Test)
-//
-// This file implements just enough of the matcher interface to allow
-// EXPECT_DEATH and friends to accept a matcher argument.
-
-
-#include <string>
-
-namespace testing {
-
-// Constructs a matcher that matches a const std::string& whose value is
-// equal to s.
-Matcher<const std::string&>::Matcher(const std::string& s) { *this = Eq(s); }
-
-// Constructs a matcher that matches a const std::string& whose value is
-// equal to s.
-Matcher<const std::string&>::Matcher(const char* s) {
-  *this = Eq(std::string(s));
-}
-
-// Constructs a matcher that matches a std::string whose value is equal to
-// s.
-Matcher<std::string>::Matcher(const std::string& s) { *this = Eq(s); }
-
-// Constructs a matcher that matches a std::string whose value is equal to
-// s.
-Matcher<std::string>::Matcher(const char* s) { *this = Eq(std::string(s)); }
-
-#if GTEST_INTERNAL_HAS_STRING_VIEW
-// Constructs a matcher that matches a const StringView& whose value is
-// equal to s.
-Matcher<const internal::StringView&>::Matcher(const std::string& s) {
-  *this = Eq(s);
-}
-
-// Constructs a matcher that matches a const StringView& whose value is
-// equal to s.
-Matcher<const internal::StringView&>::Matcher(const char* s) {
-  *this = Eq(std::string(s));
-}
-
-// Constructs a matcher that matches a const StringView& whose value is
-// equal to s.
-Matcher<const internal::StringView&>::Matcher(internal::StringView s) {
-  *this = Eq(std::string(s));
-}
-
-// Constructs a matcher that matches a StringView whose value is equal to
-// s.
-Matcher<internal::StringView>::Matcher(const std::string& s) { *this = Eq(s); }
-
-// Constructs a matcher that matches a StringView whose value is equal to
-// s.
-Matcher<internal::StringView>::Matcher(const char* s) {
-  *this = Eq(std::string(s));
-}
-
-// Constructs a matcher that matches a StringView whose value is equal to
-// s.
-Matcher<internal::StringView>::Matcher(internal::StringView s) {
-  *this = Eq(std::string(s));
-}
-#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
-
-}  // namespace testing
-// Copyright 2008, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-
-#include <limits.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <cstdint>
-#include <fstream>
-#include <memory>
-
-#if GTEST_OS_WINDOWS
-# include <windows.h>
-# include <io.h>
-# include <sys/stat.h>
-# include <map>  // Used in ThreadLocal.
-# ifdef _MSC_VER
-#  include <crtdbg.h>
-# endif  // _MSC_VER
-#else
-# include <unistd.h>
-#endif  // GTEST_OS_WINDOWS
-
-#if GTEST_OS_MAC
-# include <mach/mach_init.h>
-# include <mach/task.h>
-# include <mach/vm_map.h>
-#endif  // GTEST_OS_MAC
-
-#if GTEST_OS_DRAGONFLY || GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD || \
-    GTEST_OS_NETBSD || GTEST_OS_OPENBSD
-# include <sys/sysctl.h>
-# if GTEST_OS_DRAGONFLY || GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD
-#  include <sys/user.h>
-# endif
-#endif
-
-#if GTEST_OS_QNX
-# include <devctl.h>
-# include <fcntl.h>
-# include <sys/procfs.h>
-#endif  // GTEST_OS_QNX
-
-#if GTEST_OS_AIX
-# include <procinfo.h>
-# include <sys/types.h>
-#endif  // GTEST_OS_AIX
-
-#if GTEST_OS_FUCHSIA
-# include <zircon/process.h>
-# include <zircon/syscalls.h>
-#endif  // GTEST_OS_FUCHSIA
-
-
-namespace testing {
-namespace internal {
-
-#if defined(_MSC_VER) || defined(__BORLANDC__)
-// MSVC and C++Builder do not provide a definition of STDERR_FILENO.
-const int kStdOutFileno = 1;
-const int kStdErrFileno = 2;
-#else
-const int kStdOutFileno = STDOUT_FILENO;
-const int kStdErrFileno = STDERR_FILENO;
-#endif  // _MSC_VER
-
-#if GTEST_OS_LINUX
-
-namespace {
-template <typename T>
-T ReadProcFileField(const std::string& filename, int field) {
-  std::string dummy;
-  std::ifstream file(filename.c_str());
-  while (field-- > 0) {
-    file >> dummy;
-  }
-  T output = 0;
-  file >> output;
-  return output;
-}
-}  // namespace
-
-// Returns the number of active threads, or 0 when there is an error.
-size_t GetThreadCount() {
-  const std::string filename =
-      (Message() << "/proc/" << getpid() << "/stat").GetString();
-  return ReadProcFileField<size_t>(filename, 19);
-}
-
-#elif GTEST_OS_MAC
-
-size_t GetThreadCount() {
-  const task_t task = mach_task_self();
-  mach_msg_type_number_t thread_count;
-  thread_act_array_t thread_list;
-  const kern_return_t status = task_threads(task, &thread_list, &thread_count);
-  if (status == KERN_SUCCESS) {
-    // task_threads allocates resources in thread_list and we need to free them
-    // to avoid leaks.
-    vm_deallocate(task,
-                  reinterpret_cast<vm_address_t>(thread_list),
-                  sizeof(thread_t) * thread_count);
-    return static_cast<size_t>(thread_count);
-  } else {
-    return 0;
-  }
-}
-
-#elif GTEST_OS_DRAGONFLY || GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD || \
-      GTEST_OS_NETBSD
-
-#if GTEST_OS_NETBSD
-#undef KERN_PROC
-#define KERN_PROC KERN_PROC2
-#define kinfo_proc kinfo_proc2
-#endif
-
-#if GTEST_OS_DRAGONFLY
-#define KP_NLWP(kp) (kp.kp_nthreads)
-#elif GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD
-#define KP_NLWP(kp) (kp.ki_numthreads)
-#elif GTEST_OS_NETBSD
-#define KP_NLWP(kp) (kp.p_nlwps)
-#endif
-
-// Returns the number of threads running in the process, or 0 to indicate that
-// we cannot detect it.
-size_t GetThreadCount() {
-  int mib[] = {
-    CTL_KERN,
-    KERN_PROC,
-    KERN_PROC_PID,
-    getpid(),
-#if GTEST_OS_NETBSD
-    sizeof(struct kinfo_proc),
-    1,
-#endif
-  };
-  u_int miblen = sizeof(mib) / sizeof(mib[0]);
-  struct kinfo_proc info;
-  size_t size = sizeof(info);
-  if (sysctl(mib, miblen, &info, &size, NULL, 0)) {
-    return 0;
-  }
-  return static_cast<size_t>(KP_NLWP(info));
-}
-#elif GTEST_OS_OPENBSD
-
-// Returns the number of threads running in the process, or 0 to indicate that
-// we cannot detect it.
-size_t GetThreadCount() {
-  int mib[] = {
-    CTL_KERN,
-    KERN_PROC,
-    KERN_PROC_PID | KERN_PROC_SHOW_THREADS,
-    getpid(),
-    sizeof(struct kinfo_proc),
-    0,
-  };
-  u_int miblen = sizeof(mib) / sizeof(mib[0]);
-
-  // get number of structs
-  size_t size;
-  if (sysctl(mib, miblen, NULL, &size, NULL, 0)) {
-    return 0;
-  }
-
-  mib[5] = static_cast<int>(size / static_cast<size_t>(mib[4]));
-
-  // populate array of structs
-  struct kinfo_proc info[mib[5]];
-  if (sysctl(mib, miblen, &info, &size, NULL, 0)) {
-    return 0;
-  }
-
-  // exclude empty members
-  size_t nthreads = 0;
-  for (size_t i = 0; i < size / static_cast<size_t>(mib[4]); i++) {
-    if (info[i].p_tid != -1)
-      nthreads++;
-  }
-  return nthreads;
-}
-
-#elif GTEST_OS_QNX
-
-// Returns the number of threads running in the process, or 0 to indicate that
-// we cannot detect it.
-size_t GetThreadCount() {
-  const int fd = open("/proc/self/as", O_RDONLY);
-  if (fd < 0) {
-    return 0;
-  }
-  procfs_info process_info;
-  const int status =
-      devctl(fd, DCMD_PROC_INFO, &process_info, sizeof(process_info), nullptr);
-  close(fd);
-  if (status == EOK) {
-    return static_cast<size_t>(process_info.num_threads);
-  } else {
-    return 0;
-  }
-}
-
-#elif GTEST_OS_AIX
-
-size_t GetThreadCount() {
-  struct procentry64 entry;
-  pid_t pid = getpid();
-  int status = getprocs64(&entry, sizeof(entry), nullptr, 0, &pid, 1);
-  if (status == 1) {
-    return entry.pi_thcount;
-  } else {
-    return 0;
-  }
-}
-
-#elif GTEST_OS_FUCHSIA
-
-size_t GetThreadCount() {
-  int dummy_buffer;
-  size_t avail;
-  zx_status_t status = zx_object_get_info(
-      zx_process_self(),
-      ZX_INFO_PROCESS_THREADS,
-      &dummy_buffer,
-      0,
-      nullptr,
-      &avail);
-  if (status == ZX_OK) {
-    return avail;
-  } else {
-    return 0;
-  }
-}
-
-#else
-
-size_t GetThreadCount() {
-  // There's no portable way to detect the number of threads, so we just
-  // return 0 to indicate that we cannot detect it.
-  return 0;
-}
-
-#endif  // GTEST_OS_LINUX
-
-#if GTEST_IS_THREADSAFE && GTEST_OS_WINDOWS
-
-void SleepMilliseconds(int n) {
-  ::Sleep(static_cast<DWORD>(n));
-}
-
-AutoHandle::AutoHandle()
-    : handle_(INVALID_HANDLE_VALUE) {}
-
-AutoHandle::AutoHandle(Handle handle)
-    : handle_(handle) {}
-
-AutoHandle::~AutoHandle() {
-  Reset();
-}
-
-AutoHandle::Handle AutoHandle::Get() const {
-  return handle_;
-}
-
-void AutoHandle::Reset() {
-  Reset(INVALID_HANDLE_VALUE);
-}
-
-void AutoHandle::Reset(HANDLE handle) {
-  // Resetting with the same handle we already own is invalid.
-  if (handle_ != handle) {
-    if (IsCloseable()) {
-      ::CloseHandle(handle_);
-    }
-    handle_ = handle;
-  } else {
-    GTEST_CHECK_(!IsCloseable())
-        << "Resetting a valid handle to itself is likely a programmer error "
-            "and thus not allowed.";
-  }
-}
-
-bool AutoHandle::IsCloseable() const {
-  // Different Windows APIs may use either of these values to represent an
-  // invalid handle.
-  return handle_ != nullptr && handle_ != INVALID_HANDLE_VALUE;
-}
-
-Notification::Notification()
-    : event_(::CreateEvent(nullptr,     // Default security attributes.
-                           TRUE,        // Do not reset automatically.
-                           FALSE,       // Initially unset.
-                           nullptr)) {  // Anonymous event.
-  GTEST_CHECK_(event_.Get() != nullptr);
-}
-
-void Notification::Notify() {
-  GTEST_CHECK_(::SetEvent(event_.Get()) != FALSE);
-}
-
-void Notification::WaitForNotification() {
-  GTEST_CHECK_(
-      ::WaitForSingleObject(event_.Get(), INFINITE) == WAIT_OBJECT_0);
-}
-
-Mutex::Mutex()
-    : owner_thread_id_(0),
-      type_(kDynamic),
-      critical_section_init_phase_(0),
-      critical_section_(new CRITICAL_SECTION) {
-  ::InitializeCriticalSection(critical_section_);
-}
-
-Mutex::~Mutex() {
-  // Static mutexes are leaked intentionally. It is not thread-safe to try
-  // to clean them up.
-  if (type_ == kDynamic) {
-    ::DeleteCriticalSection(critical_section_);
-    delete critical_section_;
-    critical_section_ = nullptr;
-  }
-}
-
-void Mutex::Lock() {
-  ThreadSafeLazyInit();
-  ::EnterCriticalSection(critical_section_);
-  owner_thread_id_ = ::GetCurrentThreadId();
-}
-
-void Mutex::Unlock() {
-  ThreadSafeLazyInit();
-  // We don't protect writing to owner_thread_id_ here, as it's the
-  // caller's responsibility to ensure that the current thread holds the
-  // mutex when this is called.
-  owner_thread_id_ = 0;
-  ::LeaveCriticalSection(critical_section_);
-}
-
-// Does nothing if the current thread holds the mutex. Otherwise, crashes
-// with high probability.
-void Mutex::AssertHeld() {
-  ThreadSafeLazyInit();
-  GTEST_CHECK_(owner_thread_id_ == ::GetCurrentThreadId())
-      << "The current thread is not holding the mutex @" << this;
-}
-
-namespace {
-
-#ifdef _MSC_VER
-// Use the RAII idiom to flag mem allocs that are intentionally never
-// deallocated. The motivation is to silence the false positive mem leaks
-// that are reported by the debug version of MS's CRT which can only detect
-// if an alloc is missing a matching deallocation.
-// Example:
-//    MemoryIsNotDeallocated memory_is_not_deallocated;
-//    critical_section_ = new CRITICAL_SECTION;
-//
-class MemoryIsNotDeallocated
-{
- public:
-  MemoryIsNotDeallocated() : old_crtdbg_flag_(0) {
-    old_crtdbg_flag_ = _CrtSetDbgFlag(_CRTDBG_REPORT_FLAG);
-    // Set heap allocation block type to _IGNORE_BLOCK so that MS debug CRT
-    // doesn't report mem leak if there's no matching deallocation.
-    _CrtSetDbgFlag(old_crtdbg_flag_ & ~_CRTDBG_ALLOC_MEM_DF);
-  }
-
-  ~MemoryIsNotDeallocated() {
-    // Restore the original _CRTDBG_ALLOC_MEM_DF flag
-    _CrtSetDbgFlag(old_crtdbg_flag_);
-  }
-
- private:
-  int old_crtdbg_flag_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(MemoryIsNotDeallocated);
-};
-#endif  // _MSC_VER
-
-}  // namespace
-
-// Initializes owner_thread_id_ and critical_section_ in static mutexes.
-void Mutex::ThreadSafeLazyInit() {
-  // Dynamic mutexes are initialized in the constructor.
-  if (type_ == kStatic) {
-    switch (
-        ::InterlockedCompareExchange(&critical_section_init_phase_, 1L, 0L)) {
-      case 0:
-        // If critical_section_init_phase_ was 0 before the exchange, we
-        // are the first to test it and need to perform the initialization.
-        owner_thread_id_ = 0;
-        {
-          // Use RAII to flag that following mem alloc is never deallocated.
-#ifdef _MSC_VER
-          MemoryIsNotDeallocated memory_is_not_deallocated;
-#endif  // _MSC_VER
-          critical_section_ = new CRITICAL_SECTION;
-        }
-        ::InitializeCriticalSection(critical_section_);
-        // Updates the critical_section_init_phase_ to 2 to signal
-        // initialization complete.
-        GTEST_CHECK_(::InterlockedCompareExchange(
-                          &critical_section_init_phase_, 2L, 1L) ==
-                      1L);
-        break;
-      case 1:
-        // Somebody else is already initializing the mutex; spin until they
-        // are done.
-        while (::InterlockedCompareExchange(&critical_section_init_phase_,
-                                            2L,
-                                            2L) != 2L) {
-          // Possibly yields the rest of the thread's time slice to other
-          // threads.
-          ::Sleep(0);
-        }
-        break;
-
-      case 2:
-        break;  // The mutex is already initialized and ready for use.
-
-      default:
-        GTEST_CHECK_(false)
-            << "Unexpected value of critical_section_init_phase_ "
-            << "while initializing a static mutex.";
-    }
-  }
-}
-
-namespace {
-
-class ThreadWithParamSupport : public ThreadWithParamBase {
- public:
-  static HANDLE CreateThread(Runnable* runnable,
-                             Notification* thread_can_start) {
-    ThreadMainParam* param = new ThreadMainParam(runnable, thread_can_start);
-    DWORD thread_id;
-    HANDLE thread_handle = ::CreateThread(
-        nullptr,  // Default security.
-        0,        // Default stack size.
-        &ThreadWithParamSupport::ThreadMain,
-        param,        // Parameter to ThreadMainStatic
-        0x0,          // Default creation flags.
-        &thread_id);  // Need a valid pointer for the call to work under Win98.
-    GTEST_CHECK_(thread_handle != nullptr)
-        << "CreateThread failed with error " << ::GetLastError() << ".";
-    if (thread_handle == nullptr) {
-      delete param;
-    }
-    return thread_handle;
-  }
-
- private:
-  struct ThreadMainParam {
-    ThreadMainParam(Runnable* runnable, Notification* thread_can_start)
-        : runnable_(runnable),
-          thread_can_start_(thread_can_start) {
-    }
-    std::unique_ptr<Runnable> runnable_;
-    // Does not own.
-    Notification* thread_can_start_;
-  };
-
-  static DWORD WINAPI ThreadMain(void* ptr) {
-    // Transfers ownership.
-    std::unique_ptr<ThreadMainParam> param(static_cast<ThreadMainParam*>(ptr));
-    if (param->thread_can_start_ != nullptr)
-      param->thread_can_start_->WaitForNotification();
-    param->runnable_->Run();
-    return 0;
-  }
-
-  // Prohibit instantiation.
-  ThreadWithParamSupport();
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParamSupport);
-};
-
-}  // namespace
-
-ThreadWithParamBase::ThreadWithParamBase(Runnable *runnable,
-                                         Notification* thread_can_start)
-      : thread_(ThreadWithParamSupport::CreateThread(runnable,
-                                                     thread_can_start)) {
-}
-
-ThreadWithParamBase::~ThreadWithParamBase() {
-  Join();
-}
-
-void ThreadWithParamBase::Join() {
-  GTEST_CHECK_(::WaitForSingleObject(thread_.Get(), INFINITE) == WAIT_OBJECT_0)
-      << "Failed to join the thread with error " << ::GetLastError() << ".";
-}
-
-// Maps a thread to a set of ThreadIdToThreadLocals that have values
-// instantiated on that thread and notifies them when the thread exits.  A
-// ThreadLocal instance is expected to persist until all threads it has
-// values on have terminated.
-class ThreadLocalRegistryImpl {
- public:
-  // Registers thread_local_instance as having value on the current thread.
-  // Returns a value that can be used to identify the thread from other threads.
-  static ThreadLocalValueHolderBase* GetValueOnCurrentThread(
-      const ThreadLocalBase* thread_local_instance) {
-#ifdef _MSC_VER
-    MemoryIsNotDeallocated memory_is_not_deallocated;
-#endif  // _MSC_VER
-    DWORD current_thread = ::GetCurrentThreadId();
-    MutexLock lock(&mutex_);
-    ThreadIdToThreadLocals* const thread_to_thread_locals =
-        GetThreadLocalsMapLocked();
-    ThreadIdToThreadLocals::iterator thread_local_pos =
-        thread_to_thread_locals->find(current_thread);
-    if (thread_local_pos == thread_to_thread_locals->end()) {
-      thread_local_pos = thread_to_thread_locals->insert(
-          std::make_pair(current_thread, ThreadLocalValues())).first;
-      StartWatcherThreadFor(current_thread);
-    }
-    ThreadLocalValues& thread_local_values = thread_local_pos->second;
-    ThreadLocalValues::iterator value_pos =
-        thread_local_values.find(thread_local_instance);
-    if (value_pos == thread_local_values.end()) {
-      value_pos =
-          thread_local_values
-              .insert(std::make_pair(
-                  thread_local_instance,
-                  std::shared_ptr<ThreadLocalValueHolderBase>(
-                      thread_local_instance->NewValueForCurrentThread())))
-              .first;
-    }
-    return value_pos->second.get();
-  }
-
-  static void OnThreadLocalDestroyed(
-      const ThreadLocalBase* thread_local_instance) {
-    std::vector<std::shared_ptr<ThreadLocalValueHolderBase> > value_holders;
-    // Clean up the ThreadLocalValues data structure while holding the lock, but
-    // defer the destruction of the ThreadLocalValueHolderBases.
-    {
-      MutexLock lock(&mutex_);
-      ThreadIdToThreadLocals* const thread_to_thread_locals =
-          GetThreadLocalsMapLocked();
-      for (ThreadIdToThreadLocals::iterator it =
-          thread_to_thread_locals->begin();
-          it != thread_to_thread_locals->end();
-          ++it) {
-        ThreadLocalValues& thread_local_values = it->second;
-        ThreadLocalValues::iterator value_pos =
-            thread_local_values.find(thread_local_instance);
-        if (value_pos != thread_local_values.end()) {
-          value_holders.push_back(value_pos->second);
-          thread_local_values.erase(value_pos);
-          // This 'if' can only be successful at most once, so theoretically we
-          // could break out of the loop here, but we don't bother doing so.
-        }
-      }
-    }
-    // Outside the lock, let the destructor for 'value_holders' deallocate the
-    // ThreadLocalValueHolderBases.
-  }
-
-  static void OnThreadExit(DWORD thread_id) {
-    GTEST_CHECK_(thread_id != 0) << ::GetLastError();
-    std::vector<std::shared_ptr<ThreadLocalValueHolderBase> > value_holders;
-    // Clean up the ThreadIdToThreadLocals data structure while holding the
-    // lock, but defer the destruction of the ThreadLocalValueHolderBases.
-    {
-      MutexLock lock(&mutex_);
-      ThreadIdToThreadLocals* const thread_to_thread_locals =
-          GetThreadLocalsMapLocked();
-      ThreadIdToThreadLocals::iterator thread_local_pos =
-          thread_to_thread_locals->find(thread_id);
-      if (thread_local_pos != thread_to_thread_locals->end()) {
-        ThreadLocalValues& thread_local_values = thread_local_pos->second;
-        for (ThreadLocalValues::iterator value_pos =
-            thread_local_values.begin();
-            value_pos != thread_local_values.end();
-            ++value_pos) {
-          value_holders.push_back(value_pos->second);
-        }
-        thread_to_thread_locals->erase(thread_local_pos);
-      }
-    }
-    // Outside the lock, let the destructor for 'value_holders' deallocate the
-    // ThreadLocalValueHolderBases.
-  }
-
- private:
-  // In a particular thread, maps a ThreadLocal object to its value.
-  typedef std::map<const ThreadLocalBase*,
-                   std::shared_ptr<ThreadLocalValueHolderBase> >
-      ThreadLocalValues;
-  // Stores all ThreadIdToThreadLocals having values in a thread, indexed by
-  // thread's ID.
-  typedef std::map<DWORD, ThreadLocalValues> ThreadIdToThreadLocals;
-
-  // Holds the thread id and thread handle that we pass from
-  // StartWatcherThreadFor to WatcherThreadFunc.
-  typedef std::pair<DWORD, HANDLE> ThreadIdAndHandle;
-
-  static void StartWatcherThreadFor(DWORD thread_id) {
-    // The returned handle will be kept in thread_map and closed by
-    // watcher_thread in WatcherThreadFunc.
-    HANDLE thread = ::OpenThread(SYNCHRONIZE | THREAD_QUERY_INFORMATION,
-                                 FALSE,
-                                 thread_id);
-    GTEST_CHECK_(thread != nullptr);
-    // We need to pass a valid thread ID pointer into CreateThread for it
-    // to work correctly under Win98.
-    DWORD watcher_thread_id;
-    HANDLE watcher_thread = ::CreateThread(
-        nullptr,  // Default security.
-        0,        // Default stack size
-        &ThreadLocalRegistryImpl::WatcherThreadFunc,
-        reinterpret_cast<LPVOID>(new ThreadIdAndHandle(thread_id, thread)),
-        CREATE_SUSPENDED, &watcher_thread_id);
-    GTEST_CHECK_(watcher_thread != nullptr);
-    // Give the watcher thread the same priority as ours to avoid being
-    // blocked by it.
-    ::SetThreadPriority(watcher_thread,
-                        ::GetThreadPriority(::GetCurrentThread()));
-    ::ResumeThread(watcher_thread);
-    ::CloseHandle(watcher_thread);
-  }
-
-  // Monitors exit from a given thread and notifies those
-  // ThreadIdToThreadLocals about thread termination.
-  static DWORD WINAPI WatcherThreadFunc(LPVOID param) {
-    const ThreadIdAndHandle* tah =
-        reinterpret_cast<const ThreadIdAndHandle*>(param);
-    GTEST_CHECK_(
-        ::WaitForSingleObject(tah->second, INFINITE) == WAIT_OBJECT_0);
-    OnThreadExit(tah->first);
-    ::CloseHandle(tah->second);
-    delete tah;
-    return 0;
-  }
-
-  // Returns map of thread local instances.
-  static ThreadIdToThreadLocals* GetThreadLocalsMapLocked() {
-    mutex_.AssertHeld();
-#ifdef _MSC_VER
-    MemoryIsNotDeallocated memory_is_not_deallocated;
-#endif  // _MSC_VER
-    static ThreadIdToThreadLocals* map = new ThreadIdToThreadLocals();
-    return map;
-  }
-
-  // Protects access to GetThreadLocalsMapLocked() and its return value.
-  static Mutex mutex_;
-  // Protects access to GetThreadMapLocked() and its return value.
-  static Mutex thread_map_mutex_;
-};
-
-Mutex ThreadLocalRegistryImpl::mutex_(Mutex::kStaticMutex);  // NOLINT
-Mutex ThreadLocalRegistryImpl::thread_map_mutex_(Mutex::kStaticMutex);  // NOLINT
-
-ThreadLocalValueHolderBase* ThreadLocalRegistry::GetValueOnCurrentThread(
-      const ThreadLocalBase* thread_local_instance) {
-  return ThreadLocalRegistryImpl::GetValueOnCurrentThread(
-      thread_local_instance);
-}
-
-void ThreadLocalRegistry::OnThreadLocalDestroyed(
-      const ThreadLocalBase* thread_local_instance) {
-  ThreadLocalRegistryImpl::OnThreadLocalDestroyed(thread_local_instance);
-}
-
-#endif  // GTEST_IS_THREADSAFE && GTEST_OS_WINDOWS
-
-#if GTEST_USES_POSIX_RE
-
-// Implements RE.  Currently only needed for death tests.
-
-RE::~RE() {
-  if (is_valid_) {
-    // regfree'ing an invalid regex might crash because the content
-    // of the regex is undefined. Since the regex's are essentially
-    // the same, one cannot be valid (or invalid) without the other
-    // being so too.
-    regfree(&partial_regex_);
-    regfree(&full_regex_);
-  }
-  free(const_cast<char*>(pattern_));
-}
-
-// Returns true if and only if regular expression re matches the entire str.
-bool RE::FullMatch(const char* str, const RE& re) {
-  if (!re.is_valid_) return false;
-
-  regmatch_t match;
-  return regexec(&re.full_regex_, str, 1, &match, 0) == 0;
-}
-
-// Returns true if and only if regular expression re matches a substring of
-// str (including str itself).
-bool RE::PartialMatch(const char* str, const RE& re) {
-  if (!re.is_valid_) return false;
-
-  regmatch_t match;
-  return regexec(&re.partial_regex_, str, 1, &match, 0) == 0;
-}
-
-// Initializes an RE from its string representation.
-void RE::Init(const char* regex) {
-  pattern_ = posix::StrDup(regex);
-
-  // Reserves enough bytes to hold the regular expression used for a
-  // full match.
-  const size_t full_regex_len = strlen(regex) + 10;
-  char* const full_pattern = new char[full_regex_len];
-
-  snprintf(full_pattern, full_regex_len, "^(%s)$", regex);
-  is_valid_ = regcomp(&full_regex_, full_pattern, REG_EXTENDED) == 0;
-  // We want to call regcomp(&partial_regex_, ...) even if the
-  // previous expression returns false.  Otherwise partial_regex_ may
-  // not be properly initialized can may cause trouble when it's
-  // freed.
-  //
-  // Some implementation of POSIX regex (e.g. on at least some
-  // versions of Cygwin) doesn't accept the empty string as a valid
-  // regex.  We change it to an equivalent form "()" to be safe.
-  if (is_valid_) {
-    const char* const partial_regex = (*regex == '\0') ? "()" : regex;
-    is_valid_ = regcomp(&partial_regex_, partial_regex, REG_EXTENDED) == 0;
-  }
-  EXPECT_TRUE(is_valid_)
-      << "Regular expression \"" << regex
-      << "\" is not a valid POSIX Extended regular expression.";
-
-  delete[] full_pattern;
-}
-
-#elif GTEST_USES_SIMPLE_RE
-
-// Returns true if and only if ch appears anywhere in str (excluding the
-// terminating '\0' character).
-bool IsInSet(char ch, const char* str) {
-  return ch != '\0' && strchr(str, ch) != nullptr;
-}
-
-// Returns true if and only if ch belongs to the given classification.
-// Unlike similar functions in <ctype.h>, these aren't affected by the
-// current locale.
-bool IsAsciiDigit(char ch) { return '0' <= ch && ch <= '9'; }
-bool IsAsciiPunct(char ch) {
-  return IsInSet(ch, "^-!\"#$%&'()*+,./:;<=>?@[\\]_`{|}~");
-}
-bool IsRepeat(char ch) { return IsInSet(ch, "?*+"); }
-bool IsAsciiWhiteSpace(char ch) { return IsInSet(ch, " \f\n\r\t\v"); }
-bool IsAsciiWordChar(char ch) {
-  return ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') ||
-      ('0' <= ch && ch <= '9') || ch == '_';
-}
-
-// Returns true if and only if "\\c" is a supported escape sequence.
-bool IsValidEscape(char c) {
-  return (IsAsciiPunct(c) || IsInSet(c, "dDfnrsStvwW"));
-}
-
-// Returns true if and only if the given atom (specified by escaped and
-// pattern) matches ch.  The result is undefined if the atom is invalid.
-bool AtomMatchesChar(bool escaped, char pattern_char, char ch) {
-  if (escaped) {  // "\\p" where p is pattern_char.
-    switch (pattern_char) {
-      case 'd': return IsAsciiDigit(ch);
-      case 'D': return !IsAsciiDigit(ch);
-      case 'f': return ch == '\f';
-      case 'n': return ch == '\n';
-      case 'r': return ch == '\r';
-      case 's': return IsAsciiWhiteSpace(ch);
-      case 'S': return !IsAsciiWhiteSpace(ch);
-      case 't': return ch == '\t';
-      case 'v': return ch == '\v';
-      case 'w': return IsAsciiWordChar(ch);
-      case 'W': return !IsAsciiWordChar(ch);
-    }
-    return IsAsciiPunct(pattern_char) && pattern_char == ch;
-  }
-
-  return (pattern_char == '.' && ch != '\n') || pattern_char == ch;
-}
-
-// Helper function used by ValidateRegex() to format error messages.
-static std::string FormatRegexSyntaxError(const char* regex, int index) {
-  return (Message() << "Syntax error at index " << index
-          << " in simple regular expression \"" << regex << "\": ").GetString();
-}
-
-// Generates non-fatal failures and returns false if regex is invalid;
-// otherwise returns true.
-bool ValidateRegex(const char* regex) {
-  if (regex == nullptr) {
-    ADD_FAILURE() << "NULL is not a valid simple regular expression.";
-    return false;
-  }
-
-  bool is_valid = true;
-
-  // True if and only if ?, *, or + can follow the previous atom.
-  bool prev_repeatable = false;
-  for (int i = 0; regex[i]; i++) {
-    if (regex[i] == '\\') {  // An escape sequence
-      i++;
-      if (regex[i] == '\0') {
-        ADD_FAILURE() << FormatRegexSyntaxError(regex, i - 1)
-                      << "'\\' cannot appear at the end.";
-        return false;
-      }
-
-      if (!IsValidEscape(regex[i])) {
-        ADD_FAILURE() << FormatRegexSyntaxError(regex, i - 1)
-                      << "invalid escape sequence \"\\" << regex[i] << "\".";
-        is_valid = false;
-      }
-      prev_repeatable = true;
-    } else {  // Not an escape sequence.
-      const char ch = regex[i];
-
-      if (ch == '^' && i > 0) {
-        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
-                      << "'^' can only appear at the beginning.";
-        is_valid = false;
-      } else if (ch == '$' && regex[i + 1] != '\0') {
-        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
-                      << "'$' can only appear at the end.";
-        is_valid = false;
-      } else if (IsInSet(ch, "()[]{}|")) {
-        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
-                      << "'" << ch << "' is unsupported.";
-        is_valid = false;
-      } else if (IsRepeat(ch) && !prev_repeatable) {
-        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
-                      << "'" << ch << "' can only follow a repeatable token.";
-        is_valid = false;
-      }
-
-      prev_repeatable = !IsInSet(ch, "^$?*+");
-    }
-  }
-
-  return is_valid;
-}
-
-// Matches a repeated regex atom followed by a valid simple regular
-// expression.  The regex atom is defined as c if escaped is false,
-// or \c otherwise.  repeat is the repetition meta character (?, *,
-// or +).  The behavior is undefined if str contains too many
-// characters to be indexable by size_t, in which case the test will
-// probably time out anyway.  We are fine with this limitation as
-// std::string has it too.
-bool MatchRepetitionAndRegexAtHead(
-    bool escaped, char c, char repeat, const char* regex,
-    const char* str) {
-  const size_t min_count = (repeat == '+') ? 1 : 0;
-  const size_t max_count = (repeat == '?') ? 1 :
-      static_cast<size_t>(-1) - 1;
-  // We cannot call numeric_limits::max() as it conflicts with the
-  // max() macro on Windows.
-
-  for (size_t i = 0; i <= max_count; ++i) {
-    // We know that the atom matches each of the first i characters in str.
-    if (i >= min_count && MatchRegexAtHead(regex, str + i)) {
-      // We have enough matches at the head, and the tail matches too.
-      // Since we only care about *whether* the pattern matches str
-      // (as opposed to *how* it matches), there is no need to find a
-      // greedy match.
-      return true;
-    }
-    if (str[i] == '\0' || !AtomMatchesChar(escaped, c, str[i]))
-      return false;
-  }
-  return false;
-}
-
-// Returns true if and only if regex matches a prefix of str. regex must
-// be a valid simple regular expression and not start with "^", or the
-// result is undefined.
-bool MatchRegexAtHead(const char* regex, const char* str) {
-  if (*regex == '\0')  // An empty regex matches a prefix of anything.
-    return true;
-
-  // "$" only matches the end of a string.  Note that regex being
-  // valid guarantees that there's nothing after "$" in it.
-  if (*regex == '$')
-    return *str == '\0';
-
-  // Is the first thing in regex an escape sequence?
-  const bool escaped = *regex == '\\';
-  if (escaped)
-    ++regex;
-  if (IsRepeat(regex[1])) {
-    // MatchRepetitionAndRegexAtHead() calls MatchRegexAtHead(), so
-    // here's an indirect recursion.  It terminates as the regex gets
-    // shorter in each recursion.
-    return MatchRepetitionAndRegexAtHead(
-        escaped, regex[0], regex[1], regex + 2, str);
-  } else {
-    // regex isn't empty, isn't "$", and doesn't start with a
-    // repetition.  We match the first atom of regex with the first
-    // character of str and recurse.
-    return (*str != '\0') && AtomMatchesChar(escaped, *regex, *str) &&
-        MatchRegexAtHead(regex + 1, str + 1);
-  }
-}
-
-// Returns true if and only if regex matches any substring of str.  regex must
-// be a valid simple regular expression, or the result is undefined.
-//
-// The algorithm is recursive, but the recursion depth doesn't exceed
-// the regex length, so we won't need to worry about running out of
-// stack space normally.  In rare cases the time complexity can be
-// exponential with respect to the regex length + the string length,
-// but usually it's must faster (often close to linear).
-bool MatchRegexAnywhere(const char* regex, const char* str) {
-  if (regex == nullptr || str == nullptr) return false;
-
-  if (*regex == '^')
-    return MatchRegexAtHead(regex + 1, str);
-
-  // A successful match can be anywhere in str.
-  do {
-    if (MatchRegexAtHead(regex, str))
-      return true;
-  } while (*str++ != '\0');
-  return false;
-}
-
-// Implements the RE class.
-
-RE::~RE() {
-  free(const_cast<char*>(pattern_));
-  free(const_cast<char*>(full_pattern_));
-}
-
-// Returns true if and only if regular expression re matches the entire str.
-bool RE::FullMatch(const char* str, const RE& re) {
-  return re.is_valid_ && MatchRegexAnywhere(re.full_pattern_, str);
-}
-
-// Returns true if and only if regular expression re matches a substring of
-// str (including str itself).
-bool RE::PartialMatch(const char* str, const RE& re) {
-  return re.is_valid_ && MatchRegexAnywhere(re.pattern_, str);
-}
-
-// Initializes an RE from its string representation.
-void RE::Init(const char* regex) {
-  pattern_ = full_pattern_ = nullptr;
-  if (regex != nullptr) {
-    pattern_ = posix::StrDup(regex);
-  }
-
-  is_valid_ = ValidateRegex(regex);
-  if (!is_valid_) {
-    // No need to calculate the full pattern when the regex is invalid.
-    return;
-  }
-
-  const size_t len = strlen(regex);
-  // Reserves enough bytes to hold the regular expression used for a
-  // full match: we need space to prepend a '^', append a '$', and
-  // terminate the string with '\0'.
-  char* buffer = static_cast<char*>(malloc(len + 3));
-  full_pattern_ = buffer;
-
-  if (*regex != '^')
-    *buffer++ = '^';  // Makes sure full_pattern_ starts with '^'.
-
-  // We don't use snprintf or strncpy, as they trigger a warning when
-  // compiled with VC++ 8.0.
-  memcpy(buffer, regex, len);
-  buffer += len;
-
-  if (len == 0 || regex[len - 1] != '$')
-    *buffer++ = '$';  // Makes sure full_pattern_ ends with '$'.
-
-  *buffer = '\0';
-}
-
-#endif  // GTEST_USES_POSIX_RE
-
-const char kUnknownFile[] = "unknown file";
-
-// Formats a source file path and a line number as they would appear
-// in an error message from the compiler used to compile this code.
-GTEST_API_ ::std::string FormatFileLocation(const char* file, int line) {
-  const std::string file_name(file == nullptr ? kUnknownFile : file);
-
-  if (line < 0) {
-    return file_name + ":";
-  }
-#ifdef _MSC_VER
-  return file_name + "(" + StreamableToString(line) + "):";
-#else
-  return file_name + ":" + StreamableToString(line) + ":";
-#endif  // _MSC_VER
-}
-
-// Formats a file location for compiler-independent XML output.
-// Although this function is not platform dependent, we put it next to
-// FormatFileLocation in order to contrast the two functions.
-// Note that FormatCompilerIndependentFileLocation() does NOT append colon
-// to the file location it produces, unlike FormatFileLocation().
-GTEST_API_ ::std::string FormatCompilerIndependentFileLocation(
-    const char* file, int line) {
-  const std::string file_name(file == nullptr ? kUnknownFile : file);
-
-  if (line < 0)
-    return file_name;
-  else
-    return file_name + ":" + StreamableToString(line);
-}
-
-GTestLog::GTestLog(GTestLogSeverity severity, const char* file, int line)
-    : severity_(severity) {
-  const char* const marker =
-      severity == GTEST_INFO ?    "[  INFO ]" :
-      severity == GTEST_WARNING ? "[WARNING]" :
-      severity == GTEST_ERROR ?   "[ ERROR ]" : "[ FATAL ]";
-  GetStream() << ::std::endl << marker << " "
-              << FormatFileLocation(file, line).c_str() << ": ";
-}
-
-// Flushes the buffers and, if severity is GTEST_FATAL, aborts the program.
-GTestLog::~GTestLog() {
-  GetStream() << ::std::endl;
-  if (severity_ == GTEST_FATAL) {
-    fflush(stderr);
-    posix::Abort();
-  }
-}
-
-// Disable Microsoft deprecation warnings for POSIX functions called from
-// this class (creat, dup, dup2, and close)
-GTEST_DISABLE_MSC_DEPRECATED_PUSH_()
-
-#if GTEST_HAS_STREAM_REDIRECTION
-
-// Object that captures an output stream (stdout/stderr).
-class CapturedStream {
- public:
-  // The ctor redirects the stream to a temporary file.
-  explicit CapturedStream(int fd) : fd_(fd), uncaptured_fd_(dup(fd)) {
-# if GTEST_OS_WINDOWS
-    char temp_dir_path[MAX_PATH + 1] = { '\0' };  // NOLINT
-    char temp_file_path[MAX_PATH + 1] = { '\0' };  // NOLINT
-
-    ::GetTempPathA(sizeof(temp_dir_path), temp_dir_path);
-    const UINT success = ::GetTempFileNameA(temp_dir_path,
-                                            "gtest_redir",
-                                            0,  // Generate unique file name.
-                                            temp_file_path);
-    GTEST_CHECK_(success != 0)
-        << "Unable to create a temporary file in " << temp_dir_path;
-    const int captured_fd = creat(temp_file_path, _S_IREAD | _S_IWRITE);
-    GTEST_CHECK_(captured_fd != -1) << "Unable to open temporary file "
-                                    << temp_file_path;
-    filename_ = temp_file_path;
-# else
-    // There's no guarantee that a test has write access to the current
-    // directory, so we create the temporary file in a temporary directory.
-    std::string name_template;
-
-#  if GTEST_OS_LINUX_ANDROID
-    // Note: Android applications are expected to call the framework's
-    // Context.getExternalStorageDirectory() method through JNI to get
-    // the location of the world-writable SD Card directory. However,
-    // this requires a Context handle, which cannot be retrieved
-    // globally from native code. Doing so also precludes running the
-    // code as part of a regular standalone executable, which doesn't
-    // run in a Dalvik process (e.g. when running it through 'adb shell').
-    //
-    // The location /data/local/tmp is directly accessible from native code.
-    // '/sdcard' and other variants cannot be relied on, as they are not
-    // guaranteed to be mounted, or may have a delay in mounting.
-    name_template = "/data/local/tmp/";
-#  elif GTEST_OS_IOS
-    char user_temp_dir[PATH_MAX + 1];
-
-    // Documented alternative to NSTemporaryDirectory() (for obtaining creating
-    // a temporary directory) at
-    // https://developer.apple.com/library/archive/documentation/Security/Conceptual/SecureCodingGuide/Articles/RaceConditions.html#//apple_ref/doc/uid/TP40002585-SW10
-    //
-    // _CS_DARWIN_USER_TEMP_DIR (as well as _CS_DARWIN_USER_CACHE_DIR) is not
-    // documented in the confstr() man page at
-    // https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/confstr.3.html#//apple_ref/doc/man/3/confstr
-    // but are still available, according to the WebKit patches at
-    // https://trac.webkit.org/changeset/262004/webkit
-    // https://trac.webkit.org/changeset/263705/webkit
-    //
-    // The confstr() implementation falls back to getenv("TMPDIR"). See
-    // https://opensource.apple.com/source/Libc/Libc-1439.100.3/gen/confstr.c.auto.html
-    ::confstr(_CS_DARWIN_USER_TEMP_DIR, user_temp_dir, sizeof(user_temp_dir));
-
-    name_template = user_temp_dir;
-    if (name_template.back() != GTEST_PATH_SEP_[0])
-      name_template.push_back(GTEST_PATH_SEP_[0]);
-#  else
-    name_template = "/tmp/";
-#  endif
-    name_template.append("gtest_captured_stream.XXXXXX");
-
-    // mkstemp() modifies the string bytes in place, and does not go beyond the
-    // string's length. This results in well-defined behavior in C++17.
-    //
-    // The const_cast is needed below C++17. The constraints on std::string
-    // implementations in C++11 and above make assumption behind the const_cast
-    // fairly safe.
-    const int captured_fd = ::mkstemp(const_cast<char*>(name_template.data()));
-    if (captured_fd == -1) {
-      GTEST_LOG_(WARNING)
-          << "Failed to create tmp file " << name_template
-          << " for test; does the test have access to the /tmp directory?";
-    }
-    filename_ = std::move(name_template);
-# endif  // GTEST_OS_WINDOWS
-    fflush(nullptr);
-    dup2(captured_fd, fd_);
-    close(captured_fd);
-  }
-
-  ~CapturedStream() {
-    remove(filename_.c_str());
-  }
-
-  std::string GetCapturedString() {
-    if (uncaptured_fd_ != -1) {
-      // Restores the original stream.
-      fflush(nullptr);
-      dup2(uncaptured_fd_, fd_);
-      close(uncaptured_fd_);
-      uncaptured_fd_ = -1;
-    }
-
-    FILE* const file = posix::FOpen(filename_.c_str(), "r");
-    if (file == nullptr) {
-      GTEST_LOG_(FATAL) << "Failed to open tmp file " << filename_
-                        << " for capturing stream.";
-    }
-    const std::string content = ReadEntireFile(file);
-    posix::FClose(file);
-    return content;
-  }
-
- private:
-  const int fd_;  // A stream to capture.
-  int uncaptured_fd_;
-  // Name of the temporary file holding the stderr output.
-  ::std::string filename_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(CapturedStream);
-};
-
-GTEST_DISABLE_MSC_DEPRECATED_POP_()
-
-static CapturedStream* g_captured_stderr = nullptr;
-static CapturedStream* g_captured_stdout = nullptr;
-
-// Starts capturing an output stream (stdout/stderr).
-static void CaptureStream(int fd, const char* stream_name,
-                          CapturedStream** stream) {
-  if (*stream != nullptr) {
-    GTEST_LOG_(FATAL) << "Only one " << stream_name
-                      << " capturer can exist at a time.";
-  }
-  *stream = new CapturedStream(fd);
-}
-
-// Stops capturing the output stream and returns the captured string.
-static std::string GetCapturedStream(CapturedStream** captured_stream) {
-  const std::string content = (*captured_stream)->GetCapturedString();
-
-  delete *captured_stream;
-  *captured_stream = nullptr;
-
-  return content;
-}
-
-// Starts capturing stdout.
-void CaptureStdout() {
-  CaptureStream(kStdOutFileno, "stdout", &g_captured_stdout);
-}
-
-// Starts capturing stderr.
-void CaptureStderr() {
-  CaptureStream(kStdErrFileno, "stderr", &g_captured_stderr);
-}
-
-// Stops capturing stdout and returns the captured string.
-std::string GetCapturedStdout() {
-  return GetCapturedStream(&g_captured_stdout);
-}
-
-// Stops capturing stderr and returns the captured string.
-std::string GetCapturedStderr() {
-  return GetCapturedStream(&g_captured_stderr);
-}
-
-#endif  // GTEST_HAS_STREAM_REDIRECTION
-
-
-
-
-
-size_t GetFileSize(FILE* file) {
-  fseek(file, 0, SEEK_END);
-  return static_cast<size_t>(ftell(file));
-}
-
-std::string ReadEntireFile(FILE* file) {
-  const size_t file_size = GetFileSize(file);
-  char* const buffer = new char[file_size];
-
-  size_t bytes_last_read = 0;  // # of bytes read in the last fread()
-  size_t bytes_read = 0;       // # of bytes read so far
-
-  fseek(file, 0, SEEK_SET);
-
-  // Keeps reading the file until we cannot read further or the
-  // pre-determined file size is reached.
-  do {
-    bytes_last_read = fread(buffer+bytes_read, 1, file_size-bytes_read, file);
-    bytes_read += bytes_last_read;
-  } while (bytes_last_read > 0 && bytes_read < file_size);
-
-  const std::string content(buffer, bytes_read);
-  delete[] buffer;
-
-  return content;
-}
-
-#if GTEST_HAS_DEATH_TEST
-static const std::vector<std::string>* g_injected_test_argvs =
-    nullptr;  // Owned.
-
-std::vector<std::string> GetInjectableArgvs() {
-  if (g_injected_test_argvs != nullptr) {
-    return *g_injected_test_argvs;
-  }
-  return GetArgvs();
-}
-
-void SetInjectableArgvs(const std::vector<std::string>* new_argvs) {
-  if (g_injected_test_argvs != new_argvs) delete g_injected_test_argvs;
-  g_injected_test_argvs = new_argvs;
-}
-
-void SetInjectableArgvs(const std::vector<std::string>& new_argvs) {
-  SetInjectableArgvs(
-      new std::vector<std::string>(new_argvs.begin(), new_argvs.end()));
-}
-
-void ClearInjectableArgvs() {
-  delete g_injected_test_argvs;
-  g_injected_test_argvs = nullptr;
-}
-#endif  // GTEST_HAS_DEATH_TEST
-
-#if GTEST_OS_WINDOWS_MOBILE
-namespace posix {
-void Abort() {
-  DebugBreak();
-  TerminateProcess(GetCurrentProcess(), 1);
-}
-}  // namespace posix
-#endif  // GTEST_OS_WINDOWS_MOBILE
-
-// Returns the name of the environment variable corresponding to the
-// given flag.  For example, FlagToEnvVar("foo") will return
-// "GTEST_FOO" in the open-source version.
-static std::string FlagToEnvVar(const char* flag) {
-  const std::string full_flag =
-      (Message() << GTEST_FLAG_PREFIX_ << flag).GetString();
-
-  Message env_var;
-  for (size_t i = 0; i != full_flag.length(); i++) {
-    env_var << ToUpper(full_flag.c_str()[i]);
-  }
-
-  return env_var.GetString();
-}
-
-// Parses 'str' for a 32-bit signed integer.  If successful, writes
-// the result to *value and returns true; otherwise leaves *value
-// unchanged and returns false.
-bool ParseInt32(const Message& src_text, const char* str, int32_t* value) {
-  // Parses the environment variable as a decimal integer.
-  char* end = nullptr;
-  const long long_value = strtol(str, &end, 10);  // NOLINT
-
-  // Has strtol() consumed all characters in the string?
-  if (*end != '\0') {
-    // No - an invalid character was encountered.
-    Message msg;
-    msg << "WARNING: " << src_text
-        << " is expected to be a 32-bit integer, but actually"
-        << " has value \"" << str << "\".\n";
-    printf("%s", msg.GetString().c_str());
-    fflush(stdout);
-    return false;
-  }
-
-  // Is the parsed value in the range of an int32_t?
-  const auto result = static_cast<int32_t>(long_value);
-  if (long_value == LONG_MAX || long_value == LONG_MIN ||
-      // The parsed value overflows as a long.  (strtol() returns
-      // LONG_MAX or LONG_MIN when the input overflows.)
-      result != long_value
-      // The parsed value overflows as an int32_t.
-      ) {
-    Message msg;
-    msg << "WARNING: " << src_text
-        << " is expected to be a 32-bit integer, but actually"
-        << " has value " << str << ", which overflows.\n";
-    printf("%s", msg.GetString().c_str());
-    fflush(stdout);
-    return false;
-  }
-
-  *value = result;
-  return true;
-}
-
-// Reads and returns the Boolean environment variable corresponding to
-// the given flag; if it's not set, returns default_value.
-//
-// The value is considered true if and only if it's not "0".
-bool BoolFromGTestEnv(const char* flag, bool default_value) {
-#if defined(GTEST_GET_BOOL_FROM_ENV_)
-  return GTEST_GET_BOOL_FROM_ENV_(flag, default_value);
-#else
-  const std::string env_var = FlagToEnvVar(flag);
-  const char* const string_value = posix::GetEnv(env_var.c_str());
-  return string_value == nullptr ? default_value
-                                 : strcmp(string_value, "0") != 0;
-#endif  // defined(GTEST_GET_BOOL_FROM_ENV_)
-}
-
-// Reads and returns a 32-bit integer stored in the environment
-// variable corresponding to the given flag; if it isn't set or
-// doesn't represent a valid 32-bit integer, returns default_value.
-int32_t Int32FromGTestEnv(const char* flag, int32_t default_value) {
-#if defined(GTEST_GET_INT32_FROM_ENV_)
-  return GTEST_GET_INT32_FROM_ENV_(flag, default_value);
-#else
-  const std::string env_var = FlagToEnvVar(flag);
-  const char* const string_value = posix::GetEnv(env_var.c_str());
-  if (string_value == nullptr) {
-    // The environment variable is not set.
-    return default_value;
-  }
-
-  int32_t result = default_value;
-  if (!ParseInt32(Message() << "Environment variable " << env_var,
-                  string_value, &result)) {
-    printf("The default value %s is used.\n",
-           (Message() << default_value).GetString().c_str());
-    fflush(stdout);
-    return default_value;
-  }
-
-  return result;
-#endif  // defined(GTEST_GET_INT32_FROM_ENV_)
-}
-
-// As a special case for the 'output' flag, if GTEST_OUTPUT is not
-// set, we look for XML_OUTPUT_FILE, which is set by the Bazel build
-// system.  The value of XML_OUTPUT_FILE is a filename without the
-// "xml:" prefix of GTEST_OUTPUT.
-// Note that this is meant to be called at the call site so it does
-// not check that the flag is 'output'
-// In essence this checks an env variable called XML_OUTPUT_FILE
-// and if it is set we prepend "xml:" to its value, if it not set we return ""
-std::string OutputFlagAlsoCheckEnvVar(){
-  std::string default_value_for_output_flag = "";
-  const char* xml_output_file_env = posix::GetEnv("XML_OUTPUT_FILE");
-  if (nullptr != xml_output_file_env) {
-    default_value_for_output_flag = std::string("xml:") + xml_output_file_env;
-  }
-  return default_value_for_output_flag;
-}
-
-// Reads and returns the string environment variable corresponding to
-// the given flag; if it's not set, returns default_value.
-const char* StringFromGTestEnv(const char* flag, const char* default_value) {
-#if defined(GTEST_GET_STRING_FROM_ENV_)
-  return GTEST_GET_STRING_FROM_ENV_(flag, default_value);
-#else
-  const std::string env_var = FlagToEnvVar(flag);
-  const char* const value = posix::GetEnv(env_var.c_str());
-  return value == nullptr ? default_value : value;
-#endif  // defined(GTEST_GET_STRING_FROM_ENV_)
-}
-
-}  // namespace internal
-}  // namespace testing
-// Copyright 2007, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-// Google Test - The Google C++ Testing and Mocking Framework
-//
-// This file implements a universal value printer that can print a
-// value of any type T:
-//
-//   void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr);
-//
-// It uses the << operator when possible, and prints the bytes in the
-// object otherwise.  A user can override its behavior for a class
-// type Foo by defining either operator<<(::std::ostream&, const Foo&)
-// or void PrintTo(const Foo&, ::std::ostream*) in the namespace that
-// defines Foo.
-
-
-#include <stdio.h>
-
-#include <cctype>
-#include <cstdint>
-#include <cwchar>
-#include <ostream>  // NOLINT
-#include <string>
-#include <type_traits>
-
-
-namespace testing {
-
-namespace {
-
-using ::std::ostream;
-
-// Prints a segment of bytes in the given object.
-GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
-GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
-GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
-GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
-void PrintByteSegmentInObjectTo(const unsigned char* obj_bytes, size_t start,
-                                size_t count, ostream* os) {
-  char text[5] = "";
-  for (size_t i = 0; i != count; i++) {
-    const size_t j = start + i;
-    if (i != 0) {
-      // Organizes the bytes into groups of 2 for easy parsing by
-      // human.
-      if ((j % 2) == 0)
-        *os << ' ';
-      else
-        *os << '-';
-    }
-    GTEST_SNPRINTF_(text, sizeof(text), "%02X", obj_bytes[j]);
-    *os << text;
-  }
-}
-
-// Prints the bytes in the given value to the given ostream.
-void PrintBytesInObjectToImpl(const unsigned char* obj_bytes, size_t count,
-                              ostream* os) {
-  // Tells the user how big the object is.
-  *os << count << "-byte object <";
-
-  const size_t kThreshold = 132;
-  const size_t kChunkSize = 64;
-  // If the object size is bigger than kThreshold, we'll have to omit
-  // some details by printing only the first and the last kChunkSize
-  // bytes.
-  if (count < kThreshold) {
-    PrintByteSegmentInObjectTo(obj_bytes, 0, count, os);
-  } else {
-    PrintByteSegmentInObjectTo(obj_bytes, 0, kChunkSize, os);
-    *os << " ... ";
-    // Rounds up to 2-byte boundary.
-    const size_t resume_pos = (count - kChunkSize + 1)/2*2;
-    PrintByteSegmentInObjectTo(obj_bytes, resume_pos, count - resume_pos, os);
-  }
-  *os << ">";
-}
-
-// Helpers for widening a character to char32_t. Since the standard does not
-// specify if char / wchar_t is signed or unsigned, it is important to first
-// convert it to the unsigned type of the same width before widening it to
-// char32_t.
-template <typename CharType>
-char32_t ToChar32(CharType in) {
-  return static_cast<char32_t>(
-      static_cast<typename std::make_unsigned<CharType>::type>(in));
-}
-
-}  // namespace
-
-namespace internal {
-
-// Delegates to PrintBytesInObjectToImpl() to print the bytes in the
-// given object.  The delegation simplifies the implementation, which
-// uses the << operator and thus is easier done outside of the
-// ::testing::internal namespace, which contains a << operator that
-// sometimes conflicts with the one in STL.
-void PrintBytesInObjectTo(const unsigned char* obj_bytes, size_t count,
-                          ostream* os) {
-  PrintBytesInObjectToImpl(obj_bytes, count, os);
-}
-
-// Depending on the value of a char (or wchar_t), we print it in one
-// of three formats:
-//   - as is if it's a printable ASCII (e.g. 'a', '2', ' '),
-//   - as a hexadecimal escape sequence (e.g. '\x7F'), or
-//   - as a special escape sequence (e.g. '\r', '\n').
-enum CharFormat {
-  kAsIs,
-  kHexEscape,
-  kSpecialEscape
-};
-
-// Returns true if c is a printable ASCII character.  We test the
-// value of c directly instead of calling isprint(), which is buggy on
-// Windows Mobile.
-inline bool IsPrintableAscii(char32_t c) { return 0x20 <= c && c <= 0x7E; }
-
-// Prints c (of type char, char8_t, char16_t, char32_t, or wchar_t) as a
-// character literal without the quotes, escaping it when necessary; returns how
-// c was formatted.
-template <typename Char>
-static CharFormat PrintAsCharLiteralTo(Char c, ostream* os) {
-  const char32_t u_c = ToChar32(c);
-  switch (u_c) {
-    case L'\0':
-      *os << "\\0";
-      break;
-    case L'\'':
-      *os << "\\'";
-      break;
-    case L'\\':
-      *os << "\\\\";
-      break;
-    case L'\a':
-      *os << "\\a";
-      break;
-    case L'\b':
-      *os << "\\b";
-      break;
-    case L'\f':
-      *os << "\\f";
-      break;
-    case L'\n':
-      *os << "\\n";
-      break;
-    case L'\r':
-      *os << "\\r";
-      break;
-    case L'\t':
-      *os << "\\t";
-      break;
-    case L'\v':
-      *os << "\\v";
-      break;
-    default:
-      if (IsPrintableAscii(u_c)) {
-        *os << static_cast<char>(c);
-        return kAsIs;
-      } else {
-        ostream::fmtflags flags = os->flags();
-        *os << "\\x" << std::hex << std::uppercase << static_cast<int>(u_c);
-        os->flags(flags);
-        return kHexEscape;
-      }
-  }
-  return kSpecialEscape;
-}
-
-// Prints a char32_t c as if it's part of a string literal, escaping it when
-// necessary; returns how c was formatted.
-static CharFormat PrintAsStringLiteralTo(char32_t c, ostream* os) {
-  switch (c) {
-    case L'\'':
-      *os << "'";
-      return kAsIs;
-    case L'"':
-      *os << "\\\"";
-      return kSpecialEscape;
-    default:
-      return PrintAsCharLiteralTo(c, os);
-  }
-}
-
-static const char* GetCharWidthPrefix(char) {
-  return "";
-}
-
-static const char* GetCharWidthPrefix(signed char) {
-  return "";
-}
-
-static const char* GetCharWidthPrefix(unsigned char) {
-  return "";
-}
-
-#ifdef __cpp_char8_t
-static const char* GetCharWidthPrefix(char8_t) {
-  return "u8";
-}
-#endif
-
-static const char* GetCharWidthPrefix(char16_t) {
-  return "u";
-}
-
-static const char* GetCharWidthPrefix(char32_t) {
-  return "U";
-}
-
-static const char* GetCharWidthPrefix(wchar_t) {
-  return "L";
-}
-
-// Prints a char c as if it's part of a string literal, escaping it when
-// necessary; returns how c was formatted.
-static CharFormat PrintAsStringLiteralTo(char c, ostream* os) {
-  return PrintAsStringLiteralTo(ToChar32(c), os);
-}
-
-#ifdef __cpp_char8_t
-static CharFormat PrintAsStringLiteralTo(char8_t c, ostream* os) {
-  return PrintAsStringLiteralTo(ToChar32(c), os);
-}
-#endif
-
-static CharFormat PrintAsStringLiteralTo(char16_t c, ostream* os) {
-  return PrintAsStringLiteralTo(ToChar32(c), os);
-}
-
-static CharFormat PrintAsStringLiteralTo(wchar_t c, ostream* os) {
-  return PrintAsStringLiteralTo(ToChar32(c), os);
-}
-
-// Prints a character c (of type char, char8_t, char16_t, char32_t, or wchar_t)
-// and its code. '\0' is printed as "'\\0'", other unprintable characters are
-// also properly escaped using the standard C++ escape sequence.
-template <typename Char>
-void PrintCharAndCodeTo(Char c, ostream* os) {
-  // First, print c as a literal in the most readable form we can find.
-  *os << GetCharWidthPrefix(c) << "'";
-  const CharFormat format = PrintAsCharLiteralTo(c, os);
-  *os << "'";
-
-  // To aid user debugging, we also print c's code in decimal, unless
-  // it's 0 (in which case c was printed as '\\0', making the code
-  // obvious).
-  if (c == 0)
-    return;
-  *os << " (" << static_cast<int>(c);
-
-  // For more convenience, we print c's code again in hexadecimal,
-  // unless c was already printed in the form '\x##' or the code is in
-  // [1, 9].
-  if (format == kHexEscape || (1 <= c && c <= 9)) {
-    // Do nothing.
-  } else {
-    *os << ", 0x" << String::FormatHexInt(static_cast<int>(c));
-  }
-  *os << ")";
-}
-
-void PrintTo(unsigned char c, ::std::ostream* os) { PrintCharAndCodeTo(c, os); }
-void PrintTo(signed char c, ::std::ostream* os) { PrintCharAndCodeTo(c, os); }
-
-// Prints a wchar_t as a symbol if it is printable or as its internal
-// code otherwise and also as its code.  L'\0' is printed as "L'\\0'".
-void PrintTo(wchar_t wc, ostream* os) { PrintCharAndCodeTo(wc, os); }
-
-// TODO(dcheng): Consider making this delegate to PrintCharAndCodeTo() as well.
-void PrintTo(char32_t c, ::std::ostream* os) {
-  *os << std::hex << "U+" << std::uppercase << std::setfill('0') << std::setw(4)
-      << static_cast<uint32_t>(c);
-}
-
-// Prints the given array of characters to the ostream.  CharType must be either
-// char, char8_t, char16_t, char32_t, or wchar_t.
-// The array starts at begin, the length is len, it may include '\0' characters
-// and may not be NUL-terminated.
-template <typename CharType>
-GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
-GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
-GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
-GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
-static CharFormat PrintCharsAsStringTo(
-    const CharType* begin, size_t len, ostream* os) {
-  const char* const quote_prefix = GetCharWidthPrefix(*begin);
-  *os << quote_prefix << "\"";
-  bool is_previous_hex = false;
-  CharFormat print_format = kAsIs;
-  for (size_t index = 0; index < len; ++index) {
-    const CharType cur = begin[index];
-    if (is_previous_hex && IsXDigit(cur)) {
-      // Previous character is of '\x..' form and this character can be
-      // interpreted as another hexadecimal digit in its number. Break string to
-      // disambiguate.
-      *os << "\" " << quote_prefix << "\"";
-    }
-    is_previous_hex = PrintAsStringLiteralTo(cur, os) == kHexEscape;
-    // Remember if any characters required hex escaping.
-    if (is_previous_hex) {
-      print_format = kHexEscape;
-    }
-  }
-  *os << "\"";
-  return print_format;
-}
-
-// Prints a (const) char/wchar_t array of 'len' elements, starting at address
-// 'begin'.  CharType must be either char or wchar_t.
-template <typename CharType>
-GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
-GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
-GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
-GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
-static void UniversalPrintCharArray(
-    const CharType* begin, size_t len, ostream* os) {
-  // The code
-  //   const char kFoo[] = "foo";
-  // generates an array of 4, not 3, elements, with the last one being '\0'.
-  //
-  // Therefore when printing a char array, we don't print the last element if
-  // it's '\0', such that the output matches the string literal as it's
-  // written in the source code.
-  if (len > 0 && begin[len - 1] == '\0') {
-    PrintCharsAsStringTo(begin, len - 1, os);
-    return;
-  }
-
-  // If, however, the last element in the array is not '\0', e.g.
-  //    const char kFoo[] = { 'f', 'o', 'o' };
-  // we must print the entire array.  We also print a message to indicate
-  // that the array is not NUL-terminated.
-  PrintCharsAsStringTo(begin, len, os);
-  *os << " (no terminating NUL)";
-}
-
-// Prints a (const) char array of 'len' elements, starting at address 'begin'.
-void UniversalPrintArray(const char* begin, size_t len, ostream* os) {
-  UniversalPrintCharArray(begin, len, os);
-}
-
-#ifdef __cpp_char8_t
-// Prints a (const) char8_t array of 'len' elements, starting at address
-// 'begin'.
-void UniversalPrintArray(const char8_t* begin, size_t len, ostream* os) {
-  UniversalPrintCharArray(begin, len, os);
-}
-#endif
-
-// Prints a (const) char16_t array of 'len' elements, starting at address
-// 'begin'.
-void UniversalPrintArray(const char16_t* begin, size_t len, ostream* os) {
-  UniversalPrintCharArray(begin, len, os);
-}
-
-// Prints a (const) char32_t array of 'len' elements, starting at address
-// 'begin'.
-void UniversalPrintArray(const char32_t* begin, size_t len, ostream* os) {
-  UniversalPrintCharArray(begin, len, os);
-}
-
-// Prints a (const) wchar_t array of 'len' elements, starting at address
-// 'begin'.
-void UniversalPrintArray(const wchar_t* begin, size_t len, ostream* os) {
-  UniversalPrintCharArray(begin, len, os);
-}
-
-namespace {
-
-// Prints a null-terminated C-style string to the ostream.
-template <typename Char>
-void PrintCStringTo(const Char* s, ostream* os) {
-  if (s == nullptr) {
-    *os << "NULL";
-  } else {
-    *os << ImplicitCast_<const void*>(s) << " pointing to ";
-    PrintCharsAsStringTo(s, std::char_traits<Char>::length(s), os);
-  }
-}
-
-}  // anonymous namespace
-
-void PrintTo(const char* s, ostream* os) { PrintCStringTo(s, os); }
-
-#ifdef __cpp_char8_t
-void PrintTo(const char8_t* s, ostream* os) { PrintCStringTo(s, os); }
-#endif
-
-void PrintTo(const char16_t* s, ostream* os) { PrintCStringTo(s, os); }
-
-void PrintTo(const char32_t* s, ostream* os) { PrintCStringTo(s, os); }
-
-// MSVC compiler can be configured to define whar_t as a typedef
-// of unsigned short. Defining an overload for const wchar_t* in that case
-// would cause pointers to unsigned shorts be printed as wide strings,
-// possibly accessing more memory than intended and causing invalid
-// memory accesses. MSVC defines _NATIVE_WCHAR_T_DEFINED symbol when
-// wchar_t is implemented as a native type.
-#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
-// Prints the given wide C string to the ostream.
-void PrintTo(const wchar_t* s, ostream* os) { PrintCStringTo(s, os); }
-#endif  // wchar_t is native
-
-namespace {
-
-bool ContainsUnprintableControlCodes(const char* str, size_t length) {
-  const unsigned char *s = reinterpret_cast<const unsigned char *>(str);
-
-  for (size_t i = 0; i < length; i++) {
-    unsigned char ch = *s++;
-    if (std::iscntrl(ch)) {
-        switch (ch) {
-        case '\t':
-        case '\n':
-        case '\r':
-          break;
-        default:
-          return true;
-        }
-      }
-  }
-  return false;
-}
-
-bool IsUTF8TrailByte(unsigned char t) { return 0x80 <= t && t<= 0xbf; }
-
-bool IsValidUTF8(const char* str, size_t length) {
-  const unsigned char *s = reinterpret_cast<const unsigned char *>(str);
-
-  for (size_t i = 0; i < length;) {
-    unsigned char lead = s[i++];
-
-    if (lead <= 0x7f) {
-      continue;  // single-byte character (ASCII) 0..7F
-    }
-    if (lead < 0xc2) {
-      return false;  // trail byte or non-shortest form
-    } else if (lead <= 0xdf && (i + 1) <= length && IsUTF8TrailByte(s[i])) {
-      ++i;  // 2-byte character
-    } else if (0xe0 <= lead && lead <= 0xef && (i + 2) <= length &&
-               IsUTF8TrailByte(s[i]) &&
-               IsUTF8TrailByte(s[i + 1]) &&
-               // check for non-shortest form and surrogate
-               (lead != 0xe0 || s[i] >= 0xa0) &&
-               (lead != 0xed || s[i] < 0xa0)) {
-      i += 2;  // 3-byte character
-    } else if (0xf0 <= lead && lead <= 0xf4 && (i + 3) <= length &&
-               IsUTF8TrailByte(s[i]) &&
-               IsUTF8TrailByte(s[i + 1]) &&
-               IsUTF8TrailByte(s[i + 2]) &&
-               // check for non-shortest form
-               (lead != 0xf0 || s[i] >= 0x90) &&
-               (lead != 0xf4 || s[i] < 0x90)) {
-      i += 3;  // 4-byte character
-    } else {
-      return false;
-    }
-  }
-  return true;
-}
-
-void ConditionalPrintAsText(const char* str, size_t length, ostream* os) {
-  if (!ContainsUnprintableControlCodes(str, length) &&
-      IsValidUTF8(str, length)) {
-    *os << "\n    As Text: \"" << str << "\"";
-  }
-}
-
-}  // anonymous namespace
-
-void PrintStringTo(const ::std::string& s, ostream* os) {
-  if (PrintCharsAsStringTo(s.data(), s.size(), os) == kHexEscape) {
-    if (GTEST_FLAG(print_utf8)) {
-      ConditionalPrintAsText(s.data(), s.size(), os);
-    }
-  }
-}
-
-#ifdef __cpp_char8_t
-void PrintU8StringTo(const ::std::u8string& s, ostream* os) {
-  PrintCharsAsStringTo(s.data(), s.size(), os);
-}
-#endif
-
-void PrintU16StringTo(const ::std::u16string& s, ostream* os) {
-  PrintCharsAsStringTo(s.data(), s.size(), os);
-}
-
-void PrintU32StringTo(const ::std::u32string& s, ostream* os) {
-  PrintCharsAsStringTo(s.data(), s.size(), os);
-}
-
-#if GTEST_HAS_STD_WSTRING
-void PrintWideStringTo(const ::std::wstring& s, ostream* os) {
-  PrintCharsAsStringTo(s.data(), s.size(), os);
-}
-#endif  // GTEST_HAS_STD_WSTRING
-
-}  // namespace internal
-
-}  // namespace testing
-// Copyright 2008, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-//
-// The Google C++ Testing and Mocking Framework (Google Test)
-
-
-
-namespace testing {
-
-using internal::GetUnitTestImpl;
-
-// Gets the summary of the failure message by omitting the stack trace
-// in it.
-std::string TestPartResult::ExtractSummary(const char* message) {
-  const char* const stack_trace = strstr(message, internal::kStackTraceMarker);
-  return stack_trace == nullptr ? message : std::string(message, stack_trace);
-}
-
-// Prints a TestPartResult object.
-std::ostream& operator<<(std::ostream& os, const TestPartResult& result) {
-  return os << internal::FormatFileLocation(result.file_name(),
-                                            result.line_number())
-            << " "
-            << (result.type() == TestPartResult::kSuccess
-                    ? "Success"
-                    : result.type() == TestPartResult::kSkip
-                          ? "Skipped"
-                          : result.type() == TestPartResult::kFatalFailure
-                                ? "Fatal failure"
-                                : "Non-fatal failure")
-            << ":\n"
-            << result.message() << std::endl;
-}
-
-// Appends a TestPartResult to the array.
-void TestPartResultArray::Append(const TestPartResult& result) {
-  array_.push_back(result);
-}
-
-// Returns the TestPartResult at the given index (0-based).
-const TestPartResult& TestPartResultArray::GetTestPartResult(int index) const {
-  if (index < 0 || index >= size()) {
-    printf("\nInvalid index (%d) into TestPartResultArray.\n", index);
-    internal::posix::Abort();
-  }
-
-  return array_[static_cast<size_t>(index)];
-}
-
-// Returns the number of TestPartResult objects in the array.
-int TestPartResultArray::size() const {
-  return static_cast<int>(array_.size());
-}
-
-namespace internal {
-
-HasNewFatalFailureHelper::HasNewFatalFailureHelper()
-    : has_new_fatal_failure_(false),
-      original_reporter_(GetUnitTestImpl()->
-                         GetTestPartResultReporterForCurrentThread()) {
-  GetUnitTestImpl()->SetTestPartResultReporterForCurrentThread(this);
-}
-
-HasNewFatalFailureHelper::~HasNewFatalFailureHelper() {
-  GetUnitTestImpl()->SetTestPartResultReporterForCurrentThread(
-      original_reporter_);
-}
-
-void HasNewFatalFailureHelper::ReportTestPartResult(
-    const TestPartResult& result) {
-  if (result.fatally_failed())
-    has_new_fatal_failure_ = true;
-  original_reporter_->ReportTestPartResult(result);
-}
-
-}  // namespace internal
-
-}  // namespace testing
-// Copyright 2008 Google Inc.
-// All Rights Reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-
-
-namespace testing {
-namespace internal {
-
-// Skips to the first non-space char in str. Returns an empty string if str
-// contains only whitespace characters.
-static const char* SkipSpaces(const char* str) {
-  while (IsSpace(*str))
-    str++;
-  return str;
-}
-
-static std::vector<std::string> SplitIntoTestNames(const char* src) {
-  std::vector<std::string> name_vec;
-  src = SkipSpaces(src);
-  for (; src != nullptr; src = SkipComma(src)) {
-    name_vec.push_back(StripTrailingSpaces(GetPrefixUntilComma(src)));
-  }
-  return name_vec;
-}
-
-// Verifies that registered_tests match the test names in
-// registered_tests_; returns registered_tests if successful, or
-// aborts the program otherwise.
-const char* TypedTestSuitePState::VerifyRegisteredTestNames(
-    const char* test_suite_name, const char* file, int line,
-    const char* registered_tests) {
-  RegisterTypeParameterizedTestSuite(test_suite_name, CodeLocation(file, line));
-
-  typedef RegisteredTestsMap::const_iterator RegisteredTestIter;
-  registered_ = true;
-
-  std::vector<std::string> name_vec = SplitIntoTestNames(registered_tests);
-
-  Message errors;
-
-  std::set<std::string> tests;
-  for (std::vector<std::string>::const_iterator name_it = name_vec.begin();
-       name_it != name_vec.end(); ++name_it) {
-    const std::string& name = *name_it;
-    if (tests.count(name) != 0) {
-      errors << "Test " << name << " is listed more than once.\n";
-      continue;
-    }
-
-    if (registered_tests_.count(name) != 0) {
-      tests.insert(name);
-    } else {
-      errors << "No test named " << name
-             << " can be found in this test suite.\n";
-    }
-  }
-
-  for (RegisteredTestIter it = registered_tests_.begin();
-       it != registered_tests_.end();
-       ++it) {
-    if (tests.count(it->first) == 0) {
-      errors << "You forgot to list test " << it->first << ".\n";
-    }
-  }
-
-  const std::string& errors_str = errors.GetString();
-  if (errors_str != "") {
-    fprintf(stderr, "%s %s", FormatFileLocation(file, line).c_str(),
-            errors_str.c_str());
-    fflush(stderr);
-    posix::Abort();
-  }
-
-  return registered_tests;
-}
-
-}  // namespace internal
-}  // namespace testing
diff --git a/test/gtest/gtest.h b/test/gtest/gtest.h
deleted file mode 100644
index e749057..0000000
--- a/test/gtest/gtest.h
+++ /dev/null
@@ -1,12377 +0,0 @@
-// Copyright 2005, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-//
-// The Google C++ Testing and Mocking Framework (Google Test)
-//
-// This header file defines the public API for Google Test.  It should be
-// included by any test program that uses Google Test.
-//
-// IMPORTANT NOTE: Due to limitation of the C++ language, we have to
-// leave some internal implementation details in this header file.
-// They are clearly marked by comments like this:
-//
-//   // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-//
-// Such code is NOT meant to be used by a user directly, and is subject
-// to CHANGE WITHOUT NOTICE.  Therefore DO NOT DEPEND ON IT in a user
-// program!
-//
-// Acknowledgment: Google Test borrowed the idea of automatic test
-// registration from Barthelemy Dagenais' (barthelemy@prologique.com)
-// easyUnit framework.
-
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_H_
-#define GOOGLETEST_INCLUDE_GTEST_GTEST_H_
-
-#include <cstddef>
-#include <limits>
-#include <memory>
-#include <ostream>
-#include <type_traits>
-#include <vector>
-
-// Copyright 2005, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// The Google C++ Testing and Mocking Framework (Google Test)
-//
-// This header file declares functions and macros used internally by
-// Google Test.  They are subject to change without notice.
-
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
-#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
-
-// Copyright 2005, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// Low-level types and utilities for porting Google Test to various
-// platforms.  All macros ending with _ and symbols defined in an
-// internal namespace are subject to change without notice.  Code
-// outside Google Test MUST NOT USE THEM DIRECTLY.  Macros that don't
-// end with _ are part of Google Test's public API and can be used by
-// code outside Google Test.
-//
-// This file is fundamental to Google Test.  All other Google Test source
-// files are expected to #include this.  Therefore, it cannot #include
-// any other Google Test header.
-
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_
-#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_
-
-// Environment-describing macros
-// -----------------------------
-//
-// Google Test can be used in many different environments.  Macros in
-// this section tell Google Test what kind of environment it is being
-// used in, such that Google Test can provide environment-specific
-// features and implementations.
-//
-// Google Test tries to automatically detect the properties of its
-// environment, so users usually don't need to worry about these
-// macros.  However, the automatic detection is not perfect.
-// Sometimes it's necessary for a user to define some of the following
-// macros in the build script to override Google Test's decisions.
-//
-// If the user doesn't define a macro in the list, Google Test will
-// provide a default definition.  After this header is #included, all
-// macros in this list will be defined to either 1 or 0.
-//
-// Notes to maintainers:
-//   - Each macro here is a user-tweakable knob; do not grow the list
-//     lightly.
-//   - Use #if to key off these macros.  Don't use #ifdef or "#if
-//     defined(...)", which will not work as these macros are ALWAYS
-//     defined.
-//
-//   GTEST_HAS_CLONE          - Define it to 1/0 to indicate that clone(2)
-//                              is/isn't available.
-//   GTEST_HAS_EXCEPTIONS     - Define it to 1/0 to indicate that exceptions
-//                              are enabled.
-//   GTEST_HAS_POSIX_RE       - Define it to 1/0 to indicate that POSIX regular
-//                              expressions are/aren't available.
-//   GTEST_HAS_PTHREAD        - Define it to 1/0 to indicate that <pthread.h>
-//                              is/isn't available.
-//   GTEST_HAS_RTTI           - Define it to 1/0 to indicate that RTTI is/isn't
-//                              enabled.
-//   GTEST_HAS_STD_WSTRING    - Define it to 1/0 to indicate that
-//                              std::wstring does/doesn't work (Google Test can
-//                              be used where std::wstring is unavailable).
-//   GTEST_HAS_SEH            - Define it to 1/0 to indicate whether the
-//                              compiler supports Microsoft's "Structured
-//                              Exception Handling".
-//   GTEST_HAS_STREAM_REDIRECTION
-//                            - Define it to 1/0 to indicate whether the
-//                              platform supports I/O stream redirection using
-//                              dup() and dup2().
-//   GTEST_LINKED_AS_SHARED_LIBRARY
-//                            - Define to 1 when compiling tests that use
-//                              Google Test as a shared library (known as
-//                              DLL on Windows).
-//   GTEST_CREATE_SHARED_LIBRARY
-//                            - Define to 1 when compiling Google Test itself
-//                              as a shared library.
-//   GTEST_DEFAULT_DEATH_TEST_STYLE
-//                            - The default value of --gtest_death_test_style.
-//                              The legacy default has been "fast" in the open
-//                              source version since 2008. The recommended value
-//                              is "threadsafe", and can be set in
-//                              custom/gtest-port.h.
-
-// Platform-indicating macros
-// --------------------------
-//
-// Macros indicating the platform on which Google Test is being used
-// (a macro is defined to 1 if compiled on the given platform;
-// otherwise UNDEFINED -- it's never defined to 0.).  Google Test
-// defines these macros automatically.  Code outside Google Test MUST
-// NOT define them.
-//
-//   GTEST_OS_AIX      - IBM AIX
-//   GTEST_OS_CYGWIN   - Cygwin
-//   GTEST_OS_DRAGONFLY - DragonFlyBSD
-//   GTEST_OS_FREEBSD  - FreeBSD
-//   GTEST_OS_FUCHSIA  - Fuchsia
-//   GTEST_OS_GNU_KFREEBSD - GNU/kFreeBSD
-//   GTEST_OS_HAIKU    - Haiku
-//   GTEST_OS_HPUX     - HP-UX
-//   GTEST_OS_LINUX    - Linux
-//     GTEST_OS_LINUX_ANDROID - Google Android
-//   GTEST_OS_MAC      - Mac OS X
-//     GTEST_OS_IOS    - iOS
-//   GTEST_OS_NACL     - Google Native Client (NaCl)
-//   GTEST_OS_NETBSD   - NetBSD
-//   GTEST_OS_OPENBSD  - OpenBSD
-//   GTEST_OS_OS2      - OS/2
-//   GTEST_OS_QNX      - QNX
-//   GTEST_OS_SOLARIS  - Sun Solaris
-//   GTEST_OS_WINDOWS  - Windows (Desktop, MinGW, or Mobile)
-//     GTEST_OS_WINDOWS_DESKTOP  - Windows Desktop
-//     GTEST_OS_WINDOWS_MINGW    - MinGW
-//     GTEST_OS_WINDOWS_MOBILE   - Windows Mobile
-//     GTEST_OS_WINDOWS_PHONE    - Windows Phone
-//     GTEST_OS_WINDOWS_RT       - Windows Store App/WinRT
-//   GTEST_OS_ZOS      - z/OS
-//
-// Among the platforms, Cygwin, Linux, Mac OS X, and Windows have the
-// most stable support.  Since core members of the Google Test project
-// don't have access to other platforms, support for them may be less
-// stable.  If you notice any problems on your platform, please notify
-// googletestframework@googlegroups.com (patches for fixing them are
-// even more welcome!).
-//
-// It is possible that none of the GTEST_OS_* macros are defined.
-
-// Feature-indicating macros
-// -------------------------
-//
-// Macros indicating which Google Test features are available (a macro
-// is defined to 1 if the corresponding feature is supported;
-// otherwise UNDEFINED -- it's never defined to 0.).  Google Test
-// defines these macros automatically.  Code outside Google Test MUST
-// NOT define them.
-//
-// These macros are public so that portable tests can be written.
-// Such tests typically surround code using a feature with an #if
-// which controls that code.  For example:
-//
-// #if GTEST_HAS_DEATH_TEST
-//   EXPECT_DEATH(DoSomethingDeadly());
-// #endif
-//
-//   GTEST_HAS_DEATH_TEST   - death tests
-//   GTEST_HAS_TYPED_TEST   - typed tests
-//   GTEST_HAS_TYPED_TEST_P - type-parameterized tests
-//   GTEST_IS_THREADSAFE    - Google Test is thread-safe.
-//   GOOGLETEST_CM0007 DO NOT DELETE
-//   GTEST_USES_POSIX_RE    - enhanced POSIX regex is used. Do not confuse with
-//                            GTEST_HAS_POSIX_RE (see above) which users can
-//                            define themselves.
-//   GTEST_USES_SIMPLE_RE   - our own simple regex is used;
-//                            the above RE\b(s) are mutually exclusive.
-
-// Misc public macros
-// ------------------
-//
-//   GTEST_FLAG(flag_name)  - references the variable corresponding to
-//                            the given Google Test flag.
-
-// Internal utilities
-// ------------------
-//
-// The following macros and utilities are for Google Test's INTERNAL
-// use only.  Code outside Google Test MUST NOT USE THEM DIRECTLY.
-//
-// Macros for basic C++ coding:
-//   GTEST_AMBIGUOUS_ELSE_BLOCKER_ - for disabling a gcc warning.
-//   GTEST_ATTRIBUTE_UNUSED_  - declares that a class' instances or a
-//                              variable don't have to be used.
-//   GTEST_DISALLOW_ASSIGN_   - disables copy operator=.
-//   GTEST_DISALLOW_COPY_AND_ASSIGN_ - disables copy ctor and operator=.
-//   GTEST_DISALLOW_MOVE_ASSIGN_   - disables move operator=.
-//   GTEST_DISALLOW_MOVE_AND_ASSIGN_ - disables move ctor and operator=.
-//   GTEST_MUST_USE_RESULT_   - declares that a function's result must be used.
-//   GTEST_INTENTIONAL_CONST_COND_PUSH_ - start code section where MSVC C4127 is
-//                                        suppressed (constant conditional).
-//   GTEST_INTENTIONAL_CONST_COND_POP_  - finish code section where MSVC C4127
-//                                        is suppressed.
-//   GTEST_INTERNAL_HAS_ANY - for enabling UniversalPrinter<std::any> or
-//                            UniversalPrinter<absl::any> specializations.
-//   GTEST_INTERNAL_HAS_OPTIONAL - for enabling UniversalPrinter<std::optional>
-//   or
-//                                 UniversalPrinter<absl::optional>
-//                                 specializations.
-//   GTEST_INTERNAL_HAS_STRING_VIEW - for enabling Matcher<std::string_view> or
-//                                    Matcher<absl::string_view>
-//                                    specializations.
-//   GTEST_INTERNAL_HAS_VARIANT - for enabling UniversalPrinter<std::variant> or
-//                                UniversalPrinter<absl::variant>
-//                                specializations.
-//
-// Synchronization:
-//   Mutex, MutexLock, ThreadLocal, GetThreadCount()
-//                            - synchronization primitives.
-//
-// Regular expressions:
-//   RE             - a simple regular expression class using the POSIX
-//                    Extended Regular Expression syntax on UNIX-like platforms
-//                    GOOGLETEST_CM0008 DO NOT DELETE
-//                    or a reduced regular exception syntax on other
-//                    platforms, including Windows.
-// Logging:
-//   GTEST_LOG_()   - logs messages at the specified severity level.
-//   LogToStderr()  - directs all log messages to stderr.
-//   FlushInfoLog() - flushes informational log messages.
-//
-// Stdout and stderr capturing:
-//   CaptureStdout()     - starts capturing stdout.
-//   GetCapturedStdout() - stops capturing stdout and returns the captured
-//                         string.
-//   CaptureStderr()     - starts capturing stderr.
-//   GetCapturedStderr() - stops capturing stderr and returns the captured
-//                         string.
-//
-// Integer types:
-//   TypeWithSize   - maps an integer to a int type.
-//   TimeInMillis   - integers of known sizes.
-//   BiggestInt     - the biggest signed integer type.
-//
-// Command-line utilities:
-//   GTEST_DECLARE_*()  - declares a flag.
-//   GTEST_DEFINE_*()   - defines a flag.
-//   GetInjectableArgvs() - returns the command line as a vector of strings.
-//
-// Environment variable utilities:
-//   GetEnv()             - gets the value of an environment variable.
-//   BoolFromGTestEnv()   - parses a bool environment variable.
-//   Int32FromGTestEnv()  - parses an int32_t environment variable.
-//   StringFromGTestEnv() - parses a string environment variable.
-//
-// Deprecation warnings:
-//   GTEST_INTERNAL_DEPRECATED(message) - attribute marking a function as
-//                                        deprecated; calling a marked function
-//                                        should generate a compiler warning
-
-#include <ctype.h>   // for isspace, etc
-#include <stddef.h>  // for ptrdiff_t
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <cerrno>
-#include <cstdint>
-#include <limits>
-#include <type_traits>
-
-#ifndef _WIN32_WCE
-# include <sys/types.h>
-# include <sys/stat.h>
-#endif  // !_WIN32_WCE
-
-#if defined __APPLE__
-# include <AvailabilityMacros.h>
-# include <TargetConditionals.h>
-#endif
-
-#include <iostream>  // NOLINT
-#include <locale>
-#include <memory>
-#include <string>  // NOLINT
-#include <tuple>
-#include <vector>  // NOLINT
-
-// Copyright 2015, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// Injection point for custom user configurations. See README for details
-//
-// ** Custom implementation starts here **
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PORT_H_
-#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PORT_H_
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PORT_H_
-// Copyright 2015, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// The Google C++ Testing and Mocking Framework (Google Test)
-//
-// This header file defines the GTEST_OS_* macro.
-// It is separate from gtest-port.h so that custom/gtest-port.h can include it.
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_ARCH_H_
-#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_ARCH_H_
-
-// Determines the platform on which Google Test is compiled.
-#ifdef __CYGWIN__
-# define GTEST_OS_CYGWIN 1
-# elif defined(__MINGW__) || defined(__MINGW32__) || defined(__MINGW64__)
-#  define GTEST_OS_WINDOWS_MINGW 1
-#  define GTEST_OS_WINDOWS 1
-#elif defined _WIN32
-# define GTEST_OS_WINDOWS 1
-# ifdef _WIN32_WCE
-#  define GTEST_OS_WINDOWS_MOBILE 1
-# elif defined(WINAPI_FAMILY)
-#  include <winapifamily.h>
-#  if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
-#   define GTEST_OS_WINDOWS_DESKTOP 1
-#  elif WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_PHONE_APP)
-#   define GTEST_OS_WINDOWS_PHONE 1
-#  elif WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP)
-#   define GTEST_OS_WINDOWS_RT 1
-#  elif WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_TV_TITLE)
-#   define GTEST_OS_WINDOWS_PHONE 1
-#   define GTEST_OS_WINDOWS_TV_TITLE 1
-#  else
-    // WINAPI_FAMILY defined but no known partition matched.
-    // Default to desktop.
-#   define GTEST_OS_WINDOWS_DESKTOP 1
-#  endif
-# else
-#  define GTEST_OS_WINDOWS_DESKTOP 1
-# endif  // _WIN32_WCE
-#elif defined __OS2__
-# define GTEST_OS_OS2 1
-#elif defined __APPLE__
-# define GTEST_OS_MAC 1
-# include <TargetConditionals.h>
-# if TARGET_OS_IPHONE
-#  define GTEST_OS_IOS 1
-# endif
-#elif defined __DragonFly__
-# define GTEST_OS_DRAGONFLY 1
-#elif defined __FreeBSD__
-# define GTEST_OS_FREEBSD 1
-#elif defined __Fuchsia__
-# define GTEST_OS_FUCHSIA 1
-#elif defined(__GLIBC__) && defined(__FreeBSD_kernel__)
-# define GTEST_OS_GNU_KFREEBSD 1
-#elif defined __linux__
-# define GTEST_OS_LINUX 1
-# if defined __ANDROID__
-#  define GTEST_OS_LINUX_ANDROID 1
-# endif
-#elif defined __MVS__
-# define GTEST_OS_ZOS 1
-#elif defined(__sun) && defined(__SVR4)
-# define GTEST_OS_SOLARIS 1
-#elif defined(_AIX)
-# define GTEST_OS_AIX 1
-#elif defined(__hpux)
-# define GTEST_OS_HPUX 1
-#elif defined __native_client__
-# define GTEST_OS_NACL 1
-#elif defined __NetBSD__
-# define GTEST_OS_NETBSD 1
-#elif defined __OpenBSD__
-# define GTEST_OS_OPENBSD 1
-#elif defined __QNX__
-# define GTEST_OS_QNX 1
-#elif defined(__HAIKU__)
-#define GTEST_OS_HAIKU 1
-#elif defined ESP8266
-#define GTEST_OS_ESP8266 1
-#elif defined ESP32
-#define GTEST_OS_ESP32 1
-#elif defined(__XTENSA__)
-#define GTEST_OS_XTENSA 1
-#endif  // __CYGWIN__
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_ARCH_H_
-
-#if !defined(GTEST_DEV_EMAIL_)
-# define GTEST_DEV_EMAIL_ "googletestframework@@googlegroups.com"
-# define GTEST_FLAG_PREFIX_ "gtest_"
-# define GTEST_FLAG_PREFIX_DASH_ "gtest-"
-# define GTEST_FLAG_PREFIX_UPPER_ "GTEST_"
-# define GTEST_NAME_ "Google Test"
-# define GTEST_PROJECT_URL_ "https://github.com/google/googletest/"
-#endif  // !defined(GTEST_DEV_EMAIL_)
-
-#if !defined(GTEST_INIT_GOOGLE_TEST_NAME_)
-# define GTEST_INIT_GOOGLE_TEST_NAME_ "testing::InitGoogleTest"
-#endif  // !defined(GTEST_INIT_GOOGLE_TEST_NAME_)
-
-// Determines the version of gcc that is used to compile this.
-#ifdef __GNUC__
-// 40302 means version 4.3.2.
-# define GTEST_GCC_VER_ \
-    (__GNUC__*10000 + __GNUC_MINOR__*100 + __GNUC_PATCHLEVEL__)
-#endif  // __GNUC__
-
-// Macros for disabling Microsoft Visual C++ warnings.
-//
-//   GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800 4385)
-//   /* code that triggers warnings C4800 and C4385 */
-//   GTEST_DISABLE_MSC_WARNINGS_POP_()
-#if defined(_MSC_VER)
-# define GTEST_DISABLE_MSC_WARNINGS_PUSH_(warnings) \
-    __pragma(warning(push))                        \
-    __pragma(warning(disable: warnings))
-# define GTEST_DISABLE_MSC_WARNINGS_POP_()          \
-    __pragma(warning(pop))
-#else
-// Not all compilers are MSVC
-# define GTEST_DISABLE_MSC_WARNINGS_PUSH_(warnings)
-# define GTEST_DISABLE_MSC_WARNINGS_POP_()
-#endif
-
-// Clang on Windows does not understand MSVC's pragma warning.
-// We need clang-specific way to disable function deprecation warning.
-#ifdef __clang__
-# define GTEST_DISABLE_MSC_DEPRECATED_PUSH_()                         \
-    _Pragma("clang diagnostic push")                                  \
-    _Pragma("clang diagnostic ignored \"-Wdeprecated-declarations\"") \
-    _Pragma("clang diagnostic ignored \"-Wdeprecated-implementations\"")
-#define GTEST_DISABLE_MSC_DEPRECATED_POP_() \
-    _Pragma("clang diagnostic pop")
-#else
-# define GTEST_DISABLE_MSC_DEPRECATED_PUSH_() \
-    GTEST_DISABLE_MSC_WARNINGS_PUSH_(4996)
-# define GTEST_DISABLE_MSC_DEPRECATED_POP_() \
-    GTEST_DISABLE_MSC_WARNINGS_POP_()
-#endif
-
-// Brings in definitions for functions used in the testing::internal::posix
-// namespace (read, write, close, chdir, isatty, stat). We do not currently
-// use them on Windows Mobile.
-#if GTEST_OS_WINDOWS
-# if !GTEST_OS_WINDOWS_MOBILE
-#  include <direct.h>
-#  include <io.h>
-# endif
-// In order to avoid having to include <windows.h>, use forward declaration
-#if GTEST_OS_WINDOWS_MINGW && !defined(__MINGW64_VERSION_MAJOR)
-// MinGW defined _CRITICAL_SECTION and _RTL_CRITICAL_SECTION as two
-// separate (equivalent) structs, instead of using typedef
-typedef struct _CRITICAL_SECTION GTEST_CRITICAL_SECTION;
-#else
-// Assume CRITICAL_SECTION is a typedef of _RTL_CRITICAL_SECTION.
-// This assumption is verified by
-// WindowsTypesTest.CRITICAL_SECTIONIs_RTL_CRITICAL_SECTION.
-typedef struct _RTL_CRITICAL_SECTION GTEST_CRITICAL_SECTION;
-#endif
-#elif GTEST_OS_XTENSA
-#include <unistd.h>
-// Xtensa toolchains define strcasecmp in the string.h header instead of
-// strings.h. string.h is already included.
-#else
-// This assumes that non-Windows OSes provide unistd.h. For OSes where this
-// is not the case, we need to include headers that provide the functions
-// mentioned above.
-# include <unistd.h>
-# include <strings.h>
-#endif  // GTEST_OS_WINDOWS
-
-#if GTEST_OS_LINUX_ANDROID
-// Used to define __ANDROID_API__ matching the target NDK API level.
-#  include <android/api-level.h>  // NOLINT
-#endif
-
-// Defines this to true if and only if Google Test can use POSIX regular
-// expressions.
-#ifndef GTEST_HAS_POSIX_RE
-# if GTEST_OS_LINUX_ANDROID
-// On Android, <regex.h> is only available starting with Gingerbread.
-#  define GTEST_HAS_POSIX_RE (__ANDROID_API__ >= 9)
-# else
-#define GTEST_HAS_POSIX_RE (!GTEST_OS_WINDOWS && !GTEST_OS_XTENSA)
-# endif
-#endif
-
-#if GTEST_USES_PCRE
-// The appropriate headers have already been included.
-
-#elif GTEST_HAS_POSIX_RE
-
-// On some platforms, <regex.h> needs someone to define size_t, and
-// won't compile otherwise.  We can #include it here as we already
-// included <stdlib.h>, which is guaranteed to define size_t through
-// <stddef.h>.
-# include <regex.h>  // NOLINT
-
-# define GTEST_USES_POSIX_RE 1
-
-#elif GTEST_OS_WINDOWS
-
-// <regex.h> is not available on Windows.  Use our own simple regex
-// implementation instead.
-# define GTEST_USES_SIMPLE_RE 1
-
-#else
-
-// <regex.h> may not be available on this platform.  Use our own
-// simple regex implementation instead.
-# define GTEST_USES_SIMPLE_RE 1
-
-#endif  // GTEST_USES_PCRE
-
-#ifndef GTEST_HAS_EXCEPTIONS
-// The user didn't tell us whether exceptions are enabled, so we need
-// to figure it out.
-# if defined(_MSC_VER) && defined(_CPPUNWIND)
-// MSVC defines _CPPUNWIND to 1 if and only if exceptions are enabled.
-#  define GTEST_HAS_EXCEPTIONS 1
-# elif defined(__BORLANDC__)
-// C++Builder's implementation of the STL uses the _HAS_EXCEPTIONS
-// macro to enable exceptions, so we'll do the same.
-// Assumes that exceptions are enabled by default.
-#  ifndef _HAS_EXCEPTIONS
-#   define _HAS_EXCEPTIONS 1
-#  endif  // _HAS_EXCEPTIONS
-#  define GTEST_HAS_EXCEPTIONS _HAS_EXCEPTIONS
-# elif defined(__clang__)
-// clang defines __EXCEPTIONS if and only if exceptions are enabled before clang
-// 220714, but if and only if cleanups are enabled after that. In Obj-C++ files,
-// there can be cleanups for ObjC exceptions which also need cleanups, even if
-// C++ exceptions are disabled. clang has __has_feature(cxx_exceptions) which
-// checks for C++ exceptions starting at clang r206352, but which checked for
-// cleanups prior to that. To reliably check for C++ exception availability with
-// clang, check for
-// __EXCEPTIONS && __has_feature(cxx_exceptions).
-#  define GTEST_HAS_EXCEPTIONS (__EXCEPTIONS && __has_feature(cxx_exceptions))
-# elif defined(__GNUC__) && __EXCEPTIONS
-// gcc defines __EXCEPTIONS to 1 if and only if exceptions are enabled.
-#  define GTEST_HAS_EXCEPTIONS 1
-# elif defined(__SUNPRO_CC)
-// Sun Pro CC supports exceptions.  However, there is no compile-time way of
-// detecting whether they are enabled or not.  Therefore, we assume that
-// they are enabled unless the user tells us otherwise.
-#  define GTEST_HAS_EXCEPTIONS 1
-# elif defined(__IBMCPP__) && __EXCEPTIONS
-// xlC defines __EXCEPTIONS to 1 if and only if exceptions are enabled.
-#  define GTEST_HAS_EXCEPTIONS 1
-# elif defined(__HP_aCC)
-// Exception handling is in effect by default in HP aCC compiler. It has to
-// be turned of by +noeh compiler option if desired.
-#  define GTEST_HAS_EXCEPTIONS 1
-# else
-// For other compilers, we assume exceptions are disabled to be
-// conservative.
-#  define GTEST_HAS_EXCEPTIONS 0
-# endif  // defined(_MSC_VER) || defined(__BORLANDC__)
-#endif  // GTEST_HAS_EXCEPTIONS
-
-#ifndef GTEST_HAS_STD_WSTRING
-// The user didn't tell us whether ::std::wstring is available, so we need
-// to figure it out.
-// Cygwin 1.7 and below doesn't support ::std::wstring.
-// Solaris' libc++ doesn't support it either.  Android has
-// no support for it at least as recent as Froyo (2.2).
-#define GTEST_HAS_STD_WSTRING                                         \
-  (!(GTEST_OS_LINUX_ANDROID || GTEST_OS_CYGWIN || GTEST_OS_SOLARIS || \
-     GTEST_OS_HAIKU || GTEST_OS_ESP32 || GTEST_OS_ESP8266 || GTEST_OS_XTENSA))
-
-#endif  // GTEST_HAS_STD_WSTRING
-
-// Determines whether RTTI is available.
-#ifndef GTEST_HAS_RTTI
-// The user didn't tell us whether RTTI is enabled, so we need to
-// figure it out.
-
-# ifdef _MSC_VER
-
-#ifdef _CPPRTTI  // MSVC defines this macro if and only if RTTI is enabled.
-#   define GTEST_HAS_RTTI 1
-#  else
-#   define GTEST_HAS_RTTI 0
-#  endif
-
-// Starting with version 4.3.2, gcc defines __GXX_RTTI if and only if RTTI is
-// enabled.
-# elif defined(__GNUC__)
-
-#  ifdef __GXX_RTTI
-// When building against STLport with the Android NDK and with
-// -frtti -fno-exceptions, the build fails at link time with undefined
-// references to __cxa_bad_typeid. Note sure if STL or toolchain bug,
-// so disable RTTI when detected.
-#   if GTEST_OS_LINUX_ANDROID && defined(_STLPORT_MAJOR) && \
-       !defined(__EXCEPTIONS)
-#    define GTEST_HAS_RTTI 0
-#   else
-#    define GTEST_HAS_RTTI 1
-#   endif  // GTEST_OS_LINUX_ANDROID && __STLPORT_MAJOR && !__EXCEPTIONS
-#  else
-#   define GTEST_HAS_RTTI 0
-#  endif  // __GXX_RTTI
-
-// Clang defines __GXX_RTTI starting with version 3.0, but its manual recommends
-// using has_feature instead. has_feature(cxx_rtti) is supported since 2.7, the
-// first version with C++ support.
-# elif defined(__clang__)
-
-#  define GTEST_HAS_RTTI __has_feature(cxx_rtti)
-
-// Starting with version 9.0 IBM Visual Age defines __RTTI_ALL__ to 1 if
-// both the typeid and dynamic_cast features are present.
-# elif defined(__IBMCPP__) && (__IBMCPP__ >= 900)
-
-#  ifdef __RTTI_ALL__
-#   define GTEST_HAS_RTTI 1
-#  else
-#   define GTEST_HAS_RTTI 0
-#  endif
-
-# else
-
-// For all other compilers, we assume RTTI is enabled.
-#  define GTEST_HAS_RTTI 1
-
-# endif  // _MSC_VER
-
-#endif  // GTEST_HAS_RTTI
-
-// It's this header's responsibility to #include <typeinfo> when RTTI
-// is enabled.
-#if GTEST_HAS_RTTI
-# include <typeinfo>
-#endif
-
-// Determines whether Google Test can use the pthreads library.
-#ifndef GTEST_HAS_PTHREAD
-// The user didn't tell us explicitly, so we make reasonable assumptions about
-// which platforms have pthreads support.
-//
-// To disable threading support in Google Test, add -DGTEST_HAS_PTHREAD=0
-// to your compiler flags.
-#define GTEST_HAS_PTHREAD                                                      \
-  (GTEST_OS_LINUX || GTEST_OS_MAC || GTEST_OS_HPUX || GTEST_OS_QNX ||          \
-   GTEST_OS_FREEBSD || GTEST_OS_NACL || GTEST_OS_NETBSD || GTEST_OS_FUCHSIA || \
-   GTEST_OS_DRAGONFLY || GTEST_OS_GNU_KFREEBSD || GTEST_OS_OPENBSD ||          \
-   GTEST_OS_HAIKU)
-#endif  // GTEST_HAS_PTHREAD
-
-#if GTEST_HAS_PTHREAD
-// gtest-port.h guarantees to #include <pthread.h> when GTEST_HAS_PTHREAD is
-// true.
-# include <pthread.h>  // NOLINT
-
-// For timespec and nanosleep, used below.
-# include <time.h>  // NOLINT
-#endif
-
-// Determines whether clone(2) is supported.
-// Usually it will only be available on Linux, excluding
-// Linux on the Itanium architecture.
-// Also see http://linux.die.net/man/2/clone.
-#ifndef GTEST_HAS_CLONE
-// The user didn't tell us, so we need to figure it out.
-
-# if GTEST_OS_LINUX && !defined(__ia64__)
-#  if GTEST_OS_LINUX_ANDROID
-// On Android, clone() became available at different API levels for each 32-bit
-// architecture.
-#    if defined(__LP64__) || \
-        (defined(__arm__) && __ANDROID_API__ >= 9) || \
-        (defined(__mips__) && __ANDROID_API__ >= 12) || \
-        (defined(__i386__) && __ANDROID_API__ >= 17)
-#     define GTEST_HAS_CLONE 1
-#    else
-#     define GTEST_HAS_CLONE 0
-#    endif
-#  else
-#   define GTEST_HAS_CLONE 1
-#  endif
-# else
-#  define GTEST_HAS_CLONE 0
-# endif  // GTEST_OS_LINUX && !defined(__ia64__)
-
-#endif  // GTEST_HAS_CLONE
-
-// Determines whether to support stream redirection. This is used to test
-// output correctness and to implement death tests.
-#ifndef GTEST_HAS_STREAM_REDIRECTION
-// By default, we assume that stream redirection is supported on all
-// platforms except known mobile ones.
-#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_PHONE || \
-    GTEST_OS_WINDOWS_RT || GTEST_OS_ESP8266 || GTEST_OS_XTENSA
-#  define GTEST_HAS_STREAM_REDIRECTION 0
-# else
-#  define GTEST_HAS_STREAM_REDIRECTION 1
-# endif  // !GTEST_OS_WINDOWS_MOBILE
-#endif  // GTEST_HAS_STREAM_REDIRECTION
-
-// Determines whether to support death tests.
-// pops up a dialog window that cannot be suppressed programmatically.
-#if (GTEST_OS_LINUX || GTEST_OS_CYGWIN || GTEST_OS_SOLARIS ||             \
-     (GTEST_OS_MAC && !GTEST_OS_IOS) ||                                   \
-     (GTEST_OS_WINDOWS_DESKTOP && _MSC_VER) || GTEST_OS_WINDOWS_MINGW ||  \
-     GTEST_OS_AIX || GTEST_OS_HPUX || GTEST_OS_OPENBSD || GTEST_OS_QNX || \
-     GTEST_OS_FREEBSD || GTEST_OS_NETBSD || GTEST_OS_FUCHSIA ||           \
-     GTEST_OS_DRAGONFLY || GTEST_OS_GNU_KFREEBSD || GTEST_OS_HAIKU)
-# define GTEST_HAS_DEATH_TEST 1
-#endif
-
-// Determines whether to support type-driven tests.
-
-// Typed tests need <typeinfo> and variadic macros, which GCC, VC++ 8.0,
-// Sun Pro CC, IBM Visual Age, and HP aCC support.
-#if defined(__GNUC__) || defined(_MSC_VER) || defined(__SUNPRO_CC) || \
-    defined(__IBMCPP__) || defined(__HP_aCC)
-# define GTEST_HAS_TYPED_TEST 1
-# define GTEST_HAS_TYPED_TEST_P 1
-#endif
-
-// Determines whether the system compiler uses UTF-16 for encoding wide strings.
-#define GTEST_WIDE_STRING_USES_UTF16_ \
-  (GTEST_OS_WINDOWS || GTEST_OS_CYGWIN || GTEST_OS_AIX || GTEST_OS_OS2)
-
-// Determines whether test results can be streamed to a socket.
-#if GTEST_OS_LINUX || GTEST_OS_GNU_KFREEBSD || GTEST_OS_DRAGONFLY || \
-    GTEST_OS_FREEBSD || GTEST_OS_NETBSD || GTEST_OS_OPENBSD
-# define GTEST_CAN_STREAM_RESULTS_ 1
-#endif
-
-// Defines some utility macros.
-
-// The GNU compiler emits a warning if nested "if" statements are followed by
-// an "else" statement and braces are not used to explicitly disambiguate the
-// "else" binding.  This leads to problems with code like:
-//
-//   if (gate)
-//     ASSERT_*(condition) << "Some message";
-//
-// The "switch (0) case 0:" idiom is used to suppress this.
-#ifdef __INTEL_COMPILER
-# define GTEST_AMBIGUOUS_ELSE_BLOCKER_
-#else
-# define GTEST_AMBIGUOUS_ELSE_BLOCKER_ switch (0) case 0: default:  // NOLINT
-#endif
-
-// Use this annotation at the end of a struct/class definition to
-// prevent the compiler from optimizing away instances that are never
-// used.  This is useful when all interesting logic happens inside the
-// c'tor and / or d'tor.  Example:
-//
-//   struct Foo {
-//     Foo() { ... }
-//   } GTEST_ATTRIBUTE_UNUSED_;
-//
-// Also use it after a variable or parameter declaration to tell the
-// compiler the variable/parameter does not have to be used.
-#if defined(__GNUC__) && !defined(COMPILER_ICC)
-# define GTEST_ATTRIBUTE_UNUSED_ __attribute__ ((unused))
-#elif defined(__clang__)
-# if __has_attribute(unused)
-#  define GTEST_ATTRIBUTE_UNUSED_ __attribute__ ((unused))
-# endif
-#endif
-#ifndef GTEST_ATTRIBUTE_UNUSED_
-# define GTEST_ATTRIBUTE_UNUSED_
-#endif
-
-// Use this annotation before a function that takes a printf format string.
-#if (defined(__GNUC__) || defined(__clang__)) && !defined(COMPILER_ICC)
-# if defined(__MINGW_PRINTF_FORMAT)
-// MinGW has two different printf implementations. Ensure the format macro
-// matches the selected implementation. See
-// https://sourceforge.net/p/mingw-w64/wiki2/gnu%20printf/.
-#  define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check) \
-       __attribute__((__format__(__MINGW_PRINTF_FORMAT, string_index, \
-                                 first_to_check)))
-# else
-#  define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check) \
-       __attribute__((__format__(__printf__, string_index, first_to_check)))
-# endif
-#else
-# define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check)
-#endif
-
-
-// A macro to disallow copy operator=
-// This should be used in the private: declarations for a class.
-#define GTEST_DISALLOW_ASSIGN_(type) \
-  type& operator=(type const &) = delete
-
-// A macro to disallow copy constructor and operator=
-// This should be used in the private: declarations for a class.
-#define GTEST_DISALLOW_COPY_AND_ASSIGN_(type) \
-  type(type const&) = delete;                 \
-  type& operator=(type const&) = delete
-
-// A macro to disallow move operator=
-// This should be used in the private: declarations for a class.
-#define GTEST_DISALLOW_MOVE_ASSIGN_(type) \
-  type& operator=(type &&) noexcept = delete
-
-// A macro to disallow move constructor and operator=
-// This should be used in the private: declarations for a class.
-#define GTEST_DISALLOW_MOVE_AND_ASSIGN_(type) \
-  type(type&&) noexcept = delete;             \
-  type& operator=(type&&) noexcept = delete
-
-// Tell the compiler to warn about unused return values for functions declared
-// with this macro.  The macro should be used on function declarations
-// following the argument list:
-//
-//   Sprocket* AllocateSprocket() GTEST_MUST_USE_RESULT_;
-#if defined(__GNUC__) && !defined(COMPILER_ICC)
-# define GTEST_MUST_USE_RESULT_ __attribute__ ((warn_unused_result))
-#else
-# define GTEST_MUST_USE_RESULT_
-#endif  // __GNUC__ && !COMPILER_ICC
-
-// MS C++ compiler emits warning when a conditional expression is compile time
-// constant. In some contexts this warning is false positive and needs to be
-// suppressed. Use the following two macros in such cases:
-//
-// GTEST_INTENTIONAL_CONST_COND_PUSH_()
-// while (true) {
-// GTEST_INTENTIONAL_CONST_COND_POP_()
-// }
-# define GTEST_INTENTIONAL_CONST_COND_PUSH_() \
-    GTEST_DISABLE_MSC_WARNINGS_PUSH_(4127)
-# define GTEST_INTENTIONAL_CONST_COND_POP_() \
-    GTEST_DISABLE_MSC_WARNINGS_POP_()
-
-// Determine whether the compiler supports Microsoft's Structured Exception
-// Handling.  This is supported by several Windows compilers but generally
-// does not exist on any other system.
-#ifndef GTEST_HAS_SEH
-// The user didn't tell us, so we need to figure it out.
-
-# if defined(_MSC_VER) || defined(__BORLANDC__)
-// These two compilers are known to support SEH.
-#  define GTEST_HAS_SEH 1
-# else
-// Assume no SEH.
-#  define GTEST_HAS_SEH 0
-# endif
-
-#endif  // GTEST_HAS_SEH
-
-#ifndef GTEST_IS_THREADSAFE
-
-#define GTEST_IS_THREADSAFE                                                 \
-  (GTEST_HAS_MUTEX_AND_THREAD_LOCAL_ ||                                     \
-   (GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT) || \
-   GTEST_HAS_PTHREAD)
-
-#endif  // GTEST_IS_THREADSAFE
-
-// GTEST_API_ qualifies all symbols that must be exported. The definitions below
-// are guarded by #ifndef to give embedders a chance to define GTEST_API_ in
-// gtest/internal/custom/gtest-port.h
-#ifndef GTEST_API_
-
-#ifdef _MSC_VER
-# if GTEST_LINKED_AS_SHARED_LIBRARY
-#  define GTEST_API_ __declspec(dllimport)
-# elif GTEST_CREATE_SHARED_LIBRARY
-#  define GTEST_API_ __declspec(dllexport)
-# endif
-#elif __GNUC__ >= 4 || defined(__clang__)
-# define GTEST_API_ __attribute__((visibility ("default")))
-#endif  // _MSC_VER
-
-#endif  // GTEST_API_
-
-#ifndef GTEST_API_
-# define GTEST_API_
-#endif  // GTEST_API_
-
-#ifndef GTEST_DEFAULT_DEATH_TEST_STYLE
-# define GTEST_DEFAULT_DEATH_TEST_STYLE  "fast"
-#endif  // GTEST_DEFAULT_DEATH_TEST_STYLE
-
-#ifdef __GNUC__
-// Ask the compiler to never inline a given function.
-# define GTEST_NO_INLINE_ __attribute__((noinline))
-#else
-# define GTEST_NO_INLINE_
-#endif
-
-// _LIBCPP_VERSION is defined by the libc++ library from the LLVM project.
-#if !defined(GTEST_HAS_CXXABI_H_)
-# if defined(__GLIBCXX__) || (defined(_LIBCPP_VERSION) && !defined(_MSC_VER))
-#  define GTEST_HAS_CXXABI_H_ 1
-# else
-#  define GTEST_HAS_CXXABI_H_ 0
-# endif
-#endif
-
-// A function level attribute to disable checking for use of uninitialized
-// memory when built with MemorySanitizer.
-#if defined(__clang__)
-# if __has_feature(memory_sanitizer)
-#  define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_ \
-       __attribute__((no_sanitize_memory))
-# else
-#  define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
-# endif  // __has_feature(memory_sanitizer)
-#else
-# define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
-#endif  // __clang__
-
-// A function level attribute to disable AddressSanitizer instrumentation.
-#if defined(__clang__)
-# if __has_feature(address_sanitizer)
-#  define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_ \
-       __attribute__((no_sanitize_address))
-# else
-#  define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
-# endif  // __has_feature(address_sanitizer)
-#else
-# define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
-#endif  // __clang__
-
-// A function level attribute to disable HWAddressSanitizer instrumentation.
-#if defined(__clang__)
-# if __has_feature(hwaddress_sanitizer)
-#  define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_ \
-       __attribute__((no_sanitize("hwaddress")))
-# else
-#  define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
-# endif  // __has_feature(hwaddress_sanitizer)
-#else
-# define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
-#endif  // __clang__
-
-// A function level attribute to disable ThreadSanitizer instrumentation.
-#if defined(__clang__)
-# if __has_feature(thread_sanitizer)
-#  define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_ \
-       __attribute__((no_sanitize_thread))
-# else
-#  define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
-# endif  // __has_feature(thread_sanitizer)
-#else
-# define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
-#endif  // __clang__
-
-namespace testing {
-
-class Message;
-
-// Legacy imports for backwards compatibility.
-// New code should use std:: names directly.
-using std::get;
-using std::make_tuple;
-using std::tuple;
-using std::tuple_element;
-using std::tuple_size;
-
-namespace internal {
-
-// A secret type that Google Test users don't know about.  It has no
-// definition on purpose.  Therefore it's impossible to create a
-// Secret object, which is what we want.
-class Secret;
-
-// The GTEST_COMPILE_ASSERT_ is a legacy macro used to verify that a compile
-// time expression is true (in new code, use static_assert instead). For
-// example, you could use it to verify the size of a static array:
-//
-//   GTEST_COMPILE_ASSERT_(GTEST_ARRAY_SIZE_(names) == NUM_NAMES,
-//                         names_incorrect_size);
-//
-// The second argument to the macro must be a valid C++ identifier. If the
-// expression is false, compiler will issue an error containing this identifier.
-#define GTEST_COMPILE_ASSERT_(expr, msg) static_assert(expr, #msg)
-
-// A helper for suppressing warnings on constant condition.  It just
-// returns 'condition'.
-GTEST_API_ bool IsTrue(bool condition);
-
-// Defines RE.
-
-#if GTEST_USES_PCRE
-// if used, PCRE is injected by custom/gtest-port.h
-#elif GTEST_USES_POSIX_RE || GTEST_USES_SIMPLE_RE
-
-// A simple C++ wrapper for <regex.h>.  It uses the POSIX Extended
-// Regular Expression syntax.
-class GTEST_API_ RE {
- public:
-  // A copy constructor is required by the Standard to initialize object
-  // references from r-values.
-  RE(const RE& other) { Init(other.pattern()); }
-
-  // Constructs an RE from a string.
-  RE(const ::std::string& regex) { Init(regex.c_str()); }  // NOLINT
-
-  RE(const char* regex) { Init(regex); }  // NOLINT
-  ~RE();
-
-  // Returns the string representation of the regex.
-  const char* pattern() const { return pattern_; }
-
-  // FullMatch(str, re) returns true if and only if regular expression re
-  // matches the entire str.
-  // PartialMatch(str, re) returns true if and only if regular expression re
-  // matches a substring of str (including str itself).
-  static bool FullMatch(const ::std::string& str, const RE& re) {
-    return FullMatch(str.c_str(), re);
-  }
-  static bool PartialMatch(const ::std::string& str, const RE& re) {
-    return PartialMatch(str.c_str(), re);
-  }
-
-  static bool FullMatch(const char* str, const RE& re);
-  static bool PartialMatch(const char* str, const RE& re);
-
- private:
-  void Init(const char* regex);
-  const char* pattern_;
-  bool is_valid_;
-
-# if GTEST_USES_POSIX_RE
-
-  regex_t full_regex_;     // For FullMatch().
-  regex_t partial_regex_;  // For PartialMatch().
-
-# else  // GTEST_USES_SIMPLE_RE
-
-  const char* full_pattern_;  // For FullMatch();
-
-# endif
-};
-
-#endif  // GTEST_USES_PCRE
-
-// Formats a source file path and a line number as they would appear
-// in an error message from the compiler used to compile this code.
-GTEST_API_ ::std::string FormatFileLocation(const char* file, int line);
-
-// Formats a file location for compiler-independent XML output.
-// Although this function is not platform dependent, we put it next to
-// FormatFileLocation in order to contrast the two functions.
-GTEST_API_ ::std::string FormatCompilerIndependentFileLocation(const char* file,
-                                                               int line);
-
-// Defines logging utilities:
-//   GTEST_LOG_(severity) - logs messages at the specified severity level. The
-//                          message itself is streamed into the macro.
-//   LogToStderr()  - directs all log messages to stderr.
-//   FlushInfoLog() - flushes informational log messages.
-
-enum GTestLogSeverity {
-  GTEST_INFO,
-  GTEST_WARNING,
-  GTEST_ERROR,
-  GTEST_FATAL
-};
-
-// Formats log entry severity, provides a stream object for streaming the
-// log message, and terminates the message with a newline when going out of
-// scope.
-class GTEST_API_ GTestLog {
- public:
-  GTestLog(GTestLogSeverity severity, const char* file, int line);
-
-  // Flushes the buffers and, if severity is GTEST_FATAL, aborts the program.
-  ~GTestLog();
-
-  ::std::ostream& GetStream() { return ::std::cerr; }
-
- private:
-  const GTestLogSeverity severity_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(GTestLog);
-};
-
-#if !defined(GTEST_LOG_)
-
-# define GTEST_LOG_(severity) \
-    ::testing::internal::GTestLog(::testing::internal::GTEST_##severity, \
-                                  __FILE__, __LINE__).GetStream()
-
-inline void LogToStderr() {}
-inline void FlushInfoLog() { fflush(nullptr); }
-
-#endif  // !defined(GTEST_LOG_)
-
-#if !defined(GTEST_CHECK_)
-// INTERNAL IMPLEMENTATION - DO NOT USE.
-//
-// GTEST_CHECK_ is an all-mode assert. It aborts the program if the condition
-// is not satisfied.
-//  Synopsys:
-//    GTEST_CHECK_(boolean_condition);
-//     or
-//    GTEST_CHECK_(boolean_condition) << "Additional message";
-//
-//    This checks the condition and if the condition is not satisfied
-//    it prints message about the condition violation, including the
-//    condition itself, plus additional message streamed into it, if any,
-//    and then it aborts the program. It aborts the program irrespective of
-//    whether it is built in the debug mode or not.
-# define GTEST_CHECK_(condition) \
-    GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
-    if (::testing::internal::IsTrue(condition)) \
-      ; \
-    else \
-      GTEST_LOG_(FATAL) << "Condition " #condition " failed. "
-#endif  // !defined(GTEST_CHECK_)
-
-// An all-mode assert to verify that the given POSIX-style function
-// call returns 0 (indicating success).  Known limitation: this
-// doesn't expand to a balanced 'if' statement, so enclose the macro
-// in {} if you need to use it as the only statement in an 'if'
-// branch.
-#define GTEST_CHECK_POSIX_SUCCESS_(posix_call) \
-  if (const int gtest_error = (posix_call)) \
-    GTEST_LOG_(FATAL) << #posix_call << "failed with error " \
-                      << gtest_error
-
-// Transforms "T" into "const T&" according to standard reference collapsing
-// rules (this is only needed as a backport for C++98 compilers that do not
-// support reference collapsing). Specifically, it transforms:
-//
-//   char         ==> const char&
-//   const char   ==> const char&
-//   char&        ==> char&
-//   const char&  ==> const char&
-//
-// Note that the non-const reference will not have "const" added. This is
-// standard, and necessary so that "T" can always bind to "const T&".
-template <typename T>
-struct ConstRef { typedef const T& type; };
-template <typename T>
-struct ConstRef<T&> { typedef T& type; };
-
-// The argument T must depend on some template parameters.
-#define GTEST_REFERENCE_TO_CONST_(T) \
-  typename ::testing::internal::ConstRef<T>::type
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// Use ImplicitCast_ as a safe version of static_cast for upcasting in
-// the type hierarchy (e.g. casting a Foo* to a SuperclassOfFoo* or a
-// const Foo*).  When you use ImplicitCast_, the compiler checks that
-// the cast is safe.  Such explicit ImplicitCast_s are necessary in
-// surprisingly many situations where C++ demands an exact type match
-// instead of an argument type convertable to a target type.
-//
-// The syntax for using ImplicitCast_ is the same as for static_cast:
-//
-//   ImplicitCast_<ToType>(expr)
-//
-// ImplicitCast_ would have been part of the C++ standard library,
-// but the proposal was submitted too late.  It will probably make
-// its way into the language in the future.
-//
-// This relatively ugly name is intentional. It prevents clashes with
-// similar functions users may have (e.g., implicit_cast). The internal
-// namespace alone is not enough because the function can be found by ADL.
-template<typename To>
-inline To ImplicitCast_(To x) { return x; }
-
-// When you upcast (that is, cast a pointer from type Foo to type
-// SuperclassOfFoo), it's fine to use ImplicitCast_<>, since upcasts
-// always succeed.  When you downcast (that is, cast a pointer from
-// type Foo to type SubclassOfFoo), static_cast<> isn't safe, because
-// how do you know the pointer is really of type SubclassOfFoo?  It
-// could be a bare Foo, or of type DifferentSubclassOfFoo.  Thus,
-// when you downcast, you should use this macro.  In debug mode, we
-// use dynamic_cast<> to double-check the downcast is legal (we die
-// if it's not).  In normal mode, we do the efficient static_cast<>
-// instead.  Thus, it's important to test in debug mode to make sure
-// the cast is legal!
-//    This is the only place in the code we should use dynamic_cast<>.
-// In particular, you SHOULDN'T be using dynamic_cast<> in order to
-// do RTTI (eg code like this:
-//    if (dynamic_cast<Subclass1>(foo)) HandleASubclass1Object(foo);
-//    if (dynamic_cast<Subclass2>(foo)) HandleASubclass2Object(foo);
-// You should design the code some other way not to need this.
-//
-// This relatively ugly name is intentional. It prevents clashes with
-// similar functions users may have (e.g., down_cast). The internal
-// namespace alone is not enough because the function can be found by ADL.
-template<typename To, typename From>  // use like this: DownCast_<T*>(foo);
-inline To DownCast_(From* f) {  // so we only accept pointers
-  // Ensures that To is a sub-type of From *.  This test is here only
-  // for compile-time type checking, and has no overhead in an
-  // optimized build at run-time, as it will be optimized away
-  // completely.
-  GTEST_INTENTIONAL_CONST_COND_PUSH_()
-  if (false) {
-  GTEST_INTENTIONAL_CONST_COND_POP_()
-  const To to = nullptr;
-  ::testing::internal::ImplicitCast_<From*>(to);
-  }
-
-#if GTEST_HAS_RTTI
-  // RTTI: debug mode only!
-  GTEST_CHECK_(f == nullptr || dynamic_cast<To>(f) != nullptr);
-#endif
-  return static_cast<To>(f);
-}
-
-// Downcasts the pointer of type Base to Derived.
-// Derived must be a subclass of Base. The parameter MUST
-// point to a class of type Derived, not any subclass of it.
-// When RTTI is available, the function performs a runtime
-// check to enforce this.
-template <class Derived, class Base>
-Derived* CheckedDowncastToActualType(Base* base) {
-#if GTEST_HAS_RTTI
-  GTEST_CHECK_(typeid(*base) == typeid(Derived));
-#endif
-
-#if GTEST_HAS_DOWNCAST_
-  return ::down_cast<Derived*>(base);
-#elif GTEST_HAS_RTTI
-  return dynamic_cast<Derived*>(base);  // NOLINT
-#else
-  return static_cast<Derived*>(base);  // Poor man's downcast.
-#endif
-}
-
-#if GTEST_HAS_STREAM_REDIRECTION
-
-// Defines the stderr capturer:
-//   CaptureStdout     - starts capturing stdout.
-//   GetCapturedStdout - stops capturing stdout and returns the captured string.
-//   CaptureStderr     - starts capturing stderr.
-//   GetCapturedStderr - stops capturing stderr and returns the captured string.
-//
-GTEST_API_ void CaptureStdout();
-GTEST_API_ std::string GetCapturedStdout();
-GTEST_API_ void CaptureStderr();
-GTEST_API_ std::string GetCapturedStderr();
-
-#endif  // GTEST_HAS_STREAM_REDIRECTION
-// Returns the size (in bytes) of a file.
-GTEST_API_ size_t GetFileSize(FILE* file);
-
-// Reads the entire content of a file as a string.
-GTEST_API_ std::string ReadEntireFile(FILE* file);
-
-// All command line arguments.
-GTEST_API_ std::vector<std::string> GetArgvs();
-
-#if GTEST_HAS_DEATH_TEST
-
-std::vector<std::string> GetInjectableArgvs();
-// Deprecated: pass the args vector by value instead.
-void SetInjectableArgvs(const std::vector<std::string>* new_argvs);
-void SetInjectableArgvs(const std::vector<std::string>& new_argvs);
-void ClearInjectableArgvs();
-
-#endif  // GTEST_HAS_DEATH_TEST
-
-// Defines synchronization primitives.
-#if GTEST_IS_THREADSAFE
-# if GTEST_HAS_PTHREAD
-// Sleeps for (roughly) n milliseconds.  This function is only for testing
-// Google Test's own constructs.  Don't use it in user tests, either
-// directly or indirectly.
-inline void SleepMilliseconds(int n) {
-  const timespec time = {
-    0,                  // 0 seconds.
-    n * 1000L * 1000L,  // And n ms.
-  };
-  nanosleep(&time, nullptr);
-}
-# endif  // GTEST_HAS_PTHREAD
-
-# if GTEST_HAS_NOTIFICATION_
-// Notification has already been imported into the namespace.
-// Nothing to do here.
-
-# elif GTEST_HAS_PTHREAD
-// Allows a controller thread to pause execution of newly created
-// threads until notified.  Instances of this class must be created
-// and destroyed in the controller thread.
-//
-// This class is only for testing Google Test's own constructs. Do not
-// use it in user tests, either directly or indirectly.
-class Notification {
- public:
-  Notification() : notified_(false) {
-    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_init(&mutex_, nullptr));
-  }
-  ~Notification() {
-    pthread_mutex_destroy(&mutex_);
-  }
-
-  // Notifies all threads created with this notification to start. Must
-  // be called from the controller thread.
-  void Notify() {
-    pthread_mutex_lock(&mutex_);
-    notified_ = true;
-    pthread_mutex_unlock(&mutex_);
-  }
-
-  // Blocks until the controller thread notifies. Must be called from a test
-  // thread.
-  void WaitForNotification() {
-    for (;;) {
-      pthread_mutex_lock(&mutex_);
-      const bool notified = notified_;
-      pthread_mutex_unlock(&mutex_);
-      if (notified)
-        break;
-      SleepMilliseconds(10);
-    }
-  }
-
- private:
-  pthread_mutex_t mutex_;
-  bool notified_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(Notification);
-};
-
-# elif GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
-
-GTEST_API_ void SleepMilliseconds(int n);
-
-// Provides leak-safe Windows kernel handle ownership.
-// Used in death tests and in threading support.
-class GTEST_API_ AutoHandle {
- public:
-  // Assume that Win32 HANDLE type is equivalent to void*. Doing so allows us to
-  // avoid including <windows.h> in this header file. Including <windows.h> is
-  // undesirable because it defines a lot of symbols and macros that tend to
-  // conflict with client code. This assumption is verified by
-  // WindowsTypesTest.HANDLEIsVoidStar.
-  typedef void* Handle;
-  AutoHandle();
-  explicit AutoHandle(Handle handle);
-
-  ~AutoHandle();
-
-  Handle Get() const;
-  void Reset();
-  void Reset(Handle handle);
-
- private:
-  // Returns true if and only if the handle is a valid handle object that can be
-  // closed.
-  bool IsCloseable() const;
-
-  Handle handle_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(AutoHandle);
-};
-
-// Allows a controller thread to pause execution of newly created
-// threads until notified.  Instances of this class must be created
-// and destroyed in the controller thread.
-//
-// This class is only for testing Google Test's own constructs. Do not
-// use it in user tests, either directly or indirectly.
-class GTEST_API_ Notification {
- public:
-  Notification();
-  void Notify();
-  void WaitForNotification();
-
- private:
-  AutoHandle event_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(Notification);
-};
-# endif  // GTEST_HAS_NOTIFICATION_
-
-// On MinGW, we can have both GTEST_OS_WINDOWS and GTEST_HAS_PTHREAD
-// defined, but we don't want to use MinGW's pthreads implementation, which
-// has conformance problems with some versions of the POSIX standard.
-# if GTEST_HAS_PTHREAD && !GTEST_OS_WINDOWS_MINGW
-
-// As a C-function, ThreadFuncWithCLinkage cannot be templated itself.
-// Consequently, it cannot select a correct instantiation of ThreadWithParam
-// in order to call its Run(). Introducing ThreadWithParamBase as a
-// non-templated base class for ThreadWithParam allows us to bypass this
-// problem.
-class ThreadWithParamBase {
- public:
-  virtual ~ThreadWithParamBase() {}
-  virtual void Run() = 0;
-};
-
-// pthread_create() accepts a pointer to a function type with the C linkage.
-// According to the Standard (7.5/1), function types with different linkages
-// are different even if they are otherwise identical.  Some compilers (for
-// example, SunStudio) treat them as different types.  Since class methods
-// cannot be defined with C-linkage we need to define a free C-function to
-// pass into pthread_create().
-extern "C" inline void* ThreadFuncWithCLinkage(void* thread) {
-  static_cast<ThreadWithParamBase*>(thread)->Run();
-  return nullptr;
-}
-
-// Helper class for testing Google Test's multi-threading constructs.
-// To use it, write:
-//
-//   void ThreadFunc(int param) { /* Do things with param */ }
-//   Notification thread_can_start;
-//   ...
-//   // The thread_can_start parameter is optional; you can supply NULL.
-//   ThreadWithParam<int> thread(&ThreadFunc, 5, &thread_can_start);
-//   thread_can_start.Notify();
-//
-// These classes are only for testing Google Test's own constructs. Do
-// not use them in user tests, either directly or indirectly.
-template <typename T>
-class ThreadWithParam : public ThreadWithParamBase {
- public:
-  typedef void UserThreadFunc(T);
-
-  ThreadWithParam(UserThreadFunc* func, T param, Notification* thread_can_start)
-      : func_(func),
-        param_(param),
-        thread_can_start_(thread_can_start),
-        finished_(false) {
-    ThreadWithParamBase* const base = this;
-    // The thread can be created only after all fields except thread_
-    // have been initialized.
-    GTEST_CHECK_POSIX_SUCCESS_(
-        pthread_create(&thread_, nullptr, &ThreadFuncWithCLinkage, base));
-  }
-  ~ThreadWithParam() override { Join(); }
-
-  void Join() {
-    if (!finished_) {
-      GTEST_CHECK_POSIX_SUCCESS_(pthread_join(thread_, nullptr));
-      finished_ = true;
-    }
-  }
-
-  void Run() override {
-    if (thread_can_start_ != nullptr) thread_can_start_->WaitForNotification();
-    func_(param_);
-  }
-
- private:
-  UserThreadFunc* const func_;  // User-supplied thread function.
-  const T param_;  // User-supplied parameter to the thread function.
-  // When non-NULL, used to block execution until the controller thread
-  // notifies.
-  Notification* const thread_can_start_;
-  bool finished_;  // true if and only if we know that the thread function has
-                   // finished.
-  pthread_t thread_;  // The native thread object.
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParam);
-};
-# endif  // !GTEST_OS_WINDOWS && GTEST_HAS_PTHREAD ||
-         // GTEST_HAS_MUTEX_AND_THREAD_LOCAL_
-
-# if GTEST_HAS_MUTEX_AND_THREAD_LOCAL_
-// Mutex and ThreadLocal have already been imported into the namespace.
-// Nothing to do here.
-
-# elif GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
-
-// Mutex implements mutex on Windows platforms.  It is used in conjunction
-// with class MutexLock:
-//
-//   Mutex mutex;
-//   ...
-//   MutexLock lock(&mutex);  // Acquires the mutex and releases it at the
-//                            // end of the current scope.
-//
-// A static Mutex *must* be defined or declared using one of the following
-// macros:
-//   GTEST_DEFINE_STATIC_MUTEX_(g_some_mutex);
-//   GTEST_DECLARE_STATIC_MUTEX_(g_some_mutex);
-//
-// (A non-static Mutex is defined/declared in the usual way).
-class GTEST_API_ Mutex {
- public:
-  enum MutexType { kStatic = 0, kDynamic = 1 };
-  // We rely on kStaticMutex being 0 as it is to what the linker initializes
-  // type_ in static mutexes.  critical_section_ will be initialized lazily
-  // in ThreadSafeLazyInit().
-  enum StaticConstructorSelector { kStaticMutex = 0 };
-
-  // This constructor intentionally does nothing.  It relies on type_ being
-  // statically initialized to 0 (effectively setting it to kStatic) and on
-  // ThreadSafeLazyInit() to lazily initialize the rest of the members.
-  explicit Mutex(StaticConstructorSelector /*dummy*/) {}
-
-  Mutex();
-  ~Mutex();
-
-  void Lock();
-
-  void Unlock();
-
-  // Does nothing if the current thread holds the mutex. Otherwise, crashes
-  // with high probability.
-  void AssertHeld();
-
- private:
-  // Initializes owner_thread_id_ and critical_section_ in static mutexes.
-  void ThreadSafeLazyInit();
-
-  // Per https://blogs.msdn.microsoft.com/oldnewthing/20040223-00/?p=40503,
-  // we assume that 0 is an invalid value for thread IDs.
-  unsigned int owner_thread_id_;
-
-  // For static mutexes, we rely on these members being initialized to zeros
-  // by the linker.
-  MutexType type_;
-  long critical_section_init_phase_;  // NOLINT
-  GTEST_CRITICAL_SECTION* critical_section_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(Mutex);
-};
-
-# define GTEST_DECLARE_STATIC_MUTEX_(mutex) \
-    extern ::testing::internal::Mutex mutex
-
-# define GTEST_DEFINE_STATIC_MUTEX_(mutex) \
-    ::testing::internal::Mutex mutex(::testing::internal::Mutex::kStaticMutex)
-
-// We cannot name this class MutexLock because the ctor declaration would
-// conflict with a macro named MutexLock, which is defined on some
-// platforms. That macro is used as a defensive measure to prevent against
-// inadvertent misuses of MutexLock like "MutexLock(&mu)" rather than
-// "MutexLock l(&mu)".  Hence the typedef trick below.
-class GTestMutexLock {
- public:
-  explicit GTestMutexLock(Mutex* mutex)
-      : mutex_(mutex) { mutex_->Lock(); }
-
-  ~GTestMutexLock() { mutex_->Unlock(); }
-
- private:
-  Mutex* const mutex_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(GTestMutexLock);
-};
-
-typedef GTestMutexLock MutexLock;
-
-// Base class for ValueHolder<T>.  Allows a caller to hold and delete a value
-// without knowing its type.
-class ThreadLocalValueHolderBase {
- public:
-  virtual ~ThreadLocalValueHolderBase() {}
-};
-
-// Provides a way for a thread to send notifications to a ThreadLocal
-// regardless of its parameter type.
-class ThreadLocalBase {
- public:
-  // Creates a new ValueHolder<T> object holding a default value passed to
-  // this ThreadLocal<T>'s constructor and returns it.  It is the caller's
-  // responsibility not to call this when the ThreadLocal<T> instance already
-  // has a value on the current thread.
-  virtual ThreadLocalValueHolderBase* NewValueForCurrentThread() const = 0;
-
- protected:
-  ThreadLocalBase() {}
-  virtual ~ThreadLocalBase() {}
-
- private:
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadLocalBase);
-};
-
-// Maps a thread to a set of ThreadLocals that have values instantiated on that
-// thread and notifies them when the thread exits.  A ThreadLocal instance is
-// expected to persist until all threads it has values on have terminated.
-class GTEST_API_ ThreadLocalRegistry {
- public:
-  // Registers thread_local_instance as having value on the current thread.
-  // Returns a value that can be used to identify the thread from other threads.
-  static ThreadLocalValueHolderBase* GetValueOnCurrentThread(
-      const ThreadLocalBase* thread_local_instance);
-
-  // Invoked when a ThreadLocal instance is destroyed.
-  static void OnThreadLocalDestroyed(
-      const ThreadLocalBase* thread_local_instance);
-};
-
-class GTEST_API_ ThreadWithParamBase {
- public:
-  void Join();
-
- protected:
-  class Runnable {
-   public:
-    virtual ~Runnable() {}
-    virtual void Run() = 0;
-  };
-
-  ThreadWithParamBase(Runnable *runnable, Notification* thread_can_start);
-  virtual ~ThreadWithParamBase();
-
- private:
-  AutoHandle thread_;
-};
-
-// Helper class for testing Google Test's multi-threading constructs.
-template <typename T>
-class ThreadWithParam : public ThreadWithParamBase {
- public:
-  typedef void UserThreadFunc(T);
-
-  ThreadWithParam(UserThreadFunc* func, T param, Notification* thread_can_start)
-      : ThreadWithParamBase(new RunnableImpl(func, param), thread_can_start) {
-  }
-  virtual ~ThreadWithParam() {}
-
- private:
-  class RunnableImpl : public Runnable {
-   public:
-    RunnableImpl(UserThreadFunc* func, T param)
-        : func_(func),
-          param_(param) {
-    }
-    virtual ~RunnableImpl() {}
-    virtual void Run() {
-      func_(param_);
-    }
-
-   private:
-    UserThreadFunc* const func_;
-    const T param_;
-
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(RunnableImpl);
-  };
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParam);
-};
-
-// Implements thread-local storage on Windows systems.
-//
-//   // Thread 1
-//   ThreadLocal<int> tl(100);  // 100 is the default value for each thread.
-//
-//   // Thread 2
-//   tl.set(150);  // Changes the value for thread 2 only.
-//   EXPECT_EQ(150, tl.get());
-//
-//   // Thread 1
-//   EXPECT_EQ(100, tl.get());  // In thread 1, tl has the original value.
-//   tl.set(200);
-//   EXPECT_EQ(200, tl.get());
-//
-// The template type argument T must have a public copy constructor.
-// In addition, the default ThreadLocal constructor requires T to have
-// a public default constructor.
-//
-// The users of a TheadLocal instance have to make sure that all but one
-// threads (including the main one) using that instance have exited before
-// destroying it. Otherwise, the per-thread objects managed for them by the
-// ThreadLocal instance are not guaranteed to be destroyed on all platforms.
-//
-// Google Test only uses global ThreadLocal objects.  That means they
-// will die after main() has returned.  Therefore, no per-thread
-// object managed by Google Test will be leaked as long as all threads
-// using Google Test have exited when main() returns.
-template <typename T>
-class ThreadLocal : public ThreadLocalBase {
- public:
-  ThreadLocal() : default_factory_(new DefaultValueHolderFactory()) {}
-  explicit ThreadLocal(const T& value)
-      : default_factory_(new InstanceValueHolderFactory(value)) {}
-
-  ~ThreadLocal() { ThreadLocalRegistry::OnThreadLocalDestroyed(this); }
-
-  T* pointer() { return GetOrCreateValue(); }
-  const T* pointer() const { return GetOrCreateValue(); }
-  const T& get() const { return *pointer(); }
-  void set(const T& value) { *pointer() = value; }
-
- private:
-  // Holds a value of T.  Can be deleted via its base class without the caller
-  // knowing the type of T.
-  class ValueHolder : public ThreadLocalValueHolderBase {
-   public:
-    ValueHolder() : value_() {}
-    explicit ValueHolder(const T& value) : value_(value) {}
-
-    T* pointer() { return &value_; }
-
-   private:
-    T value_;
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(ValueHolder);
-  };
-
-
-  T* GetOrCreateValue() const {
-    return static_cast<ValueHolder*>(
-        ThreadLocalRegistry::GetValueOnCurrentThread(this))->pointer();
-  }
-
-  virtual ThreadLocalValueHolderBase* NewValueForCurrentThread() const {
-    return default_factory_->MakeNewHolder();
-  }
-
-  class ValueHolderFactory {
-   public:
-    ValueHolderFactory() {}
-    virtual ~ValueHolderFactory() {}
-    virtual ValueHolder* MakeNewHolder() const = 0;
-
-   private:
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(ValueHolderFactory);
-  };
-
-  class DefaultValueHolderFactory : public ValueHolderFactory {
-   public:
-    DefaultValueHolderFactory() {}
-    ValueHolder* MakeNewHolder() const override { return new ValueHolder(); }
-
-   private:
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(DefaultValueHolderFactory);
-  };
-
-  class InstanceValueHolderFactory : public ValueHolderFactory {
-   public:
-    explicit InstanceValueHolderFactory(const T& value) : value_(value) {}
-    ValueHolder* MakeNewHolder() const override {
-      return new ValueHolder(value_);
-    }
-
-   private:
-    const T value_;  // The value for each thread.
-
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(InstanceValueHolderFactory);
-  };
-
-  std::unique_ptr<ValueHolderFactory> default_factory_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadLocal);
-};
-
-# elif GTEST_HAS_PTHREAD
-
-// MutexBase and Mutex implement mutex on pthreads-based platforms.
-class MutexBase {
- public:
-  // Acquires this mutex.
-  void Lock() {
-    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_lock(&mutex_));
-    owner_ = pthread_self();
-    has_owner_ = true;
-  }
-
-  // Releases this mutex.
-  void Unlock() {
-    // Since the lock is being released the owner_ field should no longer be
-    // considered valid. We don't protect writing to has_owner_ here, as it's
-    // the caller's responsibility to ensure that the current thread holds the
-    // mutex when this is called.
-    has_owner_ = false;
-    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_unlock(&mutex_));
-  }
-
-  // Does nothing if the current thread holds the mutex. Otherwise, crashes
-  // with high probability.
-  void AssertHeld() const {
-    GTEST_CHECK_(has_owner_ && pthread_equal(owner_, pthread_self()))
-        << "The current thread is not holding the mutex @" << this;
-  }
-
-  // A static mutex may be used before main() is entered.  It may even
-  // be used before the dynamic initialization stage.  Therefore we
-  // must be able to initialize a static mutex object at link time.
-  // This means MutexBase has to be a POD and its member variables
-  // have to be public.
- public:
-  pthread_mutex_t mutex_;  // The underlying pthread mutex.
-  // has_owner_ indicates whether the owner_ field below contains a valid thread
-  // ID and is therefore safe to inspect (e.g., to use in pthread_equal()). All
-  // accesses to the owner_ field should be protected by a check of this field.
-  // An alternative might be to memset() owner_ to all zeros, but there's no
-  // guarantee that a zero'd pthread_t is necessarily invalid or even different
-  // from pthread_self().
-  bool has_owner_;
-  pthread_t owner_;  // The thread holding the mutex.
-};
-
-// Forward-declares a static mutex.
-#  define GTEST_DECLARE_STATIC_MUTEX_(mutex) \
-     extern ::testing::internal::MutexBase mutex
-
-// Defines and statically (i.e. at link time) initializes a static mutex.
-// The initialization list here does not explicitly initialize each field,
-// instead relying on default initialization for the unspecified fields. In
-// particular, the owner_ field (a pthread_t) is not explicitly initialized.
-// This allows initialization to work whether pthread_t is a scalar or struct.
-// The flag -Wmissing-field-initializers must not be specified for this to work.
-#define GTEST_DEFINE_STATIC_MUTEX_(mutex) \
-  ::testing::internal::MutexBase mutex = {PTHREAD_MUTEX_INITIALIZER, false, 0}
-
-// The Mutex class can only be used for mutexes created at runtime. It
-// shares its API with MutexBase otherwise.
-class Mutex : public MutexBase {
- public:
-  Mutex() {
-    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_init(&mutex_, nullptr));
-    has_owner_ = false;
-  }
-  ~Mutex() {
-    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_destroy(&mutex_));
-  }
-
- private:
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(Mutex);
-};
-
-// We cannot name this class MutexLock because the ctor declaration would
-// conflict with a macro named MutexLock, which is defined on some
-// platforms. That macro is used as a defensive measure to prevent against
-// inadvertent misuses of MutexLock like "MutexLock(&mu)" rather than
-// "MutexLock l(&mu)".  Hence the typedef trick below.
-class GTestMutexLock {
- public:
-  explicit GTestMutexLock(MutexBase* mutex)
-      : mutex_(mutex) { mutex_->Lock(); }
-
-  ~GTestMutexLock() { mutex_->Unlock(); }
-
- private:
-  MutexBase* const mutex_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(GTestMutexLock);
-};
-
-typedef GTestMutexLock MutexLock;
-
-// Helpers for ThreadLocal.
-
-// pthread_key_create() requires DeleteThreadLocalValue() to have
-// C-linkage.  Therefore it cannot be templatized to access
-// ThreadLocal<T>.  Hence the need for class
-// ThreadLocalValueHolderBase.
-class ThreadLocalValueHolderBase {
- public:
-  virtual ~ThreadLocalValueHolderBase() {}
-};
-
-// Called by pthread to delete thread-local data stored by
-// pthread_setspecific().
-extern "C" inline void DeleteThreadLocalValue(void* value_holder) {
-  delete static_cast<ThreadLocalValueHolderBase*>(value_holder);
-}
-
-// Implements thread-local storage on pthreads-based systems.
-template <typename T>
-class GTEST_API_ ThreadLocal {
- public:
-  ThreadLocal()
-      : key_(CreateKey()), default_factory_(new DefaultValueHolderFactory()) {}
-  explicit ThreadLocal(const T& value)
-      : key_(CreateKey()),
-        default_factory_(new InstanceValueHolderFactory(value)) {}
-
-  ~ThreadLocal() {
-    // Destroys the managed object for the current thread, if any.
-    DeleteThreadLocalValue(pthread_getspecific(key_));
-
-    // Releases resources associated with the key.  This will *not*
-    // delete managed objects for other threads.
-    GTEST_CHECK_POSIX_SUCCESS_(pthread_key_delete(key_));
-  }
-
-  T* pointer() { return GetOrCreateValue(); }
-  const T* pointer() const { return GetOrCreateValue(); }
-  const T& get() const { return *pointer(); }
-  void set(const T& value) { *pointer() = value; }
-
- private:
-  // Holds a value of type T.
-  class ValueHolder : public ThreadLocalValueHolderBase {
-   public:
-    ValueHolder() : value_() {}
-    explicit ValueHolder(const T& value) : value_(value) {}
-
-    T* pointer() { return &value_; }
-
-   private:
-    T value_;
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(ValueHolder);
-  };
-
-  static pthread_key_t CreateKey() {
-    pthread_key_t key;
-    // When a thread exits, DeleteThreadLocalValue() will be called on
-    // the object managed for that thread.
-    GTEST_CHECK_POSIX_SUCCESS_(
-        pthread_key_create(&key, &DeleteThreadLocalValue));
-    return key;
-  }
-
-  T* GetOrCreateValue() const {
-    ThreadLocalValueHolderBase* const holder =
-        static_cast<ThreadLocalValueHolderBase*>(pthread_getspecific(key_));
-    if (holder != nullptr) {
-      return CheckedDowncastToActualType<ValueHolder>(holder)->pointer();
-    }
-
-    ValueHolder* const new_holder = default_factory_->MakeNewHolder();
-    ThreadLocalValueHolderBase* const holder_base = new_holder;
-    GTEST_CHECK_POSIX_SUCCESS_(pthread_setspecific(key_, holder_base));
-    return new_holder->pointer();
-  }
-
-  class ValueHolderFactory {
-   public:
-    ValueHolderFactory() {}
-    virtual ~ValueHolderFactory() {}
-    virtual ValueHolder* MakeNewHolder() const = 0;
-
-   private:
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(ValueHolderFactory);
-  };
-
-  class DefaultValueHolderFactory : public ValueHolderFactory {
-   public:
-    DefaultValueHolderFactory() {}
-    ValueHolder* MakeNewHolder() const override { return new ValueHolder(); }
-
-   private:
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(DefaultValueHolderFactory);
-  };
-
-  class InstanceValueHolderFactory : public ValueHolderFactory {
-   public:
-    explicit InstanceValueHolderFactory(const T& value) : value_(value) {}
-    ValueHolder* MakeNewHolder() const override {
-      return new ValueHolder(value_);
-    }
-
-   private:
-    const T value_;  // The value for each thread.
-
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(InstanceValueHolderFactory);
-  };
-
-  // A key pthreads uses for looking up per-thread values.
-  const pthread_key_t key_;
-  std::unique_ptr<ValueHolderFactory> default_factory_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadLocal);
-};
-
-# endif  // GTEST_HAS_MUTEX_AND_THREAD_LOCAL_
-
-#else  // GTEST_IS_THREADSAFE
-
-// A dummy implementation of synchronization primitives (mutex, lock,
-// and thread-local variable).  Necessary for compiling Google Test where
-// mutex is not supported - using Google Test in multiple threads is not
-// supported on such platforms.
-
-class Mutex {
- public:
-  Mutex() {}
-  void Lock() {}
-  void Unlock() {}
-  void AssertHeld() const {}
-};
-
-# define GTEST_DECLARE_STATIC_MUTEX_(mutex) \
-  extern ::testing::internal::Mutex mutex
-
-# define GTEST_DEFINE_STATIC_MUTEX_(mutex) ::testing::internal::Mutex mutex
-
-// We cannot name this class MutexLock because the ctor declaration would
-// conflict with a macro named MutexLock, which is defined on some
-// platforms. That macro is used as a defensive measure to prevent against
-// inadvertent misuses of MutexLock like "MutexLock(&mu)" rather than
-// "MutexLock l(&mu)".  Hence the typedef trick below.
-class GTestMutexLock {
- public:
-  explicit GTestMutexLock(Mutex*) {}  // NOLINT
-};
-
-typedef GTestMutexLock MutexLock;
-
-template <typename T>
-class GTEST_API_ ThreadLocal {
- public:
-  ThreadLocal() : value_() {}
-  explicit ThreadLocal(const T& value) : value_(value) {}
-  T* pointer() { return &value_; }
-  const T* pointer() const { return &value_; }
-  const T& get() const { return value_; }
-  void set(const T& value) { value_ = value; }
- private:
-  T value_;
-};
-
-#endif  // GTEST_IS_THREADSAFE
-
-// Returns the number of threads running in the process, or 0 to indicate that
-// we cannot detect it.
-GTEST_API_ size_t GetThreadCount();
-
-#if GTEST_OS_WINDOWS
-# define GTEST_PATH_SEP_ "\\"
-# define GTEST_HAS_ALT_PATH_SEP_ 1
-#else
-# define GTEST_PATH_SEP_ "/"
-# define GTEST_HAS_ALT_PATH_SEP_ 0
-#endif  // GTEST_OS_WINDOWS
-
-// Utilities for char.
-
-// isspace(int ch) and friends accept an unsigned char or EOF.  char
-// may be signed, depending on the compiler (or compiler flags).
-// Therefore we need to cast a char to unsigned char before calling
-// isspace(), etc.
-
-inline bool IsAlpha(char ch) {
-  return isalpha(static_cast<unsigned char>(ch)) != 0;
-}
-inline bool IsAlNum(char ch) {
-  return isalnum(static_cast<unsigned char>(ch)) != 0;
-}
-inline bool IsDigit(char ch) {
-  return isdigit(static_cast<unsigned char>(ch)) != 0;
-}
-inline bool IsLower(char ch) {
-  return islower(static_cast<unsigned char>(ch)) != 0;
-}
-inline bool IsSpace(char ch) {
-  return isspace(static_cast<unsigned char>(ch)) != 0;
-}
-inline bool IsUpper(char ch) {
-  return isupper(static_cast<unsigned char>(ch)) != 0;
-}
-inline bool IsXDigit(char ch) {
-  return isxdigit(static_cast<unsigned char>(ch)) != 0;
-}
-#ifdef __cpp_char8_t
-inline bool IsXDigit(char8_t ch) {
-  return isxdigit(static_cast<unsigned char>(ch)) != 0;
-}
-#endif
-inline bool IsXDigit(char16_t ch) {
-  const unsigned char low_byte = static_cast<unsigned char>(ch);
-  return ch == low_byte && isxdigit(low_byte) != 0;
-}
-inline bool IsXDigit(char32_t ch) {
-  const unsigned char low_byte = static_cast<unsigned char>(ch);
-  return ch == low_byte && isxdigit(low_byte) != 0;
-}
-inline bool IsXDigit(wchar_t ch) {
-  const unsigned char low_byte = static_cast<unsigned char>(ch);
-  return ch == low_byte && isxdigit(low_byte) != 0;
-}
-
-inline char ToLower(char ch) {
-  return static_cast<char>(tolower(static_cast<unsigned char>(ch)));
-}
-inline char ToUpper(char ch) {
-  return static_cast<char>(toupper(static_cast<unsigned char>(ch)));
-}
-
-inline std::string StripTrailingSpaces(std::string str) {
-  std::string::iterator it = str.end();
-  while (it != str.begin() && IsSpace(*--it))
-    it = str.erase(it);
-  return str;
-}
-
-// The testing::internal::posix namespace holds wrappers for common
-// POSIX functions.  These wrappers hide the differences between
-// Windows/MSVC and POSIX systems.  Since some compilers define these
-// standard functions as macros, the wrapper cannot have the same name
-// as the wrapped function.
-
-namespace posix {
-
-// Functions with a different name on Windows.
-
-#if GTEST_OS_WINDOWS
-
-typedef struct _stat StatStruct;
-
-# ifdef __BORLANDC__
-inline int DoIsATTY(int fd) { return isatty(fd); }
-inline int StrCaseCmp(const char* s1, const char* s2) {
-  return stricmp(s1, s2);
-}
-inline char* StrDup(const char* src) { return strdup(src); }
-# else  // !__BORLANDC__
-#  if GTEST_OS_WINDOWS_MOBILE
-inline int DoIsATTY(int /* fd */) { return 0; }
-#  else
-inline int DoIsATTY(int fd) { return _isatty(fd); }
-#  endif  // GTEST_OS_WINDOWS_MOBILE
-inline int StrCaseCmp(const char* s1, const char* s2) {
-  return _stricmp(s1, s2);
-}
-inline char* StrDup(const char* src) { return _strdup(src); }
-# endif  // __BORLANDC__
-
-# if GTEST_OS_WINDOWS_MOBILE
-inline int FileNo(FILE* file) { return reinterpret_cast<int>(_fileno(file)); }
-// Stat(), RmDir(), and IsDir() are not needed on Windows CE at this
-// time and thus not defined there.
-# else
-inline int FileNo(FILE* file) { return _fileno(file); }
-inline int Stat(const char* path, StatStruct* buf) { return _stat(path, buf); }
-inline int RmDir(const char* dir) { return _rmdir(dir); }
-inline bool IsDir(const StatStruct& st) {
-  return (_S_IFDIR & st.st_mode) != 0;
-}
-# endif  // GTEST_OS_WINDOWS_MOBILE
-
-#elif GTEST_OS_ESP8266
-typedef struct stat StatStruct;
-
-inline int FileNo(FILE* file) { return fileno(file); }
-inline int DoIsATTY(int fd) { return isatty(fd); }
-inline int Stat(const char* path, StatStruct* buf) {
-  // stat function not implemented on ESP8266
-  return 0;
-}
-inline int StrCaseCmp(const char* s1, const char* s2) {
-  return strcasecmp(s1, s2);
-}
-inline char* StrDup(const char* src) { return strdup(src); }
-inline int RmDir(const char* dir) { return rmdir(dir); }
-inline bool IsDir(const StatStruct& st) { return S_ISDIR(st.st_mode); }
-
-#else
-
-typedef struct stat StatStruct;
-
-inline int FileNo(FILE* file) { return fileno(file); }
-inline int DoIsATTY(int fd) { return isatty(fd); }
-inline int Stat(const char* path, StatStruct* buf) { return stat(path, buf); }
-inline int StrCaseCmp(const char* s1, const char* s2) {
-  return strcasecmp(s1, s2);
-}
-inline char* StrDup(const char* src) { return strdup(src); }
-inline int RmDir(const char* dir) { return rmdir(dir); }
-inline bool IsDir(const StatStruct& st) { return S_ISDIR(st.st_mode); }
-
-#endif  // GTEST_OS_WINDOWS
-
-inline int IsATTY(int fd) {
-  // DoIsATTY might change errno (for example ENOTTY in case you redirect stdout
-  // to a file on Linux), which is unexpected, so save the previous value, and
-  // restore it after the call.
-  int savedErrno = errno;
-  int isAttyValue = DoIsATTY(fd);
-  errno = savedErrno;
-
-  return isAttyValue;
-}
-
-// Functions deprecated by MSVC 8.0.
-
-GTEST_DISABLE_MSC_DEPRECATED_PUSH_()
-
-// ChDir(), FReopen(), FDOpen(), Read(), Write(), Close(), and
-// StrError() aren't needed on Windows CE at this time and thus not
-// defined there.
-
-#if !GTEST_OS_WINDOWS_MOBILE && !GTEST_OS_WINDOWS_PHONE && \
-    !GTEST_OS_WINDOWS_RT && !GTEST_OS_ESP8266 && !GTEST_OS_XTENSA
-inline int ChDir(const char* dir) { return chdir(dir); }
-#endif
-inline FILE* FOpen(const char* path, const char* mode) {
-#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
-  struct wchar_codecvt : public std::codecvt<wchar_t, char, std::mbstate_t> {};
-  std::wstring_convert<wchar_codecvt> converter;
-  std::wstring wide_path = converter.from_bytes(path);
-  std::wstring wide_mode = converter.from_bytes(mode);
-  return _wfopen(wide_path.c_str(), wide_mode.c_str());
-#else  // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
-  return fopen(path, mode);
-#endif  // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
-}
-#if !GTEST_OS_WINDOWS_MOBILE
-inline FILE *FReopen(const char* path, const char* mode, FILE* stream) {
-  return freopen(path, mode, stream);
-}
-inline FILE* FDOpen(int fd, const char* mode) { return fdopen(fd, mode); }
-#endif
-inline int FClose(FILE* fp) { return fclose(fp); }
-#if !GTEST_OS_WINDOWS_MOBILE
-inline int Read(int fd, void* buf, unsigned int count) {
-  return static_cast<int>(read(fd, buf, count));
-}
-inline int Write(int fd, const void* buf, unsigned int count) {
-  return static_cast<int>(write(fd, buf, count));
-}
-inline int Close(int fd) { return close(fd); }
-inline const char* StrError(int errnum) { return strerror(errnum); }
-#endif
-inline const char* GetEnv(const char* name) {
-#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_PHONE || \
-    GTEST_OS_WINDOWS_RT || GTEST_OS_ESP8266 || GTEST_OS_XTENSA
-  // We are on an embedded platform, which has no environment variables.
-  static_cast<void>(name);  // To prevent 'unused argument' warning.
-  return nullptr;
-#elif defined(__BORLANDC__) || defined(__SunOS_5_8) || defined(__SunOS_5_9)
-  // Environment variables which we programmatically clear will be set to the
-  // empty string rather than unset (NULL).  Handle that case.
-  const char* const env = getenv(name);
-  return (env != nullptr && env[0] != '\0') ? env : nullptr;
-#else
-  return getenv(name);
-#endif
-}
-
-GTEST_DISABLE_MSC_DEPRECATED_POP_()
-
-#if GTEST_OS_WINDOWS_MOBILE
-// Windows CE has no C library. The abort() function is used in
-// several places in Google Test. This implementation provides a reasonable
-// imitation of standard behaviour.
-[[noreturn]] void Abort();
-#else
-[[noreturn]] inline void Abort() { abort(); }
-#endif  // GTEST_OS_WINDOWS_MOBILE
-
-}  // namespace posix
-
-// MSVC "deprecates" snprintf and issues warnings wherever it is used.  In
-// order to avoid these warnings, we need to use _snprintf or _snprintf_s on
-// MSVC-based platforms.  We map the GTEST_SNPRINTF_ macro to the appropriate
-// function in order to achieve that.  We use macro definition here because
-// snprintf is a variadic function.
-#if _MSC_VER && !GTEST_OS_WINDOWS_MOBILE
-// MSVC 2005 and above support variadic macros.
-# define GTEST_SNPRINTF_(buffer, size, format, ...) \
-     _snprintf_s(buffer, size, size, format, __VA_ARGS__)
-#elif defined(_MSC_VER)
-// Windows CE does not define _snprintf_s
-# define GTEST_SNPRINTF_ _snprintf
-#else
-# define GTEST_SNPRINTF_ snprintf
-#endif
-
-// The biggest signed integer type the compiler supports.
-//
-// long long is guaranteed to be at least 64-bits in C++11.
-using BiggestInt = long long;  // NOLINT
-
-// The maximum number a BiggestInt can represent.
-constexpr BiggestInt kMaxBiggestInt = (std::numeric_limits<BiggestInt>::max)();
-
-// This template class serves as a compile-time function from size to
-// type.  It maps a size in bytes to a primitive type with that
-// size. e.g.
-//
-//   TypeWithSize<4>::UInt
-//
-// is typedef-ed to be unsigned int (unsigned integer made up of 4
-// bytes).
-//
-// Such functionality should belong to STL, but I cannot find it
-// there.
-//
-// Google Test uses this class in the implementation of floating-point
-// comparison.
-//
-// For now it only handles UInt (unsigned int) as that's all Google Test
-// needs.  Other types can be easily added in the future if need
-// arises.
-template <size_t size>
-class TypeWithSize {
- public:
-  // This prevents the user from using TypeWithSize<N> with incorrect
-  // values of N.
-  using UInt = void;
-};
-
-// The specialization for size 4.
-template <>
-class TypeWithSize<4> {
- public:
-  using Int = std::int32_t;
-  using UInt = std::uint32_t;
-};
-
-// The specialization for size 8.
-template <>
-class TypeWithSize<8> {
- public:
-  using Int = std::int64_t;
-  using UInt = std::uint64_t;
-};
-
-// Integer types of known sizes.
-using TimeInMillis = int64_t;  // Represents time in milliseconds.
-
-// Utilities for command line flags and environment variables.
-
-// Macro for referencing flags.
-#if !defined(GTEST_FLAG)
-# define GTEST_FLAG(name) FLAGS_gtest_##name
-#endif  // !defined(GTEST_FLAG)
-
-#if !defined(GTEST_USE_OWN_FLAGFILE_FLAG_)
-# define GTEST_USE_OWN_FLAGFILE_FLAG_ 1
-#endif  // !defined(GTEST_USE_OWN_FLAGFILE_FLAG_)
-
-#if !defined(GTEST_DECLARE_bool_)
-# define GTEST_FLAG_SAVER_ ::testing::internal::GTestFlagSaver
-
-// Macros for declaring flags.
-# define GTEST_DECLARE_bool_(name) GTEST_API_ extern bool GTEST_FLAG(name)
-# define GTEST_DECLARE_int32_(name) \
-    GTEST_API_ extern std::int32_t GTEST_FLAG(name)
-# define GTEST_DECLARE_string_(name) \
-    GTEST_API_ extern ::std::string GTEST_FLAG(name)
-
-// Macros for defining flags.
-# define GTEST_DEFINE_bool_(name, default_val, doc) \
-    GTEST_API_ bool GTEST_FLAG(name) = (default_val)
-# define GTEST_DEFINE_int32_(name, default_val, doc) \
-    GTEST_API_ std::int32_t GTEST_FLAG(name) = (default_val)
-# define GTEST_DEFINE_string_(name, default_val, doc) \
-    GTEST_API_ ::std::string GTEST_FLAG(name) = (default_val)
-
-#endif  // !defined(GTEST_DECLARE_bool_)
-
-// Thread annotations
-#if !defined(GTEST_EXCLUSIVE_LOCK_REQUIRED_)
-# define GTEST_EXCLUSIVE_LOCK_REQUIRED_(locks)
-# define GTEST_LOCK_EXCLUDED_(locks)
-#endif  // !defined(GTEST_EXCLUSIVE_LOCK_REQUIRED_)
-
-// Parses 'str' for a 32-bit signed integer.  If successful, writes the result
-// to *value and returns true; otherwise leaves *value unchanged and returns
-// false.
-GTEST_API_ bool ParseInt32(const Message& src_text, const char* str,
-                           int32_t* value);
-
-// Parses a bool/int32_t/string from the environment variable
-// corresponding to the given Google Test flag.
-bool BoolFromGTestEnv(const char* flag, bool default_val);
-GTEST_API_ int32_t Int32FromGTestEnv(const char* flag, int32_t default_val);
-std::string OutputFlagAlsoCheckEnvVar();
-const char* StringFromGTestEnv(const char* flag, const char* default_val);
-
-}  // namespace internal
-}  // namespace testing
-
-#if !defined(GTEST_INTERNAL_DEPRECATED)
-
-// Internal Macro to mark an API deprecated, for googletest usage only
-// Usage: class GTEST_INTERNAL_DEPRECATED(message) MyClass or
-// GTEST_INTERNAL_DEPRECATED(message) <return_type> myFunction(); Every usage of
-// a deprecated entity will trigger a warning when compiled with
-// `-Wdeprecated-declarations` option (clang, gcc, any __GNUC__ compiler).
-// For msvc /W3 option will need to be used
-// Note that for 'other' compilers this macro evaluates to nothing to prevent
-// compilations errors.
-#if defined(_MSC_VER)
-#define GTEST_INTERNAL_DEPRECATED(message) __declspec(deprecated(message))
-#elif defined(__GNUC__)
-#define GTEST_INTERNAL_DEPRECATED(message) __attribute__((deprecated(message)))
-#else
-#define GTEST_INTERNAL_DEPRECATED(message)
-#endif
-
-#endif  // !defined(GTEST_INTERNAL_DEPRECATED)
-
-#if GTEST_HAS_ABSL
-// Always use absl::any for UniversalPrinter<> specializations if googletest
-// is built with absl support.
-#define GTEST_INTERNAL_HAS_ANY 1
-#include "absl/types/any.h"
-namespace testing {
-namespace internal {
-using Any = ::absl::any;
-}  // namespace internal
-}  // namespace testing
-#else
-#ifdef __has_include
-#if __has_include(<any>) && __cplusplus >= 201703L
-// Otherwise for C++17 and higher use std::any for UniversalPrinter<>
-// specializations.
-#define GTEST_INTERNAL_HAS_ANY 1
-#include <any>
-namespace testing {
-namespace internal {
-using Any = ::std::any;
-}  // namespace internal
-}  // namespace testing
-// The case where absl is configured NOT to alias std::any is not
-// supported.
-#endif  // __has_include(<any>) && __cplusplus >= 201703L
-#endif  // __has_include
-#endif  // GTEST_HAS_ABSL
-
-#if GTEST_HAS_ABSL
-// Always use absl::optional for UniversalPrinter<> specializations if
-// googletest is built with absl support.
-#define GTEST_INTERNAL_HAS_OPTIONAL 1
-#include "absl/types/optional.h"
-namespace testing {
-namespace internal {
-template <typename T>
-using Optional = ::absl::optional<T>;
-}  // namespace internal
-}  // namespace testing
-#else
-#ifdef __has_include
-#if __has_include(<optional>) && __cplusplus >= 201703L
-// Otherwise for C++17 and higher use std::optional for UniversalPrinter<>
-// specializations.
-#define GTEST_INTERNAL_HAS_OPTIONAL 1
-#include <optional>
-namespace testing {
-namespace internal {
-template <typename T>
-using Optional = ::std::optional<T>;
-}  // namespace internal
-}  // namespace testing
-// The case where absl is configured NOT to alias std::optional is not
-// supported.
-#endif  // __has_include(<optional>) && __cplusplus >= 201703L
-#endif  // __has_include
-#endif  // GTEST_HAS_ABSL
-
-#if GTEST_HAS_ABSL
-// Always use absl::string_view for Matcher<> specializations if googletest
-// is built with absl support.
-# define GTEST_INTERNAL_HAS_STRING_VIEW 1
-#include "absl/strings/string_view.h"
-namespace testing {
-namespace internal {
-using StringView = ::absl::string_view;
-}  // namespace internal
-}  // namespace testing
-#else
-# ifdef __has_include
-#   if __has_include(<string_view>) && __cplusplus >= 201703L
-// Otherwise for C++17 and higher use std::string_view for Matcher<>
-// specializations.
-#   define GTEST_INTERNAL_HAS_STRING_VIEW 1
-#include <string_view>
-namespace testing {
-namespace internal {
-using StringView = ::std::string_view;
-}  // namespace internal
-}  // namespace testing
-// The case where absl is configured NOT to alias std::string_view is not
-// supported.
-#  endif  // __has_include(<string_view>) && __cplusplus >= 201703L
-# endif  // __has_include
-#endif  // GTEST_HAS_ABSL
-
-#if GTEST_HAS_ABSL
-// Always use absl::variant for UniversalPrinter<> specializations if googletest
-// is built with absl support.
-#define GTEST_INTERNAL_HAS_VARIANT 1
-#include "absl/types/variant.h"
-namespace testing {
-namespace internal {
-template <typename... T>
-using Variant = ::absl::variant<T...>;
-}  // namespace internal
-}  // namespace testing
-#else
-#ifdef __has_include
-#if __has_include(<variant>) && __cplusplus >= 201703L
-// Otherwise for C++17 and higher use std::variant for UniversalPrinter<>
-// specializations.
-#define GTEST_INTERNAL_HAS_VARIANT 1
-#include <variant>
-namespace testing {
-namespace internal {
-template <typename... T>
-using Variant = ::std::variant<T...>;
-}  // namespace internal
-}  // namespace testing
-// The case where absl is configured NOT to alias std::variant is not supported.
-#endif  // __has_include(<variant>) && __cplusplus >= 201703L
-#endif  // __has_include
-#endif  // GTEST_HAS_ABSL
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_
-
-#if GTEST_OS_LINUX
-# include <stdlib.h>
-# include <sys/types.h>
-# include <sys/wait.h>
-# include <unistd.h>
-#endif  // GTEST_OS_LINUX
-
-#if GTEST_HAS_EXCEPTIONS
-# include <stdexcept>
-#endif
-
-#include <ctype.h>
-#include <float.h>
-#include <string.h>
-#include <cstdint>
-#include <iomanip>
-#include <limits>
-#include <map>
-#include <set>
-#include <string>
-#include <type_traits>
-#include <vector>
-
-// Copyright 2005, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-//
-// The Google C++ Testing and Mocking Framework (Google Test)
-//
-// This header file defines the Message class.
-//
-// IMPORTANT NOTE: Due to limitation of the C++ language, we have to
-// leave some internal implementation details in this header file.
-// They are clearly marked by comments like this:
-//
-//   // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-//
-// Such code is NOT meant to be used by a user directly, and is subject
-// to CHANGE WITHOUT NOTICE.  Therefore DO NOT DEPEND ON IT in a user
-// program!
-
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_MESSAGE_H_
-#define GOOGLETEST_INCLUDE_GTEST_GTEST_MESSAGE_H_
-
-#include <limits>
-#include <memory>
-#include <sstream>
-
-
-GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
-/* class A needs to have dll-interface to be used by clients of class B */)
-
-// Ensures that there is at least one operator<< in the global namespace.
-// See Message& operator<<(...) below for why.
-void operator<<(const testing::internal::Secret&, int);
-
-namespace testing {
-
-// The Message class works like an ostream repeater.
-//
-// Typical usage:
-//
-//   1. You stream a bunch of values to a Message object.
-//      It will remember the text in a stringstream.
-//   2. Then you stream the Message object to an ostream.
-//      This causes the text in the Message to be streamed
-//      to the ostream.
-//
-// For example;
-//
-//   testing::Message foo;
-//   foo << 1 << " != " << 2;
-//   std::cout << foo;
-//
-// will print "1 != 2".
-//
-// Message is not intended to be inherited from.  In particular, its
-// destructor is not virtual.
-//
-// Note that stringstream behaves differently in gcc and in MSVC.  You
-// can stream a NULL char pointer to it in the former, but not in the
-// latter (it causes an access violation if you do).  The Message
-// class hides this difference by treating a NULL char pointer as
-// "(null)".
-class GTEST_API_ Message {
- private:
-  // The type of basic IO manipulators (endl, ends, and flush) for
-  // narrow streams.
-  typedef std::ostream& (*BasicNarrowIoManip)(std::ostream&);
-
- public:
-  // Constructs an empty Message.
-  Message();
-
-  // Copy constructor.
-  Message(const Message& msg) : ss_(new ::std::stringstream) {  // NOLINT
-    *ss_ << msg.GetString();
-  }
-
-  // Constructs a Message from a C-string.
-  explicit Message(const char* str) : ss_(new ::std::stringstream) {
-    *ss_ << str;
-  }
-
-  // Streams a non-pointer value to this object.
-  template <typename T>
-  inline Message& operator <<(const T& val) {
-    // Some libraries overload << for STL containers.  These
-    // overloads are defined in the global namespace instead of ::std.
-    //
-    // C++'s symbol lookup rule (i.e. Koenig lookup) says that these
-    // overloads are visible in either the std namespace or the global
-    // namespace, but not other namespaces, including the testing
-    // namespace which Google Test's Message class is in.
-    //
-    // To allow STL containers (and other types that has a << operator
-    // defined in the global namespace) to be used in Google Test
-    // assertions, testing::Message must access the custom << operator
-    // from the global namespace.  With this using declaration,
-    // overloads of << defined in the global namespace and those
-    // visible via Koenig lookup are both exposed in this function.
-    using ::operator <<;
-    *ss_ << val;
-    return *this;
-  }
-
-  // Streams a pointer value to this object.
-  //
-  // This function is an overload of the previous one.  When you
-  // stream a pointer to a Message, this definition will be used as it
-  // is more specialized.  (The C++ Standard, section
-  // [temp.func.order].)  If you stream a non-pointer, then the
-  // previous definition will be used.
-  //
-  // The reason for this overload is that streaming a NULL pointer to
-  // ostream is undefined behavior.  Depending on the compiler, you
-  // may get "0", "(nil)", "(null)", or an access violation.  To
-  // ensure consistent result across compilers, we always treat NULL
-  // as "(null)".
-  template <typename T>
-  inline Message& operator <<(T* const& pointer) {  // NOLINT
-    if (pointer == nullptr) {
-      *ss_ << "(null)";
-    } else {
-      *ss_ << pointer;
-    }
-    return *this;
-  }
-
-  // Since the basic IO manipulators are overloaded for both narrow
-  // and wide streams, we have to provide this specialized definition
-  // of operator <<, even though its body is the same as the
-  // templatized version above.  Without this definition, streaming
-  // endl or other basic IO manipulators to Message will confuse the
-  // compiler.
-  Message& operator <<(BasicNarrowIoManip val) {
-    *ss_ << val;
-    return *this;
-  }
-
-  // Instead of 1/0, we want to see true/false for bool values.
-  Message& operator <<(bool b) {
-    return *this << (b ? "true" : "false");
-  }
-
-  // These two overloads allow streaming a wide C string to a Message
-  // using the UTF-8 encoding.
-  Message& operator <<(const wchar_t* wide_c_str);
-  Message& operator <<(wchar_t* wide_c_str);
-
-#if GTEST_HAS_STD_WSTRING
-  // Converts the given wide string to a narrow string using the UTF-8
-  // encoding, and streams the result to this Message object.
-  Message& operator <<(const ::std::wstring& wstr);
-#endif  // GTEST_HAS_STD_WSTRING
-
-  // Gets the text streamed to this object so far as an std::string.
-  // Each '\0' character in the buffer is replaced with "\\0".
-  //
-  // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-  std::string GetString() const;
-
- private:
-  // We'll hold the text streamed to this object here.
-  const std::unique_ptr< ::std::stringstream> ss_;
-
-  // We declare (but don't implement) this to prevent the compiler
-  // from implementing the assignment operator.
-  void operator=(const Message&);
-};
-
-// Streams a Message to an ostream.
-inline std::ostream& operator <<(std::ostream& os, const Message& sb) {
-  return os << sb.GetString();
-}
-
-namespace internal {
-
-// Converts a streamable value to an std::string.  A NULL pointer is
-// converted to "(null)".  When the input value is a ::string,
-// ::std::string, ::wstring, or ::std::wstring object, each NUL
-// character in it is replaced with "\\0".
-template <typename T>
-std::string StreamableToString(const T& streamable) {
-  return (Message() << streamable).GetString();
-}
-
-}  // namespace internal
-}  // namespace testing
-
-GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_MESSAGE_H_
-// Copyright 2008, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// Google Test filepath utilities
-//
-// This header file declares classes and functions used internally by
-// Google Test.  They are subject to change without notice.
-//
-// This file is #included in gtest/internal/gtest-internal.h.
-// Do not include this header file separately!
-
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_FILEPATH_H_
-#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_FILEPATH_H_
-
-// Copyright 2005, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// The Google C++ Testing and Mocking Framework (Google Test)
-//
-// This header file declares the String class and functions used internally by
-// Google Test.  They are subject to change without notice. They should not used
-// by code external to Google Test.
-//
-// This header file is #included by gtest-internal.h.
-// It should not be #included by other files.
-
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_STRING_H_
-#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_STRING_H_
-
-#ifdef __BORLANDC__
-// string.h is not guaranteed to provide strcpy on C++ Builder.
-# include <mem.h>
-#endif
-
-#include <string.h>
-#include <cstdint>
-#include <string>
-
-
-namespace testing {
-namespace internal {
-
-// String - an abstract class holding static string utilities.
-class GTEST_API_ String {
- public:
-  // Static utility methods
-
-  // Clones a 0-terminated C string, allocating memory using new.  The
-  // caller is responsible for deleting the return value using
-  // delete[].  Returns the cloned string, or NULL if the input is
-  // NULL.
-  //
-  // This is different from strdup() in string.h, which allocates
-  // memory using malloc().
-  static const char* CloneCString(const char* c_str);
-
-#if GTEST_OS_WINDOWS_MOBILE
-  // Windows CE does not have the 'ANSI' versions of Win32 APIs. To be
-  // able to pass strings to Win32 APIs on CE we need to convert them
-  // to 'Unicode', UTF-16.
-
-  // Creates a UTF-16 wide string from the given ANSI string, allocating
-  // memory using new. The caller is responsible for deleting the return
-  // value using delete[]. Returns the wide string, or NULL if the
-  // input is NULL.
-  //
-  // The wide string is created using the ANSI codepage (CP_ACP) to
-  // match the behaviour of the ANSI versions of Win32 calls and the
-  // C runtime.
-  static LPCWSTR AnsiToUtf16(const char* c_str);
-
-  // Creates an ANSI string from the given wide string, allocating
-  // memory using new. The caller is responsible for deleting the return
-  // value using delete[]. Returns the ANSI string, or NULL if the
-  // input is NULL.
-  //
-  // The returned string is created using the ANSI codepage (CP_ACP) to
-  // match the behaviour of the ANSI versions of Win32 calls and the
-  // C runtime.
-  static const char* Utf16ToAnsi(LPCWSTR utf16_str);
-#endif
-
-  // Compares two C strings.  Returns true if and only if they have the same
-  // content.
-  //
-  // Unlike strcmp(), this function can handle NULL argument(s).  A
-  // NULL C string is considered different to any non-NULL C string,
-  // including the empty string.
-  static bool CStringEquals(const char* lhs, const char* rhs);
-
-  // Converts a wide C string to a String using the UTF-8 encoding.
-  // NULL will be converted to "(null)".  If an error occurred during
-  // the conversion, "(failed to convert from wide string)" is
-  // returned.
-  static std::string ShowWideCString(const wchar_t* wide_c_str);
-
-  // Compares two wide C strings.  Returns true if and only if they have the
-  // same content.
-  //
-  // Unlike wcscmp(), this function can handle NULL argument(s).  A
-  // NULL C string is considered different to any non-NULL C string,
-  // including the empty string.
-  static bool WideCStringEquals(const wchar_t* lhs, const wchar_t* rhs);
-
-  // Compares two C strings, ignoring case.  Returns true if and only if
-  // they have the same content.
-  //
-  // Unlike strcasecmp(), this function can handle NULL argument(s).
-  // A NULL C string is considered different to any non-NULL C string,
-  // including the empty string.
-  static bool CaseInsensitiveCStringEquals(const char* lhs,
-                                           const char* rhs);
-
-  // Compares two wide C strings, ignoring case.  Returns true if and only if
-  // they have the same content.
-  //
-  // Unlike wcscasecmp(), this function can handle NULL argument(s).
-  // A NULL C string is considered different to any non-NULL wide C string,
-  // including the empty string.
-  // NB: The implementations on different platforms slightly differ.
-  // On windows, this method uses _wcsicmp which compares according to LC_CTYPE
-  // environment variable. On GNU platform this method uses wcscasecmp
-  // which compares according to LC_CTYPE category of the current locale.
-  // On MacOS X, it uses towlower, which also uses LC_CTYPE category of the
-  // current locale.
-  static bool CaseInsensitiveWideCStringEquals(const wchar_t* lhs,
-                                               const wchar_t* rhs);
-
-  // Returns true if and only if the given string ends with the given suffix,
-  // ignoring case. Any string is considered to end with an empty suffix.
-  static bool EndsWithCaseInsensitive(
-      const std::string& str, const std::string& suffix);
-
-  // Formats an int value as "%02d".
-  static std::string FormatIntWidth2(int value);  // "%02d" for width == 2
-
-  // Formats an int value to given width with leading zeros.
-  static std::string FormatIntWidthN(int value, int width);
-
-  // Formats an int value as "%X".
-  static std::string FormatHexInt(int value);
-
-  // Formats an int value as "%X".
-  static std::string FormatHexUInt32(uint32_t value);
-
-  // Formats a byte as "%02X".
-  static std::string FormatByte(unsigned char value);
-
- private:
-  String();  // Not meant to be instantiated.
-};  // class String
-
-// Gets the content of the stringstream's buffer as an std::string.  Each '\0'
-// character in the buffer is replaced with "\\0".
-GTEST_API_ std::string StringStreamToString(::std::stringstream* stream);
-
-}  // namespace internal
-}  // namespace testing
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_STRING_H_
-
-GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
-/* class A needs to have dll-interface to be used by clients of class B */)
-
-namespace testing {
-namespace internal {
-
-// FilePath - a class for file and directory pathname manipulation which
-// handles platform-specific conventions (like the pathname separator).
-// Used for helper functions for naming files in a directory for xml output.
-// Except for Set methods, all methods are const or static, which provides an
-// "immutable value object" -- useful for peace of mind.
-// A FilePath with a value ending in a path separator ("like/this/") represents
-// a directory, otherwise it is assumed to represent a file. In either case,
-// it may or may not represent an actual file or directory in the file system.
-// Names are NOT checked for syntax correctness -- no checking for illegal
-// characters, malformed paths, etc.
-
-class GTEST_API_ FilePath {
- public:
-  FilePath() : pathname_("") { }
-  FilePath(const FilePath& rhs) : pathname_(rhs.pathname_) { }
-
-  explicit FilePath(const std::string& pathname) : pathname_(pathname) {
-    Normalize();
-  }
-
-  FilePath& operator=(const FilePath& rhs) {
-    Set(rhs);
-    return *this;
-  }
-
-  void Set(const FilePath& rhs) {
-    pathname_ = rhs.pathname_;
-  }
-
-  const std::string& string() const { return pathname_; }
-  const char* c_str() const { return pathname_.c_str(); }
-
-  // Returns the current working directory, or "" if unsuccessful.
-  static FilePath GetCurrentDir();
-
-  // Given directory = "dir", base_name = "test", number = 0,
-  // extension = "xml", returns "dir/test.xml". If number is greater
-  // than zero (e.g., 12), returns "dir/test_12.xml".
-  // On Windows platform, uses \ as the separator rather than /.
-  static FilePath MakeFileName(const FilePath& directory,
-                               const FilePath& base_name,
-                               int number,
-                               const char* extension);
-
-  // Given directory = "dir", relative_path = "test.xml",
-  // returns "dir/test.xml".
-  // On Windows, uses \ as the separator rather than /.
-  static FilePath ConcatPaths(const FilePath& directory,
-                              const FilePath& relative_path);
-
-  // Returns a pathname for a file that does not currently exist. The pathname
-  // will be directory/base_name.extension or
-  // directory/base_name_<number>.extension if directory/base_name.extension
-  // already exists. The number will be incremented until a pathname is found
-  // that does not already exist.
-  // Examples: 'dir/foo_test.xml' or 'dir/foo_test_1.xml'.
-  // There could be a race condition if two or more processes are calling this
-  // function at the same time -- they could both pick the same filename.
-  static FilePath GenerateUniqueFileName(const FilePath& directory,
-                                         const FilePath& base_name,
-                                         const char* extension);
-
-  // Returns true if and only if the path is "".
-  bool IsEmpty() const { return pathname_.empty(); }
-
-  // If input name has a trailing separator character, removes it and returns
-  // the name, otherwise return the name string unmodified.
-  // On Windows platform, uses \ as the separator, other platforms use /.
-  FilePath RemoveTrailingPathSeparator() const;
-
-  // Returns a copy of the FilePath with the directory part removed.
-  // Example: FilePath("path/to/file").RemoveDirectoryName() returns
-  // FilePath("file"). If there is no directory part ("just_a_file"), it returns
-  // the FilePath unmodified. If there is no file part ("just_a_dir/") it
-  // returns an empty FilePath ("").
-  // On Windows platform, '\' is the path separator, otherwise it is '/'.
-  FilePath RemoveDirectoryName() const;
-
-  // RemoveFileName returns the directory path with the filename removed.
-  // Example: FilePath("path/to/file").RemoveFileName() returns "path/to/".
-  // If the FilePath is "a_file" or "/a_file", RemoveFileName returns
-  // FilePath("./") or, on Windows, FilePath(".\\"). If the filepath does
-  // not have a file, like "just/a/dir/", it returns the FilePath unmodified.
-  // On Windows platform, '\' is the path separator, otherwise it is '/'.
-  FilePath RemoveFileName() const;
-
-  // Returns a copy of the FilePath with the case-insensitive extension removed.
-  // Example: FilePath("dir/file.exe").RemoveExtension("EXE") returns
-  // FilePath("dir/file"). If a case-insensitive extension is not
-  // found, returns a copy of the original FilePath.
-  FilePath RemoveExtension(const char* extension) const;
-
-  // Creates directories so that path exists. Returns true if successful or if
-  // the directories already exist; returns false if unable to create
-  // directories for any reason. Will also return false if the FilePath does
-  // not represent a directory (that is, it doesn't end with a path separator).
-  bool CreateDirectoriesRecursively() const;
-
-  // Create the directory so that path exists. Returns true if successful or
-  // if the directory already exists; returns false if unable to create the
-  // directory for any reason, including if the parent directory does not
-  // exist. Not named "CreateDirectory" because that's a macro on Windows.
-  bool CreateFolder() const;
-
-  // Returns true if FilePath describes something in the file-system,
-  // either a file, directory, or whatever, and that something exists.
-  bool FileOrDirectoryExists() const;
-
-  // Returns true if pathname describes a directory in the file-system
-  // that exists.
-  bool DirectoryExists() const;
-
-  // Returns true if FilePath ends with a path separator, which indicates that
-  // it is intended to represent a directory. Returns false otherwise.
-  // This does NOT check that a directory (or file) actually exists.
-  bool IsDirectory() const;
-
-  // Returns true if pathname describes a root directory. (Windows has one
-  // root directory per disk drive.)
-  bool IsRootDirectory() const;
-
-  // Returns true if pathname describes an absolute path.
-  bool IsAbsolutePath() const;
-
- private:
-  // Replaces multiple consecutive separators with a single separator.
-  // For example, "bar///foo" becomes "bar/foo". Does not eliminate other
-  // redundancies that might be in a pathname involving "." or "..".
-  //
-  // A pathname with multiple consecutive separators may occur either through
-  // user error or as a result of some scripts or APIs that generate a pathname
-  // with a trailing separator. On other platforms the same API or script
-  // may NOT generate a pathname with a trailing "/". Then elsewhere that
-  // pathname may have another "/" and pathname components added to it,
-  // without checking for the separator already being there.
-  // The script language and operating system may allow paths like "foo//bar"
-  // but some of the functions in FilePath will not handle that correctly. In
-  // particular, RemoveTrailingPathSeparator() only removes one separator, and
-  // it is called in CreateDirectoriesRecursively() assuming that it will change
-  // a pathname from directory syntax (trailing separator) to filename syntax.
-  //
-  // On Windows this method also replaces the alternate path separator '/' with
-  // the primary path separator '\\', so that for example "bar\\/\\foo" becomes
-  // "bar\\foo".
-
-  void Normalize();
-
-  // Returns a pointer to the last occurrence of a valid path separator in
-  // the FilePath. On Windows, for example, both '/' and '\' are valid path
-  // separators. Returns NULL if no path separator was found.
-  const char* FindLastPathSeparator() const;
-
-  std::string pathname_;
-};  // class FilePath
-
-}  // namespace internal
-}  // namespace testing
-
-GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_FILEPATH_H_
-// Copyright 2008 Google Inc.
-// All Rights Reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// Type utilities needed for implementing typed and type-parameterized
-// tests.
-
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
-#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
-
-
-// #ifdef __GNUC__ is too general here.  It is possible to use gcc without using
-// libstdc++ (which is where cxxabi.h comes from).
-# if GTEST_HAS_CXXABI_H_
-#  include <cxxabi.h>
-# elif defined(__HP_aCC)
-#  include <acxx_demangle.h>
-# endif  // GTEST_HASH_CXXABI_H_
-
-namespace testing {
-namespace internal {
-
-// Canonicalizes a given name with respect to the Standard C++ Library.
-// This handles removing the inline namespace within `std` that is
-// used by various standard libraries (e.g., `std::__1`).  Names outside
-// of namespace std are returned unmodified.
-inline std::string CanonicalizeForStdLibVersioning(std::string s) {
-  static const char prefix[] = "std::__";
-  if (s.compare(0, strlen(prefix), prefix) == 0) {
-    std::string::size_type end = s.find("::", strlen(prefix));
-    if (end != s.npos) {
-      // Erase everything between the initial `std` and the second `::`.
-      s.erase(strlen("std"), end - strlen("std"));
-    }
-  }
-  return s;
-}
-
-#if GTEST_HAS_RTTI
-// GetTypeName(const std::type_info&) returns a human-readable name of type T.
-inline std::string GetTypeName(const std::type_info& type) {
-  const char* const name = type.name();
-#if GTEST_HAS_CXXABI_H_ || defined(__HP_aCC)
-  int status = 0;
-  // gcc's implementation of typeid(T).name() mangles the type name,
-  // so we have to demangle it.
-#if GTEST_HAS_CXXABI_H_
-  using abi::__cxa_demangle;
-#endif  // GTEST_HAS_CXXABI_H_
-  char* const readable_name = __cxa_demangle(name, nullptr, nullptr, &status);
-  const std::string name_str(status == 0 ? readable_name : name);
-  free(readable_name);
-  return CanonicalizeForStdLibVersioning(name_str);
-#else
-  return name;
-#endif  // GTEST_HAS_CXXABI_H_ || __HP_aCC
-}
-#endif  // GTEST_HAS_RTTI
-
-// GetTypeName<T>() returns a human-readable name of type T if and only if
-// RTTI is enabled, otherwise it returns a dummy type name.
-// NB: This function is also used in Google Mock, so don't move it inside of
-// the typed-test-only section below.
-template <typename T>
-std::string GetTypeName() {
-#if GTEST_HAS_RTTI
-  return GetTypeName(typeid(T));
-#else
-  return "<type>";
-#endif  // GTEST_HAS_RTTI
-}
-
-// A unique type indicating an empty node
-struct None {};
-
-# define GTEST_TEMPLATE_ template <typename T> class
-
-// The template "selector" struct TemplateSel<Tmpl> is used to
-// represent Tmpl, which must be a class template with one type
-// parameter, as a type.  TemplateSel<Tmpl>::Bind<T>::type is defined
-// as the type Tmpl<T>.  This allows us to actually instantiate the
-// template "selected" by TemplateSel<Tmpl>.
-//
-// This trick is necessary for simulating typedef for class templates,
-// which C++ doesn't support directly.
-template <GTEST_TEMPLATE_ Tmpl>
-struct TemplateSel {
-  template <typename T>
-  struct Bind {
-    typedef Tmpl<T> type;
-  };
-};
-
-# define GTEST_BIND_(TmplSel, T) \
-  TmplSel::template Bind<T>::type
-
-template <GTEST_TEMPLATE_ Head_, GTEST_TEMPLATE_... Tail_>
-struct Templates {
-  using Head = TemplateSel<Head_>;
-  using Tail = Templates<Tail_...>;
-};
-
-template <GTEST_TEMPLATE_ Head_>
-struct Templates<Head_> {
-  using Head = TemplateSel<Head_>;
-  using Tail = None;
-};
-
-// Tuple-like type lists
-template <typename Head_, typename... Tail_>
-struct Types {
-  using Head = Head_;
-  using Tail = Types<Tail_...>;
-};
-
-template <typename Head_>
-struct Types<Head_> {
-  using Head = Head_;
-  using Tail = None;
-};
-
-// Helper metafunctions to tell apart a single type from types
-// generated by ::testing::Types
-template <typename... Ts>
-struct ProxyTypeList {
-  using type = Types<Ts...>;
-};
-
-template <typename>
-struct is_proxy_type_list : std::false_type {};
-
-template <typename... Ts>
-struct is_proxy_type_list<ProxyTypeList<Ts...>> : std::true_type {};
-
-// Generator which conditionally creates type lists.
-// It recognizes if a requested type list should be created
-// and prevents creating a new type list nested within another one.
-template <typename T>
-struct GenerateTypeList {
- private:
-  using proxy = typename std::conditional<is_proxy_type_list<T>::value, T,
-                                          ProxyTypeList<T>>::type;
-
- public:
-  using type = typename proxy::type;
-};
-
-}  // namespace internal
-
-template <typename... Ts>
-using Types = internal::ProxyTypeList<Ts...>;
-
-}  // namespace testing
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
-
-// Due to C++ preprocessor weirdness, we need double indirection to
-// concatenate two tokens when one of them is __LINE__.  Writing
-//
-//   foo ## __LINE__
-//
-// will result in the token foo__LINE__, instead of foo followed by
-// the current line number.  For more details, see
-// http://www.parashift.com/c++-faq-lite/misc-technical-issues.html#faq-39.6
-#define GTEST_CONCAT_TOKEN_(foo, bar) GTEST_CONCAT_TOKEN_IMPL_(foo, bar)
-#define GTEST_CONCAT_TOKEN_IMPL_(foo, bar) foo ## bar
-
-// Stringifies its argument.
-// Work around a bug in visual studio which doesn't accept code like this:
-//
-//   #define GTEST_STRINGIFY_(name) #name
-//   #define MACRO(a, b, c) ... GTEST_STRINGIFY_(a) ...
-//   MACRO(, x, y)
-//
-// Complaining about the argument to GTEST_STRINGIFY_ being empty.
-// This is allowed by the spec.
-#define GTEST_STRINGIFY_HELPER_(name, ...) #name
-#define GTEST_STRINGIFY_(...) GTEST_STRINGIFY_HELPER_(__VA_ARGS__, )
-
-namespace proto2 {
-class MessageLite;
-}
-
-namespace testing {
-
-// Forward declarations.
-
-class AssertionResult;                 // Result of an assertion.
-class Message;                         // Represents a failure message.
-class Test;                            // Represents a test.
-class TestInfo;                        // Information about a test.
-class TestPartResult;                  // Result of a test part.
-class UnitTest;                        // A collection of test suites.
-
-template <typename T>
-::std::string PrintToString(const T& value);
-
-namespace internal {
-
-struct TraceInfo;                      // Information about a trace point.
-class TestInfoImpl;                    // Opaque implementation of TestInfo
-class UnitTestImpl;                    // Opaque implementation of UnitTest
-
-// The text used in failure messages to indicate the start of the
-// stack trace.
-GTEST_API_ extern const char kStackTraceMarker[];
-
-// An IgnoredValue object can be implicitly constructed from ANY value.
-class IgnoredValue {
-  struct Sink {};
- public:
-  // This constructor template allows any value to be implicitly
-  // converted to IgnoredValue.  The object has no data member and
-  // doesn't try to remember anything about the argument.  We
-  // deliberately omit the 'explicit' keyword in order to allow the
-  // conversion to be implicit.
-  // Disable the conversion if T already has a magical conversion operator.
-  // Otherwise we get ambiguity.
-  template <typename T,
-            typename std::enable_if<!std::is_convertible<T, Sink>::value,
-                                    int>::type = 0>
-  IgnoredValue(const T& /* ignored */) {}  // NOLINT(runtime/explicit)
-};
-
-// Appends the user-supplied message to the Google-Test-generated message.
-GTEST_API_ std::string AppendUserMessage(
-    const std::string& gtest_msg, const Message& user_msg);
-
-#if GTEST_HAS_EXCEPTIONS
-
-GTEST_DISABLE_MSC_WARNINGS_PUSH_(4275 \
-/* an exported class was derived from a class that was not exported */)
-
-// This exception is thrown by (and only by) a failed Google Test
-// assertion when GTEST_FLAG(throw_on_failure) is true (if exceptions
-// are enabled).  We derive it from std::runtime_error, which is for
-// errors presumably detectable only at run time.  Since
-// std::runtime_error inherits from std::exception, many testing
-// frameworks know how to extract and print the message inside it.
-class GTEST_API_ GoogleTestFailureException : public ::std::runtime_error {
- public:
-  explicit GoogleTestFailureException(const TestPartResult& failure);
-};
-
-GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4275
-
-#endif  // GTEST_HAS_EXCEPTIONS
-
-namespace edit_distance {
-// Returns the optimal edits to go from 'left' to 'right'.
-// All edits cost the same, with replace having lower priority than
-// add/remove.
-// Simple implementation of the Wagner-Fischer algorithm.
-// See http://en.wikipedia.org/wiki/Wagner-Fischer_algorithm
-enum EditType { kMatch, kAdd, kRemove, kReplace };
-GTEST_API_ std::vector<EditType> CalculateOptimalEdits(
-    const std::vector<size_t>& left, const std::vector<size_t>& right);
-
-// Same as above, but the input is represented as strings.
-GTEST_API_ std::vector<EditType> CalculateOptimalEdits(
-    const std::vector<std::string>& left,
-    const std::vector<std::string>& right);
-
-// Create a diff of the input strings in Unified diff format.
-GTEST_API_ std::string CreateUnifiedDiff(const std::vector<std::string>& left,
-                                         const std::vector<std::string>& right,
-                                         size_t context = 2);
-
-}  // namespace edit_distance
-
-// Calculate the diff between 'left' and 'right' and return it in unified diff
-// format.
-// If not null, stores in 'total_line_count' the total number of lines found
-// in left + right.
-GTEST_API_ std::string DiffStrings(const std::string& left,
-                                   const std::string& right,
-                                   size_t* total_line_count);
-
-// Constructs and returns the message for an equality assertion
-// (e.g. ASSERT_EQ, EXPECT_STREQ, etc) failure.
-//
-// The first four parameters are the expressions used in the assertion
-// and their values, as strings.  For example, for ASSERT_EQ(foo, bar)
-// where foo is 5 and bar is 6, we have:
-//
-//   expected_expression: "foo"
-//   actual_expression:   "bar"
-//   expected_value:      "5"
-//   actual_value:        "6"
-//
-// The ignoring_case parameter is true if and only if the assertion is a
-// *_STRCASEEQ*.  When it's true, the string " (ignoring case)" will
-// be inserted into the message.
-GTEST_API_ AssertionResult EqFailure(const char* expected_expression,
-                                     const char* actual_expression,
-                                     const std::string& expected_value,
-                                     const std::string& actual_value,
-                                     bool ignoring_case);
-
-// Constructs a failure message for Boolean assertions such as EXPECT_TRUE.
-GTEST_API_ std::string GetBoolAssertionFailureMessage(
-    const AssertionResult& assertion_result,
-    const char* expression_text,
-    const char* actual_predicate_value,
-    const char* expected_predicate_value);
-
-// This template class represents an IEEE floating-point number
-// (either single-precision or double-precision, depending on the
-// template parameters).
-//
-// The purpose of this class is to do more sophisticated number
-// comparison.  (Due to round-off error, etc, it's very unlikely that
-// two floating-points will be equal exactly.  Hence a naive
-// comparison by the == operation often doesn't work.)
-//
-// Format of IEEE floating-point:
-//
-//   The most-significant bit being the leftmost, an IEEE
-//   floating-point looks like
-//
-//     sign_bit exponent_bits fraction_bits
-//
-//   Here, sign_bit is a single bit that designates the sign of the
-//   number.
-//
-//   For float, there are 8 exponent bits and 23 fraction bits.
-//
-//   For double, there are 11 exponent bits and 52 fraction bits.
-//
-//   More details can be found at
-//   http://en.wikipedia.org/wiki/IEEE_floating-point_standard.
-//
-// Template parameter:
-//
-//   RawType: the raw floating-point type (either float or double)
-template <typename RawType>
-class FloatingPoint {
- public:
-  // Defines the unsigned integer type that has the same size as the
-  // floating point number.
-  typedef typename TypeWithSize<sizeof(RawType)>::UInt Bits;
-
-  // Constants.
-
-  // # of bits in a number.
-  static const size_t kBitCount = 8*sizeof(RawType);
-
-  // # of fraction bits in a number.
-  static const size_t kFractionBitCount =
-    std::numeric_limits<RawType>::digits - 1;
-
-  // # of exponent bits in a number.
-  static const size_t kExponentBitCount = kBitCount - 1 - kFractionBitCount;
-
-  // The mask for the sign bit.
-  static const Bits kSignBitMask = static_cast<Bits>(1) << (kBitCount - 1);
-
-  // The mask for the fraction bits.
-  static const Bits kFractionBitMask =
-    ~static_cast<Bits>(0) >> (kExponentBitCount + 1);
-
-  // The mask for the exponent bits.
-  static const Bits kExponentBitMask = ~(kSignBitMask | kFractionBitMask);
-
-  // How many ULP's (Units in the Last Place) we want to tolerate when
-  // comparing two numbers.  The larger the value, the more error we
-  // allow.  A 0 value means that two numbers must be exactly the same
-  // to be considered equal.
-  //
-  // The maximum error of a single floating-point operation is 0.5
-  // units in the last place.  On Intel CPU's, all floating-point
-  // calculations are done with 80-bit precision, while double has 64
-  // bits.  Therefore, 4 should be enough for ordinary use.
-  //
-  // See the following article for more details on ULP:
-  // http://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/
-  static const uint32_t kMaxUlps = 4;
-
-  // Constructs a FloatingPoint from a raw floating-point number.
-  //
-  // On an Intel CPU, passing a non-normalized NAN (Not a Number)
-  // around may change its bits, although the new value is guaranteed
-  // to be also a NAN.  Therefore, don't expect this constructor to
-  // preserve the bits in x when x is a NAN.
-  explicit FloatingPoint(const RawType& x) { u_.value_ = x; }
-
-  // Static methods
-
-  // Reinterprets a bit pattern as a floating-point number.
-  //
-  // This function is needed to test the AlmostEquals() method.
-  static RawType ReinterpretBits(const Bits bits) {
-    FloatingPoint fp(0);
-    fp.u_.bits_ = bits;
-    return fp.u_.value_;
-  }
-
-  // Returns the floating-point number that represent positive infinity.
-  static RawType Infinity() {
-    return ReinterpretBits(kExponentBitMask);
-  }
-
-  // Returns the maximum representable finite floating-point number.
-  static RawType Max();
-
-  // Non-static methods
-
-  // Returns the bits that represents this number.
-  const Bits &bits() const { return u_.bits_; }
-
-  // Returns the exponent bits of this number.
-  Bits exponent_bits() const { return kExponentBitMask & u_.bits_; }
-
-  // Returns the fraction bits of this number.
-  Bits fraction_bits() const { return kFractionBitMask & u_.bits_; }
-
-  // Returns the sign bit of this number.
-  Bits sign_bit() const { return kSignBitMask & u_.bits_; }
-
-  // Returns true if and only if this is NAN (not a number).
-  bool is_nan() const {
-    // It's a NAN if the exponent bits are all ones and the fraction
-    // bits are not entirely zeros.
-    return (exponent_bits() == kExponentBitMask) && (fraction_bits() != 0);
-  }
-
-  // Returns true if and only if this number is at most kMaxUlps ULP's away
-  // from rhs.  In particular, this function:
-  //
-  //   - returns false if either number is (or both are) NAN.
-  //   - treats really large numbers as almost equal to infinity.
-  //   - thinks +0.0 and -0.0 are 0 DLP's apart.
-  bool AlmostEquals(const FloatingPoint& rhs) const {
-    // The IEEE standard says that any comparison operation involving
-    // a NAN must return false.
-    if (is_nan() || rhs.is_nan()) return false;
-
-    return DistanceBetweenSignAndMagnitudeNumbers(u_.bits_, rhs.u_.bits_)
-        <= kMaxUlps;
-  }
-
- private:
-  // The data type used to store the actual floating-point number.
-  union FloatingPointUnion {
-    RawType value_;  // The raw floating-point number.
-    Bits bits_;      // The bits that represent the number.
-  };
-
-  // Converts an integer from the sign-and-magnitude representation to
-  // the biased representation.  More precisely, let N be 2 to the
-  // power of (kBitCount - 1), an integer x is represented by the
-  // unsigned number x + N.
-  //
-  // For instance,
-  //
-  //   -N + 1 (the most negative number representable using
-  //          sign-and-magnitude) is represented by 1;
-  //   0      is represented by N; and
-  //   N - 1  (the biggest number representable using
-  //          sign-and-magnitude) is represented by 2N - 1.
-  //
-  // Read http://en.wikipedia.org/wiki/Signed_number_representations
-  // for more details on signed number representations.
-  static Bits SignAndMagnitudeToBiased(const Bits &sam) {
-    if (kSignBitMask & sam) {
-      // sam represents a negative number.
-      return ~sam + 1;
-    } else {
-      // sam represents a positive number.
-      return kSignBitMask | sam;
-    }
-  }
-
-  // Given two numbers in the sign-and-magnitude representation,
-  // returns the distance between them as an unsigned number.
-  static Bits DistanceBetweenSignAndMagnitudeNumbers(const Bits &sam1,
-                                                     const Bits &sam2) {
-    const Bits biased1 = SignAndMagnitudeToBiased(sam1);
-    const Bits biased2 = SignAndMagnitudeToBiased(sam2);
-    return (biased1 >= biased2) ? (biased1 - biased2) : (biased2 - biased1);
-  }
-
-  FloatingPointUnion u_;
-};
-
-// We cannot use std::numeric_limits<T>::max() as it clashes with the max()
-// macro defined by <windows.h>.
-template <>
-inline float FloatingPoint<float>::Max() { return FLT_MAX; }
-template <>
-inline double FloatingPoint<double>::Max() { return DBL_MAX; }
-
-// Typedefs the instances of the FloatingPoint template class that we
-// care to use.
-typedef FloatingPoint<float> Float;
-typedef FloatingPoint<double> Double;
-
-// In order to catch the mistake of putting tests that use different
-// test fixture classes in the same test suite, we need to assign
-// unique IDs to fixture classes and compare them.  The TypeId type is
-// used to hold such IDs.  The user should treat TypeId as an opaque
-// type: the only operation allowed on TypeId values is to compare
-// them for equality using the == operator.
-typedef const void* TypeId;
-
-template <typename T>
-class TypeIdHelper {
- public:
-  // dummy_ must not have a const type.  Otherwise an overly eager
-  // compiler (e.g. MSVC 7.1 & 8.0) may try to merge
-  // TypeIdHelper<T>::dummy_ for different Ts as an "optimization".
-  static bool dummy_;
-};
-
-template <typename T>
-bool TypeIdHelper<T>::dummy_ = false;
-
-// GetTypeId<T>() returns the ID of type T.  Different values will be
-// returned for different types.  Calling the function twice with the
-// same type argument is guaranteed to return the same ID.
-template <typename T>
-TypeId GetTypeId() {
-  // The compiler is required to allocate a different
-  // TypeIdHelper<T>::dummy_ variable for each T used to instantiate
-  // the template.  Therefore, the address of dummy_ is guaranteed to
-  // be unique.
-  return &(TypeIdHelper<T>::dummy_);
-}
-
-// Returns the type ID of ::testing::Test.  Always call this instead
-// of GetTypeId< ::testing::Test>() to get the type ID of
-// ::testing::Test, as the latter may give the wrong result due to a
-// suspected linker bug when compiling Google Test as a Mac OS X
-// framework.
-GTEST_API_ TypeId GetTestTypeId();
-
-// Defines the abstract factory interface that creates instances
-// of a Test object.
-class TestFactoryBase {
- public:
-  virtual ~TestFactoryBase() {}
-
-  // Creates a test instance to run. The instance is both created and destroyed
-  // within TestInfoImpl::Run()
-  virtual Test* CreateTest() = 0;
-
- protected:
-  TestFactoryBase() {}
-
- private:
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestFactoryBase);
-};
-
-// This class provides implementation of TeastFactoryBase interface.
-// It is used in TEST and TEST_F macros.
-template <class TestClass>
-class TestFactoryImpl : public TestFactoryBase {
- public:
-  Test* CreateTest() override { return new TestClass; }
-};
-
-#if GTEST_OS_WINDOWS
-
-// Predicate-formatters for implementing the HRESULT checking macros
-// {ASSERT|EXPECT}_HRESULT_{SUCCEEDED|FAILED}
-// We pass a long instead of HRESULT to avoid causing an
-// include dependency for the HRESULT type.
-GTEST_API_ AssertionResult IsHRESULTSuccess(const char* expr,
-                                            long hr);  // NOLINT
-GTEST_API_ AssertionResult IsHRESULTFailure(const char* expr,
-                                            long hr);  // NOLINT
-
-#endif  // GTEST_OS_WINDOWS
-
-// Types of SetUpTestSuite() and TearDownTestSuite() functions.
-using SetUpTestSuiteFunc = void (*)();
-using TearDownTestSuiteFunc = void (*)();
-
-struct CodeLocation {
-  CodeLocation(const std::string& a_file, int a_line)
-      : file(a_file), line(a_line) {}
-
-  std::string file;
-  int line;
-};
-
-//  Helper to identify which setup function for TestCase / TestSuite to call.
-//  Only one function is allowed, either TestCase or TestSute but not both.
-
-// Utility functions to help SuiteApiResolver
-using SetUpTearDownSuiteFuncType = void (*)();
-
-inline SetUpTearDownSuiteFuncType GetNotDefaultOrNull(
-    SetUpTearDownSuiteFuncType a, SetUpTearDownSuiteFuncType def) {
-  return a == def ? nullptr : a;
-}
-
-template <typename T>
-//  Note that SuiteApiResolver inherits from T because
-//  SetUpTestSuite()/TearDownTestSuite() could be protected. Ths way
-//  SuiteApiResolver can access them.
-struct SuiteApiResolver : T {
-  // testing::Test is only forward declared at this point. So we make it a
-  // dependend class for the compiler to be OK with it.
-  using Test =
-      typename std::conditional<sizeof(T) != 0, ::testing::Test, void>::type;
-
-  static SetUpTearDownSuiteFuncType GetSetUpCaseOrSuite(const char* filename,
-                                                        int line_num) {
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-    SetUpTearDownSuiteFuncType test_case_fp =
-        GetNotDefaultOrNull(&T::SetUpTestCase, &Test::SetUpTestCase);
-    SetUpTearDownSuiteFuncType test_suite_fp =
-        GetNotDefaultOrNull(&T::SetUpTestSuite, &Test::SetUpTestSuite);
-
-    GTEST_CHECK_(!test_case_fp || !test_suite_fp)
-        << "Test can not provide both SetUpTestSuite and SetUpTestCase, please "
-           "make sure there is only one present at "
-        << filename << ":" << line_num;
-
-    return test_case_fp != nullptr ? test_case_fp : test_suite_fp;
-#else
-    (void)(filename);
-    (void)(line_num);
-    return &T::SetUpTestSuite;
-#endif
-  }
-
-  static SetUpTearDownSuiteFuncType GetTearDownCaseOrSuite(const char* filename,
-                                                           int line_num) {
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-    SetUpTearDownSuiteFuncType test_case_fp =
-        GetNotDefaultOrNull(&T::TearDownTestCase, &Test::TearDownTestCase);
-    SetUpTearDownSuiteFuncType test_suite_fp =
-        GetNotDefaultOrNull(&T::TearDownTestSuite, &Test::TearDownTestSuite);
-
-    GTEST_CHECK_(!test_case_fp || !test_suite_fp)
-        << "Test can not provide both TearDownTestSuite and TearDownTestCase,"
-           " please make sure there is only one present at"
-        << filename << ":" << line_num;
-
-    return test_case_fp != nullptr ? test_case_fp : test_suite_fp;
-#else
-    (void)(filename);
-    (void)(line_num);
-    return &T::TearDownTestSuite;
-#endif
-  }
-};
-
-// Creates a new TestInfo object and registers it with Google Test;
-// returns the created object.
-//
-// Arguments:
-//
-//   test_suite_name:  name of the test suite
-//   name:             name of the test
-//   type_param:       the name of the test's type parameter, or NULL if
-//                     this is not a typed or a type-parameterized test.
-//   value_param:      text representation of the test's value parameter,
-//                     or NULL if this is not a type-parameterized test.
-//   code_location:    code location where the test is defined
-//   fixture_class_id: ID of the test fixture class
-//   set_up_tc:        pointer to the function that sets up the test suite
-//   tear_down_tc:     pointer to the function that tears down the test suite
-//   factory:          pointer to the factory that creates a test object.
-//                     The newly created TestInfo instance will assume
-//                     ownership of the factory object.
-GTEST_API_ TestInfo* MakeAndRegisterTestInfo(
-    const char* test_suite_name, const char* name, const char* type_param,
-    const char* value_param, CodeLocation code_location,
-    TypeId fixture_class_id, SetUpTestSuiteFunc set_up_tc,
-    TearDownTestSuiteFunc tear_down_tc, TestFactoryBase* factory);
-
-// If *pstr starts with the given prefix, modifies *pstr to be right
-// past the prefix and returns true; otherwise leaves *pstr unchanged
-// and returns false.  None of pstr, *pstr, and prefix can be NULL.
-GTEST_API_ bool SkipPrefix(const char* prefix, const char** pstr);
-
-GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
-/* class A needs to have dll-interface to be used by clients of class B */)
-
-// State of the definition of a type-parameterized test suite.
-class GTEST_API_ TypedTestSuitePState {
- public:
-  TypedTestSuitePState() : registered_(false) {}
-
-  // Adds the given test name to defined_test_names_ and return true
-  // if the test suite hasn't been registered; otherwise aborts the
-  // program.
-  bool AddTestName(const char* file, int line, const char* case_name,
-                   const char* test_name) {
-    if (registered_) {
-      fprintf(stderr,
-              "%s Test %s must be defined before "
-              "REGISTER_TYPED_TEST_SUITE_P(%s, ...).\n",
-              FormatFileLocation(file, line).c_str(), test_name, case_name);
-      fflush(stderr);
-      posix::Abort();
-    }
-    registered_tests_.insert(
-        ::std::make_pair(test_name, CodeLocation(file, line)));
-    return true;
-  }
-
-  bool TestExists(const std::string& test_name) const {
-    return registered_tests_.count(test_name) > 0;
-  }
-
-  const CodeLocation& GetCodeLocation(const std::string& test_name) const {
-    RegisteredTestsMap::const_iterator it = registered_tests_.find(test_name);
-    GTEST_CHECK_(it != registered_tests_.end());
-    return it->second;
-  }
-
-  // Verifies that registered_tests match the test names in
-  // defined_test_names_; returns registered_tests if successful, or
-  // aborts the program otherwise.
-  const char* VerifyRegisteredTestNames(const char* test_suite_name,
-                                        const char* file, int line,
-                                        const char* registered_tests);
-
- private:
-  typedef ::std::map<std::string, CodeLocation> RegisteredTestsMap;
-
-  bool registered_;
-  RegisteredTestsMap registered_tests_;
-};
-
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-using TypedTestCasePState = TypedTestSuitePState;
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
-
-// Skips to the first non-space char after the first comma in 'str';
-// returns NULL if no comma is found in 'str'.
-inline const char* SkipComma(const char* str) {
-  const char* comma = strchr(str, ',');
-  if (comma == nullptr) {
-    return nullptr;
-  }
-  while (IsSpace(*(++comma))) {}
-  return comma;
-}
-
-// Returns the prefix of 'str' before the first comma in it; returns
-// the entire string if it contains no comma.
-inline std::string GetPrefixUntilComma(const char* str) {
-  const char* comma = strchr(str, ',');
-  return comma == nullptr ? str : std::string(str, comma);
-}
-
-// Splits a given string on a given delimiter, populating a given
-// vector with the fields.
-void SplitString(const ::std::string& str, char delimiter,
-                 ::std::vector< ::std::string>* dest);
-
-// The default argument to the template below for the case when the user does
-// not provide a name generator.
-struct DefaultNameGenerator {
-  template <typename T>
-  static std::string GetName(int i) {
-    return StreamableToString(i);
-  }
-};
-
-template <typename Provided = DefaultNameGenerator>
-struct NameGeneratorSelector {
-  typedef Provided type;
-};
-
-template <typename NameGenerator>
-void GenerateNamesRecursively(internal::None, std::vector<std::string>*, int) {}
-
-template <typename NameGenerator, typename Types>
-void GenerateNamesRecursively(Types, std::vector<std::string>* result, int i) {
-  result->push_back(NameGenerator::template GetName<typename Types::Head>(i));
-  GenerateNamesRecursively<NameGenerator>(typename Types::Tail(), result,
-                                          i + 1);
-}
-
-template <typename NameGenerator, typename Types>
-std::vector<std::string> GenerateNames() {
-  std::vector<std::string> result;
-  GenerateNamesRecursively<NameGenerator>(Types(), &result, 0);
-  return result;
-}
-
-// TypeParameterizedTest<Fixture, TestSel, Types>::Register()
-// registers a list of type-parameterized tests with Google Test.  The
-// return value is insignificant - we just need to return something
-// such that we can call this function in a namespace scope.
-//
-// Implementation note: The GTEST_TEMPLATE_ macro declares a template
-// template parameter.  It's defined in gtest-type-util.h.
-template <GTEST_TEMPLATE_ Fixture, class TestSel, typename Types>
-class TypeParameterizedTest {
- public:
-  // 'index' is the index of the test in the type list 'Types'
-  // specified in INSTANTIATE_TYPED_TEST_SUITE_P(Prefix, TestSuite,
-  // Types).  Valid values for 'index' are [0, N - 1] where N is the
-  // length of Types.
-  static bool Register(const char* prefix, const CodeLocation& code_location,
-                       const char* case_name, const char* test_names, int index,
-                       const std::vector<std::string>& type_names =
-                           GenerateNames<DefaultNameGenerator, Types>()) {
-    typedef typename Types::Head Type;
-    typedef Fixture<Type> FixtureClass;
-    typedef typename GTEST_BIND_(TestSel, Type) TestClass;
-
-    // First, registers the first type-parameterized test in the type
-    // list.
-    MakeAndRegisterTestInfo(
-        (std::string(prefix) + (prefix[0] == '\0' ? "" : "/") + case_name +
-         "/" + type_names[static_cast<size_t>(index)])
-            .c_str(),
-        StripTrailingSpaces(GetPrefixUntilComma(test_names)).c_str(),
-        GetTypeName<Type>().c_str(),
-        nullptr,  // No value parameter.
-        code_location, GetTypeId<FixtureClass>(),
-        SuiteApiResolver<TestClass>::GetSetUpCaseOrSuite(
-            code_location.file.c_str(), code_location.line),
-        SuiteApiResolver<TestClass>::GetTearDownCaseOrSuite(
-            code_location.file.c_str(), code_location.line),
-        new TestFactoryImpl<TestClass>);
-
-    // Next, recurses (at compile time) with the tail of the type list.
-    return TypeParameterizedTest<Fixture, TestSel,
-                                 typename Types::Tail>::Register(prefix,
-                                                                 code_location,
-                                                                 case_name,
-                                                                 test_names,
-                                                                 index + 1,
-                                                                 type_names);
-  }
-};
-
-// The base case for the compile time recursion.
-template <GTEST_TEMPLATE_ Fixture, class TestSel>
-class TypeParameterizedTest<Fixture, TestSel, internal::None> {
- public:
-  static bool Register(const char* /*prefix*/, const CodeLocation&,
-                       const char* /*case_name*/, const char* /*test_names*/,
-                       int /*index*/,
-                       const std::vector<std::string>& =
-                           std::vector<std::string>() /*type_names*/) {
-    return true;
-  }
-};
-
-GTEST_API_ void RegisterTypeParameterizedTestSuite(const char* test_suite_name,
-                                                   CodeLocation code_location);
-GTEST_API_ void RegisterTypeParameterizedTestSuiteInstantiation(
-    const char* case_name);
-
-// TypeParameterizedTestSuite<Fixture, Tests, Types>::Register()
-// registers *all combinations* of 'Tests' and 'Types' with Google
-// Test.  The return value is insignificant - we just need to return
-// something such that we can call this function in a namespace scope.
-template <GTEST_TEMPLATE_ Fixture, typename Tests, typename Types>
-class TypeParameterizedTestSuite {
- public:
-  static bool Register(const char* prefix, CodeLocation code_location,
-                       const TypedTestSuitePState* state, const char* case_name,
-                       const char* test_names,
-                       const std::vector<std::string>& type_names =
-                           GenerateNames<DefaultNameGenerator, Types>()) {
-    RegisterTypeParameterizedTestSuiteInstantiation(case_name);
-    std::string test_name = StripTrailingSpaces(
-        GetPrefixUntilComma(test_names));
-    if (!state->TestExists(test_name)) {
-      fprintf(stderr, "Failed to get code location for test %s.%s at %s.",
-              case_name, test_name.c_str(),
-              FormatFileLocation(code_location.file.c_str(),
-                                 code_location.line).c_str());
-      fflush(stderr);
-      posix::Abort();
-    }
-    const CodeLocation& test_location = state->GetCodeLocation(test_name);
-
-    typedef typename Tests::Head Head;
-
-    // First, register the first test in 'Test' for each type in 'Types'.
-    TypeParameterizedTest<Fixture, Head, Types>::Register(
-        prefix, test_location, case_name, test_names, 0, type_names);
-
-    // Next, recurses (at compile time) with the tail of the test list.
-    return TypeParameterizedTestSuite<Fixture, typename Tests::Tail,
-                                      Types>::Register(prefix, code_location,
-                                                       state, case_name,
-                                                       SkipComma(test_names),
-                                                       type_names);
-  }
-};
-
-// The base case for the compile time recursion.
-template <GTEST_TEMPLATE_ Fixture, typename Types>
-class TypeParameterizedTestSuite<Fixture, internal::None, Types> {
- public:
-  static bool Register(const char* /*prefix*/, const CodeLocation&,
-                       const TypedTestSuitePState* /*state*/,
-                       const char* /*case_name*/, const char* /*test_names*/,
-                       const std::vector<std::string>& =
-                           std::vector<std::string>() /*type_names*/) {
-    return true;
-  }
-};
-
-// Returns the current OS stack trace as an std::string.
-//
-// The maximum number of stack frames to be included is specified by
-// the gtest_stack_trace_depth flag.  The skip_count parameter
-// specifies the number of top frames to be skipped, which doesn't
-// count against the number of frames to be included.
-//
-// For example, if Foo() calls Bar(), which in turn calls
-// GetCurrentOsStackTraceExceptTop(..., 1), Foo() will be included in
-// the trace but Bar() and GetCurrentOsStackTraceExceptTop() won't.
-GTEST_API_ std::string GetCurrentOsStackTraceExceptTop(
-    UnitTest* unit_test, int skip_count);
-
-// Helpers for suppressing warnings on unreachable code or constant
-// condition.
-
-// Always returns true.
-GTEST_API_ bool AlwaysTrue();
-
-// Always returns false.
-inline bool AlwaysFalse() { return !AlwaysTrue(); }
-
-// Helper for suppressing false warning from Clang on a const char*
-// variable declared in a conditional expression always being NULL in
-// the else branch.
-struct GTEST_API_ ConstCharPtr {
-  ConstCharPtr(const char* str) : value(str) {}
-  operator bool() const { return true; }
-  const char* value;
-};
-
-// Helper for declaring std::string within 'if' statement
-// in pre C++17 build environment.
-struct TrueWithString {
-  TrueWithString() = default;
-  explicit TrueWithString(const char* str) : value(str) {}
-  explicit TrueWithString(const std::string& str) : value(str) {}
-  explicit operator bool() const { return true; }
-  std::string value;
-};
-
-// A simple Linear Congruential Generator for generating random
-// numbers with a uniform distribution.  Unlike rand() and srand(), it
-// doesn't use global state (and therefore can't interfere with user
-// code).  Unlike rand_r(), it's portable.  An LCG isn't very random,
-// but it's good enough for our purposes.
-class GTEST_API_ Random {
- public:
-  static const uint32_t kMaxRange = 1u << 31;
-
-  explicit Random(uint32_t seed) : state_(seed) {}
-
-  void Reseed(uint32_t seed) { state_ = seed; }
-
-  // Generates a random number from [0, range).  Crashes if 'range' is
-  // 0 or greater than kMaxRange.
-  uint32_t Generate(uint32_t range);
-
- private:
-  uint32_t state_;
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(Random);
-};
-
-// Turns const U&, U&, const U, and U all into U.
-#define GTEST_REMOVE_REFERENCE_AND_CONST_(T) \
-  typename std::remove_const<typename std::remove_reference<T>::type>::type
-
-// HasDebugStringAndShortDebugString<T>::value is a compile-time bool constant
-// that's true if and only if T has methods DebugString() and ShortDebugString()
-// that return std::string.
-template <typename T>
-class HasDebugStringAndShortDebugString {
- private:
-  template <typename C>
-  static auto CheckDebugString(C*) -> typename std::is_same<
-      std::string, decltype(std::declval<const C>().DebugString())>::type;
-  template <typename>
-  static std::false_type CheckDebugString(...);
-
-  template <typename C>
-  static auto CheckShortDebugString(C*) -> typename std::is_same<
-      std::string, decltype(std::declval<const C>().ShortDebugString())>::type;
-  template <typename>
-  static std::false_type CheckShortDebugString(...);
-
-  using HasDebugStringType = decltype(CheckDebugString<T>(nullptr));
-  using HasShortDebugStringType = decltype(CheckShortDebugString<T>(nullptr));
-
- public:
-  static constexpr bool value =
-      HasDebugStringType::value && HasShortDebugStringType::value;
-};
-
-template <typename T>
-constexpr bool HasDebugStringAndShortDebugString<T>::value;
-
-// When the compiler sees expression IsContainerTest<C>(0), if C is an
-// STL-style container class, the first overload of IsContainerTest
-// will be viable (since both C::iterator* and C::const_iterator* are
-// valid types and NULL can be implicitly converted to them).  It will
-// be picked over the second overload as 'int' is a perfect match for
-// the type of argument 0.  If C::iterator or C::const_iterator is not
-// a valid type, the first overload is not viable, and the second
-// overload will be picked.  Therefore, we can determine whether C is
-// a container class by checking the type of IsContainerTest<C>(0).
-// The value of the expression is insignificant.
-//
-// In C++11 mode we check the existence of a const_iterator and that an
-// iterator is properly implemented for the container.
-//
-// For pre-C++11 that we look for both C::iterator and C::const_iterator.
-// The reason is that C++ injects the name of a class as a member of the
-// class itself (e.g. you can refer to class iterator as either
-// 'iterator' or 'iterator::iterator').  If we look for C::iterator
-// only, for example, we would mistakenly think that a class named
-// iterator is an STL container.
-//
-// Also note that the simpler approach of overloading
-// IsContainerTest(typename C::const_iterator*) and
-// IsContainerTest(...) doesn't work with Visual Age C++ and Sun C++.
-typedef int IsContainer;
-template <class C,
-          class Iterator = decltype(::std::declval<const C&>().begin()),
-          class = decltype(::std::declval<const C&>().end()),
-          class = decltype(++::std::declval<Iterator&>()),
-          class = decltype(*::std::declval<Iterator>()),
-          class = typename C::const_iterator>
-IsContainer IsContainerTest(int /* dummy */) {
-  return 0;
-}
-
-typedef char IsNotContainer;
-template <class C>
-IsNotContainer IsContainerTest(long /* dummy */) { return '\0'; }
-
-// Trait to detect whether a type T is a hash table.
-// The heuristic used is that the type contains an inner type `hasher` and does
-// not contain an inner type `reverse_iterator`.
-// If the container is iterable in reverse, then order might actually matter.
-template <typename T>
-struct IsHashTable {
- private:
-  template <typename U>
-  static char test(typename U::hasher*, typename U::reverse_iterator*);
-  template <typename U>
-  static int test(typename U::hasher*, ...);
-  template <typename U>
-  static char test(...);
-
- public:
-  static const bool value = sizeof(test<T>(nullptr, nullptr)) == sizeof(int);
-};
-
-template <typename T>
-const bool IsHashTable<T>::value;
-
-template <typename C,
-          bool = sizeof(IsContainerTest<C>(0)) == sizeof(IsContainer)>
-struct IsRecursiveContainerImpl;
-
-template <typename C>
-struct IsRecursiveContainerImpl<C, false> : public std::false_type {};
-
-// Since the IsRecursiveContainerImpl depends on the IsContainerTest we need to
-// obey the same inconsistencies as the IsContainerTest, namely check if
-// something is a container is relying on only const_iterator in C++11 and
-// is relying on both const_iterator and iterator otherwise
-template <typename C>
-struct IsRecursiveContainerImpl<C, true> {
-  using value_type = decltype(*std::declval<typename C::const_iterator>());
-  using type =
-      std::is_same<typename std::remove_const<
-                       typename std::remove_reference<value_type>::type>::type,
-                   C>;
-};
-
-// IsRecursiveContainer<Type> is a unary compile-time predicate that
-// evaluates whether C is a recursive container type. A recursive container
-// type is a container type whose value_type is equal to the container type
-// itself. An example for a recursive container type is
-// boost::filesystem::path, whose iterator has a value_type that is equal to
-// boost::filesystem::path.
-template <typename C>
-struct IsRecursiveContainer : public IsRecursiveContainerImpl<C>::type {};
-
-// Utilities for native arrays.
-
-// ArrayEq() compares two k-dimensional native arrays using the
-// elements' operator==, where k can be any integer >= 0.  When k is
-// 0, ArrayEq() degenerates into comparing a single pair of values.
-
-template <typename T, typename U>
-bool ArrayEq(const T* lhs, size_t size, const U* rhs);
-
-// This generic version is used when k is 0.
-template <typename T, typename U>
-inline bool ArrayEq(const T& lhs, const U& rhs) { return lhs == rhs; }
-
-// This overload is used when k >= 1.
-template <typename T, typename U, size_t N>
-inline bool ArrayEq(const T(&lhs)[N], const U(&rhs)[N]) {
-  return internal::ArrayEq(lhs, N, rhs);
-}
-
-// This helper reduces code bloat.  If we instead put its logic inside
-// the previous ArrayEq() function, arrays with different sizes would
-// lead to different copies of the template code.
-template <typename T, typename U>
-bool ArrayEq(const T* lhs, size_t size, const U* rhs) {
-  for (size_t i = 0; i != size; i++) {
-    if (!internal::ArrayEq(lhs[i], rhs[i]))
-      return false;
-  }
-  return true;
-}
-
-// Finds the first element in the iterator range [begin, end) that
-// equals elem.  Element may be a native array type itself.
-template <typename Iter, typename Element>
-Iter ArrayAwareFind(Iter begin, Iter end, const Element& elem) {
-  for (Iter it = begin; it != end; ++it) {
-    if (internal::ArrayEq(*it, elem))
-      return it;
-  }
-  return end;
-}
-
-// CopyArray() copies a k-dimensional native array using the elements'
-// operator=, where k can be any integer >= 0.  When k is 0,
-// CopyArray() degenerates into copying a single value.
-
-template <typename T, typename U>
-void CopyArray(const T* from, size_t size, U* to);
-
-// This generic version is used when k is 0.
-template <typename T, typename U>
-inline void CopyArray(const T& from, U* to) { *to = from; }
-
-// This overload is used when k >= 1.
-template <typename T, typename U, size_t N>
-inline void CopyArray(const T(&from)[N], U(*to)[N]) {
-  internal::CopyArray(from, N, *to);
-}
-
-// This helper reduces code bloat.  If we instead put its logic inside
-// the previous CopyArray() function, arrays with different sizes
-// would lead to different copies of the template code.
-template <typename T, typename U>
-void CopyArray(const T* from, size_t size, U* to) {
-  for (size_t i = 0; i != size; i++) {
-    internal::CopyArray(from[i], to + i);
-  }
-}
-
-// The relation between an NativeArray object (see below) and the
-// native array it represents.
-// We use 2 different structs to allow non-copyable types to be used, as long
-// as RelationToSourceReference() is passed.
-struct RelationToSourceReference {};
-struct RelationToSourceCopy {};
-
-// Adapts a native array to a read-only STL-style container.  Instead
-// of the complete STL container concept, this adaptor only implements
-// members useful for Google Mock's container matchers.  New members
-// should be added as needed.  To simplify the implementation, we only
-// support Element being a raw type (i.e. having no top-level const or
-// reference modifier).  It's the client's responsibility to satisfy
-// this requirement.  Element can be an array type itself (hence
-// multi-dimensional arrays are supported).
-template <typename Element>
-class NativeArray {
- public:
-  // STL-style container typedefs.
-  typedef Element value_type;
-  typedef Element* iterator;
-  typedef const Element* const_iterator;
-
-  // Constructs from a native array. References the source.
-  NativeArray(const Element* array, size_t count, RelationToSourceReference) {
-    InitRef(array, count);
-  }
-
-  // Constructs from a native array. Copies the source.
-  NativeArray(const Element* array, size_t count, RelationToSourceCopy) {
-    InitCopy(array, count);
-  }
-
-  // Copy constructor.
-  NativeArray(const NativeArray& rhs) {
-    (this->*rhs.clone_)(rhs.array_, rhs.size_);
-  }
-
-  ~NativeArray() {
-    if (clone_ != &NativeArray::InitRef)
-      delete[] array_;
-  }
-
-  // STL-style container methods.
-  size_t size() const { return size_; }
-  const_iterator begin() const { return array_; }
-  const_iterator end() const { return array_ + size_; }
-  bool operator==(const NativeArray& rhs) const {
-    return size() == rhs.size() &&
-        ArrayEq(begin(), size(), rhs.begin());
-  }
-
- private:
-  static_assert(!std::is_const<Element>::value, "Type must not be const");
-  static_assert(!std::is_reference<Element>::value,
-                "Type must not be a reference");
-
-  // Initializes this object with a copy of the input.
-  void InitCopy(const Element* array, size_t a_size) {
-    Element* const copy = new Element[a_size];
-    CopyArray(array, a_size, copy);
-    array_ = copy;
-    size_ = a_size;
-    clone_ = &NativeArray::InitCopy;
-  }
-
-  // Initializes this object with a reference of the input.
-  void InitRef(const Element* array, size_t a_size) {
-    array_ = array;
-    size_ = a_size;
-    clone_ = &NativeArray::InitRef;
-  }
-
-  const Element* array_;
-  size_t size_;
-  void (NativeArray::*clone_)(const Element*, size_t);
-};
-
-// Backport of std::index_sequence.
-template <size_t... Is>
-struct IndexSequence {
-  using type = IndexSequence;
-};
-
-// Double the IndexSequence, and one if plus_one is true.
-template <bool plus_one, typename T, size_t sizeofT>
-struct DoubleSequence;
-template <size_t... I, size_t sizeofT>
-struct DoubleSequence<true, IndexSequence<I...>, sizeofT> {
-  using type = IndexSequence<I..., (sizeofT + I)..., 2 * sizeofT>;
-};
-template <size_t... I, size_t sizeofT>
-struct DoubleSequence<false, IndexSequence<I...>, sizeofT> {
-  using type = IndexSequence<I..., (sizeofT + I)...>;
-};
-
-// Backport of std::make_index_sequence.
-// It uses O(ln(N)) instantiation depth.
-template <size_t N>
-struct MakeIndexSequenceImpl
-    : DoubleSequence<N % 2 == 1, typename MakeIndexSequenceImpl<N / 2>::type,
-                     N / 2>::type {};
-
-template <>
-struct MakeIndexSequenceImpl<0> : IndexSequence<> {};
-
-template <size_t N>
-using MakeIndexSequence = typename MakeIndexSequenceImpl<N>::type;
-
-template <typename... T>
-using IndexSequenceFor = typename MakeIndexSequence<sizeof...(T)>::type;
-
-template <size_t>
-struct Ignore {
-  Ignore(...);  // NOLINT
-};
-
-template <typename>
-struct ElemFromListImpl;
-template <size_t... I>
-struct ElemFromListImpl<IndexSequence<I...>> {
-  // We make Ignore a template to solve a problem with MSVC.
-  // A non-template Ignore would work fine with `decltype(Ignore(I))...`, but
-  // MSVC doesn't understand how to deal with that pack expansion.
-  // Use `0 * I` to have a single instantiation of Ignore.
-  template <typename R>
-  static R Apply(Ignore<0 * I>..., R (*)(), ...);
-};
-
-template <size_t N, typename... T>
-struct ElemFromList {
-  using type =
-      decltype(ElemFromListImpl<typename MakeIndexSequence<N>::type>::Apply(
-          static_cast<T (*)()>(nullptr)...));
-};
-
-struct FlatTupleConstructTag {};
-
-template <typename... T>
-class FlatTuple;
-
-template <typename Derived, size_t I>
-struct FlatTupleElemBase;
-
-template <typename... T, size_t I>
-struct FlatTupleElemBase<FlatTuple<T...>, I> {
-  using value_type = typename ElemFromList<I, T...>::type;
-  FlatTupleElemBase() = default;
-  template <typename Arg>
-  explicit FlatTupleElemBase(FlatTupleConstructTag, Arg&& t)
-      : value(std::forward<Arg>(t)) {}
-  value_type value;
-};
-
-template <typename Derived, typename Idx>
-struct FlatTupleBase;
-
-template <size_t... Idx, typename... T>
-struct FlatTupleBase<FlatTuple<T...>, IndexSequence<Idx...>>
-    : FlatTupleElemBase<FlatTuple<T...>, Idx>... {
-  using Indices = IndexSequence<Idx...>;
-  FlatTupleBase() = default;
-  template <typename... Args>
-  explicit FlatTupleBase(FlatTupleConstructTag, Args&&... args)
-      : FlatTupleElemBase<FlatTuple<T...>, Idx>(FlatTupleConstructTag{},
-                                                std::forward<Args>(args))... {}
-
-  template <size_t I>
-  const typename ElemFromList<I, T...>::type& Get() const {
-    return FlatTupleElemBase<FlatTuple<T...>, I>::value;
-  }
-
-  template <size_t I>
-  typename ElemFromList<I, T...>::type& Get() {
-    return FlatTupleElemBase<FlatTuple<T...>, I>::value;
-  }
-
-  template <typename F>
-  auto Apply(F&& f) -> decltype(std::forward<F>(f)(this->Get<Idx>()...)) {
-    return std::forward<F>(f)(Get<Idx>()...);
-  }
-
-  template <typename F>
-  auto Apply(F&& f) const -> decltype(std::forward<F>(f)(this->Get<Idx>()...)) {
-    return std::forward<F>(f)(Get<Idx>()...);
-  }
-};
-
-// Analog to std::tuple but with different tradeoffs.
-// This class minimizes the template instantiation depth, thus allowing more
-// elements than std::tuple would. std::tuple has been seen to require an
-// instantiation depth of more than 10x the number of elements in some
-// implementations.
-// FlatTuple and ElemFromList are not recursive and have a fixed depth
-// regardless of T...
-// MakeIndexSequence, on the other hand, it is recursive but with an
-// instantiation depth of O(ln(N)).
-template <typename... T>
-class FlatTuple
-    : private FlatTupleBase<FlatTuple<T...>,
-                            typename MakeIndexSequence<sizeof...(T)>::type> {
-  using Indices = typename FlatTupleBase<
-      FlatTuple<T...>, typename MakeIndexSequence<sizeof...(T)>::type>::Indices;
-
- public:
-  FlatTuple() = default;
-  template <typename... Args>
-  explicit FlatTuple(FlatTupleConstructTag tag, Args&&... args)
-      : FlatTuple::FlatTupleBase(tag, std::forward<Args>(args)...) {}
-
-  using FlatTuple::FlatTupleBase::Apply;
-  using FlatTuple::FlatTupleBase::Get;
-};
-
-// Utility functions to be called with static_assert to induce deprecation
-// warnings.
-GTEST_INTERNAL_DEPRECATED(
-    "INSTANTIATE_TEST_CASE_P is deprecated, please use "
-    "INSTANTIATE_TEST_SUITE_P")
-constexpr bool InstantiateTestCase_P_IsDeprecated() { return true; }
-
-GTEST_INTERNAL_DEPRECATED(
-    "TYPED_TEST_CASE_P is deprecated, please use "
-    "TYPED_TEST_SUITE_P")
-constexpr bool TypedTestCase_P_IsDeprecated() { return true; }
-
-GTEST_INTERNAL_DEPRECATED(
-    "TYPED_TEST_CASE is deprecated, please use "
-    "TYPED_TEST_SUITE")
-constexpr bool TypedTestCaseIsDeprecated() { return true; }
-
-GTEST_INTERNAL_DEPRECATED(
-    "REGISTER_TYPED_TEST_CASE_P is deprecated, please use "
-    "REGISTER_TYPED_TEST_SUITE_P")
-constexpr bool RegisterTypedTestCase_P_IsDeprecated() { return true; }
-
-GTEST_INTERNAL_DEPRECATED(
-    "INSTANTIATE_TYPED_TEST_CASE_P is deprecated, please use "
-    "INSTANTIATE_TYPED_TEST_SUITE_P")
-constexpr bool InstantiateTypedTestCase_P_IsDeprecated() { return true; }
-
-}  // namespace internal
-}  // namespace testing
-
-namespace std {
-// Some standard library implementations use `struct tuple_size` and some use
-// `class tuple_size`. Clang warns about the mismatch.
-// https://reviews.llvm.org/D55466
-#ifdef __clang__
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wmismatched-tags"
-#endif
-template <typename... Ts>
-struct tuple_size<testing::internal::FlatTuple<Ts...>>
-    : std::integral_constant<size_t, sizeof...(Ts)> {};
-#ifdef __clang__
-#pragma clang diagnostic pop
-#endif
-}  // namespace std
-
-#define GTEST_MESSAGE_AT_(file, line, message, result_type) \
-  ::testing::internal::AssertHelper(result_type, file, line, message) \
-    = ::testing::Message()
-
-#define GTEST_MESSAGE_(message, result_type) \
-  GTEST_MESSAGE_AT_(__FILE__, __LINE__, message, result_type)
-
-#define GTEST_FATAL_FAILURE_(message) \
-  return GTEST_MESSAGE_(message, ::testing::TestPartResult::kFatalFailure)
-
-#define GTEST_NONFATAL_FAILURE_(message) \
-  GTEST_MESSAGE_(message, ::testing::TestPartResult::kNonFatalFailure)
-
-#define GTEST_SUCCESS_(message) \
-  GTEST_MESSAGE_(message, ::testing::TestPartResult::kSuccess)
-
-#define GTEST_SKIP_(message) \
-  return GTEST_MESSAGE_(message, ::testing::TestPartResult::kSkip)
-
-// Suppress MSVC warning 4072 (unreachable code) for the code following
-// statement if it returns or throws (or doesn't return or throw in some
-// situations).
-// NOTE: The "else" is important to keep this expansion to prevent a top-level
-// "else" from attaching to our "if".
-#define GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement) \
-  if (::testing::internal::AlwaysTrue()) {                        \
-    statement;                                                    \
-  } else                     /* NOLINT */                         \
-    static_assert(true, "")  // User must have a semicolon after expansion.
-
-#if GTEST_HAS_EXCEPTIONS
-
-namespace testing {
-namespace internal {
-
-class NeverThrown {
- public:
-  const char* what() const noexcept {
-    return "this exception should never be thrown";
-  }
-};
-
-}  // namespace internal
-}  // namespace testing
-
-#if GTEST_HAS_RTTI
-
-#define GTEST_EXCEPTION_TYPE_(e) ::testing::internal::GetTypeName(typeid(e))
-
-#else  // GTEST_HAS_RTTI
-
-#define GTEST_EXCEPTION_TYPE_(e) \
-  std::string { "an std::exception-derived error" }
-
-#endif  // GTEST_HAS_RTTI
-
-#define GTEST_TEST_THROW_CATCH_STD_EXCEPTION_(statement, expected_exception)   \
-  catch (typename std::conditional<                                            \
-         std::is_same<typename std::remove_cv<typename std::remove_reference<  \
-                          expected_exception>::type>::type,                    \
-                      std::exception>::value,                                  \
-         const ::testing::internal::NeverThrown&, const std::exception&>::type \
-             e) {                                                              \
-    gtest_msg.value = "Expected: " #statement                                  \
-                      " throws an exception of type " #expected_exception      \
-                      ".\n  Actual: it throws ";                               \
-    gtest_msg.value += GTEST_EXCEPTION_TYPE_(e);                               \
-    gtest_msg.value += " with description \"";                                 \
-    gtest_msg.value += e.what();                                               \
-    gtest_msg.value += "\".";                                                  \
-    goto GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__);                \
-  }
-
-#else  // GTEST_HAS_EXCEPTIONS
-
-#define GTEST_TEST_THROW_CATCH_STD_EXCEPTION_(statement, expected_exception)
-
-#endif  // GTEST_HAS_EXCEPTIONS
-
-#define GTEST_TEST_THROW_(statement, expected_exception, fail)              \
-  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                             \
-  if (::testing::internal::TrueWithString gtest_msg{}) {                    \
-    bool gtest_caught_expected = false;                                     \
-    try {                                                                   \
-      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement);            \
-    } catch (expected_exception const&) {                                   \
-      gtest_caught_expected = true;                                         \
-    }                                                                       \
-    GTEST_TEST_THROW_CATCH_STD_EXCEPTION_(statement, expected_exception)    \
-    catch (...) {                                                           \
-      gtest_msg.value = "Expected: " #statement                             \
-                        " throws an exception of type " #expected_exception \
-                        ".\n  Actual: it throws a different type.";         \
-      goto GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__);           \
-    }                                                                       \
-    if (!gtest_caught_expected) {                                           \
-      gtest_msg.value = "Expected: " #statement                             \
-                        " throws an exception of type " #expected_exception \
-                        ".\n  Actual: it throws nothing.";                  \
-      goto GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__);           \
-    }                                                                       \
-  } else /*NOLINT*/                                                         \
-    GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__)                   \
-        : fail(gtest_msg.value.c_str())
-
-#if GTEST_HAS_EXCEPTIONS
-
-#define GTEST_TEST_NO_THROW_CATCH_STD_EXCEPTION_()                \
-  catch (std::exception const& e) {                               \
-    gtest_msg.value = "it throws ";                               \
-    gtest_msg.value += GTEST_EXCEPTION_TYPE_(e);                  \
-    gtest_msg.value += " with description \"";                    \
-    gtest_msg.value += e.what();                                  \
-    gtest_msg.value += "\".";                                     \
-    goto GTEST_CONCAT_TOKEN_(gtest_label_testnothrow_, __LINE__); \
-  }
-
-#else  // GTEST_HAS_EXCEPTIONS
-
-#define GTEST_TEST_NO_THROW_CATCH_STD_EXCEPTION_()
-
-#endif  // GTEST_HAS_EXCEPTIONS
-
-#define GTEST_TEST_NO_THROW_(statement, fail) \
-  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
-  if (::testing::internal::TrueWithString gtest_msg{}) { \
-    try { \
-      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
-    } \
-    GTEST_TEST_NO_THROW_CATCH_STD_EXCEPTION_() \
-    catch (...) { \
-      gtest_msg.value = "it throws."; \
-      goto GTEST_CONCAT_TOKEN_(gtest_label_testnothrow_, __LINE__); \
-    } \
-  } else \
-    GTEST_CONCAT_TOKEN_(gtest_label_testnothrow_, __LINE__): \
-      fail(("Expected: " #statement " doesn't throw an exception.\n" \
-            "  Actual: " + gtest_msg.value).c_str())
-
-#define GTEST_TEST_ANY_THROW_(statement, fail) \
-  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
-  if (::testing::internal::AlwaysTrue()) { \
-    bool gtest_caught_any = false; \
-    try { \
-      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
-    } \
-    catch (...) { \
-      gtest_caught_any = true; \
-    } \
-    if (!gtest_caught_any) { \
-      goto GTEST_CONCAT_TOKEN_(gtest_label_testanythrow_, __LINE__); \
-    } \
-  } else \
-    GTEST_CONCAT_TOKEN_(gtest_label_testanythrow_, __LINE__): \
-      fail("Expected: " #statement " throws an exception.\n" \
-           "  Actual: it doesn't.")
-
-
-// Implements Boolean test assertions such as EXPECT_TRUE. expression can be
-// either a boolean expression or an AssertionResult. text is a textual
-// representation of expression as it was passed into the EXPECT_TRUE.
-#define GTEST_TEST_BOOLEAN_(expression, text, actual, expected, fail) \
-  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
-  if (const ::testing::AssertionResult gtest_ar_ = \
-      ::testing::AssertionResult(expression)) \
-    ; \
-  else \
-    fail(::testing::internal::GetBoolAssertionFailureMessage(\
-        gtest_ar_, text, #actual, #expected).c_str())
-
-#define GTEST_TEST_NO_FATAL_FAILURE_(statement, fail) \
-  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
-  if (::testing::internal::AlwaysTrue()) { \
-    ::testing::internal::HasNewFatalFailureHelper gtest_fatal_failure_checker; \
-    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
-    if (gtest_fatal_failure_checker.has_new_fatal_failure()) { \
-      goto GTEST_CONCAT_TOKEN_(gtest_label_testnofatal_, __LINE__); \
-    } \
-  } else \
-    GTEST_CONCAT_TOKEN_(gtest_label_testnofatal_, __LINE__): \
-      fail("Expected: " #statement " doesn't generate new fatal " \
-           "failures in the current thread.\n" \
-           "  Actual: it does.")
-
-// Expands to the name of the class that implements the given test.
-#define GTEST_TEST_CLASS_NAME_(test_suite_name, test_name) \
-  test_suite_name##_##test_name##_Test
-
-// Helper macro for defining tests.
-#define GTEST_TEST_(test_suite_name, test_name, parent_class, parent_id)      \
-  static_assert(sizeof(GTEST_STRINGIFY_(test_suite_name)) > 1,                \
-                "test_suite_name must not be empty");                         \
-  static_assert(sizeof(GTEST_STRINGIFY_(test_name)) > 1,                      \
-                "test_name must not be empty");                               \
-  class GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)                    \
-      : public parent_class {                                                 \
-   public:                                                                    \
-    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)() = default;           \
-    ~GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)() override = default; \
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(GTEST_TEST_CLASS_NAME_(test_suite_name,   \
-                                                           test_name));       \
-    GTEST_DISALLOW_MOVE_AND_ASSIGN_(GTEST_TEST_CLASS_NAME_(test_suite_name,   \
-                                                           test_name));       \
-                                                                              \
-   private:                                                                   \
-    void TestBody() override;                                                 \
-    static ::testing::TestInfo* const test_info_ GTEST_ATTRIBUTE_UNUSED_;     \
-  };                                                                          \
-                                                                              \
-  ::testing::TestInfo* const GTEST_TEST_CLASS_NAME_(test_suite_name,          \
-                                                    test_name)::test_info_ =  \
-      ::testing::internal::MakeAndRegisterTestInfo(                           \
-          #test_suite_name, #test_name, nullptr, nullptr,                     \
-          ::testing::internal::CodeLocation(__FILE__, __LINE__), (parent_id), \
-          ::testing::internal::SuiteApiResolver<                              \
-              parent_class>::GetSetUpCaseOrSuite(__FILE__, __LINE__),         \
-          ::testing::internal::SuiteApiResolver<                              \
-              parent_class>::GetTearDownCaseOrSuite(__FILE__, __LINE__),      \
-          new ::testing::internal::TestFactoryImpl<GTEST_TEST_CLASS_NAME_(    \
-              test_suite_name, test_name)>);                                  \
-  void GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)::TestBody()
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
-// Copyright 2005, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-//
-// The Google C++ Testing and Mocking Framework (Google Test)
-//
-// This header file defines the public API for death tests.  It is
-// #included by gtest.h so a user doesn't need to include this
-// directly.
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
-#define GOOGLETEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
-
-// Copyright 2005, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// The Google C++ Testing and Mocking Framework (Google Test)
-//
-// This header file defines internal utilities needed for implementing
-// death tests.  They are subject to change without notice.
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
-#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
-
-// Copyright 2007, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// The Google C++ Testing and Mocking Framework (Google Test)
-//
-// This file implements just enough of the matcher interface to allow
-// EXPECT_DEATH and friends to accept a matcher argument.
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
-#define GOOGLETEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
-
-#include <atomic>
-#include <memory>
-#include <ostream>
-#include <string>
-#include <type_traits>
-
-// Copyright 2007, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-// Google Test - The Google C++ Testing and Mocking Framework
-//
-// This file implements a universal value printer that can print a
-// value of any type T:
-//
-//   void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr);
-//
-// A user can teach this function how to print a class type T by
-// defining either operator<<() or PrintTo() in the namespace that
-// defines T.  More specifically, the FIRST defined function in the
-// following list will be used (assuming T is defined in namespace
-// foo):
-//
-//   1. foo::PrintTo(const T&, ostream*)
-//   2. operator<<(ostream&, const T&) defined in either foo or the
-//      global namespace.
-//
-// However if T is an STL-style container then it is printed element-wise
-// unless foo::PrintTo(const T&, ostream*) is defined. Note that
-// operator<<() is ignored for container types.
-//
-// If none of the above is defined, it will print the debug string of
-// the value if it is a protocol buffer, or print the raw bytes in the
-// value otherwise.
-//
-// To aid debugging: when T is a reference type, the address of the
-// value is also printed; when T is a (const) char pointer, both the
-// pointer value and the NUL-terminated string it points to are
-// printed.
-//
-// We also provide some convenient wrappers:
-//
-//   // Prints a value to a string.  For a (const or not) char
-//   // pointer, the NUL-terminated string (but not the pointer) is
-//   // printed.
-//   std::string ::testing::PrintToString(const T& value);
-//
-//   // Prints a value tersely: for a reference type, the referenced
-//   // value (but not the address) is printed; for a (const or not) char
-//   // pointer, the NUL-terminated string (but not the pointer) is
-//   // printed.
-//   void ::testing::internal::UniversalTersePrint(const T& value, ostream*);
-//
-//   // Prints value using the type inferred by the compiler.  The difference
-//   // from UniversalTersePrint() is that this function prints both the
-//   // pointer and the NUL-terminated string for a (const or not) char pointer.
-//   void ::testing::internal::UniversalPrint(const T& value, ostream*);
-//
-//   // Prints the fields of a tuple tersely to a string vector, one
-//   // element for each field. Tuple support must be enabled in
-//   // gtest-port.h.
-//   std::vector<string> UniversalTersePrintTupleFieldsToStrings(
-//       const Tuple& value);
-//
-// Known limitation:
-//
-// The print primitives print the elements of an STL-style container
-// using the compiler-inferred type of *iter where iter is a
-// const_iterator of the container.  When const_iterator is an input
-// iterator but not a forward iterator, this inferred type may not
-// match value_type, and the print output may be incorrect.  In
-// practice, this is rarely a problem as for most containers
-// const_iterator is a forward iterator.  We'll fix this if there's an
-// actual need for it.  Note that this fix cannot rely on value_type
-// being defined as many user-defined container types don't have
-// value_type.
-
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
-#define GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
-
-#include <functional>
-#include <memory>
-#include <ostream>  // NOLINT
-#include <sstream>
-#include <string>
-#include <tuple>
-#include <type_traits>
-#include <utility>
-#include <vector>
-
-
-namespace testing {
-
-// Definitions in the internal* namespaces are subject to change without notice.
-// DO NOT USE THEM IN USER CODE!
-namespace internal {
-
-template <typename T>
-void UniversalPrint(const T& value, ::std::ostream* os);
-
-// Used to print an STL-style container when the user doesn't define
-// a PrintTo() for it.
-struct ContainerPrinter {
-  template <typename T,
-            typename = typename std::enable_if<
-                (sizeof(IsContainerTest<T>(0)) == sizeof(IsContainer)) &&
-                !IsRecursiveContainer<T>::value>::type>
-  static void PrintValue(const T& container, std::ostream* os) {
-    const size_t kMaxCount = 32;  // The maximum number of elements to print.
-    *os << '{';
-    size_t count = 0;
-    for (auto&& elem : container) {
-      if (count > 0) {
-        *os << ',';
-        if (count == kMaxCount) {  // Enough has been printed.
-          *os << " ...";
-          break;
-        }
-      }
-      *os << ' ';
-      // We cannot call PrintTo(elem, os) here as PrintTo() doesn't
-      // handle `elem` being a native array.
-      internal::UniversalPrint(elem, os);
-      ++count;
-    }
-
-    if (count > 0) {
-      *os << ' ';
-    }
-    *os << '}';
-  }
-};
-
-// Used to print a pointer that is neither a char pointer nor a member
-// pointer, when the user doesn't define PrintTo() for it.  (A member
-// variable pointer or member function pointer doesn't really point to
-// a location in the address space.  Their representation is
-// implementation-defined.  Therefore they will be printed as raw
-// bytes.)
-struct FunctionPointerPrinter {
-  template <typename T, typename = typename std::enable_if<
-                            std::is_function<T>::value>::type>
-  static void PrintValue(T* p, ::std::ostream* os) {
-    if (p == nullptr) {
-      *os << "NULL";
-    } else {
-      // T is a function type, so '*os << p' doesn't do what we want
-      // (it just prints p as bool).  We want to print p as a const
-      // void*.
-      *os << reinterpret_cast<const void*>(p);
-    }
-  }
-};
-
-struct PointerPrinter {
-  template <typename T>
-  static void PrintValue(T* p, ::std::ostream* os) {
-    if (p == nullptr) {
-      *os << "NULL";
-    } else {
-      // T is not a function type.  We just call << to print p,
-      // relying on ADL to pick up user-defined << for their pointer
-      // types, if any.
-      *os << p;
-    }
-  }
-};
-
-namespace internal_stream_operator_without_lexical_name_lookup {
-
-// The presence of an operator<< here will terminate lexical scope lookup
-// straight away (even though it cannot be a match because of its argument
-// types). Thus, the two operator<< calls in StreamPrinter will find only ADL
-// candidates.
-struct LookupBlocker {};
-void operator<<(LookupBlocker, LookupBlocker);
-
-struct StreamPrinter {
-  template <typename T,
-            // Don't accept member pointers here. We'd print them via implicit
-            // conversion to bool, which isn't useful.
-            typename = typename std::enable_if<
-                !std::is_member_pointer<T>::value>::type,
-            // Only accept types for which we can find a streaming operator via
-            // ADL (possibly involving implicit conversions).
-            typename = decltype(std::declval<std::ostream&>()
-                                << std::declval<const T&>())>
-  static void PrintValue(const T& value, ::std::ostream* os) {
-    // Call streaming operator found by ADL, possibly with implicit conversions
-    // of the arguments.
-    *os << value;
-  }
-};
-
-}  // namespace internal_stream_operator_without_lexical_name_lookup
-
-struct ProtobufPrinter {
-  // We print a protobuf using its ShortDebugString() when the string
-  // doesn't exceed this many characters; otherwise we print it using
-  // DebugString() for better readability.
-  static const size_t kProtobufOneLinerMaxLength = 50;
-
-  template <typename T,
-            typename = typename std::enable_if<
-                internal::HasDebugStringAndShortDebugString<T>::value>::type>
-  static void PrintValue(const T& value, ::std::ostream* os) {
-    std::string pretty_str = value.ShortDebugString();
-    if (pretty_str.length() > kProtobufOneLinerMaxLength) {
-      pretty_str = "\n" + value.DebugString();
-    }
-    *os << ("<" + pretty_str + ">");
-  }
-};
-
-struct ConvertibleToIntegerPrinter {
-  // Since T has no << operator or PrintTo() but can be implicitly
-  // converted to BiggestInt, we print it as a BiggestInt.
-  //
-  // Most likely T is an enum type (either named or unnamed), in which
-  // case printing it as an integer is the desired behavior.  In case
-  // T is not an enum, printing it as an integer is the best we can do
-  // given that it has no user-defined printer.
-  static void PrintValue(internal::BiggestInt value, ::std::ostream* os) {
-    *os << value;
-  }
-};
-
-struct ConvertibleToStringViewPrinter {
-#if GTEST_INTERNAL_HAS_STRING_VIEW
-  static void PrintValue(internal::StringView value, ::std::ostream* os) {
-    internal::UniversalPrint(value, os);
-  }
-#endif
-};
-
-
-// Prints the given number of bytes in the given object to the given
-// ostream.
-GTEST_API_ void PrintBytesInObjectTo(const unsigned char* obj_bytes,
-                                     size_t count,
-                                     ::std::ostream* os);
-struct RawBytesPrinter {
-  // SFINAE on `sizeof` to make sure we have a complete type.
-  template <typename T, size_t = sizeof(T)>
-  static void PrintValue(const T& value, ::std::ostream* os) {
-    PrintBytesInObjectTo(
-        static_cast<const unsigned char*>(
-            // Load bearing cast to void* to support iOS
-            reinterpret_cast<const void*>(std::addressof(value))),
-        sizeof(value), os);
-  }
-};
-
-struct FallbackPrinter {
-  template <typename T>
-  static void PrintValue(const T&, ::std::ostream* os) {
-    *os << "(incomplete type)";
-  }
-};
-
-// Try every printer in order and return the first one that works.
-template <typename T, typename E, typename Printer, typename... Printers>
-struct FindFirstPrinter : FindFirstPrinter<T, E, Printers...> {};
-
-template <typename T, typename Printer, typename... Printers>
-struct FindFirstPrinter<
-    T, decltype(Printer::PrintValue(std::declval<const T&>(), nullptr)),
-    Printer, Printers...> {
-  using type = Printer;
-};
-
-// Select the best printer in the following order:
-//  - Print containers (they have begin/end/etc).
-//  - Print function pointers.
-//  - Print object pointers.
-//  - Use the stream operator, if available.
-//  - Print protocol buffers.
-//  - Print types convertible to BiggestInt.
-//  - Print types convertible to StringView, if available.
-//  - Fallback to printing the raw bytes of the object.
-template <typename T>
-void PrintWithFallback(const T& value, ::std::ostream* os) {
-  using Printer = typename FindFirstPrinter<
-      T, void, ContainerPrinter, FunctionPointerPrinter, PointerPrinter,
-      internal_stream_operator_without_lexical_name_lookup::StreamPrinter,
-      ProtobufPrinter, ConvertibleToIntegerPrinter,
-      ConvertibleToStringViewPrinter, RawBytesPrinter, FallbackPrinter>::type;
-  Printer::PrintValue(value, os);
-}
-
-// FormatForComparison<ToPrint, OtherOperand>::Format(value) formats a
-// value of type ToPrint that is an operand of a comparison assertion
-// (e.g. ASSERT_EQ).  OtherOperand is the type of the other operand in
-// the comparison, and is used to help determine the best way to
-// format the value.  In particular, when the value is a C string
-// (char pointer) and the other operand is an STL string object, we
-// want to format the C string as a string, since we know it is
-// compared by value with the string object.  If the value is a char
-// pointer but the other operand is not an STL string object, we don't
-// know whether the pointer is supposed to point to a NUL-terminated
-// string, and thus want to print it as a pointer to be safe.
-//
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-
-// The default case.
-template <typename ToPrint, typename OtherOperand>
-class FormatForComparison {
- public:
-  static ::std::string Format(const ToPrint& value) {
-    return ::testing::PrintToString(value);
-  }
-};
-
-// Array.
-template <typename ToPrint, size_t N, typename OtherOperand>
-class FormatForComparison<ToPrint[N], OtherOperand> {
- public:
-  static ::std::string Format(const ToPrint* value) {
-    return FormatForComparison<const ToPrint*, OtherOperand>::Format(value);
-  }
-};
-
-// By default, print C string as pointers to be safe, as we don't know
-// whether they actually point to a NUL-terminated string.
-
-#define GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(CharType)                \
-  template <typename OtherOperand>                                      \
-  class FormatForComparison<CharType*, OtherOperand> {                  \
-   public:                                                              \
-    static ::std::string Format(CharType* value) {                      \
-      return ::testing::PrintToString(static_cast<const void*>(value)); \
-    }                                                                   \
-  }
-
-GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char);
-GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char);
-GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(wchar_t);
-GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const wchar_t);
-#ifdef __cpp_char8_t
-GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char8_t);
-GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char8_t);
-#endif
-GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char16_t);
-GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char16_t);
-GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char32_t);
-GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char32_t);
-
-#undef GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_
-
-// If a C string is compared with an STL string object, we know it's meant
-// to point to a NUL-terminated string, and thus can print it as a string.
-
-#define GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(CharType, OtherStringType) \
-  template <>                                                           \
-  class FormatForComparison<CharType*, OtherStringType> {               \
-   public:                                                              \
-    static ::std::string Format(CharType* value) {                      \
-      return ::testing::PrintToString(value);                           \
-    }                                                                   \
-  }
-
-GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char, ::std::string);
-GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char, ::std::string);
-#ifdef __cpp_char8_t
-GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char8_t, ::std::u8string);
-GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char8_t, ::std::u8string);
-#endif
-GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char16_t, ::std::u16string);
-GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char16_t, ::std::u16string);
-GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char32_t, ::std::u32string);
-GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char32_t, ::std::u32string);
-
-#if GTEST_HAS_STD_WSTRING
-GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(wchar_t, ::std::wstring);
-GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const wchar_t, ::std::wstring);
-#endif
-
-#undef GTEST_IMPL_FORMAT_C_STRING_AS_STRING_
-
-// Formats a comparison assertion (e.g. ASSERT_EQ, EXPECT_LT, and etc)
-// operand to be used in a failure message.  The type (but not value)
-// of the other operand may affect the format.  This allows us to
-// print a char* as a raw pointer when it is compared against another
-// char* or void*, and print it as a C string when it is compared
-// against an std::string object, for example.
-//
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-template <typename T1, typename T2>
-std::string FormatForComparisonFailureMessage(
-    const T1& value, const T2& /* other_operand */) {
-  return FormatForComparison<T1, T2>::Format(value);
-}
-
-// UniversalPrinter<T>::Print(value, ostream_ptr) prints the given
-// value to the given ostream.  The caller must ensure that
-// 'ostream_ptr' is not NULL, or the behavior is undefined.
-//
-// We define UniversalPrinter as a class template (as opposed to a
-// function template), as we need to partially specialize it for
-// reference types, which cannot be done with function templates.
-template <typename T>
-class UniversalPrinter;
-
-// Prints the given value using the << operator if it has one;
-// otherwise prints the bytes in it.  This is what
-// UniversalPrinter<T>::Print() does when PrintTo() is not specialized
-// or overloaded for type T.
-//
-// A user can override this behavior for a class type Foo by defining
-// an overload of PrintTo() in the namespace where Foo is defined.  We
-// give the user this option as sometimes defining a << operator for
-// Foo is not desirable (e.g. the coding style may prevent doing it,
-// or there is already a << operator but it doesn't do what the user
-// wants).
-template <typename T>
-void PrintTo(const T& value, ::std::ostream* os) {
-  internal::PrintWithFallback(value, os);
-}
-
-// The following list of PrintTo() overloads tells
-// UniversalPrinter<T>::Print() how to print standard types (built-in
-// types, strings, plain arrays, and pointers).
-
-// Overloads for various char types.
-GTEST_API_ void PrintTo(unsigned char c, ::std::ostream* os);
-GTEST_API_ void PrintTo(signed char c, ::std::ostream* os);
-inline void PrintTo(char c, ::std::ostream* os) {
-  // When printing a plain char, we always treat it as unsigned.  This
-  // way, the output won't be affected by whether the compiler thinks
-  // char is signed or not.
-  PrintTo(static_cast<unsigned char>(c), os);
-}
-
-// Overloads for other simple built-in types.
-inline void PrintTo(bool x, ::std::ostream* os) {
-  *os << (x ? "true" : "false");
-}
-
-// Overload for wchar_t type.
-// Prints a wchar_t as a symbol if it is printable or as its internal
-// code otherwise and also as its decimal code (except for L'\0').
-// The L'\0' char is printed as "L'\\0'". The decimal code is printed
-// as signed integer when wchar_t is implemented by the compiler
-// as a signed type and is printed as an unsigned integer when wchar_t
-// is implemented as an unsigned type.
-GTEST_API_ void PrintTo(wchar_t wc, ::std::ostream* os);
-
-GTEST_API_ void PrintTo(char32_t c, ::std::ostream* os);
-inline void PrintTo(char16_t c, ::std::ostream* os) {
-  PrintTo(ImplicitCast_<char32_t>(c), os);
-}
-#ifdef __cpp_char8_t
-inline void PrintTo(char8_t c, ::std::ostream* os) {
-  PrintTo(ImplicitCast_<char32_t>(c), os);
-}
-#endif
-
-// Overloads for C strings.
-GTEST_API_ void PrintTo(const char* s, ::std::ostream* os);
-inline void PrintTo(char* s, ::std::ostream* os) {
-  PrintTo(ImplicitCast_<const char*>(s), os);
-}
-
-// signed/unsigned char is often used for representing binary data, so
-// we print pointers to it as void* to be safe.
-inline void PrintTo(const signed char* s, ::std::ostream* os) {
-  PrintTo(ImplicitCast_<const void*>(s), os);
-}
-inline void PrintTo(signed char* s, ::std::ostream* os) {
-  PrintTo(ImplicitCast_<const void*>(s), os);
-}
-inline void PrintTo(const unsigned char* s, ::std::ostream* os) {
-  PrintTo(ImplicitCast_<const void*>(s), os);
-}
-inline void PrintTo(unsigned char* s, ::std::ostream* os) {
-  PrintTo(ImplicitCast_<const void*>(s), os);
-}
-#ifdef __cpp_char8_t
-// Overloads for u8 strings.
-GTEST_API_ void PrintTo(const char8_t* s, ::std::ostream* os);
-inline void PrintTo(char8_t* s, ::std::ostream* os) {
-  PrintTo(ImplicitCast_<const char8_t*>(s), os);
-}
-#endif
-// Overloads for u16 strings.
-GTEST_API_ void PrintTo(const char16_t* s, ::std::ostream* os);
-inline void PrintTo(char16_t* s, ::std::ostream* os) {
-  PrintTo(ImplicitCast_<const char16_t*>(s), os);
-}
-// Overloads for u32 strings.
-GTEST_API_ void PrintTo(const char32_t* s, ::std::ostream* os);
-inline void PrintTo(char32_t* s, ::std::ostream* os) {
-  PrintTo(ImplicitCast_<const char32_t*>(s), os);
-}
-
-// MSVC can be configured to define wchar_t as a typedef of unsigned
-// short.  It defines _NATIVE_WCHAR_T_DEFINED when wchar_t is a native
-// type.  When wchar_t is a typedef, defining an overload for const
-// wchar_t* would cause unsigned short* be printed as a wide string,
-// possibly causing invalid memory accesses.
-#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
-// Overloads for wide C strings
-GTEST_API_ void PrintTo(const wchar_t* s, ::std::ostream* os);
-inline void PrintTo(wchar_t* s, ::std::ostream* os) {
-  PrintTo(ImplicitCast_<const wchar_t*>(s), os);
-}
-#endif
-
-// Overload for C arrays.  Multi-dimensional arrays are printed
-// properly.
-
-// Prints the given number of elements in an array, without printing
-// the curly braces.
-template <typename T>
-void PrintRawArrayTo(const T a[], size_t count, ::std::ostream* os) {
-  UniversalPrint(a[0], os);
-  for (size_t i = 1; i != count; i++) {
-    *os << ", ";
-    UniversalPrint(a[i], os);
-  }
-}
-
-// Overloads for ::std::string.
-GTEST_API_ void PrintStringTo(const ::std::string&s, ::std::ostream* os);
-inline void PrintTo(const ::std::string& s, ::std::ostream* os) {
-  PrintStringTo(s, os);
-}
-
-// Overloads for ::std::u8string
-#ifdef __cpp_char8_t
-GTEST_API_ void PrintU8StringTo(const ::std::u8string& s, ::std::ostream* os);
-inline void PrintTo(const ::std::u8string& s, ::std::ostream* os) {
-  PrintU8StringTo(s, os);
-}
-#endif
-
-// Overloads for ::std::u16string
-GTEST_API_ void PrintU16StringTo(const ::std::u16string& s, ::std::ostream* os);
-inline void PrintTo(const ::std::u16string& s, ::std::ostream* os) {
-  PrintU16StringTo(s, os);
-}
-
-// Overloads for ::std::u32string
-GTEST_API_ void PrintU32StringTo(const ::std::u32string& s, ::std::ostream* os);
-inline void PrintTo(const ::std::u32string& s, ::std::ostream* os) {
-  PrintU32StringTo(s, os);
-}
-
-// Overloads for ::std::wstring.
-#if GTEST_HAS_STD_WSTRING
-GTEST_API_ void PrintWideStringTo(const ::std::wstring&s, ::std::ostream* os);
-inline void PrintTo(const ::std::wstring& s, ::std::ostream* os) {
-  PrintWideStringTo(s, os);
-}
-#endif  // GTEST_HAS_STD_WSTRING
-
-#if GTEST_INTERNAL_HAS_STRING_VIEW
-// Overload for internal::StringView.
-inline void PrintTo(internal::StringView sp, ::std::ostream* os) {
-  PrintTo(::std::string(sp), os);
-}
-#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
-
-inline void PrintTo(std::nullptr_t, ::std::ostream* os) { *os << "(nullptr)"; }
-
-template <typename T>
-void PrintTo(std::reference_wrapper<T> ref, ::std::ostream* os) {
-  UniversalPrinter<T&>::Print(ref.get(), os);
-}
-
-inline const void* VoidifyPointer(const void* p) { return p; }
-inline const void* VoidifyPointer(volatile const void* p) {
-  return const_cast<const void*>(p);
-}
-
-template <typename T, typename Ptr>
-void PrintSmartPointer(const Ptr& ptr, std::ostream* os, char) {
-  if (ptr == nullptr) {
-    *os << "(nullptr)";
-  } else {
-    // We can't print the value. Just print the pointer..
-    *os << "(" << (VoidifyPointer)(ptr.get()) << ")";
-  }
-}
-template <typename T, typename Ptr,
-          typename = typename std::enable_if<!std::is_void<T>::value &&
-                                             !std::is_array<T>::value>::type>
-void PrintSmartPointer(const Ptr& ptr, std::ostream* os, int) {
-  if (ptr == nullptr) {
-    *os << "(nullptr)";
-  } else {
-    *os << "(ptr = " << (VoidifyPointer)(ptr.get()) << ", value = ";
-    UniversalPrinter<T>::Print(*ptr, os);
-    *os << ")";
-  }
-}
-
-template <typename T, typename D>
-void PrintTo(const std::unique_ptr<T, D>& ptr, std::ostream* os) {
-  (PrintSmartPointer<T>)(ptr, os, 0);
-}
-
-template <typename T>
-void PrintTo(const std::shared_ptr<T>& ptr, std::ostream* os) {
-  (PrintSmartPointer<T>)(ptr, os, 0);
-}
-
-// Helper function for printing a tuple.  T must be instantiated with
-// a tuple type.
-template <typename T>
-void PrintTupleTo(const T&, std::integral_constant<size_t, 0>,
-                  ::std::ostream*) {}
-
-template <typename T, size_t I>
-void PrintTupleTo(const T& t, std::integral_constant<size_t, I>,
-                  ::std::ostream* os) {
-  PrintTupleTo(t, std::integral_constant<size_t, I - 1>(), os);
-  GTEST_INTENTIONAL_CONST_COND_PUSH_()
-  if (I > 1) {
-    GTEST_INTENTIONAL_CONST_COND_POP_()
-    *os << ", ";
-  }
-  UniversalPrinter<typename std::tuple_element<I - 1, T>::type>::Print(
-      std::get<I - 1>(t), os);
-}
-
-template <typename... Types>
-void PrintTo(const ::std::tuple<Types...>& t, ::std::ostream* os) {
-  *os << "(";
-  PrintTupleTo(t, std::integral_constant<size_t, sizeof...(Types)>(), os);
-  *os << ")";
-}
-
-// Overload for std::pair.
-template <typename T1, typename T2>
-void PrintTo(const ::std::pair<T1, T2>& value, ::std::ostream* os) {
-  *os << '(';
-  // We cannot use UniversalPrint(value.first, os) here, as T1 may be
-  // a reference type.  The same for printing value.second.
-  UniversalPrinter<T1>::Print(value.first, os);
-  *os << ", ";
-  UniversalPrinter<T2>::Print(value.second, os);
-  *os << ')';
-}
-
-// Implements printing a non-reference type T by letting the compiler
-// pick the right overload of PrintTo() for T.
-template <typename T>
-class UniversalPrinter {
- public:
-  // MSVC warns about adding const to a function type, so we want to
-  // disable the warning.
-  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
-
-  // Note: we deliberately don't call this PrintTo(), as that name
-  // conflicts with ::testing::internal::PrintTo in the body of the
-  // function.
-  static void Print(const T& value, ::std::ostream* os) {
-    // By default, ::testing::internal::PrintTo() is used for printing
-    // the value.
-    //
-    // Thanks to Koenig look-up, if T is a class and has its own
-    // PrintTo() function defined in its namespace, that function will
-    // be visible here.  Since it is more specific than the generic ones
-    // in ::testing::internal, it will be picked by the compiler in the
-    // following statement - exactly what we want.
-    PrintTo(value, os);
-  }
-
-  GTEST_DISABLE_MSC_WARNINGS_POP_()
-};
-
-// Remove any const-qualifiers before passing a type to UniversalPrinter.
-template <typename T>
-class UniversalPrinter<const T> : public UniversalPrinter<T> {};
-
-#if GTEST_INTERNAL_HAS_ANY
-
-// Printer for std::any / absl::any
-
-template <>
-class UniversalPrinter<Any> {
- public:
-  static void Print(const Any& value, ::std::ostream* os) {
-    if (value.has_value()) {
-      *os << "value of type " << GetTypeName(value);
-    } else {
-      *os << "no value";
-    }
-  }
-
- private:
-  static std::string GetTypeName(const Any& value) {
-#if GTEST_HAS_RTTI
-    return internal::GetTypeName(value.type());
-#else
-    static_cast<void>(value);  // possibly unused
-    return "<unknown_type>";
-#endif  // GTEST_HAS_RTTI
-  }
-};
-
-#endif  // GTEST_INTERNAL_HAS_ANY
-
-#if GTEST_INTERNAL_HAS_OPTIONAL
-
-// Printer for std::optional / absl::optional
-
-template <typename T>
-class UniversalPrinter<Optional<T>> {
- public:
-  static void Print(const Optional<T>& value, ::std::ostream* os) {
-    *os << '(';
-    if (!value) {
-      *os << "nullopt";
-    } else {
-      UniversalPrint(*value, os);
-    }
-    *os << ')';
-  }
-};
-
-#endif  // GTEST_INTERNAL_HAS_OPTIONAL
-
-#if GTEST_INTERNAL_HAS_VARIANT
-
-// Printer for std::variant / absl::variant
-
-template <typename... T>
-class UniversalPrinter<Variant<T...>> {
- public:
-  static void Print(const Variant<T...>& value, ::std::ostream* os) {
-    *os << '(';
-#if GTEST_HAS_ABSL
-    absl::visit(Visitor{os, value.index()}, value);
-#else
-    std::visit(Visitor{os, value.index()}, value);
-#endif  // GTEST_HAS_ABSL
-    *os << ')';
-  }
-
- private:
-  struct Visitor {
-    template <typename U>
-    void operator()(const U& u) const {
-      *os << "'" << GetTypeName<U>() << "(index = " << index
-          << ")' with value ";
-      UniversalPrint(u, os);
-    }
-    ::std::ostream* os;
-    std::size_t index;
-  };
-};
-
-#endif  // GTEST_INTERNAL_HAS_VARIANT
-
-// UniversalPrintArray(begin, len, os) prints an array of 'len'
-// elements, starting at address 'begin'.
-template <typename T>
-void UniversalPrintArray(const T* begin, size_t len, ::std::ostream* os) {
-  if (len == 0) {
-    *os << "{}";
-  } else {
-    *os << "{ ";
-    const size_t kThreshold = 18;
-    const size_t kChunkSize = 8;
-    // If the array has more than kThreshold elements, we'll have to
-    // omit some details by printing only the first and the last
-    // kChunkSize elements.
-    if (len <= kThreshold) {
-      PrintRawArrayTo(begin, len, os);
-    } else {
-      PrintRawArrayTo(begin, kChunkSize, os);
-      *os << ", ..., ";
-      PrintRawArrayTo(begin + len - kChunkSize, kChunkSize, os);
-    }
-    *os << " }";
-  }
-}
-// This overload prints a (const) char array compactly.
-GTEST_API_ void UniversalPrintArray(
-    const char* begin, size_t len, ::std::ostream* os);
-
-#ifdef __cpp_char8_t
-// This overload prints a (const) char8_t array compactly.
-GTEST_API_ void UniversalPrintArray(const char8_t* begin, size_t len,
-                                    ::std::ostream* os);
-#endif
-
-// This overload prints a (const) char16_t array compactly.
-GTEST_API_ void UniversalPrintArray(const char16_t* begin, size_t len,
-                                    ::std::ostream* os);
-
-// This overload prints a (const) char32_t array compactly.
-GTEST_API_ void UniversalPrintArray(const char32_t* begin, size_t len,
-                                    ::std::ostream* os);
-
-// This overload prints a (const) wchar_t array compactly.
-GTEST_API_ void UniversalPrintArray(
-    const wchar_t* begin, size_t len, ::std::ostream* os);
-
-// Implements printing an array type T[N].
-template <typename T, size_t N>
-class UniversalPrinter<T[N]> {
- public:
-  // Prints the given array, omitting some elements when there are too
-  // many.
-  static void Print(const T (&a)[N], ::std::ostream* os) {
-    UniversalPrintArray(a, N, os);
-  }
-};
-
-// Implements printing a reference type T&.
-template <typename T>
-class UniversalPrinter<T&> {
- public:
-  // MSVC warns about adding const to a function type, so we want to
-  // disable the warning.
-  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
-
-  static void Print(const T& value, ::std::ostream* os) {
-    // Prints the address of the value.  We use reinterpret_cast here
-    // as static_cast doesn't compile when T is a function type.
-    *os << "@" << reinterpret_cast<const void*>(&value) << " ";
-
-    // Then prints the value itself.
-    UniversalPrint(value, os);
-  }
-
-  GTEST_DISABLE_MSC_WARNINGS_POP_()
-};
-
-// Prints a value tersely: for a reference type, the referenced value
-// (but not the address) is printed; for a (const) char pointer, the
-// NUL-terminated string (but not the pointer) is printed.
-
-template <typename T>
-class UniversalTersePrinter {
- public:
-  static void Print(const T& value, ::std::ostream* os) {
-    UniversalPrint(value, os);
-  }
-};
-template <typename T>
-class UniversalTersePrinter<T&> {
- public:
-  static void Print(const T& value, ::std::ostream* os) {
-    UniversalPrint(value, os);
-  }
-};
-template <typename T, size_t N>
-class UniversalTersePrinter<T[N]> {
- public:
-  static void Print(const T (&value)[N], ::std::ostream* os) {
-    UniversalPrinter<T[N]>::Print(value, os);
-  }
-};
-template <>
-class UniversalTersePrinter<const char*> {
- public:
-  static void Print(const char* str, ::std::ostream* os) {
-    if (str == nullptr) {
-      *os << "NULL";
-    } else {
-      UniversalPrint(std::string(str), os);
-    }
-  }
-};
-template <>
-class UniversalTersePrinter<char*> : public UniversalTersePrinter<const char*> {
-};
-
-#ifdef __cpp_char8_t
-template <>
-class UniversalTersePrinter<const char8_t*> {
- public:
-  static void Print(const char8_t* str, ::std::ostream* os) {
-    if (str == nullptr) {
-      *os << "NULL";
-    } else {
-      UniversalPrint(::std::u8string(str), os);
-    }
-  }
-};
-template <>
-class UniversalTersePrinter<char8_t*>
-    : public UniversalTersePrinter<const char8_t*> {};
-#endif
-
-template <>
-class UniversalTersePrinter<const char16_t*> {
- public:
-  static void Print(const char16_t* str, ::std::ostream* os) {
-    if (str == nullptr) {
-      *os << "NULL";
-    } else {
-      UniversalPrint(::std::u16string(str), os);
-    }
-  }
-};
-template <>
-class UniversalTersePrinter<char16_t*>
-    : public UniversalTersePrinter<const char16_t*> {};
-
-template <>
-class UniversalTersePrinter<const char32_t*> {
- public:
-  static void Print(const char32_t* str, ::std::ostream* os) {
-    if (str == nullptr) {
-      *os << "NULL";
-    } else {
-      UniversalPrint(::std::u32string(str), os);
-    }
-  }
-};
-template <>
-class UniversalTersePrinter<char32_t*>
-    : public UniversalTersePrinter<const char32_t*> {};
-
-#if GTEST_HAS_STD_WSTRING
-template <>
-class UniversalTersePrinter<const wchar_t*> {
- public:
-  static void Print(const wchar_t* str, ::std::ostream* os) {
-    if (str == nullptr) {
-      *os << "NULL";
-    } else {
-      UniversalPrint(::std::wstring(str), os);
-    }
-  }
-};
-#endif
-
-template <>
-class UniversalTersePrinter<wchar_t*> {
- public:
-  static void Print(wchar_t* str, ::std::ostream* os) {
-    UniversalTersePrinter<const wchar_t*>::Print(str, os);
-  }
-};
-
-template <typename T>
-void UniversalTersePrint(const T& value, ::std::ostream* os) {
-  UniversalTersePrinter<T>::Print(value, os);
-}
-
-// Prints a value using the type inferred by the compiler.  The
-// difference between this and UniversalTersePrint() is that for a
-// (const) char pointer, this prints both the pointer and the
-// NUL-terminated string.
-template <typename T>
-void UniversalPrint(const T& value, ::std::ostream* os) {
-  // A workarond for the bug in VC++ 7.1 that prevents us from instantiating
-  // UniversalPrinter with T directly.
-  typedef T T1;
-  UniversalPrinter<T1>::Print(value, os);
-}
-
-typedef ::std::vector< ::std::string> Strings;
-
-  // Tersely prints the first N fields of a tuple to a string vector,
-  // one element for each field.
-template <typename Tuple>
-void TersePrintPrefixToStrings(const Tuple&, std::integral_constant<size_t, 0>,
-                               Strings*) {}
-template <typename Tuple, size_t I>
-void TersePrintPrefixToStrings(const Tuple& t,
-                               std::integral_constant<size_t, I>,
-                               Strings* strings) {
-  TersePrintPrefixToStrings(t, std::integral_constant<size_t, I - 1>(),
-                            strings);
-  ::std::stringstream ss;
-  UniversalTersePrint(std::get<I - 1>(t), &ss);
-  strings->push_back(ss.str());
-}
-
-// Prints the fields of a tuple tersely to a string vector, one
-// element for each field.  See the comment before
-// UniversalTersePrint() for how we define "tersely".
-template <typename Tuple>
-Strings UniversalTersePrintTupleFieldsToStrings(const Tuple& value) {
-  Strings result;
-  TersePrintPrefixToStrings(
-      value, std::integral_constant<size_t, std::tuple_size<Tuple>::value>(),
-      &result);
-  return result;
-}
-
-}  // namespace internal
-
-template <typename T>
-::std::string PrintToString(const T& value) {
-  ::std::stringstream ss;
-  internal::UniversalTersePrinter<T>::Print(value, &ss);
-  return ss.str();
-}
-
-}  // namespace testing
-
-// Include any custom printer added by the local installation.
-// We must include this header at the end to make sure it can use the
-// declarations from this file.
-// Copyright 2015, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// This file provides an injection point for custom printers in a local
-// installation of gTest.
-// It will be included from gtest-printers.h and the overrides in this file
-// will be visible to everyone.
-//
-// Injection point for custom user configurations. See README for details
-//
-// ** Custom implementation starts here **
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PRINTERS_H_
-#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PRINTERS_H_
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PRINTERS_H_
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
-
-// MSVC warning C5046 is new as of VS2017 version 15.8.
-#if defined(_MSC_VER) && _MSC_VER >= 1915
-#define GTEST_MAYBE_5046_ 5046
-#else
-#define GTEST_MAYBE_5046_
-#endif
-
-GTEST_DISABLE_MSC_WARNINGS_PUSH_(
-    4251 GTEST_MAYBE_5046_ /* class A needs to have dll-interface to be used by
-                              clients of class B */
-    /* Symbol involving type with internal linkage not defined */)
-
-namespace testing {
-
-// To implement a matcher Foo for type T, define:
-//   1. a class FooMatcherMatcher that implements the matcher interface:
-//     using is_gtest_matcher = void;
-//     bool MatchAndExplain(const T&, std::ostream*);
-//       (MatchResultListener* can also be used instead of std::ostream*)
-//     void DescribeTo(std::ostream*);
-//     void DescribeNegationTo(std::ostream*);
-//
-//   2. a factory function that creates a Matcher<T> object from a
-//      FooMatcherMatcher.
-
-class MatchResultListener {
- public:
-  // Creates a listener object with the given underlying ostream.  The
-  // listener does not own the ostream, and does not dereference it
-  // in the constructor or destructor.
-  explicit MatchResultListener(::std::ostream* os) : stream_(os) {}
-  virtual ~MatchResultListener() = 0;  // Makes this class abstract.
-
-  // Streams x to the underlying ostream; does nothing if the ostream
-  // is NULL.
-  template <typename T>
-  MatchResultListener& operator<<(const T& x) {
-    if (stream_ != nullptr) *stream_ << x;
-    return *this;
-  }
-
-  // Returns the underlying ostream.
-  ::std::ostream* stream() { return stream_; }
-
-  // Returns true if and only if the listener is interested in an explanation
-  // of the match result.  A matcher's MatchAndExplain() method can use
-  // this information to avoid generating the explanation when no one
-  // intends to hear it.
-  bool IsInterested() const { return stream_ != nullptr; }
-
- private:
-  ::std::ostream* const stream_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(MatchResultListener);
-};
-
-inline MatchResultListener::~MatchResultListener() {
-}
-
-// An instance of a subclass of this knows how to describe itself as a
-// matcher.
-class GTEST_API_ MatcherDescriberInterface {
- public:
-  virtual ~MatcherDescriberInterface() {}
-
-  // Describes this matcher to an ostream.  The function should print
-  // a verb phrase that describes the property a value matching this
-  // matcher should have.  The subject of the verb phrase is the value
-  // being matched.  For example, the DescribeTo() method of the Gt(7)
-  // matcher prints "is greater than 7".
-  virtual void DescribeTo(::std::ostream* os) const = 0;
-
-  // Describes the negation of this matcher to an ostream.  For
-  // example, if the description of this matcher is "is greater than
-  // 7", the negated description could be "is not greater than 7".
-  // You are not required to override this when implementing
-  // MatcherInterface, but it is highly advised so that your matcher
-  // can produce good error messages.
-  virtual void DescribeNegationTo(::std::ostream* os) const {
-    *os << "not (";
-    DescribeTo(os);
-    *os << ")";
-  }
-};
-
-// The implementation of a matcher.
-template <typename T>
-class MatcherInterface : public MatcherDescriberInterface {
- public:
-  // Returns true if and only if the matcher matches x; also explains the
-  // match result to 'listener' if necessary (see the next paragraph), in
-  // the form of a non-restrictive relative clause ("which ...",
-  // "whose ...", etc) that describes x.  For example, the
-  // MatchAndExplain() method of the Pointee(...) matcher should
-  // generate an explanation like "which points to ...".
-  //
-  // Implementations of MatchAndExplain() should add an explanation of
-  // the match result *if and only if* they can provide additional
-  // information that's not already present (or not obvious) in the
-  // print-out of x and the matcher's description.  Whether the match
-  // succeeds is not a factor in deciding whether an explanation is
-  // needed, as sometimes the caller needs to print a failure message
-  // when the match succeeds (e.g. when the matcher is used inside
-  // Not()).
-  //
-  // For example, a "has at least 10 elements" matcher should explain
-  // what the actual element count is, regardless of the match result,
-  // as it is useful information to the reader; on the other hand, an
-  // "is empty" matcher probably only needs to explain what the actual
-  // size is when the match fails, as it's redundant to say that the
-  // size is 0 when the value is already known to be empty.
-  //
-  // You should override this method when defining a new matcher.
-  //
-  // It's the responsibility of the caller (Google Test) to guarantee
-  // that 'listener' is not NULL.  This helps to simplify a matcher's
-  // implementation when it doesn't care about the performance, as it
-  // can talk to 'listener' without checking its validity first.
-  // However, in order to implement dummy listeners efficiently,
-  // listener->stream() may be NULL.
-  virtual bool MatchAndExplain(T x, MatchResultListener* listener) const = 0;
-
-  // Inherits these methods from MatcherDescriberInterface:
-  //   virtual void DescribeTo(::std::ostream* os) const = 0;
-  //   virtual void DescribeNegationTo(::std::ostream* os) const;
-};
-
-namespace internal {
-
-struct AnyEq {
-  template <typename A, typename B>
-  bool operator()(const A& a, const B& b) const { return a == b; }
-};
-struct AnyNe {
-  template <typename A, typename B>
-  bool operator()(const A& a, const B& b) const { return a != b; }
-};
-struct AnyLt {
-  template <typename A, typename B>
-  bool operator()(const A& a, const B& b) const { return a < b; }
-};
-struct AnyGt {
-  template <typename A, typename B>
-  bool operator()(const A& a, const B& b) const { return a > b; }
-};
-struct AnyLe {
-  template <typename A, typename B>
-  bool operator()(const A& a, const B& b) const { return a <= b; }
-};
-struct AnyGe {
-  template <typename A, typename B>
-  bool operator()(const A& a, const B& b) const { return a >= b; }
-};
-
-// A match result listener that ignores the explanation.
-class DummyMatchResultListener : public MatchResultListener {
- public:
-  DummyMatchResultListener() : MatchResultListener(nullptr) {}
-
- private:
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(DummyMatchResultListener);
-};
-
-// A match result listener that forwards the explanation to a given
-// ostream.  The difference between this and MatchResultListener is
-// that the former is concrete.
-class StreamMatchResultListener : public MatchResultListener {
- public:
-  explicit StreamMatchResultListener(::std::ostream* os)
-      : MatchResultListener(os) {}
-
- private:
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(StreamMatchResultListener);
-};
-
-struct SharedPayloadBase {
-  std::atomic<int> ref{1};
-  void Ref() { ref.fetch_add(1, std::memory_order_relaxed); }
-  bool Unref() { return ref.fetch_sub(1, std::memory_order_acq_rel) == 1; }
-};
-
-template <typename T>
-struct SharedPayload : SharedPayloadBase {
-  explicit SharedPayload(const T& v) : value(v) {}
-  explicit SharedPayload(T&& v) : value(std::move(v)) {}
-
-  static void Destroy(SharedPayloadBase* shared) {
-    delete static_cast<SharedPayload*>(shared);
-  }
-
-  T value;
-};
-
-// An internal class for implementing Matcher<T>, which will derive
-// from it.  We put functionalities common to all Matcher<T>
-// specializations here to avoid code duplication.
-template <typename T>
-class MatcherBase : private MatcherDescriberInterface {
- public:
-  // Returns true if and only if the matcher matches x; also explains the
-  // match result to 'listener'.
-  bool MatchAndExplain(const T& x, MatchResultListener* listener) const {
-    GTEST_CHECK_(vtable_ != nullptr);
-    return vtable_->match_and_explain(*this, x, listener);
-  }
-
-  // Returns true if and only if this matcher matches x.
-  bool Matches(const T& x) const {
-    DummyMatchResultListener dummy;
-    return MatchAndExplain(x, &dummy);
-  }
-
-  // Describes this matcher to an ostream.
-  void DescribeTo(::std::ostream* os) const final {
-    GTEST_CHECK_(vtable_ != nullptr);
-    vtable_->describe(*this, os, false);
-  }
-
-  // Describes the negation of this matcher to an ostream.
-  void DescribeNegationTo(::std::ostream* os) const final {
-    GTEST_CHECK_(vtable_ != nullptr);
-    vtable_->describe(*this, os, true);
-  }
-
-  // Explains why x matches, or doesn't match, the matcher.
-  void ExplainMatchResultTo(const T& x, ::std::ostream* os) const {
-    StreamMatchResultListener listener(os);
-    MatchAndExplain(x, &listener);
-  }
-
-  // Returns the describer for this matcher object; retains ownership
-  // of the describer, which is only guaranteed to be alive when
-  // this matcher object is alive.
-  const MatcherDescriberInterface* GetDescriber() const {
-    if (vtable_ == nullptr) return nullptr;
-    return vtable_->get_describer(*this);
-  }
-
- protected:
-  MatcherBase() : vtable_(nullptr) {}
-
-  // Constructs a matcher from its implementation.
-  template <typename U>
-  explicit MatcherBase(const MatcherInterface<U>* impl) {
-    Init(impl);
-  }
-
-  template <typename M, typename = typename std::remove_reference<
-                            M>::type::is_gtest_matcher>
-  MatcherBase(M&& m) {  // NOLINT
-    Init(std::forward<M>(m));
-  }
-
-  MatcherBase(const MatcherBase& other)
-      : vtable_(other.vtable_), buffer_(other.buffer_) {
-    if (IsShared()) buffer_.shared->Ref();
-  }
-
-  MatcherBase& operator=(const MatcherBase& other) {
-    if (this == &other) return *this;
-    Destroy();
-    vtable_ = other.vtable_;
-    buffer_ = other.buffer_;
-    if (IsShared()) buffer_.shared->Ref();
-    return *this;
-  }
-
-  MatcherBase(MatcherBase&& other)
-      : vtable_(other.vtable_), buffer_(other.buffer_) {
-    other.vtable_ = nullptr;
-  }
-
-  MatcherBase& operator=(MatcherBase&& other) {
-    if (this == &other) return *this;
-    Destroy();
-    vtable_ = other.vtable_;
-    buffer_ = other.buffer_;
-    other.vtable_ = nullptr;
-    return *this;
-  }
-
-  ~MatcherBase() override { Destroy(); }
-
- private:
-  struct VTable {
-    bool (*match_and_explain)(const MatcherBase&, const T&,
-                              MatchResultListener*);
-    void (*describe)(const MatcherBase&, std::ostream*, bool negation);
-    // Returns the captured object if it implements the interface, otherwise
-    // returns the MatcherBase itself.
-    const MatcherDescriberInterface* (*get_describer)(const MatcherBase&);
-    // Called on shared instances when the reference count reaches 0.
-    void (*shared_destroy)(SharedPayloadBase*);
-  };
-
-  bool IsShared() const {
-    return vtable_ != nullptr && vtable_->shared_destroy != nullptr;
-  }
-
-  // If the implementation uses a listener, call that.
-  template <typename P>
-  static auto MatchAndExplainImpl(const MatcherBase& m, const T& value,
-                                  MatchResultListener* listener)
-      -> decltype(P::Get(m).MatchAndExplain(value, listener->stream())) {
-    return P::Get(m).MatchAndExplain(value, listener->stream());
-  }
-
-  template <typename P>
-  static auto MatchAndExplainImpl(const MatcherBase& m, const T& value,
-                                  MatchResultListener* listener)
-      -> decltype(P::Get(m).MatchAndExplain(value, listener)) {
-    return P::Get(m).MatchAndExplain(value, listener);
-  }
-
-  template <typename P>
-  static void DescribeImpl(const MatcherBase& m, std::ostream* os,
-                           bool negation) {
-    if (negation) {
-      P::Get(m).DescribeNegationTo(os);
-    } else {
-      P::Get(m).DescribeTo(os);
-    }
-  }
-
-  template <typename P>
-  static const MatcherDescriberInterface* GetDescriberImpl(
-      const MatcherBase& m) {
-    // If the impl is a MatcherDescriberInterface, then return it.
-    // Otherwise use MatcherBase itself.
-    // This allows us to implement the GetDescriber() function without support
-    // from the impl, but some users really want to get their impl back when
-    // they call GetDescriber().
-    // We use std::get on a tuple as a workaround of not having `if constexpr`.
-    return std::get<(
-        std::is_convertible<decltype(&P::Get(m)),
-                            const MatcherDescriberInterface*>::value
-            ? 1
-            : 0)>(std::make_tuple(&m, &P::Get(m)));
-  }
-
-  template <typename P>
-  const VTable* GetVTable() {
-    static constexpr VTable kVTable = {&MatchAndExplainImpl<P>,
-                                       &DescribeImpl<P>, &GetDescriberImpl<P>,
-                                       P::shared_destroy};
-    return &kVTable;
-  }
-
-  union Buffer {
-    // Add some types to give Buffer some common alignment/size use cases.
-    void* ptr;
-    double d;
-    int64_t i;
-    // And add one for the out-of-line cases.
-    SharedPayloadBase* shared;
-  };
-
-  void Destroy() {
-    if (IsShared() && buffer_.shared->Unref()) {
-      vtable_->shared_destroy(buffer_.shared);
-    }
-  }
-
-  template <typename M>
-  static constexpr bool IsInlined() {
-    return sizeof(M) <= sizeof(Buffer) && alignof(M) <= alignof(Buffer) &&
-           std::is_trivially_copy_constructible<M>::value &&
-           std::is_trivially_destructible<M>::value;
-  }
-
-  template <typename M, bool = MatcherBase::IsInlined<M>()>
-  struct ValuePolicy {
-    static const M& Get(const MatcherBase& m) {
-      // When inlined along with Init, need to be explicit to avoid violating
-      // strict aliasing rules.
-      const M *ptr = static_cast<const M*>(
-          static_cast<const void*>(&m.buffer_));
-      return *ptr;
-    }
-    static void Init(MatcherBase& m, M impl) {
-      ::new (static_cast<void*>(&m.buffer_)) M(impl);
-    }
-    static constexpr auto shared_destroy = nullptr;
-  };
-
-  template <typename M>
-  struct ValuePolicy<M, false> {
-    using Shared = SharedPayload<M>;
-    static const M& Get(const MatcherBase& m) {
-      return static_cast<Shared*>(m.buffer_.shared)->value;
-    }
-    template <typename Arg>
-    static void Init(MatcherBase& m, Arg&& arg) {
-      m.buffer_.shared = new Shared(std::forward<Arg>(arg));
-    }
-    static constexpr auto shared_destroy = &Shared::Destroy;
-  };
-
-  template <typename U, bool B>
-  struct ValuePolicy<const MatcherInterface<U>*, B> {
-    using M = const MatcherInterface<U>;
-    using Shared = SharedPayload<std::unique_ptr<M>>;
-    static const M& Get(const MatcherBase& m) {
-      return *static_cast<Shared*>(m.buffer_.shared)->value;
-    }
-    static void Init(MatcherBase& m, M* impl) {
-      m.buffer_.shared = new Shared(std::unique_ptr<M>(impl));
-    }
-
-    static constexpr auto shared_destroy = &Shared::Destroy;
-  };
-
-  template <typename M>
-  void Init(M&& m) {
-    using MM = typename std::decay<M>::type;
-    using Policy = ValuePolicy<MM>;
-    vtable_ = GetVTable<Policy>();
-    Policy::Init(*this, std::forward<M>(m));
-  }
-
-  const VTable* vtable_;
-  Buffer buffer_;
-};
-
-}  // namespace internal
-
-// A Matcher<T> is a copyable and IMMUTABLE (except by assignment)
-// object that can check whether a value of type T matches.  The
-// implementation of Matcher<T> is just a std::shared_ptr to const
-// MatcherInterface<T>.  Don't inherit from Matcher!
-template <typename T>
-class Matcher : public internal::MatcherBase<T> {
- public:
-  // Constructs a null matcher.  Needed for storing Matcher objects in STL
-  // containers.  A default-constructed matcher is not yet initialized.  You
-  // cannot use it until a valid value has been assigned to it.
-  explicit Matcher() {}  // NOLINT
-
-  // Constructs a matcher from its implementation.
-  explicit Matcher(const MatcherInterface<const T&>* impl)
-      : internal::MatcherBase<T>(impl) {}
-
-  template <typename U>
-  explicit Matcher(
-      const MatcherInterface<U>* impl,
-      typename std::enable_if<!std::is_same<U, const U&>::value>::type* =
-          nullptr)
-      : internal::MatcherBase<T>(impl) {}
-
-  template <typename M, typename = typename std::remove_reference<
-                            M>::type::is_gtest_matcher>
-  Matcher(M&& m) : internal::MatcherBase<T>(std::forward<M>(m)) {}  // NOLINT
-
-  // Implicit constructor here allows people to write
-  // EXPECT_CALL(foo, Bar(5)) instead of EXPECT_CALL(foo, Bar(Eq(5))) sometimes
-  Matcher(T value);  // NOLINT
-};
-
-// The following two specializations allow the user to write str
-// instead of Eq(str) and "foo" instead of Eq("foo") when a std::string
-// matcher is expected.
-template <>
-class GTEST_API_ Matcher<const std::string&>
-    : public internal::MatcherBase<const std::string&> {
- public:
-  Matcher() {}
-
-  explicit Matcher(const MatcherInterface<const std::string&>* impl)
-      : internal::MatcherBase<const std::string&>(impl) {}
-
-  template <typename M, typename = typename std::remove_reference<
-                            M>::type::is_gtest_matcher>
-  Matcher(M&& m)  // NOLINT
-      : internal::MatcherBase<const std::string&>(std::forward<M>(m)) {}
-
-  // Allows the user to write str instead of Eq(str) sometimes, where
-  // str is a std::string object.
-  Matcher(const std::string& s);  // NOLINT
-
-  // Allows the user to write "foo" instead of Eq("foo") sometimes.
-  Matcher(const char* s);  // NOLINT
-};
-
-template <>
-class GTEST_API_ Matcher<std::string>
-    : public internal::MatcherBase<std::string> {
- public:
-  Matcher() {}
-
-  explicit Matcher(const MatcherInterface<const std::string&>* impl)
-      : internal::MatcherBase<std::string>(impl) {}
-  explicit Matcher(const MatcherInterface<std::string>* impl)
-      : internal::MatcherBase<std::string>(impl) {}
-
-  template <typename M, typename = typename std::remove_reference<
-                            M>::type::is_gtest_matcher>
-  Matcher(M&& m)  // NOLINT
-      : internal::MatcherBase<std::string>(std::forward<M>(m)) {}
-
-  // Allows the user to write str instead of Eq(str) sometimes, where
-  // str is a string object.
-  Matcher(const std::string& s);  // NOLINT
-
-  // Allows the user to write "foo" instead of Eq("foo") sometimes.
-  Matcher(const char* s);  // NOLINT
-};
-
-#if GTEST_INTERNAL_HAS_STRING_VIEW
-// The following two specializations allow the user to write str
-// instead of Eq(str) and "foo" instead of Eq("foo") when a absl::string_view
-// matcher is expected.
-template <>
-class GTEST_API_ Matcher<const internal::StringView&>
-    : public internal::MatcherBase<const internal::StringView&> {
- public:
-  Matcher() {}
-
-  explicit Matcher(const MatcherInterface<const internal::StringView&>* impl)
-      : internal::MatcherBase<const internal::StringView&>(impl) {}
-
-  template <typename M, typename = typename std::remove_reference<
-                            M>::type::is_gtest_matcher>
-  Matcher(M&& m)  // NOLINT
-      : internal::MatcherBase<const internal::StringView&>(std::forward<M>(m)) {
-  }
-
-  // Allows the user to write str instead of Eq(str) sometimes, where
-  // str is a std::string object.
-  Matcher(const std::string& s);  // NOLINT
-
-  // Allows the user to write "foo" instead of Eq("foo") sometimes.
-  Matcher(const char* s);  // NOLINT
-
-  // Allows the user to pass absl::string_views or std::string_views directly.
-  Matcher(internal::StringView s);  // NOLINT
-};
-
-template <>
-class GTEST_API_ Matcher<internal::StringView>
-    : public internal::MatcherBase<internal::StringView> {
- public:
-  Matcher() {}
-
-  explicit Matcher(const MatcherInterface<const internal::StringView&>* impl)
-      : internal::MatcherBase<internal::StringView>(impl) {}
-  explicit Matcher(const MatcherInterface<internal::StringView>* impl)
-      : internal::MatcherBase<internal::StringView>(impl) {}
-
-  template <typename M, typename = typename std::remove_reference<
-                            M>::type::is_gtest_matcher>
-  Matcher(M&& m)  // NOLINT
-      : internal::MatcherBase<internal::StringView>(std::forward<M>(m)) {}
-
-  // Allows the user to write str instead of Eq(str) sometimes, where
-  // str is a std::string object.
-  Matcher(const std::string& s);  // NOLINT
-
-  // Allows the user to write "foo" instead of Eq("foo") sometimes.
-  Matcher(const char* s);  // NOLINT
-
-  // Allows the user to pass absl::string_views or std::string_views directly.
-  Matcher(internal::StringView s);  // NOLINT
-};
-#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
-
-// Prints a matcher in a human-readable format.
-template <typename T>
-std::ostream& operator<<(std::ostream& os, const Matcher<T>& matcher) {
-  matcher.DescribeTo(&os);
-  return os;
-}
-
-// The PolymorphicMatcher class template makes it easy to implement a
-// polymorphic matcher (i.e. a matcher that can match values of more
-// than one type, e.g. Eq(n) and NotNull()).
-//
-// To define a polymorphic matcher, a user should provide an Impl
-// class that has a DescribeTo() method and a DescribeNegationTo()
-// method, and define a member function (or member function template)
-//
-//   bool MatchAndExplain(const Value& value,
-//                        MatchResultListener* listener) const;
-//
-// See the definition of NotNull() for a complete example.
-template <class Impl>
-class PolymorphicMatcher {
- public:
-  explicit PolymorphicMatcher(const Impl& an_impl) : impl_(an_impl) {}
-
-  // Returns a mutable reference to the underlying matcher
-  // implementation object.
-  Impl& mutable_impl() { return impl_; }
-
-  // Returns an immutable reference to the underlying matcher
-  // implementation object.
-  const Impl& impl() const { return impl_; }
-
-  template <typename T>
-  operator Matcher<T>() const {
-    return Matcher<T>(new MonomorphicImpl<const T&>(impl_));
-  }
-
- private:
-  template <typename T>
-  class MonomorphicImpl : public MatcherInterface<T> {
-   public:
-    explicit MonomorphicImpl(const Impl& impl) : impl_(impl) {}
-
-    void DescribeTo(::std::ostream* os) const override { impl_.DescribeTo(os); }
-
-    void DescribeNegationTo(::std::ostream* os) const override {
-      impl_.DescribeNegationTo(os);
-    }
-
-    bool MatchAndExplain(T x, MatchResultListener* listener) const override {
-      return impl_.MatchAndExplain(x, listener);
-    }
-
-   private:
-    const Impl impl_;
-  };
-
-  Impl impl_;
-};
-
-// Creates a matcher from its implementation.
-// DEPRECATED: Especially in the generic code, prefer:
-//   Matcher<T>(new MyMatcherImpl<const T&>(...));
-//
-// MakeMatcher may create a Matcher that accepts its argument by value, which
-// leads to unnecessary copies & lack of support for non-copyable types.
-template <typename T>
-inline Matcher<T> MakeMatcher(const MatcherInterface<T>* impl) {
-  return Matcher<T>(impl);
-}
-
-// Creates a polymorphic matcher from its implementation.  This is
-// easier to use than the PolymorphicMatcher<Impl> constructor as it
-// doesn't require you to explicitly write the template argument, e.g.
-//
-//   MakePolymorphicMatcher(foo);
-// vs
-//   PolymorphicMatcher<TypeOfFoo>(foo);
-template <class Impl>
-inline PolymorphicMatcher<Impl> MakePolymorphicMatcher(const Impl& impl) {
-  return PolymorphicMatcher<Impl>(impl);
-}
-
-namespace internal {
-// Implements a matcher that compares a given value with a
-// pre-supplied value using one of the ==, <=, <, etc, operators.  The
-// two values being compared don't have to have the same type.
-//
-// The matcher defined here is polymorphic (for example, Eq(5) can be
-// used to match an int, a short, a double, etc).  Therefore we use
-// a template type conversion operator in the implementation.
-//
-// The following template definition assumes that the Rhs parameter is
-// a "bare" type (i.e. neither 'const T' nor 'T&').
-template <typename D, typename Rhs, typename Op>
-class ComparisonBase {
- public:
-  explicit ComparisonBase(const Rhs& rhs) : rhs_(rhs) {}
-
-  using is_gtest_matcher = void;
-
-  template <typename Lhs>
-  bool MatchAndExplain(const Lhs& lhs, std::ostream*) const {
-    return Op()(lhs, Unwrap(rhs_));
-  }
-  void DescribeTo(std::ostream* os) const {
-    *os << D::Desc() << " ";
-    UniversalPrint(Unwrap(rhs_), os);
-  }
-  void DescribeNegationTo(std::ostream* os) const {
-    *os << D::NegatedDesc() << " ";
-    UniversalPrint(Unwrap(rhs_), os);
-  }
-
- private:
-  template <typename T>
-  static const T& Unwrap(const T& v) {
-    return v;
-  }
-  template <typename T>
-  static const T& Unwrap(std::reference_wrapper<T> v) {
-    return v;
-  }
-
-  Rhs rhs_;
-};
-
-template <typename Rhs>
-class EqMatcher : public ComparisonBase<EqMatcher<Rhs>, Rhs, AnyEq> {
- public:
-  explicit EqMatcher(const Rhs& rhs)
-      : ComparisonBase<EqMatcher<Rhs>, Rhs, AnyEq>(rhs) { }
-  static const char* Desc() { return "is equal to"; }
-  static const char* NegatedDesc() { return "isn't equal to"; }
-};
-template <typename Rhs>
-class NeMatcher : public ComparisonBase<NeMatcher<Rhs>, Rhs, AnyNe> {
- public:
-  explicit NeMatcher(const Rhs& rhs)
-      : ComparisonBase<NeMatcher<Rhs>, Rhs, AnyNe>(rhs) { }
-  static const char* Desc() { return "isn't equal to"; }
-  static const char* NegatedDesc() { return "is equal to"; }
-};
-template <typename Rhs>
-class LtMatcher : public ComparisonBase<LtMatcher<Rhs>, Rhs, AnyLt> {
- public:
-  explicit LtMatcher(const Rhs& rhs)
-      : ComparisonBase<LtMatcher<Rhs>, Rhs, AnyLt>(rhs) { }
-  static const char* Desc() { return "is <"; }
-  static const char* NegatedDesc() { return "isn't <"; }
-};
-template <typename Rhs>
-class GtMatcher : public ComparisonBase<GtMatcher<Rhs>, Rhs, AnyGt> {
- public:
-  explicit GtMatcher(const Rhs& rhs)
-      : ComparisonBase<GtMatcher<Rhs>, Rhs, AnyGt>(rhs) { }
-  static const char* Desc() { return "is >"; }
-  static const char* NegatedDesc() { return "isn't >"; }
-};
-template <typename Rhs>
-class LeMatcher : public ComparisonBase<LeMatcher<Rhs>, Rhs, AnyLe> {
- public:
-  explicit LeMatcher(const Rhs& rhs)
-      : ComparisonBase<LeMatcher<Rhs>, Rhs, AnyLe>(rhs) { }
-  static const char* Desc() { return "is <="; }
-  static const char* NegatedDesc() { return "isn't <="; }
-};
-template <typename Rhs>
-class GeMatcher : public ComparisonBase<GeMatcher<Rhs>, Rhs, AnyGe> {
- public:
-  explicit GeMatcher(const Rhs& rhs)
-      : ComparisonBase<GeMatcher<Rhs>, Rhs, AnyGe>(rhs) { }
-  static const char* Desc() { return "is >="; }
-  static const char* NegatedDesc() { return "isn't >="; }
-};
-
-template <typename T, typename = typename std::enable_if<
-                          std::is_constructible<std::string, T>::value>::type>
-using StringLike = T;
-
-// Implements polymorphic matchers MatchesRegex(regex) and
-// ContainsRegex(regex), which can be used as a Matcher<T> as long as
-// T can be converted to a string.
-class MatchesRegexMatcher {
- public:
-  MatchesRegexMatcher(const RE* regex, bool full_match)
-      : regex_(regex), full_match_(full_match) {}
-
-#if GTEST_INTERNAL_HAS_STRING_VIEW
-  bool MatchAndExplain(const internal::StringView& s,
-                       MatchResultListener* listener) const {
-    return MatchAndExplain(std::string(s), listener);
-  }
-#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
-
-  // Accepts pointer types, particularly:
-  //   const char*
-  //   char*
-  //   const wchar_t*
-  //   wchar_t*
-  template <typename CharType>
-  bool MatchAndExplain(CharType* s, MatchResultListener* listener) const {
-    return s != nullptr && MatchAndExplain(std::string(s), listener);
-  }
-
-  // Matches anything that can convert to std::string.
-  //
-  // This is a template, not just a plain function with const std::string&,
-  // because absl::string_view has some interfering non-explicit constructors.
-  template <class MatcheeStringType>
-  bool MatchAndExplain(const MatcheeStringType& s,
-                       MatchResultListener* /* listener */) const {
-    const std::string& s2(s);
-    return full_match_ ? RE::FullMatch(s2, *regex_)
-                       : RE::PartialMatch(s2, *regex_);
-  }
-
-  void DescribeTo(::std::ostream* os) const {
-    *os << (full_match_ ? "matches" : "contains") << " regular expression ";
-    UniversalPrinter<std::string>::Print(regex_->pattern(), os);
-  }
-
-  void DescribeNegationTo(::std::ostream* os) const {
-    *os << "doesn't " << (full_match_ ? "match" : "contain")
-        << " regular expression ";
-    UniversalPrinter<std::string>::Print(regex_->pattern(), os);
-  }
-
- private:
-  const std::shared_ptr<const RE> regex_;
-  const bool full_match_;
-};
-}  // namespace internal
-
-// Matches a string that fully matches regular expression 'regex'.
-// The matcher takes ownership of 'regex'.
-inline PolymorphicMatcher<internal::MatchesRegexMatcher> MatchesRegex(
-    const internal::RE* regex) {
-  return MakePolymorphicMatcher(internal::MatchesRegexMatcher(regex, true));
-}
-template <typename T = std::string>
-PolymorphicMatcher<internal::MatchesRegexMatcher> MatchesRegex(
-    const internal::StringLike<T>& regex) {
-  return MatchesRegex(new internal::RE(std::string(regex)));
-}
-
-// Matches a string that contains regular expression 'regex'.
-// The matcher takes ownership of 'regex'.
-inline PolymorphicMatcher<internal::MatchesRegexMatcher> ContainsRegex(
-    const internal::RE* regex) {
-  return MakePolymorphicMatcher(internal::MatchesRegexMatcher(regex, false));
-}
-template <typename T = std::string>
-PolymorphicMatcher<internal::MatchesRegexMatcher> ContainsRegex(
-    const internal::StringLike<T>& regex) {
-  return ContainsRegex(new internal::RE(std::string(regex)));
-}
-
-// Creates a polymorphic matcher that matches anything equal to x.
-// Note: if the parameter of Eq() were declared as const T&, Eq("foo")
-// wouldn't compile.
-template <typename T>
-inline internal::EqMatcher<T> Eq(T x) { return internal::EqMatcher<T>(x); }
-
-// Constructs a Matcher<T> from a 'value' of type T.  The constructed
-// matcher matches any value that's equal to 'value'.
-template <typename T>
-Matcher<T>::Matcher(T value) { *this = Eq(value); }
-
-// Creates a monomorphic matcher that matches anything with type Lhs
-// and equal to rhs.  A user may need to use this instead of Eq(...)
-// in order to resolve an overloading ambiguity.
-//
-// TypedEq<T>(x) is just a convenient short-hand for Matcher<T>(Eq(x))
-// or Matcher<T>(x), but more readable than the latter.
-//
-// We could define similar monomorphic matchers for other comparison
-// operations (e.g. TypedLt, TypedGe, and etc), but decided not to do
-// it yet as those are used much less than Eq() in practice.  A user
-// can always write Matcher<T>(Lt(5)) to be explicit about the type,
-// for example.
-template <typename Lhs, typename Rhs>
-inline Matcher<Lhs> TypedEq(const Rhs& rhs) { return Eq(rhs); }
-
-// Creates a polymorphic matcher that matches anything >= x.
-template <typename Rhs>
-inline internal::GeMatcher<Rhs> Ge(Rhs x) {
-  return internal::GeMatcher<Rhs>(x);
-}
-
-// Creates a polymorphic matcher that matches anything > x.
-template <typename Rhs>
-inline internal::GtMatcher<Rhs> Gt(Rhs x) {
-  return internal::GtMatcher<Rhs>(x);
-}
-
-// Creates a polymorphic matcher that matches anything <= x.
-template <typename Rhs>
-inline internal::LeMatcher<Rhs> Le(Rhs x) {
-  return internal::LeMatcher<Rhs>(x);
-}
-
-// Creates a polymorphic matcher that matches anything < x.
-template <typename Rhs>
-inline internal::LtMatcher<Rhs> Lt(Rhs x) {
-  return internal::LtMatcher<Rhs>(x);
-}
-
-// Creates a polymorphic matcher that matches anything != x.
-template <typename Rhs>
-inline internal::NeMatcher<Rhs> Ne(Rhs x) {
-  return internal::NeMatcher<Rhs>(x);
-}
-}  // namespace testing
-
-GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251 5046
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
-
-#include <stdio.h>
-#include <memory>
-
-namespace testing {
-namespace internal {
-
-GTEST_DECLARE_string_(internal_run_death_test);
-
-// Names of the flags (needed for parsing Google Test flags).
-const char kDeathTestStyleFlag[] = "death_test_style";
-const char kDeathTestUseFork[] = "death_test_use_fork";
-const char kInternalRunDeathTestFlag[] = "internal_run_death_test";
-
-#if GTEST_HAS_DEATH_TEST
-
-GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
-/* class A needs to have dll-interface to be used by clients of class B */)
-
-// DeathTest is a class that hides much of the complexity of the
-// GTEST_DEATH_TEST_ macro.  It is abstract; its static Create method
-// returns a concrete class that depends on the prevailing death test
-// style, as defined by the --gtest_death_test_style and/or
-// --gtest_internal_run_death_test flags.
-
-// In describing the results of death tests, these terms are used with
-// the corresponding definitions:
-//
-// exit status:  The integer exit information in the format specified
-//               by wait(2)
-// exit code:    The integer code passed to exit(3), _exit(2), or
-//               returned from main()
-class GTEST_API_ DeathTest {
- public:
-  // Create returns false if there was an error determining the
-  // appropriate action to take for the current death test; for example,
-  // if the gtest_death_test_style flag is set to an invalid value.
-  // The LastMessage method will return a more detailed message in that
-  // case.  Otherwise, the DeathTest pointer pointed to by the "test"
-  // argument is set.  If the death test should be skipped, the pointer
-  // is set to NULL; otherwise, it is set to the address of a new concrete
-  // DeathTest object that controls the execution of the current test.
-  static bool Create(const char* statement, Matcher<const std::string&> matcher,
-                     const char* file, int line, DeathTest** test);
-  DeathTest();
-  virtual ~DeathTest() { }
-
-  // A helper class that aborts a death test when it's deleted.
-  class ReturnSentinel {
-   public:
-    explicit ReturnSentinel(DeathTest* test) : test_(test) { }
-    ~ReturnSentinel() { test_->Abort(TEST_ENCOUNTERED_RETURN_STATEMENT); }
-   private:
-    DeathTest* const test_;
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(ReturnSentinel);
-  } GTEST_ATTRIBUTE_UNUSED_;
-
-  // An enumeration of possible roles that may be taken when a death
-  // test is encountered.  EXECUTE means that the death test logic should
-  // be executed immediately.  OVERSEE means that the program should prepare
-  // the appropriate environment for a child process to execute the death
-  // test, then wait for it to complete.
-  enum TestRole { OVERSEE_TEST, EXECUTE_TEST };
-
-  // An enumeration of the three reasons that a test might be aborted.
-  enum AbortReason {
-    TEST_ENCOUNTERED_RETURN_STATEMENT,
-    TEST_THREW_EXCEPTION,
-    TEST_DID_NOT_DIE
-  };
-
-  // Assumes one of the above roles.
-  virtual TestRole AssumeRole() = 0;
-
-  // Waits for the death test to finish and returns its status.
-  virtual int Wait() = 0;
-
-  // Returns true if the death test passed; that is, the test process
-  // exited during the test, its exit status matches a user-supplied
-  // predicate, and its stderr output matches a user-supplied regular
-  // expression.
-  // The user-supplied predicate may be a macro expression rather
-  // than a function pointer or functor, or else Wait and Passed could
-  // be combined.
-  virtual bool Passed(bool exit_status_ok) = 0;
-
-  // Signals that the death test did not die as expected.
-  virtual void Abort(AbortReason reason) = 0;
-
-  // Returns a human-readable outcome message regarding the outcome of
-  // the last death test.
-  static const char* LastMessage();
-
-  static void set_last_death_test_message(const std::string& message);
-
- private:
-  // A string containing a description of the outcome of the last death test.
-  static std::string last_death_test_message_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(DeathTest);
-};
-
-GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
-
-// Factory interface for death tests.  May be mocked out for testing.
-class DeathTestFactory {
- public:
-  virtual ~DeathTestFactory() { }
-  virtual bool Create(const char* statement,
-                      Matcher<const std::string&> matcher, const char* file,
-                      int line, DeathTest** test) = 0;
-};
-
-// A concrete DeathTestFactory implementation for normal use.
-class DefaultDeathTestFactory : public DeathTestFactory {
- public:
-  bool Create(const char* statement, Matcher<const std::string&> matcher,
-              const char* file, int line, DeathTest** test) override;
-};
-
-// Returns true if exit_status describes a process that was terminated
-// by a signal, or exited normally with a nonzero exit code.
-GTEST_API_ bool ExitedUnsuccessfully(int exit_status);
-
-// A string passed to EXPECT_DEATH (etc.) is caught by one of these overloads
-// and interpreted as a regex (rather than an Eq matcher) for legacy
-// compatibility.
-inline Matcher<const ::std::string&> MakeDeathTestMatcher(
-    ::testing::internal::RE regex) {
-  return ContainsRegex(regex.pattern());
-}
-inline Matcher<const ::std::string&> MakeDeathTestMatcher(const char* regex) {
-  return ContainsRegex(regex);
-}
-inline Matcher<const ::std::string&> MakeDeathTestMatcher(
-    const ::std::string& regex) {
-  return ContainsRegex(regex);
-}
-
-// If a Matcher<const ::std::string&> is passed to EXPECT_DEATH (etc.), it's
-// used directly.
-inline Matcher<const ::std::string&> MakeDeathTestMatcher(
-    Matcher<const ::std::string&> matcher) {
-  return matcher;
-}
-
-// Traps C++ exceptions escaping statement and reports them as test
-// failures. Note that trapping SEH exceptions is not implemented here.
-# if GTEST_HAS_EXCEPTIONS
-#  define GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, death_test) \
-  try { \
-    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
-  } catch (const ::std::exception& gtest_exception) { \
-    fprintf(\
-        stderr, \
-        "\n%s: Caught std::exception-derived exception escaping the " \
-        "death test statement. Exception message: %s\n", \
-        ::testing::internal::FormatFileLocation(__FILE__, __LINE__).c_str(), \
-        gtest_exception.what()); \
-    fflush(stderr); \
-    death_test->Abort(::testing::internal::DeathTest::TEST_THREW_EXCEPTION); \
-  } catch (...) { \
-    death_test->Abort(::testing::internal::DeathTest::TEST_THREW_EXCEPTION); \
-  }
-
-# else
-#  define GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, death_test) \
-  GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement)
-
-# endif
-
-// This macro is for implementing ASSERT_DEATH*, EXPECT_DEATH*,
-// ASSERT_EXIT*, and EXPECT_EXIT*.
-#define GTEST_DEATH_TEST_(statement, predicate, regex_or_matcher, fail)        \
-  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                                \
-  if (::testing::internal::AlwaysTrue()) {                                     \
-    ::testing::internal::DeathTest* gtest_dt;                                  \
-    if (!::testing::internal::DeathTest::Create(                               \
-            #statement,                                                        \
-            ::testing::internal::MakeDeathTestMatcher(regex_or_matcher),       \
-            __FILE__, __LINE__, &gtest_dt)) {                                  \
-      goto GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__);                        \
-    }                                                                          \
-    if (gtest_dt != nullptr) {                                                 \
-      std::unique_ptr< ::testing::internal::DeathTest> gtest_dt_ptr(gtest_dt); \
-      switch (gtest_dt->AssumeRole()) {                                        \
-        case ::testing::internal::DeathTest::OVERSEE_TEST:                     \
-          if (!gtest_dt->Passed(predicate(gtest_dt->Wait()))) {                \
-            goto GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__);                  \
-          }                                                                    \
-          break;                                                               \
-        case ::testing::internal::DeathTest::EXECUTE_TEST: {                   \
-          ::testing::internal::DeathTest::ReturnSentinel gtest_sentinel(       \
-              gtest_dt);                                                       \
-          GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, gtest_dt);            \
-          gtest_dt->Abort(::testing::internal::DeathTest::TEST_DID_NOT_DIE);   \
-          break;                                                               \
-        }                                                                      \
-        default:                                                               \
-          break;                                                               \
-      }                                                                        \
-    }                                                                          \
-  } else                                                                       \
-    GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__)                                \
-        : fail(::testing::internal::DeathTest::LastMessage())
-// The symbol "fail" here expands to something into which a message
-// can be streamed.
-
-// This macro is for implementing ASSERT/EXPECT_DEBUG_DEATH when compiled in
-// NDEBUG mode. In this case we need the statements to be executed and the macro
-// must accept a streamed message even though the message is never printed.
-// The regex object is not evaluated, but it is used to prevent "unused"
-// warnings and to avoid an expression that doesn't compile in debug mode.
-#define GTEST_EXECUTE_STATEMENT_(statement, regex_or_matcher)    \
-  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                  \
-  if (::testing::internal::AlwaysTrue()) {                       \
-    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement);   \
-  } else if (!::testing::internal::AlwaysTrue()) {               \
-    ::testing::internal::MakeDeathTestMatcher(regex_or_matcher); \
-  } else                                                         \
-    ::testing::Message()
-
-// A class representing the parsed contents of the
-// --gtest_internal_run_death_test flag, as it existed when
-// RUN_ALL_TESTS was called.
-class InternalRunDeathTestFlag {
- public:
-  InternalRunDeathTestFlag(const std::string& a_file,
-                           int a_line,
-                           int an_index,
-                           int a_write_fd)
-      : file_(a_file), line_(a_line), index_(an_index),
-        write_fd_(a_write_fd) {}
-
-  ~InternalRunDeathTestFlag() {
-    if (write_fd_ >= 0)
-      posix::Close(write_fd_);
-  }
-
-  const std::string& file() const { return file_; }
-  int line() const { return line_; }
-  int index() const { return index_; }
-  int write_fd() const { return write_fd_; }
-
- private:
-  std::string file_;
-  int line_;
-  int index_;
-  int write_fd_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(InternalRunDeathTestFlag);
-};
-
-// Returns a newly created InternalRunDeathTestFlag object with fields
-// initialized from the GTEST_FLAG(internal_run_death_test) flag if
-// the flag is specified; otherwise returns NULL.
-InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag();
-
-#endif  // GTEST_HAS_DEATH_TEST
-
-}  // namespace internal
-}  // namespace testing
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
-
-namespace testing {
-
-// This flag controls the style of death tests.  Valid values are "threadsafe",
-// meaning that the death test child process will re-execute the test binary
-// from the start, running only a single death test, or "fast",
-// meaning that the child process will execute the test logic immediately
-// after forking.
-GTEST_DECLARE_string_(death_test_style);
-
-#if GTEST_HAS_DEATH_TEST
-
-namespace internal {
-
-// Returns a Boolean value indicating whether the caller is currently
-// executing in the context of the death test child process.  Tools such as
-// Valgrind heap checkers may need this to modify their behavior in death
-// tests.  IMPORTANT: This is an internal utility.  Using it may break the
-// implementation of death tests.  User code MUST NOT use it.
-GTEST_API_ bool InDeathTestChild();
-
-}  // namespace internal
-
-// The following macros are useful for writing death tests.
-
-// Here's what happens when an ASSERT_DEATH* or EXPECT_DEATH* is
-// executed:
-//
-//   1. It generates a warning if there is more than one active
-//   thread.  This is because it's safe to fork() or clone() only
-//   when there is a single thread.
-//
-//   2. The parent process clone()s a sub-process and runs the death
-//   test in it; the sub-process exits with code 0 at the end of the
-//   death test, if it hasn't exited already.
-//
-//   3. The parent process waits for the sub-process to terminate.
-//
-//   4. The parent process checks the exit code and error message of
-//   the sub-process.
-//
-// Examples:
-//
-//   ASSERT_DEATH(server.SendMessage(56, "Hello"), "Invalid port number");
-//   for (int i = 0; i < 5; i++) {
-//     EXPECT_DEATH(server.ProcessRequest(i),
-//                  "Invalid request .* in ProcessRequest()")
-//                  << "Failed to die on request " << i;
-//   }
-//
-//   ASSERT_EXIT(server.ExitNow(), ::testing::ExitedWithCode(0), "Exiting");
-//
-//   bool KilledBySIGHUP(int exit_code) {
-//     return WIFSIGNALED(exit_code) && WTERMSIG(exit_code) == SIGHUP;
-//   }
-//
-//   ASSERT_EXIT(client.HangUpServer(), KilledBySIGHUP, "Hanging up!");
-//
-// The final parameter to each of these macros is a matcher applied to any data
-// the sub-process wrote to stderr.  For compatibility with existing tests, a
-// bare string is interpreted as a regular expression matcher.
-//
-// On the regular expressions used in death tests:
-//
-//   GOOGLETEST_CM0005 DO NOT DELETE
-//   On POSIX-compliant systems (*nix), we use the <regex.h> library,
-//   which uses the POSIX extended regex syntax.
-//
-//   On other platforms (e.g. Windows or Mac), we only support a simple regex
-//   syntax implemented as part of Google Test.  This limited
-//   implementation should be enough most of the time when writing
-//   death tests; though it lacks many features you can find in PCRE
-//   or POSIX extended regex syntax.  For example, we don't support
-//   union ("x|y"), grouping ("(xy)"), brackets ("[xy]"), and
-//   repetition count ("x{5,7}"), among others.
-//
-//   Below is the syntax that we do support.  We chose it to be a
-//   subset of both PCRE and POSIX extended regex, so it's easy to
-//   learn wherever you come from.  In the following: 'A' denotes a
-//   literal character, period (.), or a single \\ escape sequence;
-//   'x' and 'y' denote regular expressions; 'm' and 'n' are for
-//   natural numbers.
-//
-//     c     matches any literal character c
-//     \\d   matches any decimal digit
-//     \\D   matches any character that's not a decimal digit
-//     \\f   matches \f
-//     \\n   matches \n
-//     \\r   matches \r
-//     \\s   matches any ASCII whitespace, including \n
-//     \\S   matches any character that's not a whitespace
-//     \\t   matches \t
-//     \\v   matches \v
-//     \\w   matches any letter, _, or decimal digit
-//     \\W   matches any character that \\w doesn't match
-//     \\c   matches any literal character c, which must be a punctuation
-//     .     matches any single character except \n
-//     A?    matches 0 or 1 occurrences of A
-//     A*    matches 0 or many occurrences of A
-//     A+    matches 1 or many occurrences of A
-//     ^     matches the beginning of a string (not that of each line)
-//     $     matches the end of a string (not that of each line)
-//     xy    matches x followed by y
-//
-//   If you accidentally use PCRE or POSIX extended regex features
-//   not implemented by us, you will get a run-time failure.  In that
-//   case, please try to rewrite your regular expression within the
-//   above syntax.
-//
-//   This implementation is *not* meant to be as highly tuned or robust
-//   as a compiled regex library, but should perform well enough for a
-//   death test, which already incurs significant overhead by launching
-//   a child process.
-//
-// Known caveats:
-//
-//   A "threadsafe" style death test obtains the path to the test
-//   program from argv[0] and re-executes it in the sub-process.  For
-//   simplicity, the current implementation doesn't search the PATH
-//   when launching the sub-process.  This means that the user must
-//   invoke the test program via a path that contains at least one
-//   path separator (e.g. path/to/foo_test and
-//   /absolute/path/to/bar_test are fine, but foo_test is not).  This
-//   is rarely a problem as people usually don't put the test binary
-//   directory in PATH.
-//
-
-// Asserts that a given `statement` causes the program to exit, with an
-// integer exit status that satisfies `predicate`, and emitting error output
-// that matches `matcher`.
-# define ASSERT_EXIT(statement, predicate, matcher) \
-    GTEST_DEATH_TEST_(statement, predicate, matcher, GTEST_FATAL_FAILURE_)
-
-// Like `ASSERT_EXIT`, but continues on to successive tests in the
-// test suite, if any:
-# define EXPECT_EXIT(statement, predicate, matcher) \
-    GTEST_DEATH_TEST_(statement, predicate, matcher, GTEST_NONFATAL_FAILURE_)
-
-// Asserts that a given `statement` causes the program to exit, either by
-// explicitly exiting with a nonzero exit code or being killed by a
-// signal, and emitting error output that matches `matcher`.
-# define ASSERT_DEATH(statement, matcher) \
-    ASSERT_EXIT(statement, ::testing::internal::ExitedUnsuccessfully, matcher)
-
-// Like `ASSERT_DEATH`, but continues on to successive tests in the
-// test suite, if any:
-# define EXPECT_DEATH(statement, matcher) \
-    EXPECT_EXIT(statement, ::testing::internal::ExitedUnsuccessfully, matcher)
-
-// Two predicate classes that can be used in {ASSERT,EXPECT}_EXIT*:
-
-// Tests that an exit code describes a normal exit with a given exit code.
-class GTEST_API_ ExitedWithCode {
- public:
-  explicit ExitedWithCode(int exit_code);
-  ExitedWithCode(const ExitedWithCode&) = default;
-  void operator=(const ExitedWithCode& other) = delete;
-  bool operator()(int exit_status) const;
- private:
-  const int exit_code_;
-};
-
-# if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
-// Tests that an exit code describes an exit due to termination by a
-// given signal.
-// GOOGLETEST_CM0006 DO NOT DELETE
-class GTEST_API_ KilledBySignal {
- public:
-  explicit KilledBySignal(int signum);
-  bool operator()(int exit_status) const;
- private:
-  const int signum_;
-};
-# endif  // !GTEST_OS_WINDOWS
-
-// EXPECT_DEBUG_DEATH asserts that the given statements die in debug mode.
-// The death testing framework causes this to have interesting semantics,
-// since the sideeffects of the call are only visible in opt mode, and not
-// in debug mode.
-//
-// In practice, this can be used to test functions that utilize the
-// LOG(DFATAL) macro using the following style:
-//
-// int DieInDebugOr12(int* sideeffect) {
-//   if (sideeffect) {
-//     *sideeffect = 12;
-//   }
-//   LOG(DFATAL) << "death";
-//   return 12;
-// }
-//
-// TEST(TestSuite, TestDieOr12WorksInDgbAndOpt) {
-//   int sideeffect = 0;
-//   // Only asserts in dbg.
-//   EXPECT_DEBUG_DEATH(DieInDebugOr12(&sideeffect), "death");
-//
-// #ifdef NDEBUG
-//   // opt-mode has sideeffect visible.
-//   EXPECT_EQ(12, sideeffect);
-// #else
-//   // dbg-mode no visible sideeffect.
-//   EXPECT_EQ(0, sideeffect);
-// #endif
-// }
-//
-// This will assert that DieInDebugReturn12InOpt() crashes in debug
-// mode, usually due to a DCHECK or LOG(DFATAL), but returns the
-// appropriate fallback value (12 in this case) in opt mode. If you
-// need to test that a function has appropriate side-effects in opt
-// mode, include assertions against the side-effects.  A general
-// pattern for this is:
-//
-// EXPECT_DEBUG_DEATH({
-//   // Side-effects here will have an effect after this statement in
-//   // opt mode, but none in debug mode.
-//   EXPECT_EQ(12, DieInDebugOr12(&sideeffect));
-// }, "death");
-//
-# ifdef NDEBUG
-
-#  define EXPECT_DEBUG_DEATH(statement, regex) \
-  GTEST_EXECUTE_STATEMENT_(statement, regex)
-
-#  define ASSERT_DEBUG_DEATH(statement, regex) \
-  GTEST_EXECUTE_STATEMENT_(statement, regex)
-
-# else
-
-#  define EXPECT_DEBUG_DEATH(statement, regex) \
-  EXPECT_DEATH(statement, regex)
-
-#  define ASSERT_DEBUG_DEATH(statement, regex) \
-  ASSERT_DEATH(statement, regex)
-
-# endif  // NDEBUG for EXPECT_DEBUG_DEATH
-#endif  // GTEST_HAS_DEATH_TEST
-
-// This macro is used for implementing macros such as
-// EXPECT_DEATH_IF_SUPPORTED and ASSERT_DEATH_IF_SUPPORTED on systems where
-// death tests are not supported. Those macros must compile on such systems
-// if and only if EXPECT_DEATH and ASSERT_DEATH compile with the same parameters
-// on systems that support death tests. This allows one to write such a macro on
-// a system that does not support death tests and be sure that it will compile
-// on a death-test supporting system. It is exposed publicly so that systems
-// that have death-tests with stricter requirements than GTEST_HAS_DEATH_TEST
-// can write their own equivalent of EXPECT_DEATH_IF_SUPPORTED and
-// ASSERT_DEATH_IF_SUPPORTED.
-//
-// Parameters:
-//   statement -  A statement that a macro such as EXPECT_DEATH would test
-//                for program termination. This macro has to make sure this
-//                statement is compiled but not executed, to ensure that
-//                EXPECT_DEATH_IF_SUPPORTED compiles with a certain
-//                parameter if and only if EXPECT_DEATH compiles with it.
-//   regex     -  A regex that a macro such as EXPECT_DEATH would use to test
-//                the output of statement.  This parameter has to be
-//                compiled but not evaluated by this macro, to ensure that
-//                this macro only accepts expressions that a macro such as
-//                EXPECT_DEATH would accept.
-//   terminator - Must be an empty statement for EXPECT_DEATH_IF_SUPPORTED
-//                and a return statement for ASSERT_DEATH_IF_SUPPORTED.
-//                This ensures that ASSERT_DEATH_IF_SUPPORTED will not
-//                compile inside functions where ASSERT_DEATH doesn't
-//                compile.
-//
-//  The branch that has an always false condition is used to ensure that
-//  statement and regex are compiled (and thus syntactically correct) but
-//  never executed. The unreachable code macro protects the terminator
-//  statement from generating an 'unreachable code' warning in case
-//  statement unconditionally returns or throws. The Message constructor at
-//  the end allows the syntax of streaming additional messages into the
-//  macro, for compilational compatibility with EXPECT_DEATH/ASSERT_DEATH.
-# define GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, terminator) \
-    GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
-    if (::testing::internal::AlwaysTrue()) { \
-      GTEST_LOG_(WARNING) \
-          << "Death tests are not supported on this platform.\n" \
-          << "Statement '" #statement "' cannot be verified."; \
-    } else if (::testing::internal::AlwaysFalse()) { \
-      ::testing::internal::RE::PartialMatch(".*", (regex)); \
-      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
-      terminator; \
-    } else \
-      ::testing::Message()
-
-// EXPECT_DEATH_IF_SUPPORTED(statement, regex) and
-// ASSERT_DEATH_IF_SUPPORTED(statement, regex) expand to real death tests if
-// death tests are supported; otherwise they just issue a warning.  This is
-// useful when you are combining death test assertions with normal test
-// assertions in one test.
-#if GTEST_HAS_DEATH_TEST
-# define EXPECT_DEATH_IF_SUPPORTED(statement, regex) \
-    EXPECT_DEATH(statement, regex)
-# define ASSERT_DEATH_IF_SUPPORTED(statement, regex) \
-    ASSERT_DEATH(statement, regex)
-#else
-# define EXPECT_DEATH_IF_SUPPORTED(statement, regex) \
-    GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, )
-# define ASSERT_DEATH_IF_SUPPORTED(statement, regex) \
-    GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, return)
-#endif
-
-}  // namespace testing
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
-// Copyright 2008, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// Macros and functions for implementing parameterized tests
-// in Google C++ Testing and Mocking Framework (Google Test)
-//
-// GOOGLETEST_CM0001 DO NOT DELETE
-#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PARAM_TEST_H_
-#define GOOGLETEST_INCLUDE_GTEST_GTEST_PARAM_TEST_H_
-
-// Value-parameterized tests allow you to test your code with different
-// parameters without writing multiple copies of the same test.
-//
-// Here is how you use value-parameterized tests:
-
-#if 0
-
-// To write value-parameterized tests, first you should define a fixture
-// class. It is usually derived from testing::TestWithParam<T> (see below for
-// another inheritance scheme that's sometimes useful in more complicated
-// class hierarchies), where the type of your parameter values.
-// TestWithParam<T> is itself derived from testing::Test. T can be any
-// copyable type. If it's a raw pointer, you are responsible for managing the
-// lifespan of the pointed values.
-
-class FooTest : public ::testing::TestWithParam<const char*> {
-  // You can implement all the usual class fixture members here.
-};
-
-// Then, use the TEST_P macro to define as many parameterized tests
-// for this fixture as you want. The _P suffix is for "parameterized"
-// or "pattern", whichever you prefer to think.
-
-TEST_P(FooTest, DoesBlah) {
-  // Inside a test, access the test parameter with the GetParam() method
-  // of the TestWithParam<T> class:
-  EXPECT_TRUE(foo.Blah(GetParam()));
-  ...
-}
-
-TEST_P(FooTest, HasBlahBlah) {
-  ...
-}
-
-// Finally, you can use INSTANTIATE_TEST_SUITE_P to instantiate the test
-// case with any set of parameters you want. Google Test defines a number
-// of functions for generating test parameters. They return what we call
-// (surprise!) parameter generators. Here is a summary of them, which
-// are all in the testing namespace:
-//
-//
-//  Range(begin, end [, step]) - Yields values {begin, begin+step,
-//                               begin+step+step, ...}. The values do not
-//                               include end. step defaults to 1.
-//  Values(v1, v2, ..., vN)    - Yields values {v1, v2, ..., vN}.
-//  ValuesIn(container)        - Yields values from a C-style array, an STL
-//  ValuesIn(begin,end)          container, or an iterator range [begin, end).
-//  Bool()                     - Yields sequence {false, true}.
-//  Combine(g1, g2, ..., gN)   - Yields all combinations (the Cartesian product
-//                               for the math savvy) of the values generated
-//                               by the N generators.
-//
-// For more details, see comments at the definitions of these functions below
-// in this file.
-//
-// The following statement will instantiate tests from the FooTest test suite
-// each with parameter values "meeny", "miny", and "moe".
-
-INSTANTIATE_TEST_SUITE_P(InstantiationName,
-                         FooTest,
-                         Values("meeny", "miny", "moe"));
-
-// To distinguish different instances of the pattern, (yes, you
-// can instantiate it more than once) the first argument to the
-// INSTANTIATE_TEST_SUITE_P macro is a prefix that will be added to the
-// actual test suite name. Remember to pick unique prefixes for different
-// instantiations. The tests from the instantiation above will have
-// these names:
-//
-//    * InstantiationName/FooTest.DoesBlah/0 for "meeny"
-//    * InstantiationName/FooTest.DoesBlah/1 for "miny"
-//    * InstantiationName/FooTest.DoesBlah/2 for "moe"
-//    * InstantiationName/FooTest.HasBlahBlah/0 for "meeny"
-//    * InstantiationName/FooTest.HasBlahBlah/1 for "miny"
-//    * InstantiationName/FooTest.HasBlahBlah/2 for "moe"
-//
-// You can use these names in --gtest_filter.
-//
-// This statement will instantiate all tests from FooTest again, each
-// with parameter values "cat" and "dog":
-
-const char* pets[] = {"cat", "dog"};
-INSTANTIATE_TEST_SUITE_P(AnotherInstantiationName, FooTest, ValuesIn(pets));
-
-// The tests from the instantiation above will have these names:
-//
-//    * AnotherInstantiationName/FooTest.DoesBlah/0 for "cat"
-//    * AnotherInstantiationName/FooTest.DoesBlah/1 for "dog"
-//    * AnotherInstantiationName/FooTest.HasBlahBlah/0 for "cat"
-//    * AnotherInstantiationName/FooTest.HasBlahBlah/1 for "dog"
-//
-// Please note that INSTANTIATE_TEST_SUITE_P will instantiate all tests
-// in the given test suite, whether their definitions come before or
-// AFTER the INSTANTIATE_TEST_SUITE_P statement.
-//
-// Please also note that generator expressions (including parameters to the
-// generators) are evaluated in InitGoogleTest(), after main() has started.
-// This allows the user on one hand, to adjust generator parameters in order
-// to dynamically determine a set of tests to run and on the other hand,
-// give the user a chance to inspect the generated tests with Google Test
-// reflection API before RUN_ALL_TESTS() is executed.
-//
-// You can see samples/sample7_unittest.cc and samples/sample8_unittest.cc
-// for more examples.
-//
-// In the future, we plan to publish the API for defining new parameter
-// generators. But for now this interface remains part of the internal
-// implementation and is subject to change.
-//
-//
-// A parameterized test fixture must be derived from testing::Test and from
-// testing::WithParamInterface<T>, where T is the type of the parameter
-// values. Inheriting from TestWithParam<T> satisfies that requirement because
-// TestWithParam<T> inherits from both Test and WithParamInterface. In more
-// complicated hierarchies, however, it is occasionally useful to inherit
-// separately from Test and WithParamInterface. For example:
-
-class BaseTest : public ::testing::Test {
-  // You can inherit all the usual members for a non-parameterized test
-  // fixture here.
-};
-
-class DerivedTest : public BaseTest, public ::testing::WithParamInterface<int> {
-  // The usual test fixture members go here too.
-};
-
-TEST_F(BaseTest, HasFoo) {
-  // This is an ordinary non-parameterized test.
-}
-
-TEST_P(DerivedTest, DoesBlah) {
-  // GetParam works just the same here as if you inherit from TestWithParam.
-  EXPECT_TRUE(foo.Blah(GetParam()));
-}
-
-#endif  // 0
-
-#include <iterator>
-#include <utility>
-
-// Copyright 2008 Google Inc.
-// All Rights Reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-// Type and function utilities for implementing parameterized tests.
-
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
-#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
-
-#include <ctype.h>
-
-#include <cassert>
-#include <iterator>
-#include <memory>
-#include <set>
-#include <tuple>
-#include <type_traits>
-#include <utility>
-#include <vector>
-
-// Copyright 2008, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_TEST_PART_H_
-#define GOOGLETEST_INCLUDE_GTEST_GTEST_TEST_PART_H_
-
-#include <iosfwd>
-#include <vector>
-
-GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
-/* class A needs to have dll-interface to be used by clients of class B */)
-
-namespace testing {
-
-// A copyable object representing the result of a test part (i.e. an
-// assertion or an explicit FAIL(), ADD_FAILURE(), or SUCCESS()).
-//
-// Don't inherit from TestPartResult as its destructor is not virtual.
-class GTEST_API_ TestPartResult {
- public:
-  // The possible outcomes of a test part (i.e. an assertion or an
-  // explicit SUCCEED(), FAIL(), or ADD_FAILURE()).
-  enum Type {
-    kSuccess,          // Succeeded.
-    kNonFatalFailure,  // Failed but the test can continue.
-    kFatalFailure,     // Failed and the test should be terminated.
-    kSkip              // Skipped.
-  };
-
-  // C'tor.  TestPartResult does NOT have a default constructor.
-  // Always use this constructor (with parameters) to create a
-  // TestPartResult object.
-  TestPartResult(Type a_type, const char* a_file_name, int a_line_number,
-                 const char* a_message)
-      : type_(a_type),
-        file_name_(a_file_name == nullptr ? "" : a_file_name),
-        line_number_(a_line_number),
-        summary_(ExtractSummary(a_message)),
-        message_(a_message) {}
-
-  // Gets the outcome of the test part.
-  Type type() const { return type_; }
-
-  // Gets the name of the source file where the test part took place, or
-  // NULL if it's unknown.
-  const char* file_name() const {
-    return file_name_.empty() ? nullptr : file_name_.c_str();
-  }
-
-  // Gets the line in the source file where the test part took place,
-  // or -1 if it's unknown.
-  int line_number() const { return line_number_; }
-
-  // Gets the summary of the failure message.
-  const char* summary() const { return summary_.c_str(); }
-
-  // Gets the message associated with the test part.
-  const char* message() const { return message_.c_str(); }
-
-  // Returns true if and only if the test part was skipped.
-  bool skipped() const { return type_ == kSkip; }
-
-  // Returns true if and only if the test part passed.
-  bool passed() const { return type_ == kSuccess; }
-
-  // Returns true if and only if the test part non-fatally failed.
-  bool nonfatally_failed() const { return type_ == kNonFatalFailure; }
-
-  // Returns true if and only if the test part fatally failed.
-  bool fatally_failed() const { return type_ == kFatalFailure; }
-
-  // Returns true if and only if the test part failed.
-  bool failed() const { return fatally_failed() || nonfatally_failed(); }
-
- private:
-  Type type_;
-
-  // Gets the summary of the failure message by omitting the stack
-  // trace in it.
-  static std::string ExtractSummary(const char* message);
-
-  // The name of the source file where the test part took place, or
-  // "" if the source file is unknown.
-  std::string file_name_;
-  // The line in the source file where the test part took place, or -1
-  // if the line number is unknown.
-  int line_number_;
-  std::string summary_;  // The test failure summary.
-  std::string message_;  // The test failure message.
-};
-
-// Prints a TestPartResult object.
-std::ostream& operator<<(std::ostream& os, const TestPartResult& result);
-
-// An array of TestPartResult objects.
-//
-// Don't inherit from TestPartResultArray as its destructor is not
-// virtual.
-class GTEST_API_ TestPartResultArray {
- public:
-  TestPartResultArray() {}
-
-  // Appends the given TestPartResult to the array.
-  void Append(const TestPartResult& result);
-
-  // Returns the TestPartResult at the given index (0-based).
-  const TestPartResult& GetTestPartResult(int index) const;
-
-  // Returns the number of TestPartResult objects in the array.
-  int size() const;
-
- private:
-  std::vector<TestPartResult> array_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestPartResultArray);
-};
-
-// This interface knows how to report a test part result.
-class GTEST_API_ TestPartResultReporterInterface {
- public:
-  virtual ~TestPartResultReporterInterface() {}
-
-  virtual void ReportTestPartResult(const TestPartResult& result) = 0;
-};
-
-namespace internal {
-
-// This helper class is used by {ASSERT|EXPECT}_NO_FATAL_FAILURE to check if a
-// statement generates new fatal failures. To do so it registers itself as the
-// current test part result reporter. Besides checking if fatal failures were
-// reported, it only delegates the reporting to the former result reporter.
-// The original result reporter is restored in the destructor.
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-class GTEST_API_ HasNewFatalFailureHelper
-    : public TestPartResultReporterInterface {
- public:
-  HasNewFatalFailureHelper();
-  ~HasNewFatalFailureHelper() override;
-  void ReportTestPartResult(const TestPartResult& result) override;
-  bool has_new_fatal_failure() const { return has_new_fatal_failure_; }
- private:
-  bool has_new_fatal_failure_;
-  TestPartResultReporterInterface* original_reporter_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(HasNewFatalFailureHelper);
-};
-
-}  // namespace internal
-
-}  // namespace testing
-
-GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_TEST_PART_H_
-
-namespace testing {
-// Input to a parameterized test name generator, describing a test parameter.
-// Consists of the parameter value and the integer parameter index.
-template <class ParamType>
-struct TestParamInfo {
-  TestParamInfo(const ParamType& a_param, size_t an_index) :
-    param(a_param),
-    index(an_index) {}
-  ParamType param;
-  size_t index;
-};
-
-// A builtin parameterized test name generator which returns the result of
-// testing::PrintToString.
-struct PrintToStringParamName {
-  template <class ParamType>
-  std::string operator()(const TestParamInfo<ParamType>& info) const {
-    return PrintToString(info.param);
-  }
-};
-
-namespace internal {
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-// Utility Functions
-
-// Outputs a message explaining invalid registration of different
-// fixture class for the same test suite. This may happen when
-// TEST_P macro is used to define two tests with the same name
-// but in different namespaces.
-GTEST_API_ void ReportInvalidTestSuiteType(const char* test_suite_name,
-                                           CodeLocation code_location);
-
-template <typename> class ParamGeneratorInterface;
-template <typename> class ParamGenerator;
-
-// Interface for iterating over elements provided by an implementation
-// of ParamGeneratorInterface<T>.
-template <typename T>
-class ParamIteratorInterface {
- public:
-  virtual ~ParamIteratorInterface() {}
-  // A pointer to the base generator instance.
-  // Used only for the purposes of iterator comparison
-  // to make sure that two iterators belong to the same generator.
-  virtual const ParamGeneratorInterface<T>* BaseGenerator() const = 0;
-  // Advances iterator to point to the next element
-  // provided by the generator. The caller is responsible
-  // for not calling Advance() on an iterator equal to
-  // BaseGenerator()->End().
-  virtual void Advance() = 0;
-  // Clones the iterator object. Used for implementing copy semantics
-  // of ParamIterator<T>.
-  virtual ParamIteratorInterface* Clone() const = 0;
-  // Dereferences the current iterator and provides (read-only) access
-  // to the pointed value. It is the caller's responsibility not to call
-  // Current() on an iterator equal to BaseGenerator()->End().
-  // Used for implementing ParamGenerator<T>::operator*().
-  virtual const T* Current() const = 0;
-  // Determines whether the given iterator and other point to the same
-  // element in the sequence generated by the generator.
-  // Used for implementing ParamGenerator<T>::operator==().
-  virtual bool Equals(const ParamIteratorInterface& other) const = 0;
-};
-
-// Class iterating over elements provided by an implementation of
-// ParamGeneratorInterface<T>. It wraps ParamIteratorInterface<T>
-// and implements the const forward iterator concept.
-template <typename T>
-class ParamIterator {
- public:
-  typedef T value_type;
-  typedef const T& reference;
-  typedef ptrdiff_t difference_type;
-
-  // ParamIterator assumes ownership of the impl_ pointer.
-  ParamIterator(const ParamIterator& other) : impl_(other.impl_->Clone()) {}
-  ParamIterator& operator=(const ParamIterator& other) {
-    if (this != &other)
-      impl_.reset(other.impl_->Clone());
-    return *this;
-  }
-
-  const T& operator*() const { return *impl_->Current(); }
-  const T* operator->() const { return impl_->Current(); }
-  // Prefix version of operator++.
-  ParamIterator& operator++() {
-    impl_->Advance();
-    return *this;
-  }
-  // Postfix version of operator++.
-  ParamIterator operator++(int /*unused*/) {
-    ParamIteratorInterface<T>* clone = impl_->Clone();
-    impl_->Advance();
-    return ParamIterator(clone);
-  }
-  bool operator==(const ParamIterator& other) const {
-    return impl_.get() == other.impl_.get() || impl_->Equals(*other.impl_);
-  }
-  bool operator!=(const ParamIterator& other) const {
-    return !(*this == other);
-  }
-
- private:
-  friend class ParamGenerator<T>;
-  explicit ParamIterator(ParamIteratorInterface<T>* impl) : impl_(impl) {}
-  std::unique_ptr<ParamIteratorInterface<T> > impl_;
-};
-
-// ParamGeneratorInterface<T> is the binary interface to access generators
-// defined in other translation units.
-template <typename T>
-class ParamGeneratorInterface {
- public:
-  typedef T ParamType;
-
-  virtual ~ParamGeneratorInterface() {}
-
-  // Generator interface definition
-  virtual ParamIteratorInterface<T>* Begin() const = 0;
-  virtual ParamIteratorInterface<T>* End() const = 0;
-};
-
-// Wraps ParamGeneratorInterface<T> and provides general generator syntax
-// compatible with the STL Container concept.
-// This class implements copy initialization semantics and the contained
-// ParamGeneratorInterface<T> instance is shared among all copies
-// of the original object. This is possible because that instance is immutable.
-template<typename T>
-class ParamGenerator {
- public:
-  typedef ParamIterator<T> iterator;
-
-  explicit ParamGenerator(ParamGeneratorInterface<T>* impl) : impl_(impl) {}
-  ParamGenerator(const ParamGenerator& other) : impl_(other.impl_) {}
-
-  ParamGenerator& operator=(const ParamGenerator& other) {
-    impl_ = other.impl_;
-    return *this;
-  }
-
-  iterator begin() const { return iterator(impl_->Begin()); }
-  iterator end() const { return iterator(impl_->End()); }
-
- private:
-  std::shared_ptr<const ParamGeneratorInterface<T> > impl_;
-};
-
-// Generates values from a range of two comparable values. Can be used to
-// generate sequences of user-defined types that implement operator+() and
-// operator<().
-// This class is used in the Range() function.
-template <typename T, typename IncrementT>
-class RangeGenerator : public ParamGeneratorInterface<T> {
- public:
-  RangeGenerator(T begin, T end, IncrementT step)
-      : begin_(begin), end_(end),
-        step_(step), end_index_(CalculateEndIndex(begin, end, step)) {}
-  ~RangeGenerator() override {}
-
-  ParamIteratorInterface<T>* Begin() const override {
-    return new Iterator(this, begin_, 0, step_);
-  }
-  ParamIteratorInterface<T>* End() const override {
-    return new Iterator(this, end_, end_index_, step_);
-  }
-
- private:
-  class Iterator : public ParamIteratorInterface<T> {
-   public:
-    Iterator(const ParamGeneratorInterface<T>* base, T value, int index,
-             IncrementT step)
-        : base_(base), value_(value), index_(index), step_(step) {}
-    ~Iterator() override {}
-
-    const ParamGeneratorInterface<T>* BaseGenerator() const override {
-      return base_;
-    }
-    void Advance() override {
-      value_ = static_cast<T>(value_ + step_);
-      index_++;
-    }
-    ParamIteratorInterface<T>* Clone() const override {
-      return new Iterator(*this);
-    }
-    const T* Current() const override { return &value_; }
-    bool Equals(const ParamIteratorInterface<T>& other) const override {
-      // Having the same base generator guarantees that the other
-      // iterator is of the same type and we can downcast.
-      GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
-          << "The program attempted to compare iterators "
-          << "from different generators." << std::endl;
-      const int other_index =
-          CheckedDowncastToActualType<const Iterator>(&other)->index_;
-      return index_ == other_index;
-    }
-
-   private:
-    Iterator(const Iterator& other)
-        : ParamIteratorInterface<T>(),
-          base_(other.base_), value_(other.value_), index_(other.index_),
-          step_(other.step_) {}
-
-    // No implementation - assignment is unsupported.
-    void operator=(const Iterator& other);
-
-    const ParamGeneratorInterface<T>* const base_;
-    T value_;
-    int index_;
-    const IncrementT step_;
-  };  // class RangeGenerator::Iterator
-
-  static int CalculateEndIndex(const T& begin,
-                               const T& end,
-                               const IncrementT& step) {
-    int end_index = 0;
-    for (T i = begin; i < end; i = static_cast<T>(i + step))
-      end_index++;
-    return end_index;
-  }
-
-  // No implementation - assignment is unsupported.
-  void operator=(const RangeGenerator& other);
-
-  const T begin_;
-  const T end_;
-  const IncrementT step_;
-  // The index for the end() iterator. All the elements in the generated
-  // sequence are indexed (0-based) to aid iterator comparison.
-  const int end_index_;
-};  // class RangeGenerator
-
-
-// Generates values from a pair of STL-style iterators. Used in the
-// ValuesIn() function. The elements are copied from the source range
-// since the source can be located on the stack, and the generator
-// is likely to persist beyond that stack frame.
-template <typename T>
-class ValuesInIteratorRangeGenerator : public ParamGeneratorInterface<T> {
- public:
-  template <typename ForwardIterator>
-  ValuesInIteratorRangeGenerator(ForwardIterator begin, ForwardIterator end)
-      : container_(begin, end) {}
-  ~ValuesInIteratorRangeGenerator() override {}
-
-  ParamIteratorInterface<T>* Begin() const override {
-    return new Iterator(this, container_.begin());
-  }
-  ParamIteratorInterface<T>* End() const override {
-    return new Iterator(this, container_.end());
-  }
-
- private:
-  typedef typename ::std::vector<T> ContainerType;
-
-  class Iterator : public ParamIteratorInterface<T> {
-   public:
-    Iterator(const ParamGeneratorInterface<T>* base,
-             typename ContainerType::const_iterator iterator)
-        : base_(base), iterator_(iterator) {}
-    ~Iterator() override {}
-
-    const ParamGeneratorInterface<T>* BaseGenerator() const override {
-      return base_;
-    }
-    void Advance() override {
-      ++iterator_;
-      value_.reset();
-    }
-    ParamIteratorInterface<T>* Clone() const override {
-      return new Iterator(*this);
-    }
-    // We need to use cached value referenced by iterator_ because *iterator_
-    // can return a temporary object (and of type other then T), so just
-    // having "return &*iterator_;" doesn't work.
-    // value_ is updated here and not in Advance() because Advance()
-    // can advance iterator_ beyond the end of the range, and we cannot
-    // detect that fact. The client code, on the other hand, is
-    // responsible for not calling Current() on an out-of-range iterator.
-    const T* Current() const override {
-      if (value_.get() == nullptr) value_.reset(new T(*iterator_));
-      return value_.get();
-    }
-    bool Equals(const ParamIteratorInterface<T>& other) const override {
-      // Having the same base generator guarantees that the other
-      // iterator is of the same type and we can downcast.
-      GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
-          << "The program attempted to compare iterators "
-          << "from different generators." << std::endl;
-      return iterator_ ==
-          CheckedDowncastToActualType<const Iterator>(&other)->iterator_;
-    }
-
-   private:
-    Iterator(const Iterator& other)
-          // The explicit constructor call suppresses a false warning
-          // emitted by gcc when supplied with the -Wextra option.
-        : ParamIteratorInterface<T>(),
-          base_(other.base_),
-          iterator_(other.iterator_) {}
-
-    const ParamGeneratorInterface<T>* const base_;
-    typename ContainerType::const_iterator iterator_;
-    // A cached value of *iterator_. We keep it here to allow access by
-    // pointer in the wrapping iterator's operator->().
-    // value_ needs to be mutable to be accessed in Current().
-    // Use of std::unique_ptr helps manage cached value's lifetime,
-    // which is bound by the lifespan of the iterator itself.
-    mutable std::unique_ptr<const T> value_;
-  };  // class ValuesInIteratorRangeGenerator::Iterator
-
-  // No implementation - assignment is unsupported.
-  void operator=(const ValuesInIteratorRangeGenerator& other);
-
-  const ContainerType container_;
-};  // class ValuesInIteratorRangeGenerator
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// Default parameterized test name generator, returns a string containing the
-// integer test parameter index.
-template <class ParamType>
-std::string DefaultParamName(const TestParamInfo<ParamType>& info) {
-  Message name_stream;
-  name_stream << info.index;
-  return name_stream.GetString();
-}
-
-template <typename T = int>
-void TestNotEmpty() {
-  static_assert(sizeof(T) == 0, "Empty arguments are not allowed.");
-}
-template <typename T = int>
-void TestNotEmpty(const T&) {}
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// Stores a parameter value and later creates tests parameterized with that
-// value.
-template <class TestClass>
-class ParameterizedTestFactory : public TestFactoryBase {
- public:
-  typedef typename TestClass::ParamType ParamType;
-  explicit ParameterizedTestFactory(ParamType parameter) :
-      parameter_(parameter) {}
-  Test* CreateTest() override {
-    TestClass::SetParam(&parameter_);
-    return new TestClass();
-  }
-
- private:
-  const ParamType parameter_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestFactory);
-};
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// TestMetaFactoryBase is a base class for meta-factories that create
-// test factories for passing into MakeAndRegisterTestInfo function.
-template <class ParamType>
-class TestMetaFactoryBase {
- public:
-  virtual ~TestMetaFactoryBase() {}
-
-  virtual TestFactoryBase* CreateTestFactory(ParamType parameter) = 0;
-};
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// TestMetaFactory creates test factories for passing into
-// MakeAndRegisterTestInfo function. Since MakeAndRegisterTestInfo receives
-// ownership of test factory pointer, same factory object cannot be passed
-// into that method twice. But ParameterizedTestSuiteInfo is going to call
-// it for each Test/Parameter value combination. Thus it needs meta factory
-// creator class.
-template <class TestSuite>
-class TestMetaFactory
-    : public TestMetaFactoryBase<typename TestSuite::ParamType> {
- public:
-  using ParamType = typename TestSuite::ParamType;
-
-  TestMetaFactory() {}
-
-  TestFactoryBase* CreateTestFactory(ParamType parameter) override {
-    return new ParameterizedTestFactory<TestSuite>(parameter);
-  }
-
- private:
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestMetaFactory);
-};
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// ParameterizedTestSuiteInfoBase is a generic interface
-// to ParameterizedTestSuiteInfo classes. ParameterizedTestSuiteInfoBase
-// accumulates test information provided by TEST_P macro invocations
-// and generators provided by INSTANTIATE_TEST_SUITE_P macro invocations
-// and uses that information to register all resulting test instances
-// in RegisterTests method. The ParameterizeTestSuiteRegistry class holds
-// a collection of pointers to the ParameterizedTestSuiteInfo objects
-// and calls RegisterTests() on each of them when asked.
-class ParameterizedTestSuiteInfoBase {
- public:
-  virtual ~ParameterizedTestSuiteInfoBase() {}
-
-  // Base part of test suite name for display purposes.
-  virtual const std::string& GetTestSuiteName() const = 0;
-  // Test suite id to verify identity.
-  virtual TypeId GetTestSuiteTypeId() const = 0;
-  // UnitTest class invokes this method to register tests in this
-  // test suite right before running them in RUN_ALL_TESTS macro.
-  // This method should not be called more than once on any single
-  // instance of a ParameterizedTestSuiteInfoBase derived class.
-  virtual void RegisterTests() = 0;
-
- protected:
-  ParameterizedTestSuiteInfoBase() {}
-
- private:
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestSuiteInfoBase);
-};
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// Report a the name of a test_suit as safe to ignore
-// as the side effect of construction of this type.
-struct GTEST_API_ MarkAsIgnored {
-  explicit MarkAsIgnored(const char* test_suite);
-};
-
-GTEST_API_ void InsertSyntheticTestCase(const std::string& name,
-                                        CodeLocation location, bool has_test_p);
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// ParameterizedTestSuiteInfo accumulates tests obtained from TEST_P
-// macro invocations for a particular test suite and generators
-// obtained from INSTANTIATE_TEST_SUITE_P macro invocations for that
-// test suite. It registers tests with all values generated by all
-// generators when asked.
-template <class TestSuite>
-class ParameterizedTestSuiteInfo : public ParameterizedTestSuiteInfoBase {
- public:
-  // ParamType and GeneratorCreationFunc are private types but are required
-  // for declarations of public methods AddTestPattern() and
-  // AddTestSuiteInstantiation().
-  using ParamType = typename TestSuite::ParamType;
-  // A function that returns an instance of appropriate generator type.
-  typedef ParamGenerator<ParamType>(GeneratorCreationFunc)();
-  using ParamNameGeneratorFunc = std::string(const TestParamInfo<ParamType>&);
-
-  explicit ParameterizedTestSuiteInfo(const char* name,
-                                      CodeLocation code_location)
-      : test_suite_name_(name), code_location_(code_location) {}
-
-  // Test suite base name for display purposes.
-  const std::string& GetTestSuiteName() const override {
-    return test_suite_name_;
-  }
-  // Test suite id to verify identity.
-  TypeId GetTestSuiteTypeId() const override { return GetTypeId<TestSuite>(); }
-  // TEST_P macro uses AddTestPattern() to record information
-  // about a single test in a LocalTestInfo structure.
-  // test_suite_name is the base name of the test suite (without invocation
-  // prefix). test_base_name is the name of an individual test without
-  // parameter index. For the test SequenceA/FooTest.DoBar/1 FooTest is
-  // test suite base name and DoBar is test base name.
-  void AddTestPattern(const char* test_suite_name, const char* test_base_name,
-                      TestMetaFactoryBase<ParamType>* meta_factory,
-                      CodeLocation code_location) {
-    tests_.push_back(std::shared_ptr<TestInfo>(new TestInfo(
-        test_suite_name, test_base_name, meta_factory, code_location)));
-  }
-  // INSTANTIATE_TEST_SUITE_P macro uses AddGenerator() to record information
-  // about a generator.
-  int AddTestSuiteInstantiation(const std::string& instantiation_name,
-                                GeneratorCreationFunc* func,
-                                ParamNameGeneratorFunc* name_func,
-                                const char* file, int line) {
-    instantiations_.push_back(
-        InstantiationInfo(instantiation_name, func, name_func, file, line));
-    return 0;  // Return value used only to run this method in namespace scope.
-  }
-  // UnitTest class invokes this method to register tests in this test suite
-  // right before running tests in RUN_ALL_TESTS macro.
-  // This method should not be called more than once on any single
-  // instance of a ParameterizedTestSuiteInfoBase derived class.
-  // UnitTest has a guard to prevent from calling this method more than once.
-  void RegisterTests() override {
-    bool generated_instantiations = false;
-
-    for (typename TestInfoContainer::iterator test_it = tests_.begin();
-         test_it != tests_.end(); ++test_it) {
-      std::shared_ptr<TestInfo> test_info = *test_it;
-      for (typename InstantiationContainer::iterator gen_it =
-               instantiations_.begin(); gen_it != instantiations_.end();
-               ++gen_it) {
-        const std::string& instantiation_name = gen_it->name;
-        ParamGenerator<ParamType> generator((*gen_it->generator)());
-        ParamNameGeneratorFunc* name_func = gen_it->name_func;
-        const char* file = gen_it->file;
-        int line = gen_it->line;
-
-        std::string test_suite_name;
-        if ( !instantiation_name.empty() )
-          test_suite_name = instantiation_name + "/";
-        test_suite_name += test_info->test_suite_base_name;
-
-        size_t i = 0;
-        std::set<std::string> test_param_names;
-        for (typename ParamGenerator<ParamType>::iterator param_it =
-                 generator.begin();
-             param_it != generator.end(); ++param_it, ++i) {
-          generated_instantiations = true;
-
-          Message test_name_stream;
-
-          std::string param_name = name_func(
-              TestParamInfo<ParamType>(*param_it, i));
-
-          GTEST_CHECK_(IsValidParamName(param_name))
-              << "Parameterized test name '" << param_name
-              << "' is invalid, in " << file
-              << " line " << line << std::endl;
-
-          GTEST_CHECK_(test_param_names.count(param_name) == 0)
-              << "Duplicate parameterized test name '" << param_name
-              << "', in " << file << " line " << line << std::endl;
-
-          test_param_names.insert(param_name);
-
-          if (!test_info->test_base_name.empty()) {
-            test_name_stream << test_info->test_base_name << "/";
-          }
-          test_name_stream << param_name;
-          MakeAndRegisterTestInfo(
-              test_suite_name.c_str(), test_name_stream.GetString().c_str(),
-              nullptr,  // No type parameter.
-              PrintToString(*param_it).c_str(), test_info->code_location,
-              GetTestSuiteTypeId(),
-              SuiteApiResolver<TestSuite>::GetSetUpCaseOrSuite(file, line),
-              SuiteApiResolver<TestSuite>::GetTearDownCaseOrSuite(file, line),
-              test_info->test_meta_factory->CreateTestFactory(*param_it));
-        }  // for param_it
-      }  // for gen_it
-    }  // for test_it
-
-    if (!generated_instantiations) {
-      // There are no generaotrs, or they all generate nothing ...
-      InsertSyntheticTestCase(GetTestSuiteName(), code_location_,
-                              !tests_.empty());
-    }
-  }    // RegisterTests
-
- private:
-  // LocalTestInfo structure keeps information about a single test registered
-  // with TEST_P macro.
-  struct TestInfo {
-    TestInfo(const char* a_test_suite_base_name, const char* a_test_base_name,
-             TestMetaFactoryBase<ParamType>* a_test_meta_factory,
-             CodeLocation a_code_location)
-        : test_suite_base_name(a_test_suite_base_name),
-          test_base_name(a_test_base_name),
-          test_meta_factory(a_test_meta_factory),
-          code_location(a_code_location) {}
-
-    const std::string test_suite_base_name;
-    const std::string test_base_name;
-    const std::unique_ptr<TestMetaFactoryBase<ParamType> > test_meta_factory;
-    const CodeLocation code_location;
-  };
-  using TestInfoContainer = ::std::vector<std::shared_ptr<TestInfo> >;
-  // Records data received from INSTANTIATE_TEST_SUITE_P macros:
-  //  <Instantiation name, Sequence generator creation function,
-  //     Name generator function, Source file, Source line>
-  struct InstantiationInfo {
-      InstantiationInfo(const std::string &name_in,
-                        GeneratorCreationFunc* generator_in,
-                        ParamNameGeneratorFunc* name_func_in,
-                        const char* file_in,
-                        int line_in)
-          : name(name_in),
-            generator(generator_in),
-            name_func(name_func_in),
-            file(file_in),
-            line(line_in) {}
-
-      std::string name;
-      GeneratorCreationFunc* generator;
-      ParamNameGeneratorFunc* name_func;
-      const char* file;
-      int line;
-  };
-  typedef ::std::vector<InstantiationInfo> InstantiationContainer;
-
-  static bool IsValidParamName(const std::string& name) {
-    // Check for empty string
-    if (name.empty())
-      return false;
-
-    // Check for invalid characters
-    for (std::string::size_type index = 0; index < name.size(); ++index) {
-      if (!IsAlNum(name[index]) && name[index] != '_')
-        return false;
-    }
-
-    return true;
-  }
-
-  const std::string test_suite_name_;
-  CodeLocation code_location_;
-  TestInfoContainer tests_;
-  InstantiationContainer instantiations_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestSuiteInfo);
-};  // class ParameterizedTestSuiteInfo
-
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-template <class TestCase>
-using ParameterizedTestCaseInfo = ParameterizedTestSuiteInfo<TestCase>;
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// ParameterizedTestSuiteRegistry contains a map of
-// ParameterizedTestSuiteInfoBase classes accessed by test suite names. TEST_P
-// and INSTANTIATE_TEST_SUITE_P macros use it to locate their corresponding
-// ParameterizedTestSuiteInfo descriptors.
-class ParameterizedTestSuiteRegistry {
- public:
-  ParameterizedTestSuiteRegistry() {}
-  ~ParameterizedTestSuiteRegistry() {
-    for (auto& test_suite_info : test_suite_infos_) {
-      delete test_suite_info;
-    }
-  }
-
-  // Looks up or creates and returns a structure containing information about
-  // tests and instantiations of a particular test suite.
-  template <class TestSuite>
-  ParameterizedTestSuiteInfo<TestSuite>* GetTestSuitePatternHolder(
-      const char* test_suite_name, CodeLocation code_location) {
-    ParameterizedTestSuiteInfo<TestSuite>* typed_test_info = nullptr;
-    for (auto& test_suite_info : test_suite_infos_) {
-      if (test_suite_info->GetTestSuiteName() == test_suite_name) {
-        if (test_suite_info->GetTestSuiteTypeId() != GetTypeId<TestSuite>()) {
-          // Complain about incorrect usage of Google Test facilities
-          // and terminate the program since we cannot guaranty correct
-          // test suite setup and tear-down in this case.
-          ReportInvalidTestSuiteType(test_suite_name, code_location);
-          posix::Abort();
-        } else {
-          // At this point we are sure that the object we found is of the same
-          // type we are looking for, so we downcast it to that type
-          // without further checks.
-          typed_test_info = CheckedDowncastToActualType<
-              ParameterizedTestSuiteInfo<TestSuite> >(test_suite_info);
-        }
-        break;
-      }
-    }
-    if (typed_test_info == nullptr) {
-      typed_test_info = new ParameterizedTestSuiteInfo<TestSuite>(
-          test_suite_name, code_location);
-      test_suite_infos_.push_back(typed_test_info);
-    }
-    return typed_test_info;
-  }
-  void RegisterTests() {
-    for (auto& test_suite_info : test_suite_infos_) {
-      test_suite_info->RegisterTests();
-    }
-  }
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  template <class TestCase>
-  ParameterizedTestCaseInfo<TestCase>* GetTestCasePatternHolder(
-      const char* test_case_name, CodeLocation code_location) {
-    return GetTestSuitePatternHolder<TestCase>(test_case_name, code_location);
-  }
-
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
- private:
-  using TestSuiteInfoContainer = ::std::vector<ParameterizedTestSuiteInfoBase*>;
-
-  TestSuiteInfoContainer test_suite_infos_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestSuiteRegistry);
-};
-
-// Keep track of what type-parameterized test suite are defined and
-// where as well as which are intatiated. This allows susequently
-// identifying suits that are defined but never used.
-class TypeParameterizedTestSuiteRegistry {
- public:
-  // Add a suite definition
-  void RegisterTestSuite(const char* test_suite_name,
-                         CodeLocation code_location);
-
-  // Add an instantiation of a suit.
-  void RegisterInstantiation(const char* test_suite_name);
-
-  // For each suit repored as defined but not reported as instantiation,
-  // emit a test that reports that fact (configurably, as an error).
-  void CheckForInstantiations();
-
- private:
-  struct TypeParameterizedTestSuiteInfo {
-    explicit TypeParameterizedTestSuiteInfo(CodeLocation c)
-        : code_location(c), instantiated(false) {}
-
-    CodeLocation code_location;
-    bool instantiated;
-  };
-
-  std::map<std::string, TypeParameterizedTestSuiteInfo> suites_;
-};
-
-}  // namespace internal
-
-// Forward declarations of ValuesIn(), which is implemented in
-// include/gtest/gtest-param-test.h.
-template <class Container>
-internal::ParamGenerator<typename Container::value_type> ValuesIn(
-    const Container& container);
-
-namespace internal {
-// Used in the Values() function to provide polymorphic capabilities.
-
-#ifdef _MSC_VER
-#pragma warning(push)
-#pragma warning(disable : 4100)
-#endif
-
-template <typename... Ts>
-class ValueArray {
- public:
-  explicit ValueArray(Ts... v) : v_(FlatTupleConstructTag{}, std::move(v)...) {}
-
-  template <typename T>
-  operator ParamGenerator<T>() const {  // NOLINT
-    return ValuesIn(MakeVector<T>(MakeIndexSequence<sizeof...(Ts)>()));
-  }
-
- private:
-  template <typename T, size_t... I>
-  std::vector<T> MakeVector(IndexSequence<I...>) const {
-    return std::vector<T>{static_cast<T>(v_.template Get<I>())...};
-  }
-
-  FlatTuple<Ts...> v_;
-};
-
-#ifdef _MSC_VER
-#pragma warning(pop)
-#endif
-
-template <typename... T>
-class CartesianProductGenerator
-    : public ParamGeneratorInterface<::std::tuple<T...>> {
- public:
-  typedef ::std::tuple<T...> ParamType;
-
-  CartesianProductGenerator(const std::tuple<ParamGenerator<T>...>& g)
-      : generators_(g) {}
-  ~CartesianProductGenerator() override {}
-
-  ParamIteratorInterface<ParamType>* Begin() const override {
-    return new Iterator(this, generators_, false);
-  }
-  ParamIteratorInterface<ParamType>* End() const override {
-    return new Iterator(this, generators_, true);
-  }
-
- private:
-  template <class I>
-  class IteratorImpl;
-  template <size_t... I>
-  class IteratorImpl<IndexSequence<I...>>
-      : public ParamIteratorInterface<ParamType> {
-   public:
-    IteratorImpl(const ParamGeneratorInterface<ParamType>* base,
-             const std::tuple<ParamGenerator<T>...>& generators, bool is_end)
-        : base_(base),
-          begin_(std::get<I>(generators).begin()...),
-          end_(std::get<I>(generators).end()...),
-          current_(is_end ? end_ : begin_) {
-      ComputeCurrentValue();
-    }
-    ~IteratorImpl() override {}
-
-    const ParamGeneratorInterface<ParamType>* BaseGenerator() const override {
-      return base_;
-    }
-    // Advance should not be called on beyond-of-range iterators
-    // so no component iterators must be beyond end of range, either.
-    void Advance() override {
-      assert(!AtEnd());
-      // Advance the last iterator.
-      ++std::get<sizeof...(T) - 1>(current_);
-      // if that reaches end, propagate that up.
-      AdvanceIfEnd<sizeof...(T) - 1>();
-      ComputeCurrentValue();
-    }
-    ParamIteratorInterface<ParamType>* Clone() const override {
-      return new IteratorImpl(*this);
-    }
-
-    const ParamType* Current() const override { return current_value_.get(); }
-
-    bool Equals(const ParamIteratorInterface<ParamType>& other) const override {
-      // Having the same base generator guarantees that the other
-      // iterator is of the same type and we can downcast.
-      GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
-          << "The program attempted to compare iterators "
-          << "from different generators." << std::endl;
-      const IteratorImpl* typed_other =
-          CheckedDowncastToActualType<const IteratorImpl>(&other);
-
-      // We must report iterators equal if they both point beyond their
-      // respective ranges. That can happen in a variety of fashions,
-      // so we have to consult AtEnd().
-      if (AtEnd() && typed_other->AtEnd()) return true;
-
-      bool same = true;
-      bool dummy[] = {
-          (same = same && std::get<I>(current_) ==
-                              std::get<I>(typed_other->current_))...};
-      (void)dummy;
-      return same;
-    }
-
-   private:
-    template <size_t ThisI>
-    void AdvanceIfEnd() {
-      if (std::get<ThisI>(current_) != std::get<ThisI>(end_)) return;
-
-      bool last = ThisI == 0;
-      if (last) {
-        // We are done. Nothing else to propagate.
-        return;
-      }
-
-      constexpr size_t NextI = ThisI - (ThisI != 0);
-      std::get<ThisI>(current_) = std::get<ThisI>(begin_);
-      ++std::get<NextI>(current_);
-      AdvanceIfEnd<NextI>();
-    }
-
-    void ComputeCurrentValue() {
-      if (!AtEnd())
-        current_value_ = std::make_shared<ParamType>(*std::get<I>(current_)...);
-    }
-    bool AtEnd() const {
-      bool at_end = false;
-      bool dummy[] = {
-          (at_end = at_end || std::get<I>(current_) == std::get<I>(end_))...};
-      (void)dummy;
-      return at_end;
-    }
-
-    const ParamGeneratorInterface<ParamType>* const base_;
-    std::tuple<typename ParamGenerator<T>::iterator...> begin_;
-    std::tuple<typename ParamGenerator<T>::iterator...> end_;
-    std::tuple<typename ParamGenerator<T>::iterator...> current_;
-    std::shared_ptr<ParamType> current_value_;
-  };
-
-  using Iterator = IteratorImpl<typename MakeIndexSequence<sizeof...(T)>::type>;
-
-  std::tuple<ParamGenerator<T>...> generators_;
-};
-
-template <class... Gen>
-class CartesianProductHolder {
- public:
-  CartesianProductHolder(const Gen&... g) : generators_(g...) {}
-  template <typename... T>
-  operator ParamGenerator<::std::tuple<T...>>() const {
-    return ParamGenerator<::std::tuple<T...>>(
-        new CartesianProductGenerator<T...>(generators_));
-  }
-
- private:
-  std::tuple<Gen...> generators_;
-};
-
-}  // namespace internal
-}  // namespace testing
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
-
-namespace testing {
-
-// Functions producing parameter generators.
-//
-// Google Test uses these generators to produce parameters for value-
-// parameterized tests. When a parameterized test suite is instantiated
-// with a particular generator, Google Test creates and runs tests
-// for each element in the sequence produced by the generator.
-//
-// In the following sample, tests from test suite FooTest are instantiated
-// each three times with parameter values 3, 5, and 8:
-//
-// class FooTest : public TestWithParam<int> { ... };
-//
-// TEST_P(FooTest, TestThis) {
-// }
-// TEST_P(FooTest, TestThat) {
-// }
-// INSTANTIATE_TEST_SUITE_P(TestSequence, FooTest, Values(3, 5, 8));
-//
-
-// Range() returns generators providing sequences of values in a range.
-//
-// Synopsis:
-// Range(start, end)
-//   - returns a generator producing a sequence of values {start, start+1,
-//     start+2, ..., }.
-// Range(start, end, step)
-//   - returns a generator producing a sequence of values {start, start+step,
-//     start+step+step, ..., }.
-// Notes:
-//   * The generated sequences never include end. For example, Range(1, 5)
-//     returns a generator producing a sequence {1, 2, 3, 4}. Range(1, 9, 2)
-//     returns a generator producing {1, 3, 5, 7}.
-//   * start and end must have the same type. That type may be any integral or
-//     floating-point type or a user defined type satisfying these conditions:
-//     * It must be assignable (have operator=() defined).
-//     * It must have operator+() (operator+(int-compatible type) for
-//       two-operand version).
-//     * It must have operator<() defined.
-//     Elements in the resulting sequences will also have that type.
-//   * Condition start < end must be satisfied in order for resulting sequences
-//     to contain any elements.
-//
-template <typename T, typename IncrementT>
-internal::ParamGenerator<T> Range(T start, T end, IncrementT step) {
-  return internal::ParamGenerator<T>(
-      new internal::RangeGenerator<T, IncrementT>(start, end, step));
-}
-
-template <typename T>
-internal::ParamGenerator<T> Range(T start, T end) {
-  return Range(start, end, 1);
-}
-
-// ValuesIn() function allows generation of tests with parameters coming from
-// a container.
-//
-// Synopsis:
-// ValuesIn(const T (&array)[N])
-//   - returns a generator producing sequences with elements from
-//     a C-style array.
-// ValuesIn(const Container& container)
-//   - returns a generator producing sequences with elements from
-//     an STL-style container.
-// ValuesIn(Iterator begin, Iterator end)
-//   - returns a generator producing sequences with elements from
-//     a range [begin, end) defined by a pair of STL-style iterators. These
-//     iterators can also be plain C pointers.
-//
-// Please note that ValuesIn copies the values from the containers
-// passed in and keeps them to generate tests in RUN_ALL_TESTS().
-//
-// Examples:
-//
-// This instantiates tests from test suite StringTest
-// each with C-string values of "foo", "bar", and "baz":
-//
-// const char* strings[] = {"foo", "bar", "baz"};
-// INSTANTIATE_TEST_SUITE_P(StringSequence, StringTest, ValuesIn(strings));
-//
-// This instantiates tests from test suite StlStringTest
-// each with STL strings with values "a" and "b":
-//
-// ::std::vector< ::std::string> GetParameterStrings() {
-//   ::std::vector< ::std::string> v;
-//   v.push_back("a");
-//   v.push_back("b");
-//   return v;
-// }
-//
-// INSTANTIATE_TEST_SUITE_P(CharSequence,
-//                          StlStringTest,
-//                          ValuesIn(GetParameterStrings()));
-//
-//
-// This will also instantiate tests from CharTest
-// each with parameter values 'a' and 'b':
-//
-// ::std::list<char> GetParameterChars() {
-//   ::std::list<char> list;
-//   list.push_back('a');
-//   list.push_back('b');
-//   return list;
-// }
-// ::std::list<char> l = GetParameterChars();
-// INSTANTIATE_TEST_SUITE_P(CharSequence2,
-//                          CharTest,
-//                          ValuesIn(l.begin(), l.end()));
-//
-template <typename ForwardIterator>
-internal::ParamGenerator<
-    typename std::iterator_traits<ForwardIterator>::value_type>
-ValuesIn(ForwardIterator begin, ForwardIterator end) {
-  typedef typename std::iterator_traits<ForwardIterator>::value_type ParamType;
-  return internal::ParamGenerator<ParamType>(
-      new internal::ValuesInIteratorRangeGenerator<ParamType>(begin, end));
-}
-
-template <typename T, size_t N>
-internal::ParamGenerator<T> ValuesIn(const T (&array)[N]) {
-  return ValuesIn(array, array + N);
-}
-
-template <class Container>
-internal::ParamGenerator<typename Container::value_type> ValuesIn(
-    const Container& container) {
-  return ValuesIn(container.begin(), container.end());
-}
-
-// Values() allows generating tests from explicitly specified list of
-// parameters.
-//
-// Synopsis:
-// Values(T v1, T v2, ..., T vN)
-//   - returns a generator producing sequences with elements v1, v2, ..., vN.
-//
-// For example, this instantiates tests from test suite BarTest each
-// with values "one", "two", and "three":
-//
-// INSTANTIATE_TEST_SUITE_P(NumSequence,
-//                          BarTest,
-//                          Values("one", "two", "three"));
-//
-// This instantiates tests from test suite BazTest each with values 1, 2, 3.5.
-// The exact type of values will depend on the type of parameter in BazTest.
-//
-// INSTANTIATE_TEST_SUITE_P(FloatingNumbers, BazTest, Values(1, 2, 3.5));
-//
-//
-template <typename... T>
-internal::ValueArray<T...> Values(T... v) {
-  return internal::ValueArray<T...>(std::move(v)...);
-}
-
-// Bool() allows generating tests with parameters in a set of (false, true).
-//
-// Synopsis:
-// Bool()
-//   - returns a generator producing sequences with elements {false, true}.
-//
-// It is useful when testing code that depends on Boolean flags. Combinations
-// of multiple flags can be tested when several Bool()'s are combined using
-// Combine() function.
-//
-// In the following example all tests in the test suite FlagDependentTest
-// will be instantiated twice with parameters false and true.
-//
-// class FlagDependentTest : public testing::TestWithParam<bool> {
-//   virtual void SetUp() {
-//     external_flag = GetParam();
-//   }
-// }
-// INSTANTIATE_TEST_SUITE_P(BoolSequence, FlagDependentTest, Bool());
-//
-inline internal::ParamGenerator<bool> Bool() {
-  return Values(false, true);
-}
-
-// Combine() allows the user to combine two or more sequences to produce
-// values of a Cartesian product of those sequences' elements.
-//
-// Synopsis:
-// Combine(gen1, gen2, ..., genN)
-//   - returns a generator producing sequences with elements coming from
-//     the Cartesian product of elements from the sequences generated by
-//     gen1, gen2, ..., genN. The sequence elements will have a type of
-//     std::tuple<T1, T2, ..., TN> where T1, T2, ..., TN are the types
-//     of elements from sequences produces by gen1, gen2, ..., genN.
-//
-// Example:
-//
-// This will instantiate tests in test suite AnimalTest each one with
-// the parameter values tuple("cat", BLACK), tuple("cat", WHITE),
-// tuple("dog", BLACK), and tuple("dog", WHITE):
-//
-// enum Color { BLACK, GRAY, WHITE };
-// class AnimalTest
-//     : public testing::TestWithParam<std::tuple<const char*, Color> > {...};
-//
-// TEST_P(AnimalTest, AnimalLooksNice) {...}
-//
-// INSTANTIATE_TEST_SUITE_P(AnimalVariations, AnimalTest,
-//                          Combine(Values("cat", "dog"),
-//                                  Values(BLACK, WHITE)));
-//
-// This will instantiate tests in FlagDependentTest with all variations of two
-// Boolean flags:
-//
-// class FlagDependentTest
-//     : public testing::TestWithParam<std::tuple<bool, bool> > {
-//   virtual void SetUp() {
-//     // Assigns external_flag_1 and external_flag_2 values from the tuple.
-//     std::tie(external_flag_1, external_flag_2) = GetParam();
-//   }
-// };
-//
-// TEST_P(FlagDependentTest, TestFeature1) {
-//   // Test your code using external_flag_1 and external_flag_2 here.
-// }
-// INSTANTIATE_TEST_SUITE_P(TwoBoolSequence, FlagDependentTest,
-//                          Combine(Bool(), Bool()));
-//
-template <typename... Generator>
-internal::CartesianProductHolder<Generator...> Combine(const Generator&... g) {
-  return internal::CartesianProductHolder<Generator...>(g...);
-}
-
-#define TEST_P(test_suite_name, test_name)                                     \
-  class GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)                     \
-      : public test_suite_name {                                               \
-   public:                                                                     \
-    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)() {}                    \
-    void TestBody() override;                                                  \
-                                                                               \
-   private:                                                                    \
-    static int AddToRegistry() {                                               \
-      ::testing::UnitTest::GetInstance()                                       \
-          ->parameterized_test_registry()                                      \
-          .GetTestSuitePatternHolder<test_suite_name>(                         \
-              GTEST_STRINGIFY_(test_suite_name),                               \
-              ::testing::internal::CodeLocation(__FILE__, __LINE__))           \
-          ->AddTestPattern(                                                    \
-              GTEST_STRINGIFY_(test_suite_name), GTEST_STRINGIFY_(test_name),  \
-              new ::testing::internal::TestMetaFactory<GTEST_TEST_CLASS_NAME_( \
-                  test_suite_name, test_name)>(),                              \
-              ::testing::internal::CodeLocation(__FILE__, __LINE__));          \
-      return 0;                                                                \
-    }                                                                          \
-    static int gtest_registering_dummy_ GTEST_ATTRIBUTE_UNUSED_;               \
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(GTEST_TEST_CLASS_NAME_(test_suite_name,    \
-                                                           test_name));        \
-  };                                                                           \
-  int GTEST_TEST_CLASS_NAME_(test_suite_name,                                  \
-                             test_name)::gtest_registering_dummy_ =            \
-      GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)::AddToRegistry();     \
-  void GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)::TestBody()
-
-// The last argument to INSTANTIATE_TEST_SUITE_P allows the user to specify
-// generator and an optional function or functor that generates custom test name
-// suffixes based on the test parameters. Such a function or functor should
-// accept one argument of type testing::TestParamInfo<class ParamType>, and
-// return std::string.
-//
-// testing::PrintToStringParamName is a builtin test suffix generator that
-// returns the value of testing::PrintToString(GetParam()).
-//
-// Note: test names must be non-empty, unique, and may only contain ASCII
-// alphanumeric characters or underscore. Because PrintToString adds quotes
-// to std::string and C strings, it won't work for these types.
-
-#define GTEST_EXPAND_(arg) arg
-#define GTEST_GET_FIRST_(first, ...) first
-#define GTEST_GET_SECOND_(first, second, ...) second
-
-#define INSTANTIATE_TEST_SUITE_P(prefix, test_suite_name, ...)                \
-  static ::testing::internal::ParamGenerator<test_suite_name::ParamType>      \
-      gtest_##prefix##test_suite_name##_EvalGenerator_() {                    \
-    return GTEST_EXPAND_(GTEST_GET_FIRST_(__VA_ARGS__, DUMMY_PARAM_));        \
-  }                                                                           \
-  static ::std::string gtest_##prefix##test_suite_name##_EvalGenerateName_(   \
-      const ::testing::TestParamInfo<test_suite_name::ParamType>& info) {     \
-    if (::testing::internal::AlwaysFalse()) {                                 \
-      ::testing::internal::TestNotEmpty(GTEST_EXPAND_(GTEST_GET_SECOND_(      \
-          __VA_ARGS__,                                                        \
-          ::testing::internal::DefaultParamName<test_suite_name::ParamType>,  \
-          DUMMY_PARAM_)));                                                    \
-      auto t = std::make_tuple(__VA_ARGS__);                                  \
-      static_assert(std::tuple_size<decltype(t)>::value <= 2,                 \
-                    "Too Many Args!");                                        \
-    }                                                                         \
-    return ((GTEST_EXPAND_(GTEST_GET_SECOND_(                                 \
-        __VA_ARGS__,                                                          \
-        ::testing::internal::DefaultParamName<test_suite_name::ParamType>,    \
-        DUMMY_PARAM_))))(info);                                               \
-  }                                                                           \
-  static int gtest_##prefix##test_suite_name##_dummy_                         \
-      GTEST_ATTRIBUTE_UNUSED_ =                                               \
-          ::testing::UnitTest::GetInstance()                                  \
-              ->parameterized_test_registry()                                 \
-              .GetTestSuitePatternHolder<test_suite_name>(                    \
-                  GTEST_STRINGIFY_(test_suite_name),                          \
-                  ::testing::internal::CodeLocation(__FILE__, __LINE__))      \
-              ->AddTestSuiteInstantiation(                                    \
-                  GTEST_STRINGIFY_(prefix),                                   \
-                  &gtest_##prefix##test_suite_name##_EvalGenerator_,          \
-                  &gtest_##prefix##test_suite_name##_EvalGenerateName_,       \
-                  __FILE__, __LINE__)
-
-
-// Allow Marking a Parameterized test class as not needing to be instantiated.
-#define GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(T)                   \
-  namespace gtest_do_not_use_outside_namespace_scope {}                   \
-  static const ::testing::internal::MarkAsIgnored gtest_allow_ignore_##T( \
-      GTEST_STRINGIFY_(T))
-
-// Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-#define INSTANTIATE_TEST_CASE_P                                            \
-  static_assert(::testing::internal::InstantiateTestCase_P_IsDeprecated(), \
-                "");                                                       \
-  INSTANTIATE_TEST_SUITE_P
-#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-}  // namespace testing
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_PARAM_TEST_H_
-// Copyright 2006, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-//
-// Google C++ Testing and Mocking Framework definitions useful in production code.
-// GOOGLETEST_CM0003 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PROD_H_
-#define GOOGLETEST_INCLUDE_GTEST_GTEST_PROD_H_
-
-// When you need to test the private or protected members of a class,
-// use the FRIEND_TEST macro to declare your tests as friends of the
-// class.  For example:
-//
-// class MyClass {
-//  private:
-//   void PrivateMethod();
-//   FRIEND_TEST(MyClassTest, PrivateMethodWorks);
-// };
-//
-// class MyClassTest : public testing::Test {
-//   // ...
-// };
-//
-// TEST_F(MyClassTest, PrivateMethodWorks) {
-//   // Can call MyClass::PrivateMethod() here.
-// }
-//
-// Note: The test class must be in the same namespace as the class being tested.
-// For example, putting MyClassTest in an anonymous namespace will not work.
-
-#define FRIEND_TEST(test_case_name, test_name)\
-friend class test_case_name##_##test_name##_Test
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_PROD_H_
-// Copyright 2008 Google Inc.
-// All Rights Reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_TYPED_TEST_H_
-#define GOOGLETEST_INCLUDE_GTEST_GTEST_TYPED_TEST_H_
-
-// This header implements typed tests and type-parameterized tests.
-
-// Typed (aka type-driven) tests repeat the same test for types in a
-// list.  You must know which types you want to test with when writing
-// typed tests. Here's how you do it:
-
-#if 0
-
-// First, define a fixture class template.  It should be parameterized
-// by a type.  Remember to derive it from testing::Test.
-template <typename T>
-class FooTest : public testing::Test {
- public:
-  ...
-  typedef std::list<T> List;
-  static T shared_;
-  T value_;
-};
-
-// Next, associate a list of types with the test suite, which will be
-// repeated for each type in the list.  The typedef is necessary for
-// the macro to parse correctly.
-typedef testing::Types<char, int, unsigned int> MyTypes;
-TYPED_TEST_SUITE(FooTest, MyTypes);
-
-// If the type list contains only one type, you can write that type
-// directly without Types<...>:
-//   TYPED_TEST_SUITE(FooTest, int);
-
-// Then, use TYPED_TEST() instead of TEST_F() to define as many typed
-// tests for this test suite as you want.
-TYPED_TEST(FooTest, DoesBlah) {
-  // Inside a test, refer to the special name TypeParam to get the type
-  // parameter.  Since we are inside a derived class template, C++ requires
-  // us to visit the members of FooTest via 'this'.
-  TypeParam n = this->value_;
-
-  // To visit static members of the fixture, add the TestFixture::
-  // prefix.
-  n += TestFixture::shared_;
-
-  // To refer to typedefs in the fixture, add the "typename
-  // TestFixture::" prefix.
-  typename TestFixture::List values;
-  values.push_back(n);
-  ...
-}
-
-TYPED_TEST(FooTest, HasPropertyA) { ... }
-
-// TYPED_TEST_SUITE takes an optional third argument which allows to specify a
-// class that generates custom test name suffixes based on the type. This should
-// be a class which has a static template function GetName(int index) returning
-// a string for each type. The provided integer index equals the index of the
-// type in the provided type list. In many cases the index can be ignored.
-//
-// For example:
-//   class MyTypeNames {
-//    public:
-//     template <typename T>
-//     static std::string GetName(int) {
-//       if (std::is_same<T, char>()) return "char";
-//       if (std::is_same<T, int>()) return "int";
-//       if (std::is_same<T, unsigned int>()) return "unsignedInt";
-//     }
-//   };
-//   TYPED_TEST_SUITE(FooTest, MyTypes, MyTypeNames);
-
-#endif  // 0
-
-// Type-parameterized tests are abstract test patterns parameterized
-// by a type.  Compared with typed tests, type-parameterized tests
-// allow you to define the test pattern without knowing what the type
-// parameters are.  The defined pattern can be instantiated with
-// different types any number of times, in any number of translation
-// units.
-//
-// If you are designing an interface or concept, you can define a
-// suite of type-parameterized tests to verify properties that any
-// valid implementation of the interface/concept should have.  Then,
-// each implementation can easily instantiate the test suite to verify
-// that it conforms to the requirements, without having to write
-// similar tests repeatedly.  Here's an example:
-
-#if 0
-
-// First, define a fixture class template.  It should be parameterized
-// by a type.  Remember to derive it from testing::Test.
-template <typename T>
-class FooTest : public testing::Test {
-  ...
-};
-
-// Next, declare that you will define a type-parameterized test suite
-// (the _P suffix is for "parameterized" or "pattern", whichever you
-// prefer):
-TYPED_TEST_SUITE_P(FooTest);
-
-// Then, use TYPED_TEST_P() to define as many type-parameterized tests
-// for this type-parameterized test suite as you want.
-TYPED_TEST_P(FooTest, DoesBlah) {
-  // Inside a test, refer to TypeParam to get the type parameter.
-  TypeParam n = 0;
-  ...
-}
-
-TYPED_TEST_P(FooTest, HasPropertyA) { ... }
-
-// Now the tricky part: you need to register all test patterns before
-// you can instantiate them.  The first argument of the macro is the
-// test suite name; the rest are the names of the tests in this test
-// case.
-REGISTER_TYPED_TEST_SUITE_P(FooTest,
-                            DoesBlah, HasPropertyA);
-
-// Finally, you are free to instantiate the pattern with the types you
-// want.  If you put the above code in a header file, you can #include
-// it in multiple C++ source files and instantiate it multiple times.
-//
-// To distinguish different instances of the pattern, the first
-// argument to the INSTANTIATE_* macro is a prefix that will be added
-// to the actual test suite name.  Remember to pick unique prefixes for
-// different instances.
-typedef testing::Types<char, int, unsigned int> MyTypes;
-INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, MyTypes);
-
-// If the type list contains only one type, you can write that type
-// directly without Types<...>:
-//   INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, int);
-//
-// Similar to the optional argument of TYPED_TEST_SUITE above,
-// INSTANTIATE_TEST_SUITE_P takes an optional fourth argument which allows to
-// generate custom names.
-//   INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, MyTypes, MyTypeNames);
-
-#endif  // 0
-
-
-// Implements typed tests.
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// Expands to the name of the typedef for the type parameters of the
-// given test suite.
-#define GTEST_TYPE_PARAMS_(TestSuiteName) gtest_type_params_##TestSuiteName##_
-
-// Expands to the name of the typedef for the NameGenerator, responsible for
-// creating the suffixes of the name.
-#define GTEST_NAME_GENERATOR_(TestSuiteName) \
-  gtest_type_params_##TestSuiteName##_NameGenerator
-
-#define TYPED_TEST_SUITE(CaseName, Types, ...)                          \
-  typedef ::testing::internal::GenerateTypeList<Types>::type            \
-      GTEST_TYPE_PARAMS_(CaseName);                                     \
-  typedef ::testing::internal::NameGeneratorSelector<__VA_ARGS__>::type \
-      GTEST_NAME_GENERATOR_(CaseName)
-
-#define TYPED_TEST(CaseName, TestName)                                        \
-  static_assert(sizeof(GTEST_STRINGIFY_(TestName)) > 1,                       \
-                "test-name must not be empty");                               \
-  template <typename gtest_TypeParam_>                                        \
-  class GTEST_TEST_CLASS_NAME_(CaseName, TestName)                            \
-      : public CaseName<gtest_TypeParam_> {                                   \
-   private:                                                                   \
-    typedef CaseName<gtest_TypeParam_> TestFixture;                           \
-    typedef gtest_TypeParam_ TypeParam;                                       \
-    void TestBody() override;                                                 \
-  };                                                                          \
-  static bool gtest_##CaseName##_##TestName##_registered_                     \
-      GTEST_ATTRIBUTE_UNUSED_ = ::testing::internal::TypeParameterizedTest<   \
-          CaseName,                                                           \
-          ::testing::internal::TemplateSel<GTEST_TEST_CLASS_NAME_(CaseName,   \
-                                                                  TestName)>, \
-          GTEST_TYPE_PARAMS_(                                                 \
-              CaseName)>::Register("",                                        \
-                                   ::testing::internal::CodeLocation(         \
-                                       __FILE__, __LINE__),                   \
-                                   GTEST_STRINGIFY_(CaseName),                \
-                                   GTEST_STRINGIFY_(TestName), 0,             \
-                                   ::testing::internal::GenerateNames<        \
-                                       GTEST_NAME_GENERATOR_(CaseName),       \
-                                       GTEST_TYPE_PARAMS_(CaseName)>());      \
-  template <typename gtest_TypeParam_>                                        \
-  void GTEST_TEST_CLASS_NAME_(CaseName,                                       \
-                              TestName)<gtest_TypeParam_>::TestBody()
-
-// Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-#define TYPED_TEST_CASE                                                \
-  static_assert(::testing::internal::TypedTestCaseIsDeprecated(), ""); \
-  TYPED_TEST_SUITE
-#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-// Implements type-parameterized tests.
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// Expands to the namespace name that the type-parameterized tests for
-// the given type-parameterized test suite are defined in.  The exact
-// name of the namespace is subject to change without notice.
-#define GTEST_SUITE_NAMESPACE_(TestSuiteName) gtest_suite_##TestSuiteName##_
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-//
-// Expands to the name of the variable used to remember the names of
-// the defined tests in the given test suite.
-#define GTEST_TYPED_TEST_SUITE_P_STATE_(TestSuiteName) \
-  gtest_typed_test_suite_p_state_##TestSuiteName##_
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE DIRECTLY.
-//
-// Expands to the name of the variable used to remember the names of
-// the registered tests in the given test suite.
-#define GTEST_REGISTERED_TEST_NAMES_(TestSuiteName) \
-  gtest_registered_test_names_##TestSuiteName##_
-
-// The variables defined in the type-parameterized test macros are
-// static as typically these macros are used in a .h file that can be
-// #included in multiple translation units linked together.
-#define TYPED_TEST_SUITE_P(SuiteName)              \
-  static ::testing::internal::TypedTestSuitePState \
-      GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName)
-
-// Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-#define TYPED_TEST_CASE_P                                                 \
-  static_assert(::testing::internal::TypedTestCase_P_IsDeprecated(), ""); \
-  TYPED_TEST_SUITE_P
-#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-#define TYPED_TEST_P(SuiteName, TestName)                             \
-  namespace GTEST_SUITE_NAMESPACE_(SuiteName) {                       \
-    template <typename gtest_TypeParam_>                              \
-    class TestName : public SuiteName<gtest_TypeParam_> {             \
-     private:                                                         \
-      typedef SuiteName<gtest_TypeParam_> TestFixture;                \
-      typedef gtest_TypeParam_ TypeParam;                             \
-      void TestBody() override;                                       \
-    };                                                                \
-    static bool gtest_##TestName##_defined_ GTEST_ATTRIBUTE_UNUSED_ = \
-        GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName).AddTestName(       \
-            __FILE__, __LINE__, GTEST_STRINGIFY_(SuiteName),          \
-            GTEST_STRINGIFY_(TestName));                              \
-  }                                                                   \
-  template <typename gtest_TypeParam_>                                \
-  void GTEST_SUITE_NAMESPACE_(                                        \
-      SuiteName)::TestName<gtest_TypeParam_>::TestBody()
-
-// Note: this won't work correctly if the trailing arguments are macros.
-#define REGISTER_TYPED_TEST_SUITE_P(SuiteName, ...)                         \
-  namespace GTEST_SUITE_NAMESPACE_(SuiteName) {                             \
-    typedef ::testing::internal::Templates<__VA_ARGS__> gtest_AllTests_;    \
-  }                                                                         \
-  static const char* const GTEST_REGISTERED_TEST_NAMES_(                    \
-      SuiteName) GTEST_ATTRIBUTE_UNUSED_ =                                  \
-      GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName).VerifyRegisteredTestNames( \
-          GTEST_STRINGIFY_(SuiteName), __FILE__, __LINE__, #__VA_ARGS__)
-
-// Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-#define REGISTER_TYPED_TEST_CASE_P                                           \
-  static_assert(::testing::internal::RegisterTypedTestCase_P_IsDeprecated(), \
-                "");                                                         \
-  REGISTER_TYPED_TEST_SUITE_P
-#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-#define INSTANTIATE_TYPED_TEST_SUITE_P(Prefix, SuiteName, Types, ...)       \
-  static_assert(sizeof(GTEST_STRINGIFY_(Prefix)) > 1,                       \
-                "test-suit-prefix must not be empty");                      \
-  static bool gtest_##Prefix##_##SuiteName GTEST_ATTRIBUTE_UNUSED_ =        \
-      ::testing::internal::TypeParameterizedTestSuite<                      \
-          SuiteName, GTEST_SUITE_NAMESPACE_(SuiteName)::gtest_AllTests_,    \
-          ::testing::internal::GenerateTypeList<Types>::type>::             \
-          Register(GTEST_STRINGIFY_(Prefix),                                \
-                   ::testing::internal::CodeLocation(__FILE__, __LINE__),   \
-                   &GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName),             \
-                   GTEST_STRINGIFY_(SuiteName),                             \
-                   GTEST_REGISTERED_TEST_NAMES_(SuiteName),                 \
-                   ::testing::internal::GenerateNames<                      \
-                       ::testing::internal::NameGeneratorSelector<          \
-                           __VA_ARGS__>::type,                              \
-                       ::testing::internal::GenerateTypeList<Types>::type>())
-
-// Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-#define INSTANTIATE_TYPED_TEST_CASE_P                                      \
-  static_assert(                                                           \
-      ::testing::internal::InstantiateTypedTestCase_P_IsDeprecated(), ""); \
-  INSTANTIATE_TYPED_TEST_SUITE_P
-#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_TYPED_TEST_H_
-
-GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
-/* class A needs to have dll-interface to be used by clients of class B */)
-
-namespace testing {
-
-// Silence C4100 (unreferenced formal parameter) and 4805
-// unsafe mix of type 'const int' and type 'const bool'
-#ifdef _MSC_VER
-# pragma warning(push)
-# pragma warning(disable:4805)
-# pragma warning(disable:4100)
-#endif
-
-
-// Declares the flags.
-
-// This flag temporary enables the disabled tests.
-GTEST_DECLARE_bool_(also_run_disabled_tests);
-
-// This flag brings the debugger on an assertion failure.
-GTEST_DECLARE_bool_(break_on_failure);
-
-// This flag controls whether Google Test catches all test-thrown exceptions
-// and logs them as failures.
-GTEST_DECLARE_bool_(catch_exceptions);
-
-// This flag enables using colors in terminal output. Available values are
-// "yes" to enable colors, "no" (disable colors), or "auto" (the default)
-// to let Google Test decide.
-GTEST_DECLARE_string_(color);
-
-// This flag controls whether the test runner should continue execution past
-// first failure.
-GTEST_DECLARE_bool_(fail_fast);
-
-// This flag sets up the filter to select by name using a glob pattern
-// the tests to run. If the filter is not given all tests are executed.
-GTEST_DECLARE_string_(filter);
-
-// This flag controls whether Google Test installs a signal handler that dumps
-// debugging information when fatal signals are raised.
-GTEST_DECLARE_bool_(install_failure_signal_handler);
-
-// This flag causes the Google Test to list tests. None of the tests listed
-// are actually run if the flag is provided.
-GTEST_DECLARE_bool_(list_tests);
-
-// This flag controls whether Google Test emits a detailed XML report to a file
-// in addition to its normal textual output.
-GTEST_DECLARE_string_(output);
-
-// This flags control whether Google Test prints only test failures.
-GTEST_DECLARE_bool_(brief);
-
-// This flags control whether Google Test prints the elapsed time for each
-// test.
-GTEST_DECLARE_bool_(print_time);
-
-// This flags control whether Google Test prints UTF8 characters as text.
-GTEST_DECLARE_bool_(print_utf8);
-
-// This flag specifies the random number seed.
-GTEST_DECLARE_int32_(random_seed);
-
-// This flag sets how many times the tests are repeated. The default value
-// is 1. If the value is -1 the tests are repeating forever.
-GTEST_DECLARE_int32_(repeat);
-
-// This flag controls whether Google Test includes Google Test internal
-// stack frames in failure stack traces.
-GTEST_DECLARE_bool_(show_internal_stack_frames);
-
-// When this flag is specified, tests' order is randomized on every iteration.
-GTEST_DECLARE_bool_(shuffle);
-
-// This flag specifies the maximum number of stack frames to be
-// printed in a failure message.
-GTEST_DECLARE_int32_(stack_trace_depth);
-
-// When this flag is specified, a failed assertion will throw an
-// exception if exceptions are enabled, or exit the program with a
-// non-zero code otherwise. For use with an external test framework.
-GTEST_DECLARE_bool_(throw_on_failure);
-
-// When this flag is set with a "host:port" string, on supported
-// platforms test results are streamed to the specified port on
-// the specified host machine.
-GTEST_DECLARE_string_(stream_result_to);
-
-#if GTEST_USE_OWN_FLAGFILE_FLAG_
-GTEST_DECLARE_string_(flagfile);
-#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
-
-// The upper limit for valid stack trace depths.
-const int kMaxStackTraceDepth = 100;
-
-namespace internal {
-
-class AssertHelper;
-class DefaultGlobalTestPartResultReporter;
-class ExecDeathTest;
-class NoExecDeathTest;
-class FinalSuccessChecker;
-class GTestFlagSaver;
-class StreamingListenerTest;
-class TestResultAccessor;
-class TestEventListenersAccessor;
-class TestEventRepeater;
-class UnitTestRecordPropertyTestHelper;
-class WindowsDeathTest;
-class FuchsiaDeathTest;
-class UnitTestImpl* GetUnitTestImpl();
-void ReportFailureInUnknownLocation(TestPartResult::Type result_type,
-                                    const std::string& message);
-std::set<std::string>* GetIgnoredParameterizedTestSuites();
-
-}  // namespace internal
-
-// The friend relationship of some of these classes is cyclic.
-// If we don't forward declare them the compiler might confuse the classes
-// in friendship clauses with same named classes on the scope.
-class Test;
-class TestSuite;
-
-// Old API is still available but deprecated
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-using TestCase = TestSuite;
-#endif
-class TestInfo;
-class UnitTest;
-
-// A class for indicating whether an assertion was successful.  When
-// the assertion wasn't successful, the AssertionResult object
-// remembers a non-empty message that describes how it failed.
-//
-// To create an instance of this class, use one of the factory functions
-// (AssertionSuccess() and AssertionFailure()).
-//
-// This class is useful for two purposes:
-//   1. Defining predicate functions to be used with Boolean test assertions
-//      EXPECT_TRUE/EXPECT_FALSE and their ASSERT_ counterparts
-//   2. Defining predicate-format functions to be
-//      used with predicate assertions (ASSERT_PRED_FORMAT*, etc).
-//
-// For example, if you define IsEven predicate:
-//
-//   testing::AssertionResult IsEven(int n) {
-//     if ((n % 2) == 0)
-//       return testing::AssertionSuccess();
-//     else
-//       return testing::AssertionFailure() << n << " is odd";
-//   }
-//
-// Then the failed expectation EXPECT_TRUE(IsEven(Fib(5)))
-// will print the message
-//
-//   Value of: IsEven(Fib(5))
-//     Actual: false (5 is odd)
-//   Expected: true
-//
-// instead of a more opaque
-//
-//   Value of: IsEven(Fib(5))
-//     Actual: false
-//   Expected: true
-//
-// in case IsEven is a simple Boolean predicate.
-//
-// If you expect your predicate to be reused and want to support informative
-// messages in EXPECT_FALSE and ASSERT_FALSE (negative assertions show up
-// about half as often as positive ones in our tests), supply messages for
-// both success and failure cases:
-//
-//   testing::AssertionResult IsEven(int n) {
-//     if ((n % 2) == 0)
-//       return testing::AssertionSuccess() << n << " is even";
-//     else
-//       return testing::AssertionFailure() << n << " is odd";
-//   }
-//
-// Then a statement EXPECT_FALSE(IsEven(Fib(6))) will print
-//
-//   Value of: IsEven(Fib(6))
-//     Actual: true (8 is even)
-//   Expected: false
-//
-// NB: Predicates that support negative Boolean assertions have reduced
-// performance in positive ones so be careful not to use them in tests
-// that have lots (tens of thousands) of positive Boolean assertions.
-//
-// To use this class with EXPECT_PRED_FORMAT assertions such as:
-//
-//   // Verifies that Foo() returns an even number.
-//   EXPECT_PRED_FORMAT1(IsEven, Foo());
-//
-// you need to define:
-//
-//   testing::AssertionResult IsEven(const char* expr, int n) {
-//     if ((n % 2) == 0)
-//       return testing::AssertionSuccess();
-//     else
-//       return testing::AssertionFailure()
-//         << "Expected: " << expr << " is even\n  Actual: it's " << n;
-//   }
-//
-// If Foo() returns 5, you will see the following message:
-//
-//   Expected: Foo() is even
-//     Actual: it's 5
-//
-class GTEST_API_ AssertionResult {
- public:
-  // Copy constructor.
-  // Used in EXPECT_TRUE/FALSE(assertion_result).
-  AssertionResult(const AssertionResult& other);
-
-// C4800 is a level 3 warning in Visual Studio 2015 and earlier.
-// This warning is not emitted in Visual Studio 2017.
-// This warning is off by default starting in Visual Studio 2019 but can be
-// enabled with command-line options.
-#if defined(_MSC_VER) && (_MSC_VER < 1910 || _MSC_VER >= 1920)
-  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800 /* forcing value to bool */)
-#endif
-
-  // Used in the EXPECT_TRUE/FALSE(bool_expression).
-  //
-  // T must be contextually convertible to bool.
-  //
-  // The second parameter prevents this overload from being considered if
-  // the argument is implicitly convertible to AssertionResult. In that case
-  // we want AssertionResult's copy constructor to be used.
-  template <typename T>
-  explicit AssertionResult(
-      const T& success,
-      typename std::enable_if<
-          !std::is_convertible<T, AssertionResult>::value>::type*
-      /*enabler*/
-      = nullptr)
-      : success_(success) {}
-
-#if defined(_MSC_VER) && (_MSC_VER < 1910 || _MSC_VER >= 1920)
-  GTEST_DISABLE_MSC_WARNINGS_POP_()
-#endif
-
-  // Assignment operator.
-  AssertionResult& operator=(AssertionResult other) {
-    swap(other);
-    return *this;
-  }
-
-  // Returns true if and only if the assertion succeeded.
-  operator bool() const { return success_; }  // NOLINT
-
-  // Returns the assertion's negation. Used with EXPECT/ASSERT_FALSE.
-  AssertionResult operator!() const;
-
-  // Returns the text streamed into this AssertionResult. Test assertions
-  // use it when they fail (i.e., the predicate's outcome doesn't match the
-  // assertion's expectation). When nothing has been streamed into the
-  // object, returns an empty string.
-  const char* message() const {
-    return message_.get() != nullptr ? message_->c_str() : "";
-  }
-  // Deprecated; please use message() instead.
-  const char* failure_message() const { return message(); }
-
-  // Streams a custom failure message into this object.
-  template <typename T> AssertionResult& operator<<(const T& value) {
-    AppendMessage(Message() << value);
-    return *this;
-  }
-
-  // Allows streaming basic output manipulators such as endl or flush into
-  // this object.
-  AssertionResult& operator<<(
-      ::std::ostream& (*basic_manipulator)(::std::ostream& stream)) {
-    AppendMessage(Message() << basic_manipulator);
-    return *this;
-  }
-
- private:
-  // Appends the contents of message to message_.
-  void AppendMessage(const Message& a_message) {
-    if (message_.get() == nullptr) message_.reset(new ::std::string);
-    message_->append(a_message.GetString().c_str());
-  }
-
-  // Swap the contents of this AssertionResult with other.
-  void swap(AssertionResult& other);
-
-  // Stores result of the assertion predicate.
-  bool success_;
-  // Stores the message describing the condition in case the expectation
-  // construct is not satisfied with the predicate's outcome.
-  // Referenced via a pointer to avoid taking too much stack frame space
-  // with test assertions.
-  std::unique_ptr< ::std::string> message_;
-};
-
-// Makes a successful assertion result.
-GTEST_API_ AssertionResult AssertionSuccess();
-
-// Makes a failed assertion result.
-GTEST_API_ AssertionResult AssertionFailure();
-
-// Makes a failed assertion result with the given failure message.
-// Deprecated; use AssertionFailure() << msg.
-GTEST_API_ AssertionResult AssertionFailure(const Message& msg);
-
-}  // namespace testing
-
-// Includes the auto-generated header that implements a family of generic
-// predicate assertion macros. This include comes late because it relies on
-// APIs declared above.
-// Copyright 2006, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// This file is AUTOMATICALLY GENERATED on 01/02/2019 by command
-// 'gen_gtest_pred_impl.py 5'.  DO NOT EDIT BY HAND!
-//
-// Implements a family of generic predicate assertion macros.
-// GOOGLETEST_CM0001 DO NOT DELETE
-
-#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
-#define GOOGLETEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
-
-
-namespace testing {
-
-// This header implements a family of generic predicate assertion
-// macros:
-//
-//   ASSERT_PRED_FORMAT1(pred_format, v1)
-//   ASSERT_PRED_FORMAT2(pred_format, v1, v2)
-//   ...
-//
-// where pred_format is a function or functor that takes n (in the
-// case of ASSERT_PRED_FORMATn) values and their source expression
-// text, and returns a testing::AssertionResult.  See the definition
-// of ASSERT_EQ in gtest.h for an example.
-//
-// If you don't care about formatting, you can use the more
-// restrictive version:
-//
-//   ASSERT_PRED1(pred, v1)
-//   ASSERT_PRED2(pred, v1, v2)
-//   ...
-//
-// where pred is an n-ary function or functor that returns bool,
-// and the values v1, v2, ..., must support the << operator for
-// streaming to std::ostream.
-//
-// We also define the EXPECT_* variations.
-//
-// For now we only support predicates whose arity is at most 5.
-// Please email googletestframework@googlegroups.com if you need
-// support for higher arities.
-
-// GTEST_ASSERT_ is the basic statement to which all of the assertions
-// in this file reduce.  Don't use this in your code.
-
-#define GTEST_ASSERT_(expression, on_failure) \
-  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
-  if (const ::testing::AssertionResult gtest_ar = (expression)) \
-    ; \
-  else \
-    on_failure(gtest_ar.failure_message())
-
-
-// Helper function for implementing {EXPECT|ASSERT}_PRED1.  Don't use
-// this in your code.
-template <typename Pred,
-          typename T1>
-AssertionResult AssertPred1Helper(const char* pred_text,
-                                  const char* e1,
-                                  Pred pred,
-                                  const T1& v1) {
-  if (pred(v1)) return AssertionSuccess();
-
-  return AssertionFailure()
-         << pred_text << "(" << e1 << ") evaluates to false, where"
-         << "\n"
-         << e1 << " evaluates to " << ::testing::PrintToString(v1);
-}
-
-// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT1.
-// Don't use this in your code.
-#define GTEST_PRED_FORMAT1_(pred_format, v1, on_failure)\
-  GTEST_ASSERT_(pred_format(#v1, v1), \
-                on_failure)
-
-// Internal macro for implementing {EXPECT|ASSERT}_PRED1.  Don't use
-// this in your code.
-#define GTEST_PRED1_(pred, v1, on_failure)\
-  GTEST_ASSERT_(::testing::AssertPred1Helper(#pred, \
-                                             #v1, \
-                                             pred, \
-                                             v1), on_failure)
-
-// Unary predicate assertion macros.
-#define EXPECT_PRED_FORMAT1(pred_format, v1) \
-  GTEST_PRED_FORMAT1_(pred_format, v1, GTEST_NONFATAL_FAILURE_)
-#define EXPECT_PRED1(pred, v1) \
-  GTEST_PRED1_(pred, v1, GTEST_NONFATAL_FAILURE_)
-#define ASSERT_PRED_FORMAT1(pred_format, v1) \
-  GTEST_PRED_FORMAT1_(pred_format, v1, GTEST_FATAL_FAILURE_)
-#define ASSERT_PRED1(pred, v1) \
-  GTEST_PRED1_(pred, v1, GTEST_FATAL_FAILURE_)
-
-
-
-// Helper function for implementing {EXPECT|ASSERT}_PRED2.  Don't use
-// this in your code.
-template <typename Pred,
-          typename T1,
-          typename T2>
-AssertionResult AssertPred2Helper(const char* pred_text,
-                                  const char* e1,
-                                  const char* e2,
-                                  Pred pred,
-                                  const T1& v1,
-                                  const T2& v2) {
-  if (pred(v1, v2)) return AssertionSuccess();
-
-  return AssertionFailure()
-         << pred_text << "(" << e1 << ", " << e2
-         << ") evaluates to false, where"
-         << "\n"
-         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
-         << e2 << " evaluates to " << ::testing::PrintToString(v2);
-}
-
-// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT2.
-// Don't use this in your code.
-#define GTEST_PRED_FORMAT2_(pred_format, v1, v2, on_failure)\
-  GTEST_ASSERT_(pred_format(#v1, #v2, v1, v2), \
-                on_failure)
-
-// Internal macro for implementing {EXPECT|ASSERT}_PRED2.  Don't use
-// this in your code.
-#define GTEST_PRED2_(pred, v1, v2, on_failure)\
-  GTEST_ASSERT_(::testing::AssertPred2Helper(#pred, \
-                                             #v1, \
-                                             #v2, \
-                                             pred, \
-                                             v1, \
-                                             v2), on_failure)
-
-// Binary predicate assertion macros.
-#define EXPECT_PRED_FORMAT2(pred_format, v1, v2) \
-  GTEST_PRED_FORMAT2_(pred_format, v1, v2, GTEST_NONFATAL_FAILURE_)
-#define EXPECT_PRED2(pred, v1, v2) \
-  GTEST_PRED2_(pred, v1, v2, GTEST_NONFATAL_FAILURE_)
-#define ASSERT_PRED_FORMAT2(pred_format, v1, v2) \
-  GTEST_PRED_FORMAT2_(pred_format, v1, v2, GTEST_FATAL_FAILURE_)
-#define ASSERT_PRED2(pred, v1, v2) \
-  GTEST_PRED2_(pred, v1, v2, GTEST_FATAL_FAILURE_)
-
-
-
-// Helper function for implementing {EXPECT|ASSERT}_PRED3.  Don't use
-// this in your code.
-template <typename Pred,
-          typename T1,
-          typename T2,
-          typename T3>
-AssertionResult AssertPred3Helper(const char* pred_text,
-                                  const char* e1,
-                                  const char* e2,
-                                  const char* e3,
-                                  Pred pred,
-                                  const T1& v1,
-                                  const T2& v2,
-                                  const T3& v3) {
-  if (pred(v1, v2, v3)) return AssertionSuccess();
-
-  return AssertionFailure()
-         << pred_text << "(" << e1 << ", " << e2 << ", " << e3
-         << ") evaluates to false, where"
-         << "\n"
-         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
-         << e2 << " evaluates to " << ::testing::PrintToString(v2) << "\n"
-         << e3 << " evaluates to " << ::testing::PrintToString(v3);
-}
-
-// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT3.
-// Don't use this in your code.
-#define GTEST_PRED_FORMAT3_(pred_format, v1, v2, v3, on_failure)\
-  GTEST_ASSERT_(pred_format(#v1, #v2, #v3, v1, v2, v3), \
-                on_failure)
-
-// Internal macro for implementing {EXPECT|ASSERT}_PRED3.  Don't use
-// this in your code.
-#define GTEST_PRED3_(pred, v1, v2, v3, on_failure)\
-  GTEST_ASSERT_(::testing::AssertPred3Helper(#pred, \
-                                             #v1, \
-                                             #v2, \
-                                             #v3, \
-                                             pred, \
-                                             v1, \
-                                             v2, \
-                                             v3), on_failure)
-
-// Ternary predicate assertion macros.
-#define EXPECT_PRED_FORMAT3(pred_format, v1, v2, v3) \
-  GTEST_PRED_FORMAT3_(pred_format, v1, v2, v3, GTEST_NONFATAL_FAILURE_)
-#define EXPECT_PRED3(pred, v1, v2, v3) \
-  GTEST_PRED3_(pred, v1, v2, v3, GTEST_NONFATAL_FAILURE_)
-#define ASSERT_PRED_FORMAT3(pred_format, v1, v2, v3) \
-  GTEST_PRED_FORMAT3_(pred_format, v1, v2, v3, GTEST_FATAL_FAILURE_)
-#define ASSERT_PRED3(pred, v1, v2, v3) \
-  GTEST_PRED3_(pred, v1, v2, v3, GTEST_FATAL_FAILURE_)
-
-
-
-// Helper function for implementing {EXPECT|ASSERT}_PRED4.  Don't use
-// this in your code.
-template <typename Pred,
-          typename T1,
-          typename T2,
-          typename T3,
-          typename T4>
-AssertionResult AssertPred4Helper(const char* pred_text,
-                                  const char* e1,
-                                  const char* e2,
-                                  const char* e3,
-                                  const char* e4,
-                                  Pred pred,
-                                  const T1& v1,
-                                  const T2& v2,
-                                  const T3& v3,
-                                  const T4& v4) {
-  if (pred(v1, v2, v3, v4)) return AssertionSuccess();
-
-  return AssertionFailure()
-         << pred_text << "(" << e1 << ", " << e2 << ", " << e3 << ", " << e4
-         << ") evaluates to false, where"
-         << "\n"
-         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
-         << e2 << " evaluates to " << ::testing::PrintToString(v2) << "\n"
-         << e3 << " evaluates to " << ::testing::PrintToString(v3) << "\n"
-         << e4 << " evaluates to " << ::testing::PrintToString(v4);
-}
-
-// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT4.
-// Don't use this in your code.
-#define GTEST_PRED_FORMAT4_(pred_format, v1, v2, v3, v4, on_failure)\
-  GTEST_ASSERT_(pred_format(#v1, #v2, #v3, #v4, v1, v2, v3, v4), \
-                on_failure)
-
-// Internal macro for implementing {EXPECT|ASSERT}_PRED4.  Don't use
-// this in your code.
-#define GTEST_PRED4_(pred, v1, v2, v3, v4, on_failure)\
-  GTEST_ASSERT_(::testing::AssertPred4Helper(#pred, \
-                                             #v1, \
-                                             #v2, \
-                                             #v3, \
-                                             #v4, \
-                                             pred, \
-                                             v1, \
-                                             v2, \
-                                             v3, \
-                                             v4), on_failure)
-
-// 4-ary predicate assertion macros.
-#define EXPECT_PRED_FORMAT4(pred_format, v1, v2, v3, v4) \
-  GTEST_PRED_FORMAT4_(pred_format, v1, v2, v3, v4, GTEST_NONFATAL_FAILURE_)
-#define EXPECT_PRED4(pred, v1, v2, v3, v4) \
-  GTEST_PRED4_(pred, v1, v2, v3, v4, GTEST_NONFATAL_FAILURE_)
-#define ASSERT_PRED_FORMAT4(pred_format, v1, v2, v3, v4) \
-  GTEST_PRED_FORMAT4_(pred_format, v1, v2, v3, v4, GTEST_FATAL_FAILURE_)
-#define ASSERT_PRED4(pred, v1, v2, v3, v4) \
-  GTEST_PRED4_(pred, v1, v2, v3, v4, GTEST_FATAL_FAILURE_)
-
-
-
-// Helper function for implementing {EXPECT|ASSERT}_PRED5.  Don't use
-// this in your code.
-template <typename Pred,
-          typename T1,
-          typename T2,
-          typename T3,
-          typename T4,
-          typename T5>
-AssertionResult AssertPred5Helper(const char* pred_text,
-                                  const char* e1,
-                                  const char* e2,
-                                  const char* e3,
-                                  const char* e4,
-                                  const char* e5,
-                                  Pred pred,
-                                  const T1& v1,
-                                  const T2& v2,
-                                  const T3& v3,
-                                  const T4& v4,
-                                  const T5& v5) {
-  if (pred(v1, v2, v3, v4, v5)) return AssertionSuccess();
-
-  return AssertionFailure()
-         << pred_text << "(" << e1 << ", " << e2 << ", " << e3 << ", " << e4
-         << ", " << e5 << ") evaluates to false, where"
-         << "\n"
-         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
-         << e2 << " evaluates to " << ::testing::PrintToString(v2) << "\n"
-         << e3 << " evaluates to " << ::testing::PrintToString(v3) << "\n"
-         << e4 << " evaluates to " << ::testing::PrintToString(v4) << "\n"
-         << e5 << " evaluates to " << ::testing::PrintToString(v5);
-}
-
-// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT5.
-// Don't use this in your code.
-#define GTEST_PRED_FORMAT5_(pred_format, v1, v2, v3, v4, v5, on_failure)\
-  GTEST_ASSERT_(pred_format(#v1, #v2, #v3, #v4, #v5, v1, v2, v3, v4, v5), \
-                on_failure)
-
-// Internal macro for implementing {EXPECT|ASSERT}_PRED5.  Don't use
-// this in your code.
-#define GTEST_PRED5_(pred, v1, v2, v3, v4, v5, on_failure)\
-  GTEST_ASSERT_(::testing::AssertPred5Helper(#pred, \
-                                             #v1, \
-                                             #v2, \
-                                             #v3, \
-                                             #v4, \
-                                             #v5, \
-                                             pred, \
-                                             v1, \
-                                             v2, \
-                                             v3, \
-                                             v4, \
-                                             v5), on_failure)
-
-// 5-ary predicate assertion macros.
-#define EXPECT_PRED_FORMAT5(pred_format, v1, v2, v3, v4, v5) \
-  GTEST_PRED_FORMAT5_(pred_format, v1, v2, v3, v4, v5, GTEST_NONFATAL_FAILURE_)
-#define EXPECT_PRED5(pred, v1, v2, v3, v4, v5) \
-  GTEST_PRED5_(pred, v1, v2, v3, v4, v5, GTEST_NONFATAL_FAILURE_)
-#define ASSERT_PRED_FORMAT5(pred_format, v1, v2, v3, v4, v5) \
-  GTEST_PRED_FORMAT5_(pred_format, v1, v2, v3, v4, v5, GTEST_FATAL_FAILURE_)
-#define ASSERT_PRED5(pred, v1, v2, v3, v4, v5) \
-  GTEST_PRED5_(pred, v1, v2, v3, v4, v5, GTEST_FATAL_FAILURE_)
-
-
-
-}  // namespace testing
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
-
-namespace testing {
-
-// The abstract class that all tests inherit from.
-//
-// In Google Test, a unit test program contains one or many TestSuites, and
-// each TestSuite contains one or many Tests.
-//
-// When you define a test using the TEST macro, you don't need to
-// explicitly derive from Test - the TEST macro automatically does
-// this for you.
-//
-// The only time you derive from Test is when defining a test fixture
-// to be used in a TEST_F.  For example:
-//
-//   class FooTest : public testing::Test {
-//    protected:
-//     void SetUp() override { ... }
-//     void TearDown() override { ... }
-//     ...
-//   };
-//
-//   TEST_F(FooTest, Bar) { ... }
-//   TEST_F(FooTest, Baz) { ... }
-//
-// Test is not copyable.
-class GTEST_API_ Test {
- public:
-  friend class TestInfo;
-
-  // The d'tor is virtual as we intend to inherit from Test.
-  virtual ~Test();
-
-  // Sets up the stuff shared by all tests in this test suite.
-  //
-  // Google Test will call Foo::SetUpTestSuite() before running the first
-  // test in test suite Foo.  Hence a sub-class can define its own
-  // SetUpTestSuite() method to shadow the one defined in the super
-  // class.
-  static void SetUpTestSuite() {}
-
-  // Tears down the stuff shared by all tests in this test suite.
-  //
-  // Google Test will call Foo::TearDownTestSuite() after running the last
-  // test in test suite Foo.  Hence a sub-class can define its own
-  // TearDownTestSuite() method to shadow the one defined in the super
-  // class.
-  static void TearDownTestSuite() {}
-
-  // Legacy API is deprecated but still available. Use SetUpTestSuite and
-  // TearDownTestSuite instead.
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  static void TearDownTestCase() {}
-  static void SetUpTestCase() {}
-#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  // Returns true if and only if the current test has a fatal failure.
-  static bool HasFatalFailure();
-
-  // Returns true if and only if the current test has a non-fatal failure.
-  static bool HasNonfatalFailure();
-
-  // Returns true if and only if the current test was skipped.
-  static bool IsSkipped();
-
-  // Returns true if and only if the current test has a (either fatal or
-  // non-fatal) failure.
-  static bool HasFailure() { return HasFatalFailure() || HasNonfatalFailure(); }
-
-  // Logs a property for the current test, test suite, or for the entire
-  // invocation of the test program when used outside of the context of a
-  // test suite.  Only the last value for a given key is remembered.  These
-  // are public static so they can be called from utility functions that are
-  // not members of the test fixture.  Calls to RecordProperty made during
-  // lifespan of the test (from the moment its constructor starts to the
-  // moment its destructor finishes) will be output in XML as attributes of
-  // the <testcase> element.  Properties recorded from fixture's
-  // SetUpTestSuite or TearDownTestSuite are logged as attributes of the
-  // corresponding <testsuite> element.  Calls to RecordProperty made in the
-  // global context (before or after invocation of RUN_ALL_TESTS and from
-  // SetUp/TearDown method of Environment objects registered with Google
-  // Test) will be output as attributes of the <testsuites> element.
-  static void RecordProperty(const std::string& key, const std::string& value);
-  static void RecordProperty(const std::string& key, int value);
-
- protected:
-  // Creates a Test object.
-  Test();
-
-  // Sets up the test fixture.
-  virtual void SetUp();
-
-  // Tears down the test fixture.
-  virtual void TearDown();
-
- private:
-  // Returns true if and only if the current test has the same fixture class
-  // as the first test in the current test suite.
-  static bool HasSameFixtureClass();
-
-  // Runs the test after the test fixture has been set up.
-  //
-  // A sub-class must implement this to define the test logic.
-  //
-  // DO NOT OVERRIDE THIS FUNCTION DIRECTLY IN A USER PROGRAM.
-  // Instead, use the TEST or TEST_F macro.
-  virtual void TestBody() = 0;
-
-  // Sets up, executes, and tears down the test.
-  void Run();
-
-  // Deletes self.  We deliberately pick an unusual name for this
-  // internal method to avoid clashing with names used in user TESTs.
-  void DeleteSelf_() { delete this; }
-
-  const std::unique_ptr<GTEST_FLAG_SAVER_> gtest_flag_saver_;
-
-  // Often a user misspells SetUp() as Setup() and spends a long time
-  // wondering why it is never called by Google Test.  The declaration of
-  // the following method is solely for catching such an error at
-  // compile time:
-  //
-  //   - The return type is deliberately chosen to be not void, so it
-  //   will be a conflict if void Setup() is declared in the user's
-  //   test fixture.
-  //
-  //   - This method is private, so it will be another compiler error
-  //   if the method is called from the user's test fixture.
-  //
-  // DO NOT OVERRIDE THIS FUNCTION.
-  //
-  // If you see an error about overriding the following function or
-  // about it being private, you have mis-spelled SetUp() as Setup().
-  struct Setup_should_be_spelled_SetUp {};
-  virtual Setup_should_be_spelled_SetUp* Setup() { return nullptr; }
-
-  // We disallow copying Tests.
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(Test);
-};
-
-typedef internal::TimeInMillis TimeInMillis;
-
-// A copyable object representing a user specified test property which can be
-// output as a key/value string pair.
-//
-// Don't inherit from TestProperty as its destructor is not virtual.
-class TestProperty {
- public:
-  // C'tor.  TestProperty does NOT have a default constructor.
-  // Always use this constructor (with parameters) to create a
-  // TestProperty object.
-  TestProperty(const std::string& a_key, const std::string& a_value) :
-    key_(a_key), value_(a_value) {
-  }
-
-  // Gets the user supplied key.
-  const char* key() const {
-    return key_.c_str();
-  }
-
-  // Gets the user supplied value.
-  const char* value() const {
-    return value_.c_str();
-  }
-
-  // Sets a new value, overriding the one supplied in the constructor.
-  void SetValue(const std::string& new_value) {
-    value_ = new_value;
-  }
-
- private:
-  // The key supplied by the user.
-  std::string key_;
-  // The value supplied by the user.
-  std::string value_;
-};
-
-// The result of a single Test.  This includes a list of
-// TestPartResults, a list of TestProperties, a count of how many
-// death tests there are in the Test, and how much time it took to run
-// the Test.
-//
-// TestResult is not copyable.
-class GTEST_API_ TestResult {
- public:
-  // Creates an empty TestResult.
-  TestResult();
-
-  // D'tor.  Do not inherit from TestResult.
-  ~TestResult();
-
-  // Gets the number of all test parts.  This is the sum of the number
-  // of successful test parts and the number of failed test parts.
-  int total_part_count() const;
-
-  // Returns the number of the test properties.
-  int test_property_count() const;
-
-  // Returns true if and only if the test passed (i.e. no test part failed).
-  bool Passed() const { return !Skipped() && !Failed(); }
-
-  // Returns true if and only if the test was skipped.
-  bool Skipped() const;
-
-  // Returns true if and only if the test failed.
-  bool Failed() const;
-
-  // Returns true if and only if the test fatally failed.
-  bool HasFatalFailure() const;
-
-  // Returns true if and only if the test has a non-fatal failure.
-  bool HasNonfatalFailure() const;
-
-  // Returns the elapsed time, in milliseconds.
-  TimeInMillis elapsed_time() const { return elapsed_time_; }
-
-  // Gets the time of the test case start, in ms from the start of the
-  // UNIX epoch.
-  TimeInMillis start_timestamp() const { return start_timestamp_; }
-
-  // Returns the i-th test part result among all the results. i can range from 0
-  // to total_part_count() - 1. If i is not in that range, aborts the program.
-  const TestPartResult& GetTestPartResult(int i) const;
-
-  // Returns the i-th test property. i can range from 0 to
-  // test_property_count() - 1. If i is not in that range, aborts the
-  // program.
-  const TestProperty& GetTestProperty(int i) const;
-
- private:
-  friend class TestInfo;
-  friend class TestSuite;
-  friend class UnitTest;
-  friend class internal::DefaultGlobalTestPartResultReporter;
-  friend class internal::ExecDeathTest;
-  friend class internal::TestResultAccessor;
-  friend class internal::UnitTestImpl;
-  friend class internal::WindowsDeathTest;
-  friend class internal::FuchsiaDeathTest;
-
-  // Gets the vector of TestPartResults.
-  const std::vector<TestPartResult>& test_part_results() const {
-    return test_part_results_;
-  }
-
-  // Gets the vector of TestProperties.
-  const std::vector<TestProperty>& test_properties() const {
-    return test_properties_;
-  }
-
-  // Sets the start time.
-  void set_start_timestamp(TimeInMillis start) { start_timestamp_ = start; }
-
-  // Sets the elapsed time.
-  void set_elapsed_time(TimeInMillis elapsed) { elapsed_time_ = elapsed; }
-
-  // Adds a test property to the list. The property is validated and may add
-  // a non-fatal failure if invalid (e.g., if it conflicts with reserved
-  // key names). If a property is already recorded for the same key, the
-  // value will be updated, rather than storing multiple values for the same
-  // key.  xml_element specifies the element for which the property is being
-  // recorded and is used for validation.
-  void RecordProperty(const std::string& xml_element,
-                      const TestProperty& test_property);
-
-  // Adds a failure if the key is a reserved attribute of Google Test
-  // testsuite tags.  Returns true if the property is valid.
-  // FIXME: Validate attribute names are legal and human readable.
-  static bool ValidateTestProperty(const std::string& xml_element,
-                                   const TestProperty& test_property);
-
-  // Adds a test part result to the list.
-  void AddTestPartResult(const TestPartResult& test_part_result);
-
-  // Returns the death test count.
-  int death_test_count() const { return death_test_count_; }
-
-  // Increments the death test count, returning the new count.
-  int increment_death_test_count() { return ++death_test_count_; }
-
-  // Clears the test part results.
-  void ClearTestPartResults();
-
-  // Clears the object.
-  void Clear();
-
-  // Protects mutable state of the property vector and of owned
-  // properties, whose values may be updated.
-  internal::Mutex test_properties_mutex_;
-
-  // The vector of TestPartResults
-  std::vector<TestPartResult> test_part_results_;
-  // The vector of TestProperties
-  std::vector<TestProperty> test_properties_;
-  // Running count of death tests.
-  int death_test_count_;
-  // The start time, in milliseconds since UNIX Epoch.
-  TimeInMillis start_timestamp_;
-  // The elapsed time, in milliseconds.
-  TimeInMillis elapsed_time_;
-
-  // We disallow copying TestResult.
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestResult);
-};  // class TestResult
-
-// A TestInfo object stores the following information about a test:
-//
-//   Test suite name
-//   Test name
-//   Whether the test should be run
-//   A function pointer that creates the test object when invoked
-//   Test result
-//
-// The constructor of TestInfo registers itself with the UnitTest
-// singleton such that the RUN_ALL_TESTS() macro knows which tests to
-// run.
-class GTEST_API_ TestInfo {
- public:
-  // Destructs a TestInfo object.  This function is not virtual, so
-  // don't inherit from TestInfo.
-  ~TestInfo();
-
-  // Returns the test suite name.
-  const char* test_suite_name() const { return test_suite_name_.c_str(); }
-
-// Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  const char* test_case_name() const { return test_suite_name(); }
-#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  // Returns the test name.
-  const char* name() const { return name_.c_str(); }
-
-  // Returns the name of the parameter type, or NULL if this is not a typed
-  // or a type-parameterized test.
-  const char* type_param() const {
-    if (type_param_.get() != nullptr) return type_param_->c_str();
-    return nullptr;
-  }
-
-  // Returns the text representation of the value parameter, or NULL if this
-  // is not a value-parameterized test.
-  const char* value_param() const {
-    if (value_param_.get() != nullptr) return value_param_->c_str();
-    return nullptr;
-  }
-
-  // Returns the file name where this test is defined.
-  const char* file() const { return location_.file.c_str(); }
-
-  // Returns the line where this test is defined.
-  int line() const { return location_.line; }
-
-  // Return true if this test should not be run because it's in another shard.
-  bool is_in_another_shard() const { return is_in_another_shard_; }
-
-  // Returns true if this test should run, that is if the test is not
-  // disabled (or it is disabled but the also_run_disabled_tests flag has
-  // been specified) and its full name matches the user-specified filter.
-  //
-  // Google Test allows the user to filter the tests by their full names.
-  // The full name of a test Bar in test suite Foo is defined as
-  // "Foo.Bar".  Only the tests that match the filter will run.
-  //
-  // A filter is a colon-separated list of glob (not regex) patterns,
-  // optionally followed by a '-' and a colon-separated list of
-  // negative patterns (tests to exclude).  A test is run if it
-  // matches one of the positive patterns and does not match any of
-  // the negative patterns.
-  //
-  // For example, *A*:Foo.* is a filter that matches any string that
-  // contains the character 'A' or starts with "Foo.".
-  bool should_run() const { return should_run_; }
-
-  // Returns true if and only if this test will appear in the XML report.
-  bool is_reportable() const {
-    // The XML report includes tests matching the filter, excluding those
-    // run in other shards.
-    return matches_filter_ && !is_in_another_shard_;
-  }
-
-  // Returns the result of the test.
-  const TestResult* result() const { return &result_; }
-
- private:
-#if GTEST_HAS_DEATH_TEST
-  friend class internal::DefaultDeathTestFactory;
-#endif  // GTEST_HAS_DEATH_TEST
-  friend class Test;
-  friend class TestSuite;
-  friend class internal::UnitTestImpl;
-  friend class internal::StreamingListenerTest;
-  friend TestInfo* internal::MakeAndRegisterTestInfo(
-      const char* test_suite_name, const char* name, const char* type_param,
-      const char* value_param, internal::CodeLocation code_location,
-      internal::TypeId fixture_class_id, internal::SetUpTestSuiteFunc set_up_tc,
-      internal::TearDownTestSuiteFunc tear_down_tc,
-      internal::TestFactoryBase* factory);
-
-  // Constructs a TestInfo object. The newly constructed instance assumes
-  // ownership of the factory object.
-  TestInfo(const std::string& test_suite_name, const std::string& name,
-           const char* a_type_param,   // NULL if not a type-parameterized test
-           const char* a_value_param,  // NULL if not a value-parameterized test
-           internal::CodeLocation a_code_location,
-           internal::TypeId fixture_class_id,
-           internal::TestFactoryBase* factory);
-
-  // Increments the number of death tests encountered in this test so
-  // far.
-  int increment_death_test_count() {
-    return result_.increment_death_test_count();
-  }
-
-  // Creates the test object, runs it, records its result, and then
-  // deletes it.
-  void Run();
-
-  // Skip and records the test result for this object.
-  void Skip();
-
-  static void ClearTestResult(TestInfo* test_info) {
-    test_info->result_.Clear();
-  }
-
-  // These fields are immutable properties of the test.
-  const std::string test_suite_name_;    // test suite name
-  const std::string name_;               // Test name
-  // Name of the parameter type, or NULL if this is not a typed or a
-  // type-parameterized test.
-  const std::unique_ptr<const ::std::string> type_param_;
-  // Text representation of the value parameter, or NULL if this is not a
-  // value-parameterized test.
-  const std::unique_ptr<const ::std::string> value_param_;
-  internal::CodeLocation location_;
-  const internal::TypeId fixture_class_id_;  // ID of the test fixture class
-  bool should_run_;           // True if and only if this test should run
-  bool is_disabled_;          // True if and only if this test is disabled
-  bool matches_filter_;       // True if this test matches the
-                              // user-specified filter.
-  bool is_in_another_shard_;  // Will be run in another shard.
-  internal::TestFactoryBase* const factory_;  // The factory that creates
-                                              // the test object
-
-  // This field is mutable and needs to be reset before running the
-  // test for the second time.
-  TestResult result_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestInfo);
-};
-
-// A test suite, which consists of a vector of TestInfos.
-//
-// TestSuite is not copyable.
-class GTEST_API_ TestSuite {
- public:
-  // Creates a TestSuite with the given name.
-  //
-  // TestSuite does NOT have a default constructor.  Always use this
-  // constructor to create a TestSuite object.
-  //
-  // Arguments:
-  //
-  //   name:         name of the test suite
-  //   a_type_param: the name of the test's type parameter, or NULL if
-  //                 this is not a type-parameterized test.
-  //   set_up_tc:    pointer to the function that sets up the test suite
-  //   tear_down_tc: pointer to the function that tears down the test suite
-  TestSuite(const char* name, const char* a_type_param,
-            internal::SetUpTestSuiteFunc set_up_tc,
-            internal::TearDownTestSuiteFunc tear_down_tc);
-
-  // Destructor of TestSuite.
-  virtual ~TestSuite();
-
-  // Gets the name of the TestSuite.
-  const char* name() const { return name_.c_str(); }
-
-  // Returns the name of the parameter type, or NULL if this is not a
-  // type-parameterized test suite.
-  const char* type_param() const {
-    if (type_param_.get() != nullptr) return type_param_->c_str();
-    return nullptr;
-  }
-
-  // Returns true if any test in this test suite should run.
-  bool should_run() const { return should_run_; }
-
-  // Gets the number of successful tests in this test suite.
-  int successful_test_count() const;
-
-  // Gets the number of skipped tests in this test suite.
-  int skipped_test_count() const;
-
-  // Gets the number of failed tests in this test suite.
-  int failed_test_count() const;
-
-  // Gets the number of disabled tests that will be reported in the XML report.
-  int reportable_disabled_test_count() const;
-
-  // Gets the number of disabled tests in this test suite.
-  int disabled_test_count() const;
-
-  // Gets the number of tests to be printed in the XML report.
-  int reportable_test_count() const;
-
-  // Get the number of tests in this test suite that should run.
-  int test_to_run_count() const;
-
-  // Gets the number of all tests in this test suite.
-  int total_test_count() const;
-
-  // Returns true if and only if the test suite passed.
-  bool Passed() const { return !Failed(); }
-
-  // Returns true if and only if the test suite failed.
-  bool Failed() const {
-    return failed_test_count() > 0 || ad_hoc_test_result().Failed();
-  }
-
-  // Returns the elapsed time, in milliseconds.
-  TimeInMillis elapsed_time() const { return elapsed_time_; }
-
-  // Gets the time of the test suite start, in ms from the start of the
-  // UNIX epoch.
-  TimeInMillis start_timestamp() const { return start_timestamp_; }
-
-  // Returns the i-th test among all the tests. i can range from 0 to
-  // total_test_count() - 1. If i is not in that range, returns NULL.
-  const TestInfo* GetTestInfo(int i) const;
-
-  // Returns the TestResult that holds test properties recorded during
-  // execution of SetUpTestSuite and TearDownTestSuite.
-  const TestResult& ad_hoc_test_result() const { return ad_hoc_test_result_; }
-
- private:
-  friend class Test;
-  friend class internal::UnitTestImpl;
-
-  // Gets the (mutable) vector of TestInfos in this TestSuite.
-  std::vector<TestInfo*>& test_info_list() { return test_info_list_; }
-
-  // Gets the (immutable) vector of TestInfos in this TestSuite.
-  const std::vector<TestInfo*>& test_info_list() const {
-    return test_info_list_;
-  }
-
-  // Returns the i-th test among all the tests. i can range from 0 to
-  // total_test_count() - 1. If i is not in that range, returns NULL.
-  TestInfo* GetMutableTestInfo(int i);
-
-  // Sets the should_run member.
-  void set_should_run(bool should) { should_run_ = should; }
-
-  // Adds a TestInfo to this test suite.  Will delete the TestInfo upon
-  // destruction of the TestSuite object.
-  void AddTestInfo(TestInfo * test_info);
-
-  // Clears the results of all tests in this test suite.
-  void ClearResult();
-
-  // Clears the results of all tests in the given test suite.
-  static void ClearTestSuiteResult(TestSuite* test_suite) {
-    test_suite->ClearResult();
-  }
-
-  // Runs every test in this TestSuite.
-  void Run();
-
-  // Skips the execution of tests under this TestSuite
-  void Skip();
-
-  // Runs SetUpTestSuite() for this TestSuite.  This wrapper is needed
-  // for catching exceptions thrown from SetUpTestSuite().
-  void RunSetUpTestSuite() {
-    if (set_up_tc_ != nullptr) {
-      (*set_up_tc_)();
-    }
-  }
-
-  // Runs TearDownTestSuite() for this TestSuite.  This wrapper is
-  // needed for catching exceptions thrown from TearDownTestSuite().
-  void RunTearDownTestSuite() {
-    if (tear_down_tc_ != nullptr) {
-      (*tear_down_tc_)();
-    }
-  }
-
-  // Returns true if and only if test passed.
-  static bool TestPassed(const TestInfo* test_info) {
-    return test_info->should_run() && test_info->result()->Passed();
-  }
-
-  // Returns true if and only if test skipped.
-  static bool TestSkipped(const TestInfo* test_info) {
-    return test_info->should_run() && test_info->result()->Skipped();
-  }
-
-  // Returns true if and only if test failed.
-  static bool TestFailed(const TestInfo* test_info) {
-    return test_info->should_run() && test_info->result()->Failed();
-  }
-
-  // Returns true if and only if the test is disabled and will be reported in
-  // the XML report.
-  static bool TestReportableDisabled(const TestInfo* test_info) {
-    return test_info->is_reportable() && test_info->is_disabled_;
-  }
-
-  // Returns true if and only if test is disabled.
-  static bool TestDisabled(const TestInfo* test_info) {
-    return test_info->is_disabled_;
-  }
-
-  // Returns true if and only if this test will appear in the XML report.
-  static bool TestReportable(const TestInfo* test_info) {
-    return test_info->is_reportable();
-  }
-
-  // Returns true if the given test should run.
-  static bool ShouldRunTest(const TestInfo* test_info) {
-    return test_info->should_run();
-  }
-
-  // Shuffles the tests in this test suite.
-  void ShuffleTests(internal::Random* random);
-
-  // Restores the test order to before the first shuffle.
-  void UnshuffleTests();
-
-  // Name of the test suite.
-  std::string name_;
-  // Name of the parameter type, or NULL if this is not a typed or a
-  // type-parameterized test.
-  const std::unique_ptr<const ::std::string> type_param_;
-  // The vector of TestInfos in their original order.  It owns the
-  // elements in the vector.
-  std::vector<TestInfo*> test_info_list_;
-  // Provides a level of indirection for the test list to allow easy
-  // shuffling and restoring the test order.  The i-th element in this
-  // vector is the index of the i-th test in the shuffled test list.
-  std::vector<int> test_indices_;
-  // Pointer to the function that sets up the test suite.
-  internal::SetUpTestSuiteFunc set_up_tc_;
-  // Pointer to the function that tears down the test suite.
-  internal::TearDownTestSuiteFunc tear_down_tc_;
-  // True if and only if any test in this test suite should run.
-  bool should_run_;
-  // The start time, in milliseconds since UNIX Epoch.
-  TimeInMillis start_timestamp_;
-  // Elapsed time, in milliseconds.
-  TimeInMillis elapsed_time_;
-  // Holds test properties recorded during execution of SetUpTestSuite and
-  // TearDownTestSuite.
-  TestResult ad_hoc_test_result_;
-
-  // We disallow copying TestSuites.
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestSuite);
-};
-
-// An Environment object is capable of setting up and tearing down an
-// environment.  You should subclass this to define your own
-// environment(s).
-//
-// An Environment object does the set-up and tear-down in virtual
-// methods SetUp() and TearDown() instead of the constructor and the
-// destructor, as:
-//
-//   1. You cannot safely throw from a destructor.  This is a problem
-//      as in some cases Google Test is used where exceptions are enabled, and
-//      we may want to implement ASSERT_* using exceptions where they are
-//      available.
-//   2. You cannot use ASSERT_* directly in a constructor or
-//      destructor.
-class Environment {
- public:
-  // The d'tor is virtual as we need to subclass Environment.
-  virtual ~Environment() {}
-
-  // Override this to define how to set up the environment.
-  virtual void SetUp() {}
-
-  // Override this to define how to tear down the environment.
-  virtual void TearDown() {}
- private:
-  // If you see an error about overriding the following function or
-  // about it being private, you have mis-spelled SetUp() as Setup().
-  struct Setup_should_be_spelled_SetUp {};
-  virtual Setup_should_be_spelled_SetUp* Setup() { return nullptr; }
-};
-
-#if GTEST_HAS_EXCEPTIONS
-
-// Exception which can be thrown from TestEventListener::OnTestPartResult.
-class GTEST_API_ AssertionException
-    : public internal::GoogleTestFailureException {
- public:
-  explicit AssertionException(const TestPartResult& result)
-      : GoogleTestFailureException(result) {}
-};
-
-#endif  // GTEST_HAS_EXCEPTIONS
-
-// The interface for tracing execution of tests. The methods are organized in
-// the order the corresponding events are fired.
-class TestEventListener {
- public:
-  virtual ~TestEventListener() {}
-
-  // Fired before any test activity starts.
-  virtual void OnTestProgramStart(const UnitTest& unit_test) = 0;
-
-  // Fired before each iteration of tests starts.  There may be more than
-  // one iteration if GTEST_FLAG(repeat) is set. iteration is the iteration
-  // index, starting from 0.
-  virtual void OnTestIterationStart(const UnitTest& unit_test,
-                                    int iteration) = 0;
-
-  // Fired before environment set-up for each iteration of tests starts.
-  virtual void OnEnvironmentsSetUpStart(const UnitTest& unit_test) = 0;
-
-  // Fired after environment set-up for each iteration of tests ends.
-  virtual void OnEnvironmentsSetUpEnd(const UnitTest& unit_test) = 0;
-
-  // Fired before the test suite starts.
-  virtual void OnTestSuiteStart(const TestSuite& /*test_suite*/) {}
-
-  //  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  virtual void OnTestCaseStart(const TestCase& /*test_case*/) {}
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  // Fired before the test starts.
-  virtual void OnTestStart(const TestInfo& test_info) = 0;
-
-  // Fired after a failed assertion or a SUCCEED() invocation.
-  // If you want to throw an exception from this function to skip to the next
-  // TEST, it must be AssertionException defined above, or inherited from it.
-  virtual void OnTestPartResult(const TestPartResult& test_part_result) = 0;
-
-  // Fired after the test ends.
-  virtual void OnTestEnd(const TestInfo& test_info) = 0;
-
-  // Fired after the test suite ends.
-  virtual void OnTestSuiteEnd(const TestSuite& /*test_suite*/) {}
-
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  virtual void OnTestCaseEnd(const TestCase& /*test_case*/) {}
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  // Fired before environment tear-down for each iteration of tests starts.
-  virtual void OnEnvironmentsTearDownStart(const UnitTest& unit_test) = 0;
-
-  // Fired after environment tear-down for each iteration of tests ends.
-  virtual void OnEnvironmentsTearDownEnd(const UnitTest& unit_test) = 0;
-
-  // Fired after each iteration of tests finishes.
-  virtual void OnTestIterationEnd(const UnitTest& unit_test,
-                                  int iteration) = 0;
-
-  // Fired after all test activities have ended.
-  virtual void OnTestProgramEnd(const UnitTest& unit_test) = 0;
-};
-
-// The convenience class for users who need to override just one or two
-// methods and are not concerned that a possible change to a signature of
-// the methods they override will not be caught during the build.  For
-// comments about each method please see the definition of TestEventListener
-// above.
-class EmptyTestEventListener : public TestEventListener {
- public:
-  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {}
-  void OnTestIterationStart(const UnitTest& /*unit_test*/,
-                            int /*iteration*/) override {}
-  void OnEnvironmentsSetUpStart(const UnitTest& /*unit_test*/) override {}
-  void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {}
-  void OnTestSuiteStart(const TestSuite& /*test_suite*/) override {}
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  void OnTestCaseStart(const TestCase& /*test_case*/) override {}
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  void OnTestStart(const TestInfo& /*test_info*/) override {}
-  void OnTestPartResult(const TestPartResult& /*test_part_result*/) override {}
-  void OnTestEnd(const TestInfo& /*test_info*/) override {}
-  void OnTestSuiteEnd(const TestSuite& /*test_suite*/) override {}
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  void OnTestCaseEnd(const TestCase& /*test_case*/) override {}
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  void OnEnvironmentsTearDownStart(const UnitTest& /*unit_test*/) override {}
-  void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {}
-  void OnTestIterationEnd(const UnitTest& /*unit_test*/,
-                          int /*iteration*/) override {}
-  void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {}
-};
-
-// TestEventListeners lets users add listeners to track events in Google Test.
-class GTEST_API_ TestEventListeners {
- public:
-  TestEventListeners();
-  ~TestEventListeners();
-
-  // Appends an event listener to the end of the list. Google Test assumes
-  // the ownership of the listener (i.e. it will delete the listener when
-  // the test program finishes).
-  void Append(TestEventListener* listener);
-
-  // Removes the given event listener from the list and returns it.  It then
-  // becomes the caller's responsibility to delete the listener. Returns
-  // NULL if the listener is not found in the list.
-  TestEventListener* Release(TestEventListener* listener);
-
-  // Returns the standard listener responsible for the default console
-  // output.  Can be removed from the listeners list to shut down default
-  // console output.  Note that removing this object from the listener list
-  // with Release transfers its ownership to the caller and makes this
-  // function return NULL the next time.
-  TestEventListener* default_result_printer() const {
-    return default_result_printer_;
-  }
-
-  // Returns the standard listener responsible for the default XML output
-  // controlled by the --gtest_output=xml flag.  Can be removed from the
-  // listeners list by users who want to shut down the default XML output
-  // controlled by this flag and substitute it with custom one.  Note that
-  // removing this object from the listener list with Release transfers its
-  // ownership to the caller and makes this function return NULL the next
-  // time.
-  TestEventListener* default_xml_generator() const {
-    return default_xml_generator_;
-  }
-
- private:
-  friend class TestSuite;
-  friend class TestInfo;
-  friend class internal::DefaultGlobalTestPartResultReporter;
-  friend class internal::NoExecDeathTest;
-  friend class internal::TestEventListenersAccessor;
-  friend class internal::UnitTestImpl;
-
-  // Returns repeater that broadcasts the TestEventListener events to all
-  // subscribers.
-  TestEventListener* repeater();
-
-  // Sets the default_result_printer attribute to the provided listener.
-  // The listener is also added to the listener list and previous
-  // default_result_printer is removed from it and deleted. The listener can
-  // also be NULL in which case it will not be added to the list. Does
-  // nothing if the previous and the current listener objects are the same.
-  void SetDefaultResultPrinter(TestEventListener* listener);
-
-  // Sets the default_xml_generator attribute to the provided listener.  The
-  // listener is also added to the listener list and previous
-  // default_xml_generator is removed from it and deleted. The listener can
-  // also be NULL in which case it will not be added to the list. Does
-  // nothing if the previous and the current listener objects are the same.
-  void SetDefaultXmlGenerator(TestEventListener* listener);
-
-  // Controls whether events will be forwarded by the repeater to the
-  // listeners in the list.
-  bool EventForwardingEnabled() const;
-  void SuppressEventForwarding();
-
-  // The actual list of listeners.
-  internal::TestEventRepeater* repeater_;
-  // Listener responsible for the standard result output.
-  TestEventListener* default_result_printer_;
-  // Listener responsible for the creation of the XML output file.
-  TestEventListener* default_xml_generator_;
-
-  // We disallow copying TestEventListeners.
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestEventListeners);
-};
-
-// A UnitTest consists of a vector of TestSuites.
-//
-// This is a singleton class.  The only instance of UnitTest is
-// created when UnitTest::GetInstance() is first called.  This
-// instance is never deleted.
-//
-// UnitTest is not copyable.
-//
-// This class is thread-safe as long as the methods are called
-// according to their specification.
-class GTEST_API_ UnitTest {
- public:
-  // Gets the singleton UnitTest object.  The first time this method
-  // is called, a UnitTest object is constructed and returned.
-  // Consecutive calls will return the same object.
-  static UnitTest* GetInstance();
-
-  // Runs all tests in this UnitTest object and prints the result.
-  // Returns 0 if successful, or 1 otherwise.
-  //
-  // This method can only be called from the main thread.
-  //
-  // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-  int Run() GTEST_MUST_USE_RESULT_;
-
-  // Returns the working directory when the first TEST() or TEST_F()
-  // was executed.  The UnitTest object owns the string.
-  const char* original_working_dir() const;
-
-  // Returns the TestSuite object for the test that's currently running,
-  // or NULL if no test is running.
-  const TestSuite* current_test_suite() const GTEST_LOCK_EXCLUDED_(mutex_);
-
-// Legacy API is still available but deprecated
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  const TestCase* current_test_case() const GTEST_LOCK_EXCLUDED_(mutex_);
-#endif
-
-  // Returns the TestInfo object for the test that's currently running,
-  // or NULL if no test is running.
-  const TestInfo* current_test_info() const
-      GTEST_LOCK_EXCLUDED_(mutex_);
-
-  // Returns the random seed used at the start of the current test run.
-  int random_seed() const;
-
-  // Returns the ParameterizedTestSuiteRegistry object used to keep track of
-  // value-parameterized tests and instantiate and register them.
-  //
-  // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-  internal::ParameterizedTestSuiteRegistry& parameterized_test_registry()
-      GTEST_LOCK_EXCLUDED_(mutex_);
-
-  // Gets the number of successful test suites.
-  int successful_test_suite_count() const;
-
-  // Gets the number of failed test suites.
-  int failed_test_suite_count() const;
-
-  // Gets the number of all test suites.
-  int total_test_suite_count() const;
-
-  // Gets the number of all test suites that contain at least one test
-  // that should run.
-  int test_suite_to_run_count() const;
-
-  //  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  int successful_test_case_count() const;
-  int failed_test_case_count() const;
-  int total_test_case_count() const;
-  int test_case_to_run_count() const;
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  // Gets the number of successful tests.
-  int successful_test_count() const;
-
-  // Gets the number of skipped tests.
-  int skipped_test_count() const;
-
-  // Gets the number of failed tests.
-  int failed_test_count() const;
-
-  // Gets the number of disabled tests that will be reported in the XML report.
-  int reportable_disabled_test_count() const;
-
-  // Gets the number of disabled tests.
-  int disabled_test_count() const;
-
-  // Gets the number of tests to be printed in the XML report.
-  int reportable_test_count() const;
-
-  // Gets the number of all tests.
-  int total_test_count() const;
-
-  // Gets the number of tests that should run.
-  int test_to_run_count() const;
-
-  // Gets the time of the test program start, in ms from the start of the
-  // UNIX epoch.
-  TimeInMillis start_timestamp() const;
-
-  // Gets the elapsed time, in milliseconds.
-  TimeInMillis elapsed_time() const;
-
-  // Returns true if and only if the unit test passed (i.e. all test suites
-  // passed).
-  bool Passed() const;
-
-  // Returns true if and only if the unit test failed (i.e. some test suite
-  // failed or something outside of all tests failed).
-  bool Failed() const;
-
-  // Gets the i-th test suite among all the test suites. i can range from 0 to
-  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
-  const TestSuite* GetTestSuite(int i) const;
-
-//  Legacy API is deprecated but still available
-#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-  const TestCase* GetTestCase(int i) const;
-#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
-
-  // Returns the TestResult containing information on test failures and
-  // properties logged outside of individual test suites.
-  const TestResult& ad_hoc_test_result() const;
-
-  // Returns the list of event listeners that can be used to track events
-  // inside Google Test.
-  TestEventListeners& listeners();
-
- private:
-  // Registers and returns a global test environment.  When a test
-  // program is run, all global test environments will be set-up in
-  // the order they were registered.  After all tests in the program
-  // have finished, all global test environments will be torn-down in
-  // the *reverse* order they were registered.
-  //
-  // The UnitTest object takes ownership of the given environment.
-  //
-  // This method can only be called from the main thread.
-  Environment* AddEnvironment(Environment* env);
-
-  // Adds a TestPartResult to the current TestResult object.  All
-  // Google Test assertion macros (e.g. ASSERT_TRUE, EXPECT_EQ, etc)
-  // eventually call this to report their results.  The user code
-  // should use the assertion macros instead of calling this directly.
-  void AddTestPartResult(TestPartResult::Type result_type,
-                         const char* file_name,
-                         int line_number,
-                         const std::string& message,
-                         const std::string& os_stack_trace)
-      GTEST_LOCK_EXCLUDED_(mutex_);
-
-  // Adds a TestProperty to the current TestResult object when invoked from
-  // inside a test, to current TestSuite's ad_hoc_test_result_ when invoked
-  // from SetUpTestSuite or TearDownTestSuite, or to the global property set
-  // when invoked elsewhere.  If the result already contains a property with
-  // the same key, the value will be updated.
-  void RecordProperty(const std::string& key, const std::string& value);
-
-  // Gets the i-th test suite among all the test suites. i can range from 0 to
-  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
-  TestSuite* GetMutableTestSuite(int i);
-
-  // Accessors for the implementation object.
-  internal::UnitTestImpl* impl() { return impl_; }
-  const internal::UnitTestImpl* impl() const { return impl_; }
-
-  // These classes and functions are friends as they need to access private
-  // members of UnitTest.
-  friend class ScopedTrace;
-  friend class Test;
-  friend class internal::AssertHelper;
-  friend class internal::StreamingListenerTest;
-  friend class internal::UnitTestRecordPropertyTestHelper;
-  friend Environment* AddGlobalTestEnvironment(Environment* env);
-  friend std::set<std::string>* internal::GetIgnoredParameterizedTestSuites();
-  friend internal::UnitTestImpl* internal::GetUnitTestImpl();
-  friend void internal::ReportFailureInUnknownLocation(
-      TestPartResult::Type result_type,
-      const std::string& message);
-
-  // Creates an empty UnitTest.
-  UnitTest();
-
-  // D'tor
-  virtual ~UnitTest();
-
-  // Pushes a trace defined by SCOPED_TRACE() on to the per-thread
-  // Google Test trace stack.
-  void PushGTestTrace(const internal::TraceInfo& trace)
-      GTEST_LOCK_EXCLUDED_(mutex_);
-
-  // Pops a trace from the per-thread Google Test trace stack.
-  void PopGTestTrace()
-      GTEST_LOCK_EXCLUDED_(mutex_);
-
-  // Protects mutable state in *impl_.  This is mutable as some const
-  // methods need to lock it too.
-  mutable internal::Mutex mutex_;
-
-  // Opaque implementation object.  This field is never changed once
-  // the object is constructed.  We don't mark it as const here, as
-  // doing so will cause a warning in the constructor of UnitTest.
-  // Mutable state in *impl_ is protected by mutex_.
-  internal::UnitTestImpl* impl_;
-
-  // We disallow copying UnitTest.
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(UnitTest);
-};
-
-// A convenient wrapper for adding an environment for the test
-// program.
-//
-// You should call this before RUN_ALL_TESTS() is called, probably in
-// main().  If you use gtest_main, you need to call this before main()
-// starts for it to take effect.  For example, you can define a global
-// variable like this:
-//
-//   testing::Environment* const foo_env =
-//       testing::AddGlobalTestEnvironment(new FooEnvironment);
-//
-// However, we strongly recommend you to write your own main() and
-// call AddGlobalTestEnvironment() there, as relying on initialization
-// of global variables makes the code harder to read and may cause
-// problems when you register multiple environments from different
-// translation units and the environments have dependencies among them
-// (remember that the compiler doesn't guarantee the order in which
-// global variables from different translation units are initialized).
-inline Environment* AddGlobalTestEnvironment(Environment* env) {
-  return UnitTest::GetInstance()->AddEnvironment(env);
-}
-
-// Initializes Google Test.  This must be called before calling
-// RUN_ALL_TESTS().  In particular, it parses a command line for the
-// flags that Google Test recognizes.  Whenever a Google Test flag is
-// seen, it is removed from argv, and *argc is decremented.
-//
-// No value is returned.  Instead, the Google Test flag variables are
-// updated.
-//
-// Calling the function for the second time has no user-visible effect.
-GTEST_API_ void InitGoogleTest(int* argc, char** argv);
-
-// This overloaded version can be used in Windows programs compiled in
-// UNICODE mode.
-GTEST_API_ void InitGoogleTest(int* argc, wchar_t** argv);
-
-// This overloaded version can be used on Arduino/embedded platforms where
-// there is no argc/argv.
-GTEST_API_ void InitGoogleTest();
-
-namespace internal {
-
-// Separate the error generating code from the code path to reduce the stack
-// frame size of CmpHelperEQ. This helps reduce the overhead of some sanitizers
-// when calling EXPECT_* in a tight loop.
-template <typename T1, typename T2>
-AssertionResult CmpHelperEQFailure(const char* lhs_expression,
-                                   const char* rhs_expression,
-                                   const T1& lhs, const T2& rhs) {
-  return EqFailure(lhs_expression,
-                   rhs_expression,
-                   FormatForComparisonFailureMessage(lhs, rhs),
-                   FormatForComparisonFailureMessage(rhs, lhs),
-                   false);
-}
-
-// This block of code defines operator==/!=
-// to block lexical scope lookup.
-// It prevents using invalid operator==/!= defined at namespace scope.
-struct faketype {};
-inline bool operator==(faketype, faketype) { return true; }
-inline bool operator!=(faketype, faketype) { return false; }
-
-// The helper function for {ASSERT|EXPECT}_EQ.
-template <typename T1, typename T2>
-AssertionResult CmpHelperEQ(const char* lhs_expression,
-                            const char* rhs_expression,
-                            const T1& lhs,
-                            const T2& rhs) {
-  if (lhs == rhs) {
-    return AssertionSuccess();
-  }
-
-  return CmpHelperEQFailure(lhs_expression, rhs_expression, lhs, rhs);
-}
-
-class EqHelper {
- public:
-  // This templatized version is for the general case.
-  template <
-      typename T1, typename T2,
-      // Disable this overload for cases where one argument is a pointer
-      // and the other is the null pointer constant.
-      typename std::enable_if<!std::is_integral<T1>::value ||
-                              !std::is_pointer<T2>::value>::type* = nullptr>
-  static AssertionResult Compare(const char* lhs_expression,
-                                 const char* rhs_expression, const T1& lhs,
-                                 const T2& rhs) {
-    return CmpHelperEQ(lhs_expression, rhs_expression, lhs, rhs);
-  }
-
-  // With this overloaded version, we allow anonymous enums to be used
-  // in {ASSERT|EXPECT}_EQ when compiled with gcc 4, as anonymous
-  // enums can be implicitly cast to BiggestInt.
-  //
-  // Even though its body looks the same as the above version, we
-  // cannot merge the two, as it will make anonymous enums unhappy.
-  static AssertionResult Compare(const char* lhs_expression,
-                                 const char* rhs_expression,
-                                 BiggestInt lhs,
-                                 BiggestInt rhs) {
-    return CmpHelperEQ(lhs_expression, rhs_expression, lhs, rhs);
-  }
-
-  template <typename T>
-  static AssertionResult Compare(
-      const char* lhs_expression, const char* rhs_expression,
-      // Handle cases where '0' is used as a null pointer literal.
-      std::nullptr_t /* lhs */, T* rhs) {
-    // We already know that 'lhs' is a null pointer.
-    return CmpHelperEQ(lhs_expression, rhs_expression, static_cast<T*>(nullptr),
-                       rhs);
-  }
-};
-
-// Separate the error generating code from the code path to reduce the stack
-// frame size of CmpHelperOP. This helps reduce the overhead of some sanitizers
-// when calling EXPECT_OP in a tight loop.
-template <typename T1, typename T2>
-AssertionResult CmpHelperOpFailure(const char* expr1, const char* expr2,
-                                   const T1& val1, const T2& val2,
-                                   const char* op) {
-  return AssertionFailure()
-         << "Expected: (" << expr1 << ") " << op << " (" << expr2
-         << "), actual: " << FormatForComparisonFailureMessage(val1, val2)
-         << " vs " << FormatForComparisonFailureMessage(val2, val1);
-}
-
-// A macro for implementing the helper functions needed to implement
-// ASSERT_?? and EXPECT_??.  It is here just to avoid copy-and-paste
-// of similar code.
-//
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-
-#define GTEST_IMPL_CMP_HELPER_(op_name, op)\
-template <typename T1, typename T2>\
-AssertionResult CmpHelper##op_name(const char* expr1, const char* expr2, \
-                                   const T1& val1, const T2& val2) {\
-  if (val1 op val2) {\
-    return AssertionSuccess();\
-  } else {\
-    return CmpHelperOpFailure(expr1, expr2, val1, val2, #op);\
-  }\
-}
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-
-// Implements the helper function for {ASSERT|EXPECT}_NE
-GTEST_IMPL_CMP_HELPER_(NE, !=)
-// Implements the helper function for {ASSERT|EXPECT}_LE
-GTEST_IMPL_CMP_HELPER_(LE, <=)
-// Implements the helper function for {ASSERT|EXPECT}_LT
-GTEST_IMPL_CMP_HELPER_(LT, <)
-// Implements the helper function for {ASSERT|EXPECT}_GE
-GTEST_IMPL_CMP_HELPER_(GE, >=)
-// Implements the helper function for {ASSERT|EXPECT}_GT
-GTEST_IMPL_CMP_HELPER_(GT, >)
-
-#undef GTEST_IMPL_CMP_HELPER_
-
-// The helper function for {ASSERT|EXPECT}_STREQ.
-//
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-GTEST_API_ AssertionResult CmpHelperSTREQ(const char* s1_expression,
-                                          const char* s2_expression,
-                                          const char* s1,
-                                          const char* s2);
-
-// The helper function for {ASSERT|EXPECT}_STRCASEEQ.
-//
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-GTEST_API_ AssertionResult CmpHelperSTRCASEEQ(const char* s1_expression,
-                                              const char* s2_expression,
-                                              const char* s1,
-                                              const char* s2);
-
-// The helper function for {ASSERT|EXPECT}_STRNE.
-//
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-GTEST_API_ AssertionResult CmpHelperSTRNE(const char* s1_expression,
-                                          const char* s2_expression,
-                                          const char* s1,
-                                          const char* s2);
-
-// The helper function for {ASSERT|EXPECT}_STRCASENE.
-//
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-GTEST_API_ AssertionResult CmpHelperSTRCASENE(const char* s1_expression,
-                                              const char* s2_expression,
-                                              const char* s1,
-                                              const char* s2);
-
-
-// Helper function for *_STREQ on wide strings.
-//
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-GTEST_API_ AssertionResult CmpHelperSTREQ(const char* s1_expression,
-                                          const char* s2_expression,
-                                          const wchar_t* s1,
-                                          const wchar_t* s2);
-
-// Helper function for *_STRNE on wide strings.
-//
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-GTEST_API_ AssertionResult CmpHelperSTRNE(const char* s1_expression,
-                                          const char* s2_expression,
-                                          const wchar_t* s1,
-                                          const wchar_t* s2);
-
-}  // namespace internal
-
-// IsSubstring() and IsNotSubstring() are intended to be used as the
-// first argument to {EXPECT,ASSERT}_PRED_FORMAT2(), not by
-// themselves.  They check whether needle is a substring of haystack
-// (NULL is considered a substring of itself only), and return an
-// appropriate error message when they fail.
-//
-// The {needle,haystack}_expr arguments are the stringified
-// expressions that generated the two real arguments.
-GTEST_API_ AssertionResult IsSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const char* needle, const char* haystack);
-GTEST_API_ AssertionResult IsSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const wchar_t* needle, const wchar_t* haystack);
-GTEST_API_ AssertionResult IsNotSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const char* needle, const char* haystack);
-GTEST_API_ AssertionResult IsNotSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const wchar_t* needle, const wchar_t* haystack);
-GTEST_API_ AssertionResult IsSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const ::std::string& needle, const ::std::string& haystack);
-GTEST_API_ AssertionResult IsNotSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const ::std::string& needle, const ::std::string& haystack);
-
-#if GTEST_HAS_STD_WSTRING
-GTEST_API_ AssertionResult IsSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const ::std::wstring& needle, const ::std::wstring& haystack);
-GTEST_API_ AssertionResult IsNotSubstring(
-    const char* needle_expr, const char* haystack_expr,
-    const ::std::wstring& needle, const ::std::wstring& haystack);
-#endif  // GTEST_HAS_STD_WSTRING
-
-namespace internal {
-
-// Helper template function for comparing floating-points.
-//
-// Template parameter:
-//
-//   RawType: the raw floating-point type (either float or double)
-//
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-template <typename RawType>
-AssertionResult CmpHelperFloatingPointEQ(const char* lhs_expression,
-                                         const char* rhs_expression,
-                                         RawType lhs_value,
-                                         RawType rhs_value) {
-  const FloatingPoint<RawType> lhs(lhs_value), rhs(rhs_value);
-
-  if (lhs.AlmostEquals(rhs)) {
-    return AssertionSuccess();
-  }
-
-  ::std::stringstream lhs_ss;
-  lhs_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
-         << lhs_value;
-
-  ::std::stringstream rhs_ss;
-  rhs_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
-         << rhs_value;
-
-  return EqFailure(lhs_expression,
-                   rhs_expression,
-                   StringStreamToString(&lhs_ss),
-                   StringStreamToString(&rhs_ss),
-                   false);
-}
-
-// Helper function for implementing ASSERT_NEAR.
-//
-// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
-GTEST_API_ AssertionResult DoubleNearPredFormat(const char* expr1,
-                                                const char* expr2,
-                                                const char* abs_error_expr,
-                                                double val1,
-                                                double val2,
-                                                double abs_error);
-
-// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
-// A class that enables one to stream messages to assertion macros
-class GTEST_API_ AssertHelper {
- public:
-  // Constructor.
-  AssertHelper(TestPartResult::Type type,
-               const char* file,
-               int line,
-               const char* message);
-  ~AssertHelper();
-
-  // Message assignment is a semantic trick to enable assertion
-  // streaming; see the GTEST_MESSAGE_ macro below.
-  void operator=(const Message& message) const;
-
- private:
-  // We put our data in a struct so that the size of the AssertHelper class can
-  // be as small as possible.  This is important because gcc is incapable of
-  // re-using stack space even for temporary variables, so every EXPECT_EQ
-  // reserves stack space for another AssertHelper.
-  struct AssertHelperData {
-    AssertHelperData(TestPartResult::Type t,
-                     const char* srcfile,
-                     int line_num,
-                     const char* msg)
-        : type(t), file(srcfile), line(line_num), message(msg) { }
-
-    TestPartResult::Type const type;
-    const char* const file;
-    int const line;
-    std::string const message;
-
-   private:
-    GTEST_DISALLOW_COPY_AND_ASSIGN_(AssertHelperData);
-  };
-
-  AssertHelperData* const data_;
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(AssertHelper);
-};
-
-}  // namespace internal
-
-// The pure interface class that all value-parameterized tests inherit from.
-// A value-parameterized class must inherit from both ::testing::Test and
-// ::testing::WithParamInterface. In most cases that just means inheriting
-// from ::testing::TestWithParam, but more complicated test hierarchies
-// may need to inherit from Test and WithParamInterface at different levels.
-//
-// This interface has support for accessing the test parameter value via
-// the GetParam() method.
-//
-// Use it with one of the parameter generator defining functions, like Range(),
-// Values(), ValuesIn(), Bool(), and Combine().
-//
-// class FooTest : public ::testing::TestWithParam<int> {
-//  protected:
-//   FooTest() {
-//     // Can use GetParam() here.
-//   }
-//   ~FooTest() override {
-//     // Can use GetParam() here.
-//   }
-//   void SetUp() override {
-//     // Can use GetParam() here.
-//   }
-//   void TearDown override {
-//     // Can use GetParam() here.
-//   }
-// };
-// TEST_P(FooTest, DoesBar) {
-//   // Can use GetParam() method here.
-//   Foo foo;
-//   ASSERT_TRUE(foo.DoesBar(GetParam()));
-// }
-// INSTANTIATE_TEST_SUITE_P(OneToTenRange, FooTest, ::testing::Range(1, 10));
-
-template <typename T>
-class WithParamInterface {
- public:
-  typedef T ParamType;
-  virtual ~WithParamInterface() {}
-
-  // The current parameter value. Is also available in the test fixture's
-  // constructor.
-  static const ParamType& GetParam() {
-    GTEST_CHECK_(parameter_ != nullptr)
-        << "GetParam() can only be called inside a value-parameterized test "
-        << "-- did you intend to write TEST_P instead of TEST_F?";
-    return *parameter_;
-  }
-
- private:
-  // Sets parameter value. The caller is responsible for making sure the value
-  // remains alive and unchanged throughout the current test.
-  static void SetParam(const ParamType* parameter) {
-    parameter_ = parameter;
-  }
-
-  // Static value used for accessing parameter during a test lifetime.
-  static const ParamType* parameter_;
-
-  // TestClass must be a subclass of WithParamInterface<T> and Test.
-  template <class TestClass> friend class internal::ParameterizedTestFactory;
-};
-
-template <typename T>
-const T* WithParamInterface<T>::parameter_ = nullptr;
-
-// Most value-parameterized classes can ignore the existence of
-// WithParamInterface, and can just inherit from ::testing::TestWithParam.
-
-template <typename T>
-class TestWithParam : public Test, public WithParamInterface<T> {
-};
-
-// Macros for indicating success/failure in test code.
-
-// Skips test in runtime.
-// Skipping test aborts current function.
-// Skipped tests are neither successful nor failed.
-#define GTEST_SKIP() GTEST_SKIP_("")
-
-// ADD_FAILURE unconditionally adds a failure to the current test.
-// SUCCEED generates a success - it doesn't automatically make the
-// current test successful, as a test is only successful when it has
-// no failure.
-//
-// EXPECT_* verifies that a certain condition is satisfied.  If not,
-// it behaves like ADD_FAILURE.  In particular:
-//
-//   EXPECT_TRUE  verifies that a Boolean condition is true.
-//   EXPECT_FALSE verifies that a Boolean condition is false.
-//
-// FAIL and ASSERT_* are similar to ADD_FAILURE and EXPECT_*, except
-// that they will also abort the current function on failure.  People
-// usually want the fail-fast behavior of FAIL and ASSERT_*, but those
-// writing data-driven tests often find themselves using ADD_FAILURE
-// and EXPECT_* more.
-
-// Generates a nonfatal failure with a generic message.
-#define ADD_FAILURE() GTEST_NONFATAL_FAILURE_("Failed")
-
-// Generates a nonfatal failure at the given source file location with
-// a generic message.
-#define ADD_FAILURE_AT(file, line) \
-  GTEST_MESSAGE_AT_(file, line, "Failed", \
-                    ::testing::TestPartResult::kNonFatalFailure)
-
-// Generates a fatal failure with a generic message.
-#define GTEST_FAIL() GTEST_FATAL_FAILURE_("Failed")
-
-// Like GTEST_FAIL(), but at the given source file location.
-#define GTEST_FAIL_AT(file, line)         \
-  GTEST_MESSAGE_AT_(file, line, "Failed", \
-                    ::testing::TestPartResult::kFatalFailure)
-
-// Define this macro to 1 to omit the definition of FAIL(), which is a
-// generic name and clashes with some other libraries.
-#if !GTEST_DONT_DEFINE_FAIL
-# define FAIL() GTEST_FAIL()
-#endif
-
-// Generates a success with a generic message.
-#define GTEST_SUCCEED() GTEST_SUCCESS_("Succeeded")
-
-// Define this macro to 1 to omit the definition of SUCCEED(), which
-// is a generic name and clashes with some other libraries.
-#if !GTEST_DONT_DEFINE_SUCCEED
-# define SUCCEED() GTEST_SUCCEED()
-#endif
-
-// Macros for testing exceptions.
-//
-//    * {ASSERT|EXPECT}_THROW(statement, expected_exception):
-//         Tests that the statement throws the expected exception.
-//    * {ASSERT|EXPECT}_NO_THROW(statement):
-//         Tests that the statement doesn't throw any exception.
-//    * {ASSERT|EXPECT}_ANY_THROW(statement):
-//         Tests that the statement throws an exception.
-
-#define EXPECT_THROW(statement, expected_exception) \
-  GTEST_TEST_THROW_(statement, expected_exception, GTEST_NONFATAL_FAILURE_)
-#define EXPECT_NO_THROW(statement) \
-  GTEST_TEST_NO_THROW_(statement, GTEST_NONFATAL_FAILURE_)
-#define EXPECT_ANY_THROW(statement) \
-  GTEST_TEST_ANY_THROW_(statement, GTEST_NONFATAL_FAILURE_)
-#define ASSERT_THROW(statement, expected_exception) \
-  GTEST_TEST_THROW_(statement, expected_exception, GTEST_FATAL_FAILURE_)
-#define ASSERT_NO_THROW(statement) \
-  GTEST_TEST_NO_THROW_(statement, GTEST_FATAL_FAILURE_)
-#define ASSERT_ANY_THROW(statement) \
-  GTEST_TEST_ANY_THROW_(statement, GTEST_FATAL_FAILURE_)
-
-// Boolean assertions. Condition can be either a Boolean expression or an
-// AssertionResult. For more information on how to use AssertionResult with
-// these macros see comments on that class.
-#define GTEST_EXPECT_TRUE(condition) \
-  GTEST_TEST_BOOLEAN_(condition, #condition, false, true, \
-                      GTEST_NONFATAL_FAILURE_)
-#define GTEST_EXPECT_FALSE(condition) \
-  GTEST_TEST_BOOLEAN_(!(condition), #condition, true, false, \
-                      GTEST_NONFATAL_FAILURE_)
-#define GTEST_ASSERT_TRUE(condition) \
-  GTEST_TEST_BOOLEAN_(condition, #condition, false, true, \
-                      GTEST_FATAL_FAILURE_)
-#define GTEST_ASSERT_FALSE(condition) \
-  GTEST_TEST_BOOLEAN_(!(condition), #condition, true, false, \
-                      GTEST_FATAL_FAILURE_)
-
-// Define these macros to 1 to omit the definition of the corresponding
-// EXPECT or ASSERT, which clashes with some users' own code.
-
-#if !GTEST_DONT_DEFINE_EXPECT_TRUE
-#define EXPECT_TRUE(condition) GTEST_EXPECT_TRUE(condition)
-#endif
-
-#if !GTEST_DONT_DEFINE_EXPECT_FALSE
-#define EXPECT_FALSE(condition) GTEST_EXPECT_FALSE(condition)
-#endif
-
-#if !GTEST_DONT_DEFINE_ASSERT_TRUE
-#define ASSERT_TRUE(condition) GTEST_ASSERT_TRUE(condition)
-#endif
-
-#if !GTEST_DONT_DEFINE_ASSERT_FALSE
-#define ASSERT_FALSE(condition) GTEST_ASSERT_FALSE(condition)
-#endif
-
-// Macros for testing equalities and inequalities.
-//
-//    * {ASSERT|EXPECT}_EQ(v1, v2): Tests that v1 == v2
-//    * {ASSERT|EXPECT}_NE(v1, v2): Tests that v1 != v2
-//    * {ASSERT|EXPECT}_LT(v1, v2): Tests that v1 < v2
-//    * {ASSERT|EXPECT}_LE(v1, v2): Tests that v1 <= v2
-//    * {ASSERT|EXPECT}_GT(v1, v2): Tests that v1 > v2
-//    * {ASSERT|EXPECT}_GE(v1, v2): Tests that v1 >= v2
-//
-// When they are not, Google Test prints both the tested expressions and
-// their actual values.  The values must be compatible built-in types,
-// or you will get a compiler error.  By "compatible" we mean that the
-// values can be compared by the respective operator.
-//
-// Note:
-//
-//   1. It is possible to make a user-defined type work with
-//   {ASSERT|EXPECT}_??(), but that requires overloading the
-//   comparison operators and is thus discouraged by the Google C++
-//   Usage Guide.  Therefore, you are advised to use the
-//   {ASSERT|EXPECT}_TRUE() macro to assert that two objects are
-//   equal.
-//
-//   2. The {ASSERT|EXPECT}_??() macros do pointer comparisons on
-//   pointers (in particular, C strings).  Therefore, if you use it
-//   with two C strings, you are testing how their locations in memory
-//   are related, not how their content is related.  To compare two C
-//   strings by content, use {ASSERT|EXPECT}_STR*().
-//
-//   3. {ASSERT|EXPECT}_EQ(v1, v2) is preferred to
-//   {ASSERT|EXPECT}_TRUE(v1 == v2), as the former tells you
-//   what the actual value is when it fails, and similarly for the
-//   other comparisons.
-//
-//   4. Do not depend on the order in which {ASSERT|EXPECT}_??()
-//   evaluate their arguments, which is undefined.
-//
-//   5. These macros evaluate their arguments exactly once.
-//
-// Examples:
-//
-//   EXPECT_NE(Foo(), 5);
-//   EXPECT_EQ(a_pointer, NULL);
-//   ASSERT_LT(i, array_size);
-//   ASSERT_GT(records.size(), 0) << "There is no record left.";
-
-#define EXPECT_EQ(val1, val2) \
-  EXPECT_PRED_FORMAT2(::testing::internal::EqHelper::Compare, val1, val2)
-#define EXPECT_NE(val1, val2) \
-  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperNE, val1, val2)
-#define EXPECT_LE(val1, val2) \
-  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperLE, val1, val2)
-#define EXPECT_LT(val1, val2) \
-  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperLT, val1, val2)
-#define EXPECT_GE(val1, val2) \
-  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperGE, val1, val2)
-#define EXPECT_GT(val1, val2) \
-  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperGT, val1, val2)
-
-#define GTEST_ASSERT_EQ(val1, val2) \
-  ASSERT_PRED_FORMAT2(::testing::internal::EqHelper::Compare, val1, val2)
-#define GTEST_ASSERT_NE(val1, val2) \
-  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperNE, val1, val2)
-#define GTEST_ASSERT_LE(val1, val2) \
-  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperLE, val1, val2)
-#define GTEST_ASSERT_LT(val1, val2) \
-  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperLT, val1, val2)
-#define GTEST_ASSERT_GE(val1, val2) \
-  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperGE, val1, val2)
-#define GTEST_ASSERT_GT(val1, val2) \
-  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperGT, val1, val2)
-
-// Define macro GTEST_DONT_DEFINE_ASSERT_XY to 1 to omit the definition of
-// ASSERT_XY(), which clashes with some users' own code.
-
-#if !GTEST_DONT_DEFINE_ASSERT_EQ
-# define ASSERT_EQ(val1, val2) GTEST_ASSERT_EQ(val1, val2)
-#endif
-
-#if !GTEST_DONT_DEFINE_ASSERT_NE
-# define ASSERT_NE(val1, val2) GTEST_ASSERT_NE(val1, val2)
-#endif
-
-#if !GTEST_DONT_DEFINE_ASSERT_LE
-# define ASSERT_LE(val1, val2) GTEST_ASSERT_LE(val1, val2)
-#endif
-
-#if !GTEST_DONT_DEFINE_ASSERT_LT
-# define ASSERT_LT(val1, val2) GTEST_ASSERT_LT(val1, val2)
-#endif
-
-#if !GTEST_DONT_DEFINE_ASSERT_GE
-# define ASSERT_GE(val1, val2) GTEST_ASSERT_GE(val1, val2)
-#endif
-
-#if !GTEST_DONT_DEFINE_ASSERT_GT
-# define ASSERT_GT(val1, val2) GTEST_ASSERT_GT(val1, val2)
-#endif
-
-// C-string Comparisons.  All tests treat NULL and any non-NULL string
-// as different.  Two NULLs are equal.
-//
-//    * {ASSERT|EXPECT}_STREQ(s1, s2):     Tests that s1 == s2
-//    * {ASSERT|EXPECT}_STRNE(s1, s2):     Tests that s1 != s2
-//    * {ASSERT|EXPECT}_STRCASEEQ(s1, s2): Tests that s1 == s2, ignoring case
-//    * {ASSERT|EXPECT}_STRCASENE(s1, s2): Tests that s1 != s2, ignoring case
-//
-// For wide or narrow string objects, you can use the
-// {ASSERT|EXPECT}_??() macros.
-//
-// Don't depend on the order in which the arguments are evaluated,
-// which is undefined.
-//
-// These macros evaluate their arguments exactly once.
-
-#define EXPECT_STREQ(s1, s2) \
-  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTREQ, s1, s2)
-#define EXPECT_STRNE(s1, s2) \
-  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRNE, s1, s2)
-#define EXPECT_STRCASEEQ(s1, s2) \
-  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASEEQ, s1, s2)
-#define EXPECT_STRCASENE(s1, s2)\
-  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASENE, s1, s2)
-
-#define ASSERT_STREQ(s1, s2) \
-  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTREQ, s1, s2)
-#define ASSERT_STRNE(s1, s2) \
-  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRNE, s1, s2)
-#define ASSERT_STRCASEEQ(s1, s2) \
-  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASEEQ, s1, s2)
-#define ASSERT_STRCASENE(s1, s2)\
-  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASENE, s1, s2)
-
-// Macros for comparing floating-point numbers.
-//
-//    * {ASSERT|EXPECT}_FLOAT_EQ(val1, val2):
-//         Tests that two float values are almost equal.
-//    * {ASSERT|EXPECT}_DOUBLE_EQ(val1, val2):
-//         Tests that two double values are almost equal.
-//    * {ASSERT|EXPECT}_NEAR(v1, v2, abs_error):
-//         Tests that v1 and v2 are within the given distance to each other.
-//
-// Google Test uses ULP-based comparison to automatically pick a default
-// error bound that is appropriate for the operands.  See the
-// FloatingPoint template class in gtest-internal.h if you are
-// interested in the implementation details.
-
-#define EXPECT_FLOAT_EQ(val1, val2)\
-  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<float>, \
-                      val1, val2)
-
-#define EXPECT_DOUBLE_EQ(val1, val2)\
-  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<double>, \
-                      val1, val2)
-
-#define ASSERT_FLOAT_EQ(val1, val2)\
-  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<float>, \
-                      val1, val2)
-
-#define ASSERT_DOUBLE_EQ(val1, val2)\
-  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<double>, \
-                      val1, val2)
-
-#define EXPECT_NEAR(val1, val2, abs_error)\
-  EXPECT_PRED_FORMAT3(::testing::internal::DoubleNearPredFormat, \
-                      val1, val2, abs_error)
-
-#define ASSERT_NEAR(val1, val2, abs_error)\
-  ASSERT_PRED_FORMAT3(::testing::internal::DoubleNearPredFormat, \
-                      val1, val2, abs_error)
-
-// These predicate format functions work on floating-point values, and
-// can be used in {ASSERT|EXPECT}_PRED_FORMAT2*(), e.g.
-//
-//   EXPECT_PRED_FORMAT2(testing::DoubleLE, Foo(), 5.0);
-
-// Asserts that val1 is less than, or almost equal to, val2.  Fails
-// otherwise.  In particular, it fails if either val1 or val2 is NaN.
-GTEST_API_ AssertionResult FloatLE(const char* expr1, const char* expr2,
-                                   float val1, float val2);
-GTEST_API_ AssertionResult DoubleLE(const char* expr1, const char* expr2,
-                                    double val1, double val2);
-
-
-#if GTEST_OS_WINDOWS
-
-// Macros that test for HRESULT failure and success, these are only useful
-// on Windows, and rely on Windows SDK macros and APIs to compile.
-//
-//    * {ASSERT|EXPECT}_HRESULT_{SUCCEEDED|FAILED}(expr)
-//
-// When expr unexpectedly fails or succeeds, Google Test prints the
-// expected result and the actual result with both a human-readable
-// string representation of the error, if available, as well as the
-// hex result code.
-# define EXPECT_HRESULT_SUCCEEDED(expr) \
-    EXPECT_PRED_FORMAT1(::testing::internal::IsHRESULTSuccess, (expr))
-
-# define ASSERT_HRESULT_SUCCEEDED(expr) \
-    ASSERT_PRED_FORMAT1(::testing::internal::IsHRESULTSuccess, (expr))
-
-# define EXPECT_HRESULT_FAILED(expr) \
-    EXPECT_PRED_FORMAT1(::testing::internal::IsHRESULTFailure, (expr))
-
-# define ASSERT_HRESULT_FAILED(expr) \
-    ASSERT_PRED_FORMAT1(::testing::internal::IsHRESULTFailure, (expr))
-
-#endif  // GTEST_OS_WINDOWS
-
-// Macros that execute statement and check that it doesn't generate new fatal
-// failures in the current thread.
-//
-//   * {ASSERT|EXPECT}_NO_FATAL_FAILURE(statement);
-//
-// Examples:
-//
-//   EXPECT_NO_FATAL_FAILURE(Process());
-//   ASSERT_NO_FATAL_FAILURE(Process()) << "Process() failed";
-//
-#define ASSERT_NO_FATAL_FAILURE(statement) \
-    GTEST_TEST_NO_FATAL_FAILURE_(statement, GTEST_FATAL_FAILURE_)
-#define EXPECT_NO_FATAL_FAILURE(statement) \
-    GTEST_TEST_NO_FATAL_FAILURE_(statement, GTEST_NONFATAL_FAILURE_)
-
-// Causes a trace (including the given source file path and line number,
-// and the given message) to be included in every test failure message generated
-// by code in the scope of the lifetime of an instance of this class. The effect
-// is undone with the destruction of the instance.
-//
-// The message argument can be anything streamable to std::ostream.
-//
-// Example:
-//   testing::ScopedTrace trace("file.cc", 123, "message");
-//
-class GTEST_API_ ScopedTrace {
- public:
-  // The c'tor pushes the given source file location and message onto
-  // a trace stack maintained by Google Test.
-
-  // Template version. Uses Message() to convert the values into strings.
-  // Slow, but flexible.
-  template <typename T>
-  ScopedTrace(const char* file, int line, const T& message) {
-    PushTrace(file, line, (Message() << message).GetString());
-  }
-
-  // Optimize for some known types.
-  ScopedTrace(const char* file, int line, const char* message) {
-    PushTrace(file, line, message ? message : "(null)");
-  }
-
-  ScopedTrace(const char* file, int line, const std::string& message) {
-    PushTrace(file, line, message);
-  }
-
-  // The d'tor pops the info pushed by the c'tor.
-  //
-  // Note that the d'tor is not virtual in order to be efficient.
-  // Don't inherit from ScopedTrace!
-  ~ScopedTrace();
-
- private:
-  void PushTrace(const char* file, int line, std::string message);
-
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(ScopedTrace);
-} GTEST_ATTRIBUTE_UNUSED_;  // A ScopedTrace object does its job in its
-                            // c'tor and d'tor.  Therefore it doesn't
-                            // need to be used otherwise.
-
-// Causes a trace (including the source file path, the current line
-// number, and the given message) to be included in every test failure
-// message generated by code in the current scope.  The effect is
-// undone when the control leaves the current scope.
-//
-// The message argument can be anything streamable to std::ostream.
-//
-// In the implementation, we include the current line number as part
-// of the dummy variable name, thus allowing multiple SCOPED_TRACE()s
-// to appear in the same block - as long as they are on different
-// lines.
-//
-// Assuming that each thread maintains its own stack of traces.
-// Therefore, a SCOPED_TRACE() would (correctly) only affect the
-// assertions in its own thread.
-#define SCOPED_TRACE(message) \
-  ::testing::ScopedTrace GTEST_CONCAT_TOKEN_(gtest_trace_, __LINE__)(\
-    __FILE__, __LINE__, (message))
-
-// Compile-time assertion for type equality.
-// StaticAssertTypeEq<type1, type2>() compiles if and only if type1 and type2
-// are the same type.  The value it returns is not interesting.
-//
-// Instead of making StaticAssertTypeEq a class template, we make it a
-// function template that invokes a helper class template.  This
-// prevents a user from misusing StaticAssertTypeEq<T1, T2> by
-// defining objects of that type.
-//
-// CAVEAT:
-//
-// When used inside a method of a class template,
-// StaticAssertTypeEq<T1, T2>() is effective ONLY IF the method is
-// instantiated.  For example, given:
-//
-//   template <typename T> class Foo {
-//    public:
-//     void Bar() { testing::StaticAssertTypeEq<int, T>(); }
-//   };
-//
-// the code:
-//
-//   void Test1() { Foo<bool> foo; }
-//
-// will NOT generate a compiler error, as Foo<bool>::Bar() is never
-// actually instantiated.  Instead, you need:
-//
-//   void Test2() { Foo<bool> foo; foo.Bar(); }
-//
-// to cause a compiler error.
-template <typename T1, typename T2>
-constexpr bool StaticAssertTypeEq() noexcept {
-  static_assert(std::is_same<T1, T2>::value, "T1 and T2 are not the same type");
-  return true;
-}
-
-// Defines a test.
-//
-// The first parameter is the name of the test suite, and the second
-// parameter is the name of the test within the test suite.
-//
-// The convention is to end the test suite name with "Test".  For
-// example, a test suite for the Foo class can be named FooTest.
-//
-// Test code should appear between braces after an invocation of
-// this macro.  Example:
-//
-//   TEST(FooTest, InitializesCorrectly) {
-//     Foo foo;
-//     EXPECT_TRUE(foo.StatusIsOK());
-//   }
-
-// Note that we call GetTestTypeId() instead of GetTypeId<
-// ::testing::Test>() here to get the type ID of testing::Test.  This
-// is to work around a suspected linker bug when using Google Test as
-// a framework on Mac OS X.  The bug causes GetTypeId<
-// ::testing::Test>() to return different values depending on whether
-// the call is from the Google Test framework itself or from user test
-// code.  GetTestTypeId() is guaranteed to always return the same
-// value, as it always calls GetTypeId<>() from the Google Test
-// framework.
-#define GTEST_TEST(test_suite_name, test_name)             \
-  GTEST_TEST_(test_suite_name, test_name, ::testing::Test, \
-              ::testing::internal::GetTestTypeId())
-
-// Define this macro to 1 to omit the definition of TEST(), which
-// is a generic name and clashes with some other libraries.
-#if !GTEST_DONT_DEFINE_TEST
-#define TEST(test_suite_name, test_name) GTEST_TEST(test_suite_name, test_name)
-#endif
-
-// Defines a test that uses a test fixture.
-//
-// The first parameter is the name of the test fixture class, which
-// also doubles as the test suite name.  The second parameter is the
-// name of the test within the test suite.
-//
-// A test fixture class must be declared earlier.  The user should put
-// the test code between braces after using this macro.  Example:
-//
-//   class FooTest : public testing::Test {
-//    protected:
-//     void SetUp() override { b_.AddElement(3); }
-//
-//     Foo a_;
-//     Foo b_;
-//   };
-//
-//   TEST_F(FooTest, InitializesCorrectly) {
-//     EXPECT_TRUE(a_.StatusIsOK());
-//   }
-//
-//   TEST_F(FooTest, ReturnsElementCountCorrectly) {
-//     EXPECT_EQ(a_.size(), 0);
-//     EXPECT_EQ(b_.size(), 1);
-//   }
-//
-// GOOGLETEST_CM0011 DO NOT DELETE
-#if !GTEST_DONT_DEFINE_TEST
-#define TEST_F(test_fixture, test_name)\
-  GTEST_TEST_(test_fixture, test_name, test_fixture, \
-              ::testing::internal::GetTypeId<test_fixture>())
-#endif  // !GTEST_DONT_DEFINE_TEST
-
-// Returns a path to temporary directory.
-// Tries to determine an appropriate directory for the platform.
-GTEST_API_ std::string TempDir();
-
-#ifdef _MSC_VER
-#  pragma warning(pop)
-#endif
-
-// Dynamically registers a test with the framework.
-//
-// This is an advanced API only to be used when the `TEST` macros are
-// insufficient. The macros should be preferred when possible, as they avoid
-// most of the complexity of calling this function.
-//
-// The `factory` argument is a factory callable (move-constructible) object or
-// function pointer that creates a new instance of the Test object. It
-// handles ownership to the caller. The signature of the callable is
-// `Fixture*()`, where `Fixture` is the test fixture class for the test. All
-// tests registered with the same `test_suite_name` must return the same
-// fixture type. This is checked at runtime.
-//
-// The framework will infer the fixture class from the factory and will call
-// the `SetUpTestSuite` and `TearDownTestSuite` for it.
-//
-// Must be called before `RUN_ALL_TESTS()` is invoked, otherwise behavior is
-// undefined.
-//
-// Use case example:
-//
-// class MyFixture : public ::testing::Test {
-//  public:
-//   // All of these optional, just like in regular macro usage.
-//   static void SetUpTestSuite() { ... }
-//   static void TearDownTestSuite() { ... }
-//   void SetUp() override { ... }
-//   void TearDown() override { ... }
-// };
-//
-// class MyTest : public MyFixture {
-//  public:
-//   explicit MyTest(int data) : data_(data) {}
-//   void TestBody() override { ... }
-//
-//  private:
-//   int data_;
-// };
-//
-// void RegisterMyTests(const std::vector<int>& values) {
-//   for (int v : values) {
-//     ::testing::RegisterTest(
-//         "MyFixture", ("Test" + std::to_string(v)).c_str(), nullptr,
-//         std::to_string(v).c_str(),
-//         __FILE__, __LINE__,
-//         // Important to use the fixture type as the return type here.
-//         [=]() -> MyFixture* { return new MyTest(v); });
-//   }
-// }
-// ...
-// int main(int argc, char** argv) {
-//   std::vector<int> values_to_test = LoadValuesFromConfig();
-//   RegisterMyTests(values_to_test);
-//   ...
-//   return RUN_ALL_TESTS();
-// }
-//
-template <int&... ExplicitParameterBarrier, typename Factory>
-TestInfo* RegisterTest(const char* test_suite_name, const char* test_name,
-                       const char* type_param, const char* value_param,
-                       const char* file, int line, Factory factory) {
-  using TestT = typename std::remove_pointer<decltype(factory())>::type;
-
-  class FactoryImpl : public internal::TestFactoryBase {
-   public:
-    explicit FactoryImpl(Factory f) : factory_(std::move(f)) {}
-    Test* CreateTest() override { return factory_(); }
-
-   private:
-    Factory factory_;
-  };
-
-  return internal::MakeAndRegisterTestInfo(
-      test_suite_name, test_name, type_param, value_param,
-      internal::CodeLocation(file, line), internal::GetTypeId<TestT>(),
-      internal::SuiteApiResolver<TestT>::GetSetUpCaseOrSuite(file, line),
-      internal::SuiteApiResolver<TestT>::GetTearDownCaseOrSuite(file, line),
-      new FactoryImpl{std::move(factory)});
-}
-
-}  // namespace testing
-
-// Use this function in main() to run all tests.  It returns 0 if all
-// tests are successful, or 1 otherwise.
-//
-// RUN_ALL_TESTS() should be invoked after the command line has been
-// parsed by InitGoogleTest().
-//
-// This function was formerly a macro; thus, it is in the global
-// namespace and has an all-caps name.
-int RUN_ALL_TESTS() GTEST_MUST_USE_RESULT_;
-
-inline int RUN_ALL_TESTS() {
-  return ::testing::UnitTest::GetInstance()->Run();
-}
-
-GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
-
-#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_H_
diff --git a/test/gtest/include/gtest/gtest-assertion-result.h b/test/gtest/include/gtest/gtest-assertion-result.h
new file mode 100644
index 0000000..addbb59
--- /dev/null
+++ b/test/gtest/include/gtest/gtest-assertion-result.h
@@ -0,0 +1,237 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This file implements the AssertionResult type.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_ASSERTION_RESULT_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_ASSERTION_RESULT_H_
+
+#include <memory>
+#include <ostream>
+#include <string>
+#include <type_traits>
+
+#include "gtest/gtest-message.h"
+#include "gtest/internal/gtest-port.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251                                   \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+namespace testing {
+
+// A class for indicating whether an assertion was successful.  When
+// the assertion wasn't successful, the AssertionResult object
+// remembers a non-empty message that describes how it failed.
+//
+// To create an instance of this class, use one of the factory functions
+// (AssertionSuccess() and AssertionFailure()).
+//
+// This class is useful for two purposes:
+//   1. Defining predicate functions to be used with Boolean test assertions
+//      EXPECT_TRUE/EXPECT_FALSE and their ASSERT_ counterparts
+//   2. Defining predicate-format functions to be
+//      used with predicate assertions (ASSERT_PRED_FORMAT*, etc).
+//
+// For example, if you define IsEven predicate:
+//
+//   testing::AssertionResult IsEven(int n) {
+//     if ((n % 2) == 0)
+//       return testing::AssertionSuccess();
+//     else
+//       return testing::AssertionFailure() << n << " is odd";
+//   }
+//
+// Then the failed expectation EXPECT_TRUE(IsEven(Fib(5)))
+// will print the message
+//
+//   Value of: IsEven(Fib(5))
+//     Actual: false (5 is odd)
+//   Expected: true
+//
+// instead of a more opaque
+//
+//   Value of: IsEven(Fib(5))
+//     Actual: false
+//   Expected: true
+//
+// in case IsEven is a simple Boolean predicate.
+//
+// If you expect your predicate to be reused and want to support informative
+// messages in EXPECT_FALSE and ASSERT_FALSE (negative assertions show up
+// about half as often as positive ones in our tests), supply messages for
+// both success and failure cases:
+//
+//   testing::AssertionResult IsEven(int n) {
+//     if ((n % 2) == 0)
+//       return testing::AssertionSuccess() << n << " is even";
+//     else
+//       return testing::AssertionFailure() << n << " is odd";
+//   }
+//
+// Then a statement EXPECT_FALSE(IsEven(Fib(6))) will print
+//
+//   Value of: IsEven(Fib(6))
+//     Actual: true (8 is even)
+//   Expected: false
+//
+// NB: Predicates that support negative Boolean assertions have reduced
+// performance in positive ones so be careful not to use them in tests
+// that have lots (tens of thousands) of positive Boolean assertions.
+//
+// To use this class with EXPECT_PRED_FORMAT assertions such as:
+//
+//   // Verifies that Foo() returns an even number.
+//   EXPECT_PRED_FORMAT1(IsEven, Foo());
+//
+// you need to define:
+//
+//   testing::AssertionResult IsEven(const char* expr, int n) {
+//     if ((n % 2) == 0)
+//       return testing::AssertionSuccess();
+//     else
+//       return testing::AssertionFailure()
+//         << "Expected: " << expr << " is even\n  Actual: it's " << n;
+//   }
+//
+// If Foo() returns 5, you will see the following message:
+//
+//   Expected: Foo() is even
+//     Actual: it's 5
+//
+class GTEST_API_ AssertionResult {
+ public:
+  // Copy constructor.
+  // Used in EXPECT_TRUE/FALSE(assertion_result).
+  AssertionResult(const AssertionResult& other);
+
+// C4800 is a level 3 warning in Visual Studio 2015 and earlier.
+// This warning is not emitted in Visual Studio 2017.
+// This warning is off by default starting in Visual Studio 2019 but can be
+// enabled with command-line options.
+#if defined(_MSC_VER) && (_MSC_VER < 1910 || _MSC_VER >= 1920)
+  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800 /* forcing value to bool */)
+#endif
+
+  // Used in the EXPECT_TRUE/FALSE(bool_expression).
+  //
+  // T must be contextually convertible to bool.
+  //
+  // The second parameter prevents this overload from being considered if
+  // the argument is implicitly convertible to AssertionResult. In that case
+  // we want AssertionResult's copy constructor to be used.
+  template <typename T>
+  explicit AssertionResult(
+      const T& success,
+      typename std::enable_if<
+          !std::is_convertible<T, AssertionResult>::value>::type*
+      /*enabler*/
+      = nullptr)
+      : success_(success) {}
+
+#if defined(_MSC_VER) && (_MSC_VER < 1910 || _MSC_VER >= 1920)
+  GTEST_DISABLE_MSC_WARNINGS_POP_()
+#endif
+
+  // Assignment operator.
+  AssertionResult& operator=(AssertionResult other) {
+    swap(other);
+    return *this;
+  }
+
+  // Returns true if and only if the assertion succeeded.
+  operator bool() const { return success_; }  // NOLINT
+
+  // Returns the assertion's negation. Used with EXPECT/ASSERT_FALSE.
+  AssertionResult operator!() const;
+
+  // Returns the text streamed into this AssertionResult. Test assertions
+  // use it when they fail (i.e., the predicate's outcome doesn't match the
+  // assertion's expectation). When nothing has been streamed into the
+  // object, returns an empty string.
+  const char* message() const {
+    return message_.get() != nullptr ? message_->c_str() : "";
+  }
+  // Deprecated; please use message() instead.
+  const char* failure_message() const { return message(); }
+
+  // Streams a custom failure message into this object.
+  template <typename T>
+  AssertionResult& operator<<(const T& value) {
+    AppendMessage(Message() << value);
+    return *this;
+  }
+
+  // Allows streaming basic output manipulators such as endl or flush into
+  // this object.
+  AssertionResult& operator<<(
+      ::std::ostream& (*basic_manipulator)(::std::ostream& stream)) {
+    AppendMessage(Message() << basic_manipulator);
+    return *this;
+  }
+
+ private:
+  // Appends the contents of message to message_.
+  void AppendMessage(const Message& a_message) {
+    if (message_.get() == nullptr) message_.reset(new ::std::string);
+    message_->append(a_message.GetString().c_str());
+  }
+
+  // Swap the contents of this AssertionResult with other.
+  void swap(AssertionResult& other);
+
+  // Stores result of the assertion predicate.
+  bool success_;
+  // Stores the message describing the condition in case the expectation
+  // construct is not satisfied with the predicate's outcome.
+  // Referenced via a pointer to avoid taking too much stack frame space
+  // with test assertions.
+  std::unique_ptr< ::std::string> message_;
+};
+
+// Makes a successful assertion result.
+GTEST_API_ AssertionResult AssertionSuccess();
+
+// Makes a failed assertion result.
+GTEST_API_ AssertionResult AssertionFailure();
+
+// Makes a failed assertion result with the given failure message.
+// Deprecated; use AssertionFailure() << msg.
+GTEST_API_ AssertionResult AssertionFailure(const Message& msg);
+
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4251
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_ASSERTION_RESULT_H_
diff --git a/test/gtest/include/gtest/gtest-death-test.h b/test/gtest/include/gtest/gtest-death-test.h
new file mode 100644
index 0000000..84e5a5b
--- /dev/null
+++ b/test/gtest/include/gtest/gtest-death-test.h
@@ -0,0 +1,345 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file defines the public API for death tests.  It is
+// #included by gtest.h so a user doesn't need to include this
+// directly.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
+
+#include "gtest/internal/gtest-death-test-internal.h"
+
+// This flag controls the style of death tests.  Valid values are "threadsafe",
+// meaning that the death test child process will re-execute the test binary
+// from the start, running only a single death test, or "fast",
+// meaning that the child process will execute the test logic immediately
+// after forking.
+GTEST_DECLARE_string_(death_test_style);
+
+namespace testing {
+
+#if GTEST_HAS_DEATH_TEST
+
+namespace internal {
+
+// Returns a Boolean value indicating whether the caller is currently
+// executing in the context of the death test child process.  Tools such as
+// Valgrind heap checkers may need this to modify their behavior in death
+// tests.  IMPORTANT: This is an internal utility.  Using it may break the
+// implementation of death tests.  User code MUST NOT use it.
+GTEST_API_ bool InDeathTestChild();
+
+}  // namespace internal
+
+// The following macros are useful for writing death tests.
+
+// Here's what happens when an ASSERT_DEATH* or EXPECT_DEATH* is
+// executed:
+//
+//   1. It generates a warning if there is more than one active
+//   thread.  This is because it's safe to fork() or clone() only
+//   when there is a single thread.
+//
+//   2. The parent process clone()s a sub-process and runs the death
+//   test in it; the sub-process exits with code 0 at the end of the
+//   death test, if it hasn't exited already.
+//
+//   3. The parent process waits for the sub-process to terminate.
+//
+//   4. The parent process checks the exit code and error message of
+//   the sub-process.
+//
+// Examples:
+//
+//   ASSERT_DEATH(server.SendMessage(56, "Hello"), "Invalid port number");
+//   for (int i = 0; i < 5; i++) {
+//     EXPECT_DEATH(server.ProcessRequest(i),
+//                  "Invalid request .* in ProcessRequest()")
+//                  << "Failed to die on request " << i;
+//   }
+//
+//   ASSERT_EXIT(server.ExitNow(), ::testing::ExitedWithCode(0), "Exiting");
+//
+//   bool KilledBySIGHUP(int exit_code) {
+//     return WIFSIGNALED(exit_code) && WTERMSIG(exit_code) == SIGHUP;
+//   }
+//
+//   ASSERT_EXIT(client.HangUpServer(), KilledBySIGHUP, "Hanging up!");
+//
+// The final parameter to each of these macros is a matcher applied to any data
+// the sub-process wrote to stderr.  For compatibility with existing tests, a
+// bare string is interpreted as a regular expression matcher.
+//
+// On the regular expressions used in death tests:
+//
+//   On POSIX-compliant systems (*nix), we use the <regex.h> library,
+//   which uses the POSIX extended regex syntax.
+//
+//   On other platforms (e.g. Windows or Mac), we only support a simple regex
+//   syntax implemented as part of Google Test.  This limited
+//   implementation should be enough most of the time when writing
+//   death tests; though it lacks many features you can find in PCRE
+//   or POSIX extended regex syntax.  For example, we don't support
+//   union ("x|y"), grouping ("(xy)"), brackets ("[xy]"), and
+//   repetition count ("x{5,7}"), among others.
+//
+//   Below is the syntax that we do support.  We chose it to be a
+//   subset of both PCRE and POSIX extended regex, so it's easy to
+//   learn wherever you come from.  In the following: 'A' denotes a
+//   literal character, period (.), or a single \\ escape sequence;
+//   'x' and 'y' denote regular expressions; 'm' and 'n' are for
+//   natural numbers.
+//
+//     c     matches any literal character c
+//     \\d   matches any decimal digit
+//     \\D   matches any character that's not a decimal digit
+//     \\f   matches \f
+//     \\n   matches \n
+//     \\r   matches \r
+//     \\s   matches any ASCII whitespace, including \n
+//     \\S   matches any character that's not a whitespace
+//     \\t   matches \t
+//     \\v   matches \v
+//     \\w   matches any letter, _, or decimal digit
+//     \\W   matches any character that \\w doesn't match
+//     \\c   matches any literal character c, which must be a punctuation
+//     .     matches any single character except \n
+//     A?    matches 0 or 1 occurrences of A
+//     A*    matches 0 or many occurrences of A
+//     A+    matches 1 or many occurrences of A
+//     ^     matches the beginning of a string (not that of each line)
+//     $     matches the end of a string (not that of each line)
+//     xy    matches x followed by y
+//
+//   If you accidentally use PCRE or POSIX extended regex features
+//   not implemented by us, you will get a run-time failure.  In that
+//   case, please try to rewrite your regular expression within the
+//   above syntax.
+//
+//   This implementation is *not* meant to be as highly tuned or robust
+//   as a compiled regex library, but should perform well enough for a
+//   death test, which already incurs significant overhead by launching
+//   a child process.
+//
+// Known caveats:
+//
+//   A "threadsafe" style death test obtains the path to the test
+//   program from argv[0] and re-executes it in the sub-process.  For
+//   simplicity, the current implementation doesn't search the PATH
+//   when launching the sub-process.  This means that the user must
+//   invoke the test program via a path that contains at least one
+//   path separator (e.g. path/to/foo_test and
+//   /absolute/path/to/bar_test are fine, but foo_test is not).  This
+//   is rarely a problem as people usually don't put the test binary
+//   directory in PATH.
+//
+
+// Asserts that a given `statement` causes the program to exit, with an
+// integer exit status that satisfies `predicate`, and emitting error output
+// that matches `matcher`.
+#define ASSERT_EXIT(statement, predicate, matcher) \
+  GTEST_DEATH_TEST_(statement, predicate, matcher, GTEST_FATAL_FAILURE_)
+
+// Like `ASSERT_EXIT`, but continues on to successive tests in the
+// test suite, if any:
+#define EXPECT_EXIT(statement, predicate, matcher) \
+  GTEST_DEATH_TEST_(statement, predicate, matcher, GTEST_NONFATAL_FAILURE_)
+
+// Asserts that a given `statement` causes the program to exit, either by
+// explicitly exiting with a nonzero exit code or being killed by a
+// signal, and emitting error output that matches `matcher`.
+#define ASSERT_DEATH(statement, matcher) \
+  ASSERT_EXIT(statement, ::testing::internal::ExitedUnsuccessfully, matcher)
+
+// Like `ASSERT_DEATH`, but continues on to successive tests in the
+// test suite, if any:
+#define EXPECT_DEATH(statement, matcher) \
+  EXPECT_EXIT(statement, ::testing::internal::ExitedUnsuccessfully, matcher)
+
+// Two predicate classes that can be used in {ASSERT,EXPECT}_EXIT*:
+
+// Tests that an exit code describes a normal exit with a given exit code.
+class GTEST_API_ ExitedWithCode {
+ public:
+  explicit ExitedWithCode(int exit_code);
+  ExitedWithCode(const ExitedWithCode&) = default;
+  void operator=(const ExitedWithCode& other) = delete;
+  bool operator()(int exit_status) const;
+
+ private:
+  const int exit_code_;
+};
+
+#if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+// Tests that an exit code describes an exit due to termination by a
+// given signal.
+class GTEST_API_ KilledBySignal {
+ public:
+  explicit KilledBySignal(int signum);
+  bool operator()(int exit_status) const;
+
+ private:
+  const int signum_;
+};
+#endif  // !GTEST_OS_WINDOWS
+
+// EXPECT_DEBUG_DEATH asserts that the given statements die in debug mode.
+// The death testing framework causes this to have interesting semantics,
+// since the sideeffects of the call are only visible in opt mode, and not
+// in debug mode.
+//
+// In practice, this can be used to test functions that utilize the
+// LOG(DFATAL) macro using the following style:
+//
+// int DieInDebugOr12(int* sideeffect) {
+//   if (sideeffect) {
+//     *sideeffect = 12;
+//   }
+//   LOG(DFATAL) << "death";
+//   return 12;
+// }
+//
+// TEST(TestSuite, TestDieOr12WorksInDgbAndOpt) {
+//   int sideeffect = 0;
+//   // Only asserts in dbg.
+//   EXPECT_DEBUG_DEATH(DieInDebugOr12(&sideeffect), "death");
+//
+// #ifdef NDEBUG
+//   // opt-mode has sideeffect visible.
+//   EXPECT_EQ(12, sideeffect);
+// #else
+//   // dbg-mode no visible sideeffect.
+//   EXPECT_EQ(0, sideeffect);
+// #endif
+// }
+//
+// This will assert that DieInDebugReturn12InOpt() crashes in debug
+// mode, usually due to a DCHECK or LOG(DFATAL), but returns the
+// appropriate fallback value (12 in this case) in opt mode. If you
+// need to test that a function has appropriate side-effects in opt
+// mode, include assertions against the side-effects.  A general
+// pattern for this is:
+//
+// EXPECT_DEBUG_DEATH({
+//   // Side-effects here will have an effect after this statement in
+//   // opt mode, but none in debug mode.
+//   EXPECT_EQ(12, DieInDebugOr12(&sideeffect));
+// }, "death");
+//
+#ifdef NDEBUG
+
+#define EXPECT_DEBUG_DEATH(statement, regex) \
+  GTEST_EXECUTE_STATEMENT_(statement, regex)
+
+#define ASSERT_DEBUG_DEATH(statement, regex) \
+  GTEST_EXECUTE_STATEMENT_(statement, regex)
+
+#else
+
+#define EXPECT_DEBUG_DEATH(statement, regex) EXPECT_DEATH(statement, regex)
+
+#define ASSERT_DEBUG_DEATH(statement, regex) ASSERT_DEATH(statement, regex)
+
+#endif  // NDEBUG for EXPECT_DEBUG_DEATH
+#endif  // GTEST_HAS_DEATH_TEST
+
+// This macro is used for implementing macros such as
+// EXPECT_DEATH_IF_SUPPORTED and ASSERT_DEATH_IF_SUPPORTED on systems where
+// death tests are not supported. Those macros must compile on such systems
+// if and only if EXPECT_DEATH and ASSERT_DEATH compile with the same parameters
+// on systems that support death tests. This allows one to write such a macro on
+// a system that does not support death tests and be sure that it will compile
+// on a death-test supporting system. It is exposed publicly so that systems
+// that have death-tests with stricter requirements than GTEST_HAS_DEATH_TEST
+// can write their own equivalent of EXPECT_DEATH_IF_SUPPORTED and
+// ASSERT_DEATH_IF_SUPPORTED.
+//
+// Parameters:
+//   statement -  A statement that a macro such as EXPECT_DEATH would test
+//                for program termination. This macro has to make sure this
+//                statement is compiled but not executed, to ensure that
+//                EXPECT_DEATH_IF_SUPPORTED compiles with a certain
+//                parameter if and only if EXPECT_DEATH compiles with it.
+//   regex     -  A regex that a macro such as EXPECT_DEATH would use to test
+//                the output of statement.  This parameter has to be
+//                compiled but not evaluated by this macro, to ensure that
+//                this macro only accepts expressions that a macro such as
+//                EXPECT_DEATH would accept.
+//   terminator - Must be an empty statement for EXPECT_DEATH_IF_SUPPORTED
+//                and a return statement for ASSERT_DEATH_IF_SUPPORTED.
+//                This ensures that ASSERT_DEATH_IF_SUPPORTED will not
+//                compile inside functions where ASSERT_DEATH doesn't
+//                compile.
+//
+//  The branch that has an always false condition is used to ensure that
+//  statement and regex are compiled (and thus syntactically correct) but
+//  never executed. The unreachable code macro protects the terminator
+//  statement from generating an 'unreachable code' warning in case
+//  statement unconditionally returns or throws. The Message constructor at
+//  the end allows the syntax of streaming additional messages into the
+//  macro, for compilational compatibility with EXPECT_DEATH/ASSERT_DEATH.
+#define GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, terminator)             \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                                \
+  if (::testing::internal::AlwaysTrue()) {                                     \
+    GTEST_LOG_(WARNING) << "Death tests are not supported on this platform.\n" \
+                        << "Statement '" #statement "' cannot be verified.";   \
+  } else if (::testing::internal::AlwaysFalse()) {                             \
+    ::testing::internal::RE::PartialMatch(".*", (regex));                      \
+    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement);                 \
+    terminator;                                                                \
+  } else                                                                       \
+    ::testing::Message()
+
+// EXPECT_DEATH_IF_SUPPORTED(statement, regex) and
+// ASSERT_DEATH_IF_SUPPORTED(statement, regex) expand to real death tests if
+// death tests are supported; otherwise they just issue a warning.  This is
+// useful when you are combining death test assertions with normal test
+// assertions in one test.
+#if GTEST_HAS_DEATH_TEST
+#define EXPECT_DEATH_IF_SUPPORTED(statement, regex) \
+  EXPECT_DEATH(statement, regex)
+#define ASSERT_DEATH_IF_SUPPORTED(statement, regex) \
+  ASSERT_DEATH(statement, regex)
+#else
+#define EXPECT_DEATH_IF_SUPPORTED(statement, regex) \
+  GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, )
+#define ASSERT_DEATH_IF_SUPPORTED(statement, regex) \
+  GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, return)
+#endif
+
+}  // namespace testing
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
diff --git a/test/gtest/include/gtest/gtest-matchers.h b/test/gtest/include/gtest/gtest-matchers.h
new file mode 100644
index 0000000..bffa00c
--- /dev/null
+++ b/test/gtest/include/gtest/gtest-matchers.h
@@ -0,0 +1,956 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This file implements just enough of the matcher interface to allow
+// EXPECT_DEATH and friends to accept a matcher argument.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
+
+#include <atomic>
+#include <memory>
+#include <ostream>
+#include <string>
+#include <type_traits>
+
+#include "gtest/gtest-printers.h"
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-port.h"
+
+// MSVC warning C5046 is new as of VS2017 version 15.8.
+#if defined(_MSC_VER) && _MSC_VER >= 1915
+#define GTEST_MAYBE_5046_ 5046
+#else
+#define GTEST_MAYBE_5046_
+#endif
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(
+    4251 GTEST_MAYBE_5046_ /* class A needs to have dll-interface to be used by
+                              clients of class B */
+    /* Symbol involving type with internal linkage not defined */)
+
+namespace testing {
+
+// To implement a matcher Foo for type T, define:
+//   1. a class FooMatcherMatcher that implements the matcher interface:
+//     using is_gtest_matcher = void;
+//     bool MatchAndExplain(const T&, std::ostream*);
+//       (MatchResultListener* can also be used instead of std::ostream*)
+//     void DescribeTo(std::ostream*);
+//     void DescribeNegationTo(std::ostream*);
+//
+//   2. a factory function that creates a Matcher<T> object from a
+//      FooMatcherMatcher.
+
+class MatchResultListener {
+ public:
+  // Creates a listener object with the given underlying ostream.  The
+  // listener does not own the ostream, and does not dereference it
+  // in the constructor or destructor.
+  explicit MatchResultListener(::std::ostream* os) : stream_(os) {}
+  virtual ~MatchResultListener() = 0;  // Makes this class abstract.
+
+  // Streams x to the underlying ostream; does nothing if the ostream
+  // is NULL.
+  template <typename T>
+  MatchResultListener& operator<<(const T& x) {
+    if (stream_ != nullptr) *stream_ << x;
+    return *this;
+  }
+
+  // Returns the underlying ostream.
+  ::std::ostream* stream() { return stream_; }
+
+  // Returns true if and only if the listener is interested in an explanation
+  // of the match result.  A matcher's MatchAndExplain() method can use
+  // this information to avoid generating the explanation when no one
+  // intends to hear it.
+  bool IsInterested() const { return stream_ != nullptr; }
+
+ private:
+  ::std::ostream* const stream_;
+
+  MatchResultListener(const MatchResultListener&) = delete;
+  MatchResultListener& operator=(const MatchResultListener&) = delete;
+};
+
+inline MatchResultListener::~MatchResultListener() {}
+
+// An instance of a subclass of this knows how to describe itself as a
+// matcher.
+class GTEST_API_ MatcherDescriberInterface {
+ public:
+  virtual ~MatcherDescriberInterface() {}
+
+  // Describes this matcher to an ostream.  The function should print
+  // a verb phrase that describes the property a value matching this
+  // matcher should have.  The subject of the verb phrase is the value
+  // being matched.  For example, the DescribeTo() method of the Gt(7)
+  // matcher prints "is greater than 7".
+  virtual void DescribeTo(::std::ostream* os) const = 0;
+
+  // Describes the negation of this matcher to an ostream.  For
+  // example, if the description of this matcher is "is greater than
+  // 7", the negated description could be "is not greater than 7".
+  // You are not required to override this when implementing
+  // MatcherInterface, but it is highly advised so that your matcher
+  // can produce good error messages.
+  virtual void DescribeNegationTo(::std::ostream* os) const {
+    *os << "not (";
+    DescribeTo(os);
+    *os << ")";
+  }
+};
+
+// The implementation of a matcher.
+template <typename T>
+class MatcherInterface : public MatcherDescriberInterface {
+ public:
+  // Returns true if and only if the matcher matches x; also explains the
+  // match result to 'listener' if necessary (see the next paragraph), in
+  // the form of a non-restrictive relative clause ("which ...",
+  // "whose ...", etc) that describes x.  For example, the
+  // MatchAndExplain() method of the Pointee(...) matcher should
+  // generate an explanation like "which points to ...".
+  //
+  // Implementations of MatchAndExplain() should add an explanation of
+  // the match result *if and only if* they can provide additional
+  // information that's not already present (or not obvious) in the
+  // print-out of x and the matcher's description.  Whether the match
+  // succeeds is not a factor in deciding whether an explanation is
+  // needed, as sometimes the caller needs to print a failure message
+  // when the match succeeds (e.g. when the matcher is used inside
+  // Not()).
+  //
+  // For example, a "has at least 10 elements" matcher should explain
+  // what the actual element count is, regardless of the match result,
+  // as it is useful information to the reader; on the other hand, an
+  // "is empty" matcher probably only needs to explain what the actual
+  // size is when the match fails, as it's redundant to say that the
+  // size is 0 when the value is already known to be empty.
+  //
+  // You should override this method when defining a new matcher.
+  //
+  // It's the responsibility of the caller (Google Test) to guarantee
+  // that 'listener' is not NULL.  This helps to simplify a matcher's
+  // implementation when it doesn't care about the performance, as it
+  // can talk to 'listener' without checking its validity first.
+  // However, in order to implement dummy listeners efficiently,
+  // listener->stream() may be NULL.
+  virtual bool MatchAndExplain(T x, MatchResultListener* listener) const = 0;
+
+  // Inherits these methods from MatcherDescriberInterface:
+  //   virtual void DescribeTo(::std::ostream* os) const = 0;
+  //   virtual void DescribeNegationTo(::std::ostream* os) const;
+};
+
+namespace internal {
+
+struct AnyEq {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const {
+    return a == b;
+  }
+};
+struct AnyNe {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const {
+    return a != b;
+  }
+};
+struct AnyLt {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const {
+    return a < b;
+  }
+};
+struct AnyGt {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const {
+    return a > b;
+  }
+};
+struct AnyLe {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const {
+    return a <= b;
+  }
+};
+struct AnyGe {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const {
+    return a >= b;
+  }
+};
+
+// A match result listener that ignores the explanation.
+class DummyMatchResultListener : public MatchResultListener {
+ public:
+  DummyMatchResultListener() : MatchResultListener(nullptr) {}
+
+ private:
+  DummyMatchResultListener(const DummyMatchResultListener&) = delete;
+  DummyMatchResultListener& operator=(const DummyMatchResultListener&) = delete;
+};
+
+// A match result listener that forwards the explanation to a given
+// ostream.  The difference between this and MatchResultListener is
+// that the former is concrete.
+class StreamMatchResultListener : public MatchResultListener {
+ public:
+  explicit StreamMatchResultListener(::std::ostream* os)
+      : MatchResultListener(os) {}
+
+ private:
+  StreamMatchResultListener(const StreamMatchResultListener&) = delete;
+  StreamMatchResultListener& operator=(const StreamMatchResultListener&) =
+      delete;
+};
+
+struct SharedPayloadBase {
+  std::atomic<int> ref{1};
+  void Ref() { ref.fetch_add(1, std::memory_order_relaxed); }
+  bool Unref() { return ref.fetch_sub(1, std::memory_order_acq_rel) == 1; }
+};
+
+template <typename T>
+struct SharedPayload : SharedPayloadBase {
+  explicit SharedPayload(const T& v) : value(v) {}
+  explicit SharedPayload(T&& v) : value(std::move(v)) {}
+
+  static void Destroy(SharedPayloadBase* shared) {
+    delete static_cast<SharedPayload*>(shared);
+  }
+
+  T value;
+};
+
+// An internal class for implementing Matcher<T>, which will derive
+// from it.  We put functionalities common to all Matcher<T>
+// specializations here to avoid code duplication.
+template <typename T>
+class MatcherBase : private MatcherDescriberInterface {
+ public:
+  // Returns true if and only if the matcher matches x; also explains the
+  // match result to 'listener'.
+  bool MatchAndExplain(const T& x, MatchResultListener* listener) const {
+    GTEST_CHECK_(vtable_ != nullptr);
+    return vtable_->match_and_explain(*this, x, listener);
+  }
+
+  // Returns true if and only if this matcher matches x.
+  bool Matches(const T& x) const {
+    DummyMatchResultListener dummy;
+    return MatchAndExplain(x, &dummy);
+  }
+
+  // Describes this matcher to an ostream.
+  void DescribeTo(::std::ostream* os) const final {
+    GTEST_CHECK_(vtable_ != nullptr);
+    vtable_->describe(*this, os, false);
+  }
+
+  // Describes the negation of this matcher to an ostream.
+  void DescribeNegationTo(::std::ostream* os) const final {
+    GTEST_CHECK_(vtable_ != nullptr);
+    vtable_->describe(*this, os, true);
+  }
+
+  // Explains why x matches, or doesn't match, the matcher.
+  void ExplainMatchResultTo(const T& x, ::std::ostream* os) const {
+    StreamMatchResultListener listener(os);
+    MatchAndExplain(x, &listener);
+  }
+
+  // Returns the describer for this matcher object; retains ownership
+  // of the describer, which is only guaranteed to be alive when
+  // this matcher object is alive.
+  const MatcherDescriberInterface* GetDescriber() const {
+    if (vtable_ == nullptr) return nullptr;
+    return vtable_->get_describer(*this);
+  }
+
+ protected:
+  MatcherBase() : vtable_(nullptr), buffer_() {}
+
+  // Constructs a matcher from its implementation.
+  template <typename U>
+  explicit MatcherBase(const MatcherInterface<U>* impl)
+      : vtable_(nullptr), buffer_() {
+    Init(impl);
+  }
+
+  template <typename M, typename = typename std::remove_reference<
+                            M>::type::is_gtest_matcher>
+  MatcherBase(M&& m) : vtable_(nullptr), buffer_() {  // NOLINT
+    Init(std::forward<M>(m));
+  }
+
+  MatcherBase(const MatcherBase& other)
+      : vtable_(other.vtable_), buffer_(other.buffer_) {
+    if (IsShared()) buffer_.shared->Ref();
+  }
+
+  MatcherBase& operator=(const MatcherBase& other) {
+    if (this == &other) return *this;
+    Destroy();
+    vtable_ = other.vtable_;
+    buffer_ = other.buffer_;
+    if (IsShared()) buffer_.shared->Ref();
+    return *this;
+  }
+
+  MatcherBase(MatcherBase&& other)
+      : vtable_(other.vtable_), buffer_(other.buffer_) {
+    other.vtable_ = nullptr;
+  }
+
+  MatcherBase& operator=(MatcherBase&& other) {
+    if (this == &other) return *this;
+    Destroy();
+    vtable_ = other.vtable_;
+    buffer_ = other.buffer_;
+    other.vtable_ = nullptr;
+    return *this;
+  }
+
+  ~MatcherBase() override { Destroy(); }
+
+ private:
+  struct VTable {
+    bool (*match_and_explain)(const MatcherBase&, const T&,
+                              MatchResultListener*);
+    void (*describe)(const MatcherBase&, std::ostream*, bool negation);
+    // Returns the captured object if it implements the interface, otherwise
+    // returns the MatcherBase itself.
+    const MatcherDescriberInterface* (*get_describer)(const MatcherBase&);
+    // Called on shared instances when the reference count reaches 0.
+    void (*shared_destroy)(SharedPayloadBase*);
+  };
+
+  bool IsShared() const {
+    return vtable_ != nullptr && vtable_->shared_destroy != nullptr;
+  }
+
+  // If the implementation uses a listener, call that.
+  template <typename P>
+  static auto MatchAndExplainImpl(const MatcherBase& m, const T& value,
+                                  MatchResultListener* listener)
+      -> decltype(P::Get(m).MatchAndExplain(value, listener->stream())) {
+    return P::Get(m).MatchAndExplain(value, listener->stream());
+  }
+
+  template <typename P>
+  static auto MatchAndExplainImpl(const MatcherBase& m, const T& value,
+                                  MatchResultListener* listener)
+      -> decltype(P::Get(m).MatchAndExplain(value, listener)) {
+    return P::Get(m).MatchAndExplain(value, listener);
+  }
+
+  template <typename P>
+  static void DescribeImpl(const MatcherBase& m, std::ostream* os,
+                           bool negation) {
+    if (negation) {
+      P::Get(m).DescribeNegationTo(os);
+    } else {
+      P::Get(m).DescribeTo(os);
+    }
+  }
+
+  template <typename P>
+  static const MatcherDescriberInterface* GetDescriberImpl(
+      const MatcherBase& m) {
+    // If the impl is a MatcherDescriberInterface, then return it.
+    // Otherwise use MatcherBase itself.
+    // This allows us to implement the GetDescriber() function without support
+    // from the impl, but some users really want to get their impl back when
+    // they call GetDescriber().
+    // We use std::get on a tuple as a workaround of not having `if constexpr`.
+    return std::get<(
+        std::is_convertible<decltype(&P::Get(m)),
+                            const MatcherDescriberInterface*>::value
+            ? 1
+            : 0)>(std::make_tuple(&m, &P::Get(m)));
+  }
+
+  template <typename P>
+  const VTable* GetVTable() {
+    static constexpr VTable kVTable = {&MatchAndExplainImpl<P>,
+                                       &DescribeImpl<P>, &GetDescriberImpl<P>,
+                                       P::shared_destroy};
+    return &kVTable;
+  }
+
+  union Buffer {
+    // Add some types to give Buffer some common alignment/size use cases.
+    void* ptr;
+    double d;
+    int64_t i;
+    // And add one for the out-of-line cases.
+    SharedPayloadBase* shared;
+  };
+
+  void Destroy() {
+    if (IsShared() && buffer_.shared->Unref()) {
+      vtable_->shared_destroy(buffer_.shared);
+    }
+  }
+
+  template <typename M>
+  static constexpr bool IsInlined() {
+    return sizeof(M) <= sizeof(Buffer) && alignof(M) <= alignof(Buffer) &&
+           std::is_trivially_copy_constructible<M>::value &&
+           std::is_trivially_destructible<M>::value;
+  }
+
+  template <typename M, bool = MatcherBase::IsInlined<M>()>
+  struct ValuePolicy {
+    static const M& Get(const MatcherBase& m) {
+      // When inlined along with Init, need to be explicit to avoid violating
+      // strict aliasing rules.
+      const M* ptr =
+          static_cast<const M*>(static_cast<const void*>(&m.buffer_));
+      return *ptr;
+    }
+    static void Init(MatcherBase& m, M impl) {
+      ::new (static_cast<void*>(&m.buffer_)) M(impl);
+    }
+    static constexpr auto shared_destroy = nullptr;
+  };
+
+  template <typename M>
+  struct ValuePolicy<M, false> {
+    using Shared = SharedPayload<M>;
+    static const M& Get(const MatcherBase& m) {
+      return static_cast<Shared*>(m.buffer_.shared)->value;
+    }
+    template <typename Arg>
+    static void Init(MatcherBase& m, Arg&& arg) {
+      m.buffer_.shared = new Shared(std::forward<Arg>(arg));
+    }
+    static constexpr auto shared_destroy = &Shared::Destroy;
+  };
+
+  template <typename U, bool B>
+  struct ValuePolicy<const MatcherInterface<U>*, B> {
+    using M = const MatcherInterface<U>;
+    using Shared = SharedPayload<std::unique_ptr<M>>;
+    static const M& Get(const MatcherBase& m) {
+      return *static_cast<Shared*>(m.buffer_.shared)->value;
+    }
+    static void Init(MatcherBase& m, M* impl) {
+      m.buffer_.shared = new Shared(std::unique_ptr<M>(impl));
+    }
+
+    static constexpr auto shared_destroy = &Shared::Destroy;
+  };
+
+  template <typename M>
+  void Init(M&& m) {
+    using MM = typename std::decay<M>::type;
+    using Policy = ValuePolicy<MM>;
+    vtable_ = GetVTable<Policy>();
+    Policy::Init(*this, std::forward<M>(m));
+  }
+
+  const VTable* vtable_;
+  Buffer buffer_;
+};
+
+}  // namespace internal
+
+// A Matcher<T> is a copyable and IMMUTABLE (except by assignment)
+// object that can check whether a value of type T matches.  The
+// implementation of Matcher<T> is just a std::shared_ptr to const
+// MatcherInterface<T>.  Don't inherit from Matcher!
+template <typename T>
+class Matcher : public internal::MatcherBase<T> {
+ public:
+  // Constructs a null matcher.  Needed for storing Matcher objects in STL
+  // containers.  A default-constructed matcher is not yet initialized.  You
+  // cannot use it until a valid value has been assigned to it.
+  explicit Matcher() {}  // NOLINT
+
+  // Constructs a matcher from its implementation.
+  explicit Matcher(const MatcherInterface<const T&>* impl)
+      : internal::MatcherBase<T>(impl) {}
+
+  template <typename U>
+  explicit Matcher(
+      const MatcherInterface<U>* impl,
+      typename std::enable_if<!std::is_same<U, const U&>::value>::type* =
+          nullptr)
+      : internal::MatcherBase<T>(impl) {}
+
+  template <typename M, typename = typename std::remove_reference<
+                            M>::type::is_gtest_matcher>
+  Matcher(M&& m) : internal::MatcherBase<T>(std::forward<M>(m)) {}  // NOLINT
+
+  // Implicit constructor here allows people to write
+  // EXPECT_CALL(foo, Bar(5)) instead of EXPECT_CALL(foo, Bar(Eq(5))) sometimes
+  Matcher(T value);  // NOLINT
+};
+
+// The following two specializations allow the user to write str
+// instead of Eq(str) and "foo" instead of Eq("foo") when a std::string
+// matcher is expected.
+template <>
+class GTEST_API_ Matcher<const std::string&>
+    : public internal::MatcherBase<const std::string&> {
+ public:
+  Matcher() {}
+
+  explicit Matcher(const MatcherInterface<const std::string&>* impl)
+      : internal::MatcherBase<const std::string&>(impl) {}
+
+  template <typename M, typename = typename std::remove_reference<
+                            M>::type::is_gtest_matcher>
+  Matcher(M&& m)  // NOLINT
+      : internal::MatcherBase<const std::string&>(std::forward<M>(m)) {}
+
+  // Allows the user to write str instead of Eq(str) sometimes, where
+  // str is a std::string object.
+  Matcher(const std::string& s);  // NOLINT
+
+  // Allows the user to write "foo" instead of Eq("foo") sometimes.
+  Matcher(const char* s);  // NOLINT
+};
+
+template <>
+class GTEST_API_ Matcher<std::string>
+    : public internal::MatcherBase<std::string> {
+ public:
+  Matcher() {}
+
+  explicit Matcher(const MatcherInterface<const std::string&>* impl)
+      : internal::MatcherBase<std::string>(impl) {}
+  explicit Matcher(const MatcherInterface<std::string>* impl)
+      : internal::MatcherBase<std::string>(impl) {}
+
+  template <typename M, typename = typename std::remove_reference<
+                            M>::type::is_gtest_matcher>
+  Matcher(M&& m)  // NOLINT
+      : internal::MatcherBase<std::string>(std::forward<M>(m)) {}
+
+  // Allows the user to write str instead of Eq(str) sometimes, where
+  // str is a string object.
+  Matcher(const std::string& s);  // NOLINT
+
+  // Allows the user to write "foo" instead of Eq("foo") sometimes.
+  Matcher(const char* s);  // NOLINT
+};
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+// The following two specializations allow the user to write str
+// instead of Eq(str) and "foo" instead of Eq("foo") when a absl::string_view
+// matcher is expected.
+template <>
+class GTEST_API_ Matcher<const internal::StringView&>
+    : public internal::MatcherBase<const internal::StringView&> {
+ public:
+  Matcher() {}
+
+  explicit Matcher(const MatcherInterface<const internal::StringView&>* impl)
+      : internal::MatcherBase<const internal::StringView&>(impl) {}
+
+  template <typename M, typename = typename std::remove_reference<
+                            M>::type::is_gtest_matcher>
+  Matcher(M&& m)  // NOLINT
+      : internal::MatcherBase<const internal::StringView&>(std::forward<M>(m)) {
+  }
+
+  // Allows the user to write str instead of Eq(str) sometimes, where
+  // str is a std::string object.
+  Matcher(const std::string& s);  // NOLINT
+
+  // Allows the user to write "foo" instead of Eq("foo") sometimes.
+  Matcher(const char* s);  // NOLINT
+
+  // Allows the user to pass absl::string_views or std::string_views directly.
+  Matcher(internal::StringView s);  // NOLINT
+};
+
+template <>
+class GTEST_API_ Matcher<internal::StringView>
+    : public internal::MatcherBase<internal::StringView> {
+ public:
+  Matcher() {}
+
+  explicit Matcher(const MatcherInterface<const internal::StringView&>* impl)
+      : internal::MatcherBase<internal::StringView>(impl) {}
+  explicit Matcher(const MatcherInterface<internal::StringView>* impl)
+      : internal::MatcherBase<internal::StringView>(impl) {}
+
+  template <typename M, typename = typename std::remove_reference<
+                            M>::type::is_gtest_matcher>
+  Matcher(M&& m)  // NOLINT
+      : internal::MatcherBase<internal::StringView>(std::forward<M>(m)) {}
+
+  // Allows the user to write str instead of Eq(str) sometimes, where
+  // str is a std::string object.
+  Matcher(const std::string& s);  // NOLINT
+
+  // Allows the user to write "foo" instead of Eq("foo") sometimes.
+  Matcher(const char* s);  // NOLINT
+
+  // Allows the user to pass absl::string_views or std::string_views directly.
+  Matcher(internal::StringView s);  // NOLINT
+};
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+
+// Prints a matcher in a human-readable format.
+template <typename T>
+std::ostream& operator<<(std::ostream& os, const Matcher<T>& matcher) {
+  matcher.DescribeTo(&os);
+  return os;
+}
+
+// The PolymorphicMatcher class template makes it easy to implement a
+// polymorphic matcher (i.e. a matcher that can match values of more
+// than one type, e.g. Eq(n) and NotNull()).
+//
+// To define a polymorphic matcher, a user should provide an Impl
+// class that has a DescribeTo() method and a DescribeNegationTo()
+// method, and define a member function (or member function template)
+//
+//   bool MatchAndExplain(const Value& value,
+//                        MatchResultListener* listener) const;
+//
+// See the definition of NotNull() for a complete example.
+template <class Impl>
+class PolymorphicMatcher {
+ public:
+  explicit PolymorphicMatcher(const Impl& an_impl) : impl_(an_impl) {}
+
+  // Returns a mutable reference to the underlying matcher
+  // implementation object.
+  Impl& mutable_impl() { return impl_; }
+
+  // Returns an immutable reference to the underlying matcher
+  // implementation object.
+  const Impl& impl() const { return impl_; }
+
+  template <typename T>
+  operator Matcher<T>() const {
+    return Matcher<T>(new MonomorphicImpl<const T&>(impl_));
+  }
+
+ private:
+  template <typename T>
+  class MonomorphicImpl : public MatcherInterface<T> {
+   public:
+    explicit MonomorphicImpl(const Impl& impl) : impl_(impl) {}
+
+    void DescribeTo(::std::ostream* os) const override { impl_.DescribeTo(os); }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      impl_.DescribeNegationTo(os);
+    }
+
+    bool MatchAndExplain(T x, MatchResultListener* listener) const override {
+      return impl_.MatchAndExplain(x, listener);
+    }
+
+   private:
+    const Impl impl_;
+  };
+
+  Impl impl_;
+};
+
+// Creates a matcher from its implementation.
+// DEPRECATED: Especially in the generic code, prefer:
+//   Matcher<T>(new MyMatcherImpl<const T&>(...));
+//
+// MakeMatcher may create a Matcher that accepts its argument by value, which
+// leads to unnecessary copies & lack of support for non-copyable types.
+template <typename T>
+inline Matcher<T> MakeMatcher(const MatcherInterface<T>* impl) {
+  return Matcher<T>(impl);
+}
+
+// Creates a polymorphic matcher from its implementation.  This is
+// easier to use than the PolymorphicMatcher<Impl> constructor as it
+// doesn't require you to explicitly write the template argument, e.g.
+//
+//   MakePolymorphicMatcher(foo);
+// vs
+//   PolymorphicMatcher<TypeOfFoo>(foo);
+template <class Impl>
+inline PolymorphicMatcher<Impl> MakePolymorphicMatcher(const Impl& impl) {
+  return PolymorphicMatcher<Impl>(impl);
+}
+
+namespace internal {
+// Implements a matcher that compares a given value with a
+// pre-supplied value using one of the ==, <=, <, etc, operators.  The
+// two values being compared don't have to have the same type.
+//
+// The matcher defined here is polymorphic (for example, Eq(5) can be
+// used to match an int, a short, a double, etc).  Therefore we use
+// a template type conversion operator in the implementation.
+//
+// The following template definition assumes that the Rhs parameter is
+// a "bare" type (i.e. neither 'const T' nor 'T&').
+template <typename D, typename Rhs, typename Op>
+class ComparisonBase {
+ public:
+  explicit ComparisonBase(const Rhs& rhs) : rhs_(rhs) {}
+
+  using is_gtest_matcher = void;
+
+  template <typename Lhs>
+  bool MatchAndExplain(const Lhs& lhs, std::ostream*) const {
+    return Op()(lhs, Unwrap(rhs_));
+  }
+  void DescribeTo(std::ostream* os) const {
+    *os << D::Desc() << " ";
+    UniversalPrint(Unwrap(rhs_), os);
+  }
+  void DescribeNegationTo(std::ostream* os) const {
+    *os << D::NegatedDesc() << " ";
+    UniversalPrint(Unwrap(rhs_), os);
+  }
+
+ private:
+  template <typename T>
+  static const T& Unwrap(const T& v) {
+    return v;
+  }
+  template <typename T>
+  static const T& Unwrap(std::reference_wrapper<T> v) {
+    return v;
+  }
+
+  Rhs rhs_;
+};
+
+template <typename Rhs>
+class EqMatcher : public ComparisonBase<EqMatcher<Rhs>, Rhs, AnyEq> {
+ public:
+  explicit EqMatcher(const Rhs& rhs)
+      : ComparisonBase<EqMatcher<Rhs>, Rhs, AnyEq>(rhs) {}
+  static const char* Desc() { return "is equal to"; }
+  static const char* NegatedDesc() { return "isn't equal to"; }
+};
+template <typename Rhs>
+class NeMatcher : public ComparisonBase<NeMatcher<Rhs>, Rhs, AnyNe> {
+ public:
+  explicit NeMatcher(const Rhs& rhs)
+      : ComparisonBase<NeMatcher<Rhs>, Rhs, AnyNe>(rhs) {}
+  static const char* Desc() { return "isn't equal to"; }
+  static const char* NegatedDesc() { return "is equal to"; }
+};
+template <typename Rhs>
+class LtMatcher : public ComparisonBase<LtMatcher<Rhs>, Rhs, AnyLt> {
+ public:
+  explicit LtMatcher(const Rhs& rhs)
+      : ComparisonBase<LtMatcher<Rhs>, Rhs, AnyLt>(rhs) {}
+  static const char* Desc() { return "is <"; }
+  static const char* NegatedDesc() { return "isn't <"; }
+};
+template <typename Rhs>
+class GtMatcher : public ComparisonBase<GtMatcher<Rhs>, Rhs, AnyGt> {
+ public:
+  explicit GtMatcher(const Rhs& rhs)
+      : ComparisonBase<GtMatcher<Rhs>, Rhs, AnyGt>(rhs) {}
+  static const char* Desc() { return "is >"; }
+  static const char* NegatedDesc() { return "isn't >"; }
+};
+template <typename Rhs>
+class LeMatcher : public ComparisonBase<LeMatcher<Rhs>, Rhs, AnyLe> {
+ public:
+  explicit LeMatcher(const Rhs& rhs)
+      : ComparisonBase<LeMatcher<Rhs>, Rhs, AnyLe>(rhs) {}
+  static const char* Desc() { return "is <="; }
+  static const char* NegatedDesc() { return "isn't <="; }
+};
+template <typename Rhs>
+class GeMatcher : public ComparisonBase<GeMatcher<Rhs>, Rhs, AnyGe> {
+ public:
+  explicit GeMatcher(const Rhs& rhs)
+      : ComparisonBase<GeMatcher<Rhs>, Rhs, AnyGe>(rhs) {}
+  static const char* Desc() { return "is >="; }
+  static const char* NegatedDesc() { return "isn't >="; }
+};
+
+template <typename T, typename = typename std::enable_if<
+                          std::is_constructible<std::string, T>::value>::type>
+using StringLike = T;
+
+// Implements polymorphic matchers MatchesRegex(regex) and
+// ContainsRegex(regex), which can be used as a Matcher<T> as long as
+// T can be converted to a string.
+class MatchesRegexMatcher {
+ public:
+  MatchesRegexMatcher(const RE* regex, bool full_match)
+      : regex_(regex), full_match_(full_match) {}
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  bool MatchAndExplain(const internal::StringView& s,
+                       MatchResultListener* listener) const {
+    return MatchAndExplain(std::string(s), listener);
+  }
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+
+  // Accepts pointer types, particularly:
+  //   const char*
+  //   char*
+  //   const wchar_t*
+  //   wchar_t*
+  template <typename CharType>
+  bool MatchAndExplain(CharType* s, MatchResultListener* listener) const {
+    return s != nullptr && MatchAndExplain(std::string(s), listener);
+  }
+
+  // Matches anything that can convert to std::string.
+  //
+  // This is a template, not just a plain function with const std::string&,
+  // because absl::string_view has some interfering non-explicit constructors.
+  template <class MatcheeStringType>
+  bool MatchAndExplain(const MatcheeStringType& s,
+                       MatchResultListener* /* listener */) const {
+    const std::string& s2(s);
+    return full_match_ ? RE::FullMatch(s2, *regex_)
+                       : RE::PartialMatch(s2, *regex_);
+  }
+
+  void DescribeTo(::std::ostream* os) const {
+    *os << (full_match_ ? "matches" : "contains") << " regular expression ";
+    UniversalPrinter<std::string>::Print(regex_->pattern(), os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    *os << "doesn't " << (full_match_ ? "match" : "contain")
+        << " regular expression ";
+    UniversalPrinter<std::string>::Print(regex_->pattern(), os);
+  }
+
+ private:
+  const std::shared_ptr<const RE> regex_;
+  const bool full_match_;
+};
+}  // namespace internal
+
+// Matches a string that fully matches regular expression 'regex'.
+// The matcher takes ownership of 'regex'.
+inline PolymorphicMatcher<internal::MatchesRegexMatcher> MatchesRegex(
+    const internal::RE* regex) {
+  return MakePolymorphicMatcher(internal::MatchesRegexMatcher(regex, true));
+}
+template <typename T = std::string>
+PolymorphicMatcher<internal::MatchesRegexMatcher> MatchesRegex(
+    const internal::StringLike<T>& regex) {
+  return MatchesRegex(new internal::RE(std::string(regex)));
+}
+
+// Matches a string that contains regular expression 'regex'.
+// The matcher takes ownership of 'regex'.
+inline PolymorphicMatcher<internal::MatchesRegexMatcher> ContainsRegex(
+    const internal::RE* regex) {
+  return MakePolymorphicMatcher(internal::MatchesRegexMatcher(regex, false));
+}
+template <typename T = std::string>
+PolymorphicMatcher<internal::MatchesRegexMatcher> ContainsRegex(
+    const internal::StringLike<T>& regex) {
+  return ContainsRegex(new internal::RE(std::string(regex)));
+}
+
+// Creates a polymorphic matcher that matches anything equal to x.
+// Note: if the parameter of Eq() were declared as const T&, Eq("foo")
+// wouldn't compile.
+template <typename T>
+inline internal::EqMatcher<T> Eq(T x) {
+  return internal::EqMatcher<T>(x);
+}
+
+// Constructs a Matcher<T> from a 'value' of type T.  The constructed
+// matcher matches any value that's equal to 'value'.
+template <typename T>
+Matcher<T>::Matcher(T value) {
+  *this = Eq(value);
+}
+
+// Creates a monomorphic matcher that matches anything with type Lhs
+// and equal to rhs.  A user may need to use this instead of Eq(...)
+// in order to resolve an overloading ambiguity.
+//
+// TypedEq<T>(x) is just a convenient short-hand for Matcher<T>(Eq(x))
+// or Matcher<T>(x), but more readable than the latter.
+//
+// We could define similar monomorphic matchers for other comparison
+// operations (e.g. TypedLt, TypedGe, and etc), but decided not to do
+// it yet as those are used much less than Eq() in practice.  A user
+// can always write Matcher<T>(Lt(5)) to be explicit about the type,
+// for example.
+template <typename Lhs, typename Rhs>
+inline Matcher<Lhs> TypedEq(const Rhs& rhs) {
+  return Eq(rhs);
+}
+
+// Creates a polymorphic matcher that matches anything >= x.
+template <typename Rhs>
+inline internal::GeMatcher<Rhs> Ge(Rhs x) {
+  return internal::GeMatcher<Rhs>(x);
+}
+
+// Creates a polymorphic matcher that matches anything > x.
+template <typename Rhs>
+inline internal::GtMatcher<Rhs> Gt(Rhs x) {
+  return internal::GtMatcher<Rhs>(x);
+}
+
+// Creates a polymorphic matcher that matches anything <= x.
+template <typename Rhs>
+inline internal::LeMatcher<Rhs> Le(Rhs x) {
+  return internal::LeMatcher<Rhs>(x);
+}
+
+// Creates a polymorphic matcher that matches anything < x.
+template <typename Rhs>
+inline internal::LtMatcher<Rhs> Lt(Rhs x) {
+  return internal::LtMatcher<Rhs>(x);
+}
+
+// Creates a polymorphic matcher that matches anything != x.
+template <typename Rhs>
+inline internal::NeMatcher<Rhs> Ne(Rhs x) {
+  return internal::NeMatcher<Rhs>(x);
+}
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251 5046
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
diff --git a/test/gtest/include/gtest/gtest-message.h b/test/gtest/include/gtest/gtest-message.h
new file mode 100644
index 0000000..6c8bf90
--- /dev/null
+++ b/test/gtest/include/gtest/gtest-message.h
@@ -0,0 +1,218 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file defines the Message class.
+//
+// IMPORTANT NOTE: Due to limitation of the C++ language, we have to
+// leave some internal implementation details in this header file.
+// They are clearly marked by comments like this:
+//
+//   // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+//
+// Such code is NOT meant to be used by a user directly, and is subject
+// to CHANGE WITHOUT NOTICE.  Therefore DO NOT DEPEND ON IT in a user
+// program!
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_MESSAGE_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_MESSAGE_H_
+
+#include <limits>
+#include <memory>
+#include <sstream>
+
+#include "gtest/internal/gtest-port.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+// Ensures that there is at least one operator<< in the global namespace.
+// See Message& operator<<(...) below for why.
+void operator<<(const testing::internal::Secret&, int);
+
+namespace testing {
+
+// The Message class works like an ostream repeater.
+//
+// Typical usage:
+//
+//   1. You stream a bunch of values to a Message object.
+//      It will remember the text in a stringstream.
+//   2. Then you stream the Message object to an ostream.
+//      This causes the text in the Message to be streamed
+//      to the ostream.
+//
+// For example;
+//
+//   testing::Message foo;
+//   foo << 1 << " != " << 2;
+//   std::cout << foo;
+//
+// will print "1 != 2".
+//
+// Message is not intended to be inherited from.  In particular, its
+// destructor is not virtual.
+//
+// Note that stringstream behaves differently in gcc and in MSVC.  You
+// can stream a NULL char pointer to it in the former, but not in the
+// latter (it causes an access violation if you do).  The Message
+// class hides this difference by treating a NULL char pointer as
+// "(null)".
+class GTEST_API_ Message {
+ private:
+  // The type of basic IO manipulators (endl, ends, and flush) for
+  // narrow streams.
+  typedef std::ostream& (*BasicNarrowIoManip)(std::ostream&);
+
+ public:
+  // Constructs an empty Message.
+  Message();
+
+  // Copy constructor.
+  Message(const Message& msg) : ss_(new ::std::stringstream) {  // NOLINT
+    *ss_ << msg.GetString();
+  }
+
+  // Constructs a Message from a C-string.
+  explicit Message(const char* str) : ss_(new ::std::stringstream) {
+    *ss_ << str;
+  }
+
+  // Streams a non-pointer value to this object.
+  template <typename T>
+  inline Message& operator<<(const T& val) {
+        // Some libraries overload << for STL containers.  These
+    // overloads are defined in the global namespace instead of ::std.
+    //
+    // C++'s symbol lookup rule (i.e. Koenig lookup) says that these
+    // overloads are visible in either the std namespace or the global
+    // namespace, but not other namespaces, including the testing
+    // namespace which Google Test's Message class is in.
+    //
+    // To allow STL containers (and other types that has a << operator
+    // defined in the global namespace) to be used in Google Test
+    // assertions, testing::Message must access the custom << operator
+    // from the global namespace.  With this using declaration,
+    // overloads of << defined in the global namespace and those
+    // visible via Koenig lookup are both exposed in this function.
+    using ::operator<<;
+    *ss_ << val;
+    return *this;
+  }
+
+  // Streams a pointer value to this object.
+  //
+  // This function is an overload of the previous one.  When you
+  // stream a pointer to a Message, this definition will be used as it
+  // is more specialized.  (The C++ Standard, section
+  // [temp.func.order].)  If you stream a non-pointer, then the
+  // previous definition will be used.
+  //
+  // The reason for this overload is that streaming a NULL pointer to
+  // ostream is undefined behavior.  Depending on the compiler, you
+  // may get "0", "(nil)", "(null)", or an access violation.  To
+  // ensure consistent result across compilers, we always treat NULL
+  // as "(null)".
+  template <typename T>
+  inline Message& operator<<(T* const& pointer) {  // NOLINT
+    if (pointer == nullptr) {
+      *ss_ << "(null)";
+    } else {
+      *ss_ << pointer;
+    }
+    return *this;
+  }
+
+  // Since the basic IO manipulators are overloaded for both narrow
+  // and wide streams, we have to provide this specialized definition
+  // of operator <<, even though its body is the same as the
+  // templatized version above.  Without this definition, streaming
+  // endl or other basic IO manipulators to Message will confuse the
+  // compiler.
+  Message& operator<<(BasicNarrowIoManip val) {
+    *ss_ << val;
+    return *this;
+  }
+
+  // Instead of 1/0, we want to see true/false for bool values.
+  Message& operator<<(bool b) { return *this << (b ? "true" : "false"); }
+
+  // These two overloads allow streaming a wide C string to a Message
+  // using the UTF-8 encoding.
+  Message& operator<<(const wchar_t* wide_c_str);
+  Message& operator<<(wchar_t* wide_c_str);
+
+#if GTEST_HAS_STD_WSTRING
+  // Converts the given wide string to a narrow string using the UTF-8
+  // encoding, and streams the result to this Message object.
+  Message& operator<<(const ::std::wstring& wstr);
+#endif  // GTEST_HAS_STD_WSTRING
+
+  // Gets the text streamed to this object so far as an std::string.
+  // Each '\0' character in the buffer is replaced with "\\0".
+  //
+  // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+  std::string GetString() const;
+
+ private:
+  // We'll hold the text streamed to this object here.
+  const std::unique_ptr< ::std::stringstream> ss_;
+
+  // We declare (but don't implement) this to prevent the compiler
+  // from implementing the assignment operator.
+  void operator=(const Message&);
+};
+
+// Streams a Message to an ostream.
+inline std::ostream& operator<<(std::ostream& os, const Message& sb) {
+  return os << sb.GetString();
+}
+
+namespace internal {
+
+// Converts a streamable value to an std::string.  A NULL pointer is
+// converted to "(null)".  When the input value is a ::string,
+// ::std::string, ::wstring, or ::std::wstring object, each NUL
+// character in it is replaced with "\\0".
+template <typename T>
+std::string StreamableToString(const T& streamable) {
+  return (Message() << streamable).GetString();
+}
+
+}  // namespace internal
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_MESSAGE_H_
diff --git a/test/gtest/include/gtest/gtest-param-test.h b/test/gtest/include/gtest/gtest-param-test.h
new file mode 100644
index 0000000..b55119a
--- /dev/null
+++ b/test/gtest/include/gtest/gtest-param-test.h
@@ -0,0 +1,510 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Macros and functions for implementing parameterized tests
+// in Google C++ Testing and Mocking Framework (Google Test)
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PARAM_TEST_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_PARAM_TEST_H_
+
+// Value-parameterized tests allow you to test your code with different
+// parameters without writing multiple copies of the same test.
+//
+// Here is how you use value-parameterized tests:
+
+#if 0
+
+// To write value-parameterized tests, first you should define a fixture
+// class. It is usually derived from testing::TestWithParam<T> (see below for
+// another inheritance scheme that's sometimes useful in more complicated
+// class hierarchies), where the type of your parameter values.
+// TestWithParam<T> is itself derived from testing::Test. T can be any
+// copyable type. If it's a raw pointer, you are responsible for managing the
+// lifespan of the pointed values.
+
+class FooTest : public ::testing::TestWithParam<const char*> {
+  // You can implement all the usual class fixture members here.
+};
+
+// Then, use the TEST_P macro to define as many parameterized tests
+// for this fixture as you want. The _P suffix is for "parameterized"
+// or "pattern", whichever you prefer to think.
+
+TEST_P(FooTest, DoesBlah) {
+  // Inside a test, access the test parameter with the GetParam() method
+  // of the TestWithParam<T> class:
+  EXPECT_TRUE(foo.Blah(GetParam()));
+  ...
+}
+
+TEST_P(FooTest, HasBlahBlah) {
+  ...
+}
+
+// Finally, you can use INSTANTIATE_TEST_SUITE_P to instantiate the test
+// case with any set of parameters you want. Google Test defines a number
+// of functions for generating test parameters. They return what we call
+// (surprise!) parameter generators. Here is a summary of them, which
+// are all in the testing namespace:
+//
+//
+//  Range(begin, end [, step]) - Yields values {begin, begin+step,
+//                               begin+step+step, ...}. The values do not
+//                               include end. step defaults to 1.
+//  Values(v1, v2, ..., vN)    - Yields values {v1, v2, ..., vN}.
+//  ValuesIn(container)        - Yields values from a C-style array, an STL
+//  ValuesIn(begin,end)          container, or an iterator range [begin, end).
+//  Bool()                     - Yields sequence {false, true}.
+//  Combine(g1, g2, ..., gN)   - Yields all combinations (the Cartesian product
+//                               for the math savvy) of the values generated
+//                               by the N generators.
+//
+// For more details, see comments at the definitions of these functions below
+// in this file.
+//
+// The following statement will instantiate tests from the FooTest test suite
+// each with parameter values "meeny", "miny", and "moe".
+
+INSTANTIATE_TEST_SUITE_P(InstantiationName,
+                         FooTest,
+                         Values("meeny", "miny", "moe"));
+
+// To distinguish different instances of the pattern, (yes, you
+// can instantiate it more than once) the first argument to the
+// INSTANTIATE_TEST_SUITE_P macro is a prefix that will be added to the
+// actual test suite name. Remember to pick unique prefixes for different
+// instantiations. The tests from the instantiation above will have
+// these names:
+//
+//    * InstantiationName/FooTest.DoesBlah/0 for "meeny"
+//    * InstantiationName/FooTest.DoesBlah/1 for "miny"
+//    * InstantiationName/FooTest.DoesBlah/2 for "moe"
+//    * InstantiationName/FooTest.HasBlahBlah/0 for "meeny"
+//    * InstantiationName/FooTest.HasBlahBlah/1 for "miny"
+//    * InstantiationName/FooTest.HasBlahBlah/2 for "moe"
+//
+// You can use these names in --gtest_filter.
+//
+// This statement will instantiate all tests from FooTest again, each
+// with parameter values "cat" and "dog":
+
+const char* pets[] = {"cat", "dog"};
+INSTANTIATE_TEST_SUITE_P(AnotherInstantiationName, FooTest, ValuesIn(pets));
+
+// The tests from the instantiation above will have these names:
+//
+//    * AnotherInstantiationName/FooTest.DoesBlah/0 for "cat"
+//    * AnotherInstantiationName/FooTest.DoesBlah/1 for "dog"
+//    * AnotherInstantiationName/FooTest.HasBlahBlah/0 for "cat"
+//    * AnotherInstantiationName/FooTest.HasBlahBlah/1 for "dog"
+//
+// Please note that INSTANTIATE_TEST_SUITE_P will instantiate all tests
+// in the given test suite, whether their definitions come before or
+// AFTER the INSTANTIATE_TEST_SUITE_P statement.
+//
+// Please also note that generator expressions (including parameters to the
+// generators) are evaluated in InitGoogleTest(), after main() has started.
+// This allows the user on one hand, to adjust generator parameters in order
+// to dynamically determine a set of tests to run and on the other hand,
+// give the user a chance to inspect the generated tests with Google Test
+// reflection API before RUN_ALL_TESTS() is executed.
+//
+// You can see samples/sample7_unittest.cc and samples/sample8_unittest.cc
+// for more examples.
+//
+// In the future, we plan to publish the API for defining new parameter
+// generators. But for now this interface remains part of the internal
+// implementation and is subject to change.
+//
+//
+// A parameterized test fixture must be derived from testing::Test and from
+// testing::WithParamInterface<T>, where T is the type of the parameter
+// values. Inheriting from TestWithParam<T> satisfies that requirement because
+// TestWithParam<T> inherits from both Test and WithParamInterface. In more
+// complicated hierarchies, however, it is occasionally useful to inherit
+// separately from Test and WithParamInterface. For example:
+
+class BaseTest : public ::testing::Test {
+  // You can inherit all the usual members for a non-parameterized test
+  // fixture here.
+};
+
+class DerivedTest : public BaseTest, public ::testing::WithParamInterface<int> {
+  // The usual test fixture members go here too.
+};
+
+TEST_F(BaseTest, HasFoo) {
+  // This is an ordinary non-parameterized test.
+}
+
+TEST_P(DerivedTest, DoesBlah) {
+  // GetParam works just the same here as if you inherit from TestWithParam.
+  EXPECT_TRUE(foo.Blah(GetParam()));
+}
+
+#endif  // 0
+
+#include <iterator>
+#include <utility>
+
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-param-util.h"
+#include "gtest/internal/gtest-port.h"
+
+namespace testing {
+
+// Functions producing parameter generators.
+//
+// Google Test uses these generators to produce parameters for value-
+// parameterized tests. When a parameterized test suite is instantiated
+// with a particular generator, Google Test creates and runs tests
+// for each element in the sequence produced by the generator.
+//
+// In the following sample, tests from test suite FooTest are instantiated
+// each three times with parameter values 3, 5, and 8:
+//
+// class FooTest : public TestWithParam<int> { ... };
+//
+// TEST_P(FooTest, TestThis) {
+// }
+// TEST_P(FooTest, TestThat) {
+// }
+// INSTANTIATE_TEST_SUITE_P(TestSequence, FooTest, Values(3, 5, 8));
+//
+
+// Range() returns generators providing sequences of values in a range.
+//
+// Synopsis:
+// Range(start, end)
+//   - returns a generator producing a sequence of values {start, start+1,
+//     start+2, ..., }.
+// Range(start, end, step)
+//   - returns a generator producing a sequence of values {start, start+step,
+//     start+step+step, ..., }.
+// Notes:
+//   * The generated sequences never include end. For example, Range(1, 5)
+//     returns a generator producing a sequence {1, 2, 3, 4}. Range(1, 9, 2)
+//     returns a generator producing {1, 3, 5, 7}.
+//   * start and end must have the same type. That type may be any integral or
+//     floating-point type or a user defined type satisfying these conditions:
+//     * It must be assignable (have operator=() defined).
+//     * It must have operator+() (operator+(int-compatible type) for
+//       two-operand version).
+//     * It must have operator<() defined.
+//     Elements in the resulting sequences will also have that type.
+//   * Condition start < end must be satisfied in order for resulting sequences
+//     to contain any elements.
+//
+template <typename T, typename IncrementT>
+internal::ParamGenerator<T> Range(T start, T end, IncrementT step) {
+  return internal::ParamGenerator<T>(
+      new internal::RangeGenerator<T, IncrementT>(start, end, step));
+}
+
+template <typename T>
+internal::ParamGenerator<T> Range(T start, T end) {
+  return Range(start, end, 1);
+}
+
+// ValuesIn() function allows generation of tests with parameters coming from
+// a container.
+//
+// Synopsis:
+// ValuesIn(const T (&array)[N])
+//   - returns a generator producing sequences with elements from
+//     a C-style array.
+// ValuesIn(const Container& container)
+//   - returns a generator producing sequences with elements from
+//     an STL-style container.
+// ValuesIn(Iterator begin, Iterator end)
+//   - returns a generator producing sequences with elements from
+//     a range [begin, end) defined by a pair of STL-style iterators. These
+//     iterators can also be plain C pointers.
+//
+// Please note that ValuesIn copies the values from the containers
+// passed in and keeps them to generate tests in RUN_ALL_TESTS().
+//
+// Examples:
+//
+// This instantiates tests from test suite StringTest
+// each with C-string values of "foo", "bar", and "baz":
+//
+// const char* strings[] = {"foo", "bar", "baz"};
+// INSTANTIATE_TEST_SUITE_P(StringSequence, StringTest, ValuesIn(strings));
+//
+// This instantiates tests from test suite StlStringTest
+// each with STL strings with values "a" and "b":
+//
+// ::std::vector< ::std::string> GetParameterStrings() {
+//   ::std::vector< ::std::string> v;
+//   v.push_back("a");
+//   v.push_back("b");
+//   return v;
+// }
+//
+// INSTANTIATE_TEST_SUITE_P(CharSequence,
+//                          StlStringTest,
+//                          ValuesIn(GetParameterStrings()));
+//
+//
+// This will also instantiate tests from CharTest
+// each with parameter values 'a' and 'b':
+//
+// ::std::list<char> GetParameterChars() {
+//   ::std::list<char> list;
+//   list.push_back('a');
+//   list.push_back('b');
+//   return list;
+// }
+// ::std::list<char> l = GetParameterChars();
+// INSTANTIATE_TEST_SUITE_P(CharSequence2,
+//                          CharTest,
+//                          ValuesIn(l.begin(), l.end()));
+//
+template <typename ForwardIterator>
+internal::ParamGenerator<
+    typename std::iterator_traits<ForwardIterator>::value_type>
+ValuesIn(ForwardIterator begin, ForwardIterator end) {
+  typedef typename std::iterator_traits<ForwardIterator>::value_type ParamType;
+  return internal::ParamGenerator<ParamType>(
+      new internal::ValuesInIteratorRangeGenerator<ParamType>(begin, end));
+}
+
+template <typename T, size_t N>
+internal::ParamGenerator<T> ValuesIn(const T (&array)[N]) {
+  return ValuesIn(array, array + N);
+}
+
+template <class Container>
+internal::ParamGenerator<typename Container::value_type> ValuesIn(
+    const Container& container) {
+  return ValuesIn(container.begin(), container.end());
+}
+
+// Values() allows generating tests from explicitly specified list of
+// parameters.
+//
+// Synopsis:
+// Values(T v1, T v2, ..., T vN)
+//   - returns a generator producing sequences with elements v1, v2, ..., vN.
+//
+// For example, this instantiates tests from test suite BarTest each
+// with values "one", "two", and "three":
+//
+// INSTANTIATE_TEST_SUITE_P(NumSequence,
+//                          BarTest,
+//                          Values("one", "two", "three"));
+//
+// This instantiates tests from test suite BazTest each with values 1, 2, 3.5.
+// The exact type of values will depend on the type of parameter in BazTest.
+//
+// INSTANTIATE_TEST_SUITE_P(FloatingNumbers, BazTest, Values(1, 2, 3.5));
+//
+//
+template <typename... T>
+internal::ValueArray<T...> Values(T... v) {
+  return internal::ValueArray<T...>(std::move(v)...);
+}
+
+// Bool() allows generating tests with parameters in a set of (false, true).
+//
+// Synopsis:
+// Bool()
+//   - returns a generator producing sequences with elements {false, true}.
+//
+// It is useful when testing code that depends on Boolean flags. Combinations
+// of multiple flags can be tested when several Bool()'s are combined using
+// Combine() function.
+//
+// In the following example all tests in the test suite FlagDependentTest
+// will be instantiated twice with parameters false and true.
+//
+// class FlagDependentTest : public testing::TestWithParam<bool> {
+//   virtual void SetUp() {
+//     external_flag = GetParam();
+//   }
+// }
+// INSTANTIATE_TEST_SUITE_P(BoolSequence, FlagDependentTest, Bool());
+//
+inline internal::ParamGenerator<bool> Bool() { return Values(false, true); }
+
+// Combine() allows the user to combine two or more sequences to produce
+// values of a Cartesian product of those sequences' elements.
+//
+// Synopsis:
+// Combine(gen1, gen2, ..., genN)
+//   - returns a generator producing sequences with elements coming from
+//     the Cartesian product of elements from the sequences generated by
+//     gen1, gen2, ..., genN. The sequence elements will have a type of
+//     std::tuple<T1, T2, ..., TN> where T1, T2, ..., TN are the types
+//     of elements from sequences produces by gen1, gen2, ..., genN.
+//
+// Example:
+//
+// This will instantiate tests in test suite AnimalTest each one with
+// the parameter values tuple("cat", BLACK), tuple("cat", WHITE),
+// tuple("dog", BLACK), and tuple("dog", WHITE):
+//
+// enum Color { BLACK, GRAY, WHITE };
+// class AnimalTest
+//     : public testing::TestWithParam<std::tuple<const char*, Color> > {...};
+//
+// TEST_P(AnimalTest, AnimalLooksNice) {...}
+//
+// INSTANTIATE_TEST_SUITE_P(AnimalVariations, AnimalTest,
+//                          Combine(Values("cat", "dog"),
+//                                  Values(BLACK, WHITE)));
+//
+// This will instantiate tests in FlagDependentTest with all variations of two
+// Boolean flags:
+//
+// class FlagDependentTest
+//     : public testing::TestWithParam<std::tuple<bool, bool> > {
+//   virtual void SetUp() {
+//     // Assigns external_flag_1 and external_flag_2 values from the tuple.
+//     std::tie(external_flag_1, external_flag_2) = GetParam();
+//   }
+// };
+//
+// TEST_P(FlagDependentTest, TestFeature1) {
+//   // Test your code using external_flag_1 and external_flag_2 here.
+// }
+// INSTANTIATE_TEST_SUITE_P(TwoBoolSequence, FlagDependentTest,
+//                          Combine(Bool(), Bool()));
+//
+template <typename... Generator>
+internal::CartesianProductHolder<Generator...> Combine(const Generator&... g) {
+  return internal::CartesianProductHolder<Generator...>(g...);
+}
+
+#define TEST_P(test_suite_name, test_name)                                     \
+  class GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)                     \
+      : public test_suite_name {                                               \
+   public:                                                                     \
+    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)() {}                    \
+    void TestBody() override;                                                  \
+                                                                               \
+   private:                                                                    \
+    static int AddToRegistry() {                                               \
+      ::testing::UnitTest::GetInstance()                                       \
+          ->parameterized_test_registry()                                      \
+          .GetTestSuitePatternHolder<test_suite_name>(                         \
+              GTEST_STRINGIFY_(test_suite_name),                               \
+              ::testing::internal::CodeLocation(__FILE__, __LINE__))           \
+          ->AddTestPattern(                                                    \
+              GTEST_STRINGIFY_(test_suite_name), GTEST_STRINGIFY_(test_name),  \
+              new ::testing::internal::TestMetaFactory<GTEST_TEST_CLASS_NAME_( \
+                  test_suite_name, test_name)>(),                              \
+              ::testing::internal::CodeLocation(__FILE__, __LINE__));          \
+      return 0;                                                                \
+    }                                                                          \
+    static int gtest_registering_dummy_ GTEST_ATTRIBUTE_UNUSED_;               \
+    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)                         \
+    (const GTEST_TEST_CLASS_NAME_(test_suite_name, test_name) &) = delete;     \
+    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name) & operator=(            \
+        const GTEST_TEST_CLASS_NAME_(test_suite_name,                          \
+                                     test_name) &) = delete; /* NOLINT */      \
+  };                                                                           \
+  int GTEST_TEST_CLASS_NAME_(test_suite_name,                                  \
+                             test_name)::gtest_registering_dummy_ =            \
+      GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)::AddToRegistry();     \
+  void GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)::TestBody()
+
+// The last argument to INSTANTIATE_TEST_SUITE_P allows the user to specify
+// generator and an optional function or functor that generates custom test name
+// suffixes based on the test parameters. Such a function or functor should
+// accept one argument of type testing::TestParamInfo<class ParamType>, and
+// return std::string.
+//
+// testing::PrintToStringParamName is a builtin test suffix generator that
+// returns the value of testing::PrintToString(GetParam()).
+//
+// Note: test names must be non-empty, unique, and may only contain ASCII
+// alphanumeric characters or underscore. Because PrintToString adds quotes
+// to std::string and C strings, it won't work for these types.
+
+#define GTEST_EXPAND_(arg) arg
+#define GTEST_GET_FIRST_(first, ...) first
+#define GTEST_GET_SECOND_(first, second, ...) second
+
+#define INSTANTIATE_TEST_SUITE_P(prefix, test_suite_name, ...)               \
+  static ::testing::internal::ParamGenerator<test_suite_name::ParamType>     \
+      gtest_##prefix##test_suite_name##_EvalGenerator_() {                   \
+    return GTEST_EXPAND_(GTEST_GET_FIRST_(__VA_ARGS__, DUMMY_PARAM_));       \
+  }                                                                          \
+  static ::std::string gtest_##prefix##test_suite_name##_EvalGenerateName_(  \
+      const ::testing::TestParamInfo<test_suite_name::ParamType>& info) {    \
+    if (::testing::internal::AlwaysFalse()) {                                \
+      ::testing::internal::TestNotEmpty(GTEST_EXPAND_(GTEST_GET_SECOND_(     \
+          __VA_ARGS__,                                                       \
+          ::testing::internal::DefaultParamName<test_suite_name::ParamType>, \
+          DUMMY_PARAM_)));                                                   \
+      auto t = std::make_tuple(__VA_ARGS__);                                 \
+      static_assert(std::tuple_size<decltype(t)>::value <= 2,                \
+                    "Too Many Args!");                                       \
+    }                                                                        \
+    return ((GTEST_EXPAND_(GTEST_GET_SECOND_(                                \
+        __VA_ARGS__,                                                         \
+        ::testing::internal::DefaultParamName<test_suite_name::ParamType>,   \
+        DUMMY_PARAM_))))(info);                                              \
+  }                                                                          \
+  static int gtest_##prefix##test_suite_name##_dummy_                        \
+      GTEST_ATTRIBUTE_UNUSED_ =                                              \
+          ::testing::UnitTest::GetInstance()                                 \
+              ->parameterized_test_registry()                                \
+              .GetTestSuitePatternHolder<test_suite_name>(                   \
+                  GTEST_STRINGIFY_(test_suite_name),                         \
+                  ::testing::internal::CodeLocation(__FILE__, __LINE__))     \
+              ->AddTestSuiteInstantiation(                                   \
+                  GTEST_STRINGIFY_(prefix),                                  \
+                  &gtest_##prefix##test_suite_name##_EvalGenerator_,         \
+                  &gtest_##prefix##test_suite_name##_EvalGenerateName_,      \
+                  __FILE__, __LINE__)
+
+// Allow Marking a Parameterized test class as not needing to be instantiated.
+#define GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(T)                  \
+  namespace gtest_do_not_use_outside_namespace_scope {}                   \
+  static const ::testing::internal::MarkAsIgnored gtest_allow_ignore_##T( \
+      GTEST_STRINGIFY_(T))
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+#define INSTANTIATE_TEST_CASE_P                                            \
+  static_assert(::testing::internal::InstantiateTestCase_P_IsDeprecated(), \
+                "");                                                       \
+  INSTANTIATE_TEST_SUITE_P
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+}  // namespace testing
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_PARAM_TEST_H_
diff --git a/test/gtest/include/gtest/gtest-printers.h b/test/gtest/include/gtest/gtest-printers.h
new file mode 100644
index 0000000..a91e8b8
--- /dev/null
+++ b/test/gtest/include/gtest/gtest-printers.h
@@ -0,0 +1,1048 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Test - The Google C++ Testing and Mocking Framework
+//
+// This file implements a universal value printer that can print a
+// value of any type T:
+//
+//   void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr);
+//
+// A user can teach this function how to print a class type T by
+// defining either operator<<() or PrintTo() in the namespace that
+// defines T.  More specifically, the FIRST defined function in the
+// following list will be used (assuming T is defined in namespace
+// foo):
+//
+//   1. foo::PrintTo(const T&, ostream*)
+//   2. operator<<(ostream&, const T&) defined in either foo or the
+//      global namespace.
+//
+// However if T is an STL-style container then it is printed element-wise
+// unless foo::PrintTo(const T&, ostream*) is defined. Note that
+// operator<<() is ignored for container types.
+//
+// If none of the above is defined, it will print the debug string of
+// the value if it is a protocol buffer, or print the raw bytes in the
+// value otherwise.
+//
+// To aid debugging: when T is a reference type, the address of the
+// value is also printed; when T is a (const) char pointer, both the
+// pointer value and the NUL-terminated string it points to are
+// printed.
+//
+// We also provide some convenient wrappers:
+//
+//   // Prints a value to a string.  For a (const or not) char
+//   // pointer, the NUL-terminated string (but not the pointer) is
+//   // printed.
+//   std::string ::testing::PrintToString(const T& value);
+//
+//   // Prints a value tersely: for a reference type, the referenced
+//   // value (but not the address) is printed; for a (const or not) char
+//   // pointer, the NUL-terminated string (but not the pointer) is
+//   // printed.
+//   void ::testing::internal::UniversalTersePrint(const T& value, ostream*);
+//
+//   // Prints value using the type inferred by the compiler.  The difference
+//   // from UniversalTersePrint() is that this function prints both the
+//   // pointer and the NUL-terminated string for a (const or not) char pointer.
+//   void ::testing::internal::UniversalPrint(const T& value, ostream*);
+//
+//   // Prints the fields of a tuple tersely to a string vector, one
+//   // element for each field. Tuple support must be enabled in
+//   // gtest-port.h.
+//   std::vector<string> UniversalTersePrintTupleFieldsToStrings(
+//       const Tuple& value);
+//
+// Known limitation:
+//
+// The print primitives print the elements of an STL-style container
+// using the compiler-inferred type of *iter where iter is a
+// const_iterator of the container.  When const_iterator is an input
+// iterator but not a forward iterator, this inferred type may not
+// match value_type, and the print output may be incorrect.  In
+// practice, this is rarely a problem as for most containers
+// const_iterator is a forward iterator.  We'll fix this if there's an
+// actual need for it.  Note that this fix cannot rely on value_type
+// being defined as many user-defined container types don't have
+// value_type.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
+
+#include <functional>
+#include <memory>
+#include <ostream>  // NOLINT
+#include <sstream>
+#include <string>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-port.h"
+
+namespace testing {
+
+// Definitions in the internal* namespaces are subject to change without notice.
+// DO NOT USE THEM IN USER CODE!
+namespace internal {
+
+template <typename T>
+void UniversalPrint(const T& value, ::std::ostream* os);
+
+// Used to print an STL-style container when the user doesn't define
+// a PrintTo() for it.
+struct ContainerPrinter {
+  template <typename T,
+            typename = typename std::enable_if<
+                (sizeof(IsContainerTest<T>(0)) == sizeof(IsContainer)) &&
+                !IsRecursiveContainer<T>::value>::type>
+  static void PrintValue(const T& container, std::ostream* os) {
+    const size_t kMaxCount = 32;  // The maximum number of elements to print.
+    *os << '{';
+    size_t count = 0;
+    for (auto&& elem : container) {
+      if (count > 0) {
+        *os << ',';
+        if (count == kMaxCount) {  // Enough has been printed.
+          *os << " ...";
+          break;
+        }
+      }
+      *os << ' ';
+      // We cannot call PrintTo(elem, os) here as PrintTo() doesn't
+      // handle `elem` being a native array.
+      internal::UniversalPrint(elem, os);
+      ++count;
+    }
+
+    if (count > 0) {
+      *os << ' ';
+    }
+    *os << '}';
+  }
+};
+
+// Used to print a pointer that is neither a char pointer nor a member
+// pointer, when the user doesn't define PrintTo() for it.  (A member
+// variable pointer or member function pointer doesn't really point to
+// a location in the address space.  Their representation is
+// implementation-defined.  Therefore they will be printed as raw
+// bytes.)
+struct FunctionPointerPrinter {
+  template <typename T, typename = typename std::enable_if<
+                            std::is_function<T>::value>::type>
+  static void PrintValue(T* p, ::std::ostream* os) {
+    if (p == nullptr) {
+      *os << "NULL";
+    } else {
+      // T is a function type, so '*os << p' doesn't do what we want
+      // (it just prints p as bool).  We want to print p as a const
+      // void*.
+      *os << reinterpret_cast<const void*>(p);
+    }
+  }
+};
+
+struct PointerPrinter {
+  template <typename T>
+  static void PrintValue(T* p, ::std::ostream* os) {
+    if (p == nullptr) {
+      *os << "NULL";
+    } else {
+      // T is not a function type.  We just call << to print p,
+      // relying on ADL to pick up user-defined << for their pointer
+      // types, if any.
+      *os << p;
+    }
+  }
+};
+
+namespace internal_stream_operator_without_lexical_name_lookup {
+
+// The presence of an operator<< here will terminate lexical scope lookup
+// straight away (even though it cannot be a match because of its argument
+// types). Thus, the two operator<< calls in StreamPrinter will find only ADL
+// candidates.
+struct LookupBlocker {};
+void operator<<(LookupBlocker, LookupBlocker);
+
+struct StreamPrinter {
+  template <typename T,
+            // Don't accept member pointers here. We'd print them via implicit
+            // conversion to bool, which isn't useful.
+            typename = typename std::enable_if<
+                !std::is_member_pointer<T>::value>::type,
+            // Only accept types for which we can find a streaming operator via
+            // ADL (possibly involving implicit conversions).
+            typename = decltype(std::declval<std::ostream&>()
+                                << std::declval<const T&>())>
+  static void PrintValue(const T& value, ::std::ostream* os) {
+    // Call streaming operator found by ADL, possibly with implicit conversions
+    // of the arguments.
+    *os << value;
+  }
+};
+
+}  // namespace internal_stream_operator_without_lexical_name_lookup
+
+struct ProtobufPrinter {
+  // We print a protobuf using its ShortDebugString() when the string
+  // doesn't exceed this many characters; otherwise we print it using
+  // DebugString() for better readability.
+  static const size_t kProtobufOneLinerMaxLength = 50;
+
+  template <typename T,
+            typename = typename std::enable_if<
+                internal::HasDebugStringAndShortDebugString<T>::value>::type>
+  static void PrintValue(const T& value, ::std::ostream* os) {
+    std::string pretty_str = value.ShortDebugString();
+    if (pretty_str.length() > kProtobufOneLinerMaxLength) {
+      pretty_str = "\n" + value.DebugString();
+    }
+    *os << ("<" + pretty_str + ">");
+  }
+};
+
+struct ConvertibleToIntegerPrinter {
+  // Since T has no << operator or PrintTo() but can be implicitly
+  // converted to BiggestInt, we print it as a BiggestInt.
+  //
+  // Most likely T is an enum type (either named or unnamed), in which
+  // case printing it as an integer is the desired behavior.  In case
+  // T is not an enum, printing it as an integer is the best we can do
+  // given that it has no user-defined printer.
+  static void PrintValue(internal::BiggestInt value, ::std::ostream* os) {
+    *os << value;
+  }
+};
+
+struct ConvertibleToStringViewPrinter {
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  static void PrintValue(internal::StringView value, ::std::ostream* os) {
+    internal::UniversalPrint(value, os);
+  }
+#endif
+};
+
+// Prints the given number of bytes in the given object to the given
+// ostream.
+GTEST_API_ void PrintBytesInObjectTo(const unsigned char* obj_bytes,
+                                     size_t count, ::std::ostream* os);
+struct RawBytesPrinter {
+  // SFINAE on `sizeof` to make sure we have a complete type.
+  template <typename T, size_t = sizeof(T)>
+  static void PrintValue(const T& value, ::std::ostream* os) {
+    PrintBytesInObjectTo(
+        static_cast<const unsigned char*>(
+            // Load bearing cast to void* to support iOS
+            reinterpret_cast<const void*>(std::addressof(value))),
+        sizeof(value), os);
+  }
+};
+
+struct FallbackPrinter {
+  template <typename T>
+  static void PrintValue(const T&, ::std::ostream* os) {
+    *os << "(incomplete type)";
+  }
+};
+
+// Try every printer in order and return the first one that works.
+template <typename T, typename E, typename Printer, typename... Printers>
+struct FindFirstPrinter : FindFirstPrinter<T, E, Printers...> {};
+
+template <typename T, typename Printer, typename... Printers>
+struct FindFirstPrinter<
+    T, decltype(Printer::PrintValue(std::declval<const T&>(), nullptr)),
+    Printer, Printers...> {
+  using type = Printer;
+};
+
+// Select the best printer in the following order:
+//  - Print containers (they have begin/end/etc).
+//  - Print function pointers.
+//  - Print object pointers.
+//  - Use the stream operator, if available.
+//  - Print protocol buffers.
+//  - Print types convertible to BiggestInt.
+//  - Print types convertible to StringView, if available.
+//  - Fallback to printing the raw bytes of the object.
+template <typename T>
+void PrintWithFallback(const T& value, ::std::ostream* os) {
+  using Printer = typename FindFirstPrinter<
+      T, void, ContainerPrinter, FunctionPointerPrinter, PointerPrinter,
+      internal_stream_operator_without_lexical_name_lookup::StreamPrinter,
+      ProtobufPrinter, ConvertibleToIntegerPrinter,
+      ConvertibleToStringViewPrinter, RawBytesPrinter, FallbackPrinter>::type;
+  Printer::PrintValue(value, os);
+}
+
+// FormatForComparison<ToPrint, OtherOperand>::Format(value) formats a
+// value of type ToPrint that is an operand of a comparison assertion
+// (e.g. ASSERT_EQ).  OtherOperand is the type of the other operand in
+// the comparison, and is used to help determine the best way to
+// format the value.  In particular, when the value is a C string
+// (char pointer) and the other operand is an STL string object, we
+// want to format the C string as a string, since we know it is
+// compared by value with the string object.  If the value is a char
+// pointer but the other operand is not an STL string object, we don't
+// know whether the pointer is supposed to point to a NUL-terminated
+// string, and thus want to print it as a pointer to be safe.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+
+// The default case.
+template <typename ToPrint, typename OtherOperand>
+class FormatForComparison {
+ public:
+  static ::std::string Format(const ToPrint& value) {
+    return ::testing::PrintToString(value);
+  }
+};
+
+// Array.
+template <typename ToPrint, size_t N, typename OtherOperand>
+class FormatForComparison<ToPrint[N], OtherOperand> {
+ public:
+  static ::std::string Format(const ToPrint* value) {
+    return FormatForComparison<const ToPrint*, OtherOperand>::Format(value);
+  }
+};
+
+// By default, print C string as pointers to be safe, as we don't know
+// whether they actually point to a NUL-terminated string.
+
+#define GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(CharType)                \
+  template <typename OtherOperand>                                      \
+  class FormatForComparison<CharType*, OtherOperand> {                  \
+   public:                                                              \
+    static ::std::string Format(CharType* value) {                      \
+      return ::testing::PrintToString(static_cast<const void*>(value)); \
+    }                                                                   \
+  }
+
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char);
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char);
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(wchar_t);
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const wchar_t);
+#ifdef __cpp_lib_char8_t
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char8_t);
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char8_t);
+#endif
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char16_t);
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char16_t);
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char32_t);
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char32_t);
+
+#undef GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_
+
+// If a C string is compared with an STL string object, we know it's meant
+// to point to a NUL-terminated string, and thus can print it as a string.
+
+#define GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(CharType, OtherStringType) \
+  template <>                                                            \
+  class FormatForComparison<CharType*, OtherStringType> {                \
+   public:                                                               \
+    static ::std::string Format(CharType* value) {                       \
+      return ::testing::PrintToString(value);                            \
+    }                                                                    \
+  }
+
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char, ::std::string);
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char, ::std::string);
+#ifdef __cpp_char8_t
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char8_t, ::std::u8string);
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char8_t, ::std::u8string);
+#endif
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char16_t, ::std::u16string);
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char16_t, ::std::u16string);
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char32_t, ::std::u32string);
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char32_t, ::std::u32string);
+
+#if GTEST_HAS_STD_WSTRING
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(wchar_t, ::std::wstring);
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const wchar_t, ::std::wstring);
+#endif
+
+#undef GTEST_IMPL_FORMAT_C_STRING_AS_STRING_
+
+// Formats a comparison assertion (e.g. ASSERT_EQ, EXPECT_LT, and etc)
+// operand to be used in a failure message.  The type (but not value)
+// of the other operand may affect the format.  This allows us to
+// print a char* as a raw pointer when it is compared against another
+// char* or void*, and print it as a C string when it is compared
+// against an std::string object, for example.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+template <typename T1, typename T2>
+std::string FormatForComparisonFailureMessage(const T1& value,
+                                              const T2& /* other_operand */) {
+  return FormatForComparison<T1, T2>::Format(value);
+}
+
+// UniversalPrinter<T>::Print(value, ostream_ptr) prints the given
+// value to the given ostream.  The caller must ensure that
+// 'ostream_ptr' is not NULL, or the behavior is undefined.
+//
+// We define UniversalPrinter as a class template (as opposed to a
+// function template), as we need to partially specialize it for
+// reference types, which cannot be done with function templates.
+template <typename T>
+class UniversalPrinter;
+
+// Prints the given value using the << operator if it has one;
+// otherwise prints the bytes in it.  This is what
+// UniversalPrinter<T>::Print() does when PrintTo() is not specialized
+// or overloaded for type T.
+//
+// A user can override this behavior for a class type Foo by defining
+// an overload of PrintTo() in the namespace where Foo is defined.  We
+// give the user this option as sometimes defining a << operator for
+// Foo is not desirable (e.g. the coding style may prevent doing it,
+// or there is already a << operator but it doesn't do what the user
+// wants).
+template <typename T>
+void PrintTo(const T& value, ::std::ostream* os) {
+  internal::PrintWithFallback(value, os);
+}
+
+// The following list of PrintTo() overloads tells
+// UniversalPrinter<T>::Print() how to print standard types (built-in
+// types, strings, plain arrays, and pointers).
+
+// Overloads for various char types.
+GTEST_API_ void PrintTo(unsigned char c, ::std::ostream* os);
+GTEST_API_ void PrintTo(signed char c, ::std::ostream* os);
+inline void PrintTo(char c, ::std::ostream* os) {
+  // When printing a plain char, we always treat it as unsigned.  This
+  // way, the output won't be affected by whether the compiler thinks
+  // char is signed or not.
+  PrintTo(static_cast<unsigned char>(c), os);
+}
+
+// Overloads for other simple built-in types.
+inline void PrintTo(bool x, ::std::ostream* os) {
+  *os << (x ? "true" : "false");
+}
+
+// Overload for wchar_t type.
+// Prints a wchar_t as a symbol if it is printable or as its internal
+// code otherwise and also as its decimal code (except for L'\0').
+// The L'\0' char is printed as "L'\\0'". The decimal code is printed
+// as signed integer when wchar_t is implemented by the compiler
+// as a signed type and is printed as an unsigned integer when wchar_t
+// is implemented as an unsigned type.
+GTEST_API_ void PrintTo(wchar_t wc, ::std::ostream* os);
+
+GTEST_API_ void PrintTo(char32_t c, ::std::ostream* os);
+inline void PrintTo(char16_t c, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<char32_t>(c), os);
+}
+#ifdef __cpp_char8_t
+inline void PrintTo(char8_t c, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<char32_t>(c), os);
+}
+#endif
+
+// gcc/clang __{u,}int128_t
+#if defined(__SIZEOF_INT128__)
+GTEST_API_ void PrintTo(__uint128_t v, ::std::ostream* os);
+GTEST_API_ void PrintTo(__int128_t v, ::std::ostream* os);
+#endif  // __SIZEOF_INT128__
+
+// Overloads for C strings.
+GTEST_API_ void PrintTo(const char* s, ::std::ostream* os);
+inline void PrintTo(char* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const char*>(s), os);
+}
+
+// signed/unsigned char is often used for representing binary data, so
+// we print pointers to it as void* to be safe.
+inline void PrintTo(const signed char* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const void*>(s), os);
+}
+inline void PrintTo(signed char* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const void*>(s), os);
+}
+inline void PrintTo(const unsigned char* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const void*>(s), os);
+}
+inline void PrintTo(unsigned char* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const void*>(s), os);
+}
+#ifdef __cpp_char8_t
+// Overloads for u8 strings.
+GTEST_API_ void PrintTo(const char8_t* s, ::std::ostream* os);
+inline void PrintTo(char8_t* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const char8_t*>(s), os);
+}
+#endif
+// Overloads for u16 strings.
+GTEST_API_ void PrintTo(const char16_t* s, ::std::ostream* os);
+inline void PrintTo(char16_t* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const char16_t*>(s), os);
+}
+// Overloads for u32 strings.
+GTEST_API_ void PrintTo(const char32_t* s, ::std::ostream* os);
+inline void PrintTo(char32_t* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const char32_t*>(s), os);
+}
+
+// MSVC can be configured to define wchar_t as a typedef of unsigned
+// short.  It defines _NATIVE_WCHAR_T_DEFINED when wchar_t is a native
+// type.  When wchar_t is a typedef, defining an overload for const
+// wchar_t* would cause unsigned short* be printed as a wide string,
+// possibly causing invalid memory accesses.
+#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
+// Overloads for wide C strings
+GTEST_API_ void PrintTo(const wchar_t* s, ::std::ostream* os);
+inline void PrintTo(wchar_t* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const wchar_t*>(s), os);
+}
+#endif
+
+// Overload for C arrays.  Multi-dimensional arrays are printed
+// properly.
+
+// Prints the given number of elements in an array, without printing
+// the curly braces.
+template <typename T>
+void PrintRawArrayTo(const T a[], size_t count, ::std::ostream* os) {
+  UniversalPrint(a[0], os);
+  for (size_t i = 1; i != count; i++) {
+    *os << ", ";
+    UniversalPrint(a[i], os);
+  }
+}
+
+// Overloads for ::std::string.
+GTEST_API_ void PrintStringTo(const ::std::string& s, ::std::ostream* os);
+inline void PrintTo(const ::std::string& s, ::std::ostream* os) {
+  PrintStringTo(s, os);
+}
+
+// Overloads for ::std::u8string
+#ifdef __cpp_char8_t
+GTEST_API_ void PrintU8StringTo(const ::std::u8string& s, ::std::ostream* os);
+inline void PrintTo(const ::std::u8string& s, ::std::ostream* os) {
+  PrintU8StringTo(s, os);
+}
+#endif
+
+// Overloads for ::std::u16string
+GTEST_API_ void PrintU16StringTo(const ::std::u16string& s, ::std::ostream* os);
+inline void PrintTo(const ::std::u16string& s, ::std::ostream* os) {
+  PrintU16StringTo(s, os);
+}
+
+// Overloads for ::std::u32string
+GTEST_API_ void PrintU32StringTo(const ::std::u32string& s, ::std::ostream* os);
+inline void PrintTo(const ::std::u32string& s, ::std::ostream* os) {
+  PrintU32StringTo(s, os);
+}
+
+// Overloads for ::std::wstring.
+#if GTEST_HAS_STD_WSTRING
+GTEST_API_ void PrintWideStringTo(const ::std::wstring& s, ::std::ostream* os);
+inline void PrintTo(const ::std::wstring& s, ::std::ostream* os) {
+  PrintWideStringTo(s, os);
+}
+#endif  // GTEST_HAS_STD_WSTRING
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+// Overload for internal::StringView.
+inline void PrintTo(internal::StringView sp, ::std::ostream* os) {
+  PrintTo(::std::string(sp), os);
+}
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+
+inline void PrintTo(std::nullptr_t, ::std::ostream* os) { *os << "(nullptr)"; }
+
+#if GTEST_HAS_RTTI
+inline void PrintTo(const std::type_info& info, std::ostream* os) {
+  *os << internal::GetTypeName(info);
+}
+#endif  // GTEST_HAS_RTTI
+
+template <typename T>
+void PrintTo(std::reference_wrapper<T> ref, ::std::ostream* os) {
+  UniversalPrinter<T&>::Print(ref.get(), os);
+}
+
+inline const void* VoidifyPointer(const void* p) { return p; }
+inline const void* VoidifyPointer(volatile const void* p) {
+  return const_cast<const void*>(p);
+}
+
+template <typename T, typename Ptr>
+void PrintSmartPointer(const Ptr& ptr, std::ostream* os, char) {
+  if (ptr == nullptr) {
+    *os << "(nullptr)";
+  } else {
+    // We can't print the value. Just print the pointer..
+    *os << "(" << (VoidifyPointer)(ptr.get()) << ")";
+  }
+}
+template <typename T, typename Ptr,
+          typename = typename std::enable_if<!std::is_void<T>::value &&
+                                             !std::is_array<T>::value>::type>
+void PrintSmartPointer(const Ptr& ptr, std::ostream* os, int) {
+  if (ptr == nullptr) {
+    *os << "(nullptr)";
+  } else {
+    *os << "(ptr = " << (VoidifyPointer)(ptr.get()) << ", value = ";
+    UniversalPrinter<T>::Print(*ptr, os);
+    *os << ")";
+  }
+}
+
+template <typename T, typename D>
+void PrintTo(const std::unique_ptr<T, D>& ptr, std::ostream* os) {
+  (PrintSmartPointer<T>)(ptr, os, 0);
+}
+
+template <typename T>
+void PrintTo(const std::shared_ptr<T>& ptr, std::ostream* os) {
+  (PrintSmartPointer<T>)(ptr, os, 0);
+}
+
+// Helper function for printing a tuple.  T must be instantiated with
+// a tuple type.
+template <typename T>
+void PrintTupleTo(const T&, std::integral_constant<size_t, 0>,
+                  ::std::ostream*) {}
+
+template <typename T, size_t I>
+void PrintTupleTo(const T& t, std::integral_constant<size_t, I>,
+                  ::std::ostream* os) {
+  PrintTupleTo(t, std::integral_constant<size_t, I - 1>(), os);
+  GTEST_INTENTIONAL_CONST_COND_PUSH_()
+  if (I > 1) {
+    GTEST_INTENTIONAL_CONST_COND_POP_()
+    *os << ", ";
+  }
+  UniversalPrinter<typename std::tuple_element<I - 1, T>::type>::Print(
+      std::get<I - 1>(t), os);
+}
+
+template <typename... Types>
+void PrintTo(const ::std::tuple<Types...>& t, ::std::ostream* os) {
+  *os << "(";
+  PrintTupleTo(t, std::integral_constant<size_t, sizeof...(Types)>(), os);
+  *os << ")";
+}
+
+// Overload for std::pair.
+template <typename T1, typename T2>
+void PrintTo(const ::std::pair<T1, T2>& value, ::std::ostream* os) {
+  *os << '(';
+  // We cannot use UniversalPrint(value.first, os) here, as T1 may be
+  // a reference type.  The same for printing value.second.
+  UniversalPrinter<T1>::Print(value.first, os);
+  *os << ", ";
+  UniversalPrinter<T2>::Print(value.second, os);
+  *os << ')';
+}
+
+// Implements printing a non-reference type T by letting the compiler
+// pick the right overload of PrintTo() for T.
+template <typename T>
+class UniversalPrinter {
+ public:
+  // MSVC warns about adding const to a function type, so we want to
+  // disable the warning.
+  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
+
+  // Note: we deliberately don't call this PrintTo(), as that name
+  // conflicts with ::testing::internal::PrintTo in the body of the
+  // function.
+  static void Print(const T& value, ::std::ostream* os) {
+    // By default, ::testing::internal::PrintTo() is used for printing
+    // the value.
+    //
+    // Thanks to Koenig look-up, if T is a class and has its own
+    // PrintTo() function defined in its namespace, that function will
+    // be visible here.  Since it is more specific than the generic ones
+    // in ::testing::internal, it will be picked by the compiler in the
+    // following statement - exactly what we want.
+    PrintTo(value, os);
+  }
+
+  GTEST_DISABLE_MSC_WARNINGS_POP_()
+};
+
+// Remove any const-qualifiers before passing a type to UniversalPrinter.
+template <typename T>
+class UniversalPrinter<const T> : public UniversalPrinter<T> {};
+
+#if GTEST_INTERNAL_HAS_ANY
+
+// Printer for std::any / absl::any
+
+template <>
+class UniversalPrinter<Any> {
+ public:
+  static void Print(const Any& value, ::std::ostream* os) {
+    if (value.has_value()) {
+      *os << "value of type " << GetTypeName(value);
+    } else {
+      *os << "no value";
+    }
+  }
+
+ private:
+  static std::string GetTypeName(const Any& value) {
+#if GTEST_HAS_RTTI
+    return internal::GetTypeName(value.type());
+#else
+    static_cast<void>(value);  // possibly unused
+    return "<unknown_type>";
+#endif  // GTEST_HAS_RTTI
+  }
+};
+
+#endif  // GTEST_INTERNAL_HAS_ANY
+
+#if GTEST_INTERNAL_HAS_OPTIONAL
+
+// Printer for std::optional / absl::optional
+
+template <typename T>
+class UniversalPrinter<Optional<T>> {
+ public:
+  static void Print(const Optional<T>& value, ::std::ostream* os) {
+    *os << '(';
+    if (!value) {
+      *os << "nullopt";
+    } else {
+      UniversalPrint(*value, os);
+    }
+    *os << ')';
+  }
+};
+
+template <>
+class UniversalPrinter<decltype(Nullopt())> {
+ public:
+  static void Print(decltype(Nullopt()), ::std::ostream* os) {
+    *os << "(nullopt)";
+  }
+};
+
+#endif  // GTEST_INTERNAL_HAS_OPTIONAL
+
+#if GTEST_INTERNAL_HAS_VARIANT
+
+// Printer for std::variant / absl::variant
+
+template <typename... T>
+class UniversalPrinter<Variant<T...>> {
+ public:
+  static void Print(const Variant<T...>& value, ::std::ostream* os) {
+    *os << '(';
+#if GTEST_HAS_ABSL
+    absl::visit(Visitor{os, value.index()}, value);
+#else
+    std::visit(Visitor{os, value.index()}, value);
+#endif  // GTEST_HAS_ABSL
+    *os << ')';
+  }
+
+ private:
+  struct Visitor {
+    template <typename U>
+    void operator()(const U& u) const {
+      *os << "'" << GetTypeName<U>() << "(index = " << index
+          << ")' with value ";
+      UniversalPrint(u, os);
+    }
+    ::std::ostream* os;
+    std::size_t index;
+  };
+};
+
+#endif  // GTEST_INTERNAL_HAS_VARIANT
+
+// UniversalPrintArray(begin, len, os) prints an array of 'len'
+// elements, starting at address 'begin'.
+template <typename T>
+void UniversalPrintArray(const T* begin, size_t len, ::std::ostream* os) {
+  if (len == 0) {
+    *os << "{}";
+  } else {
+    *os << "{ ";
+    const size_t kThreshold = 18;
+    const size_t kChunkSize = 8;
+    // If the array has more than kThreshold elements, we'll have to
+    // omit some details by printing only the first and the last
+    // kChunkSize elements.
+    if (len <= kThreshold) {
+      PrintRawArrayTo(begin, len, os);
+    } else {
+      PrintRawArrayTo(begin, kChunkSize, os);
+      *os << ", ..., ";
+      PrintRawArrayTo(begin + len - kChunkSize, kChunkSize, os);
+    }
+    *os << " }";
+  }
+}
+// This overload prints a (const) char array compactly.
+GTEST_API_ void UniversalPrintArray(const char* begin, size_t len,
+                                    ::std::ostream* os);
+
+#ifdef __cpp_char8_t
+// This overload prints a (const) char8_t array compactly.
+GTEST_API_ void UniversalPrintArray(const char8_t* begin, size_t len,
+                                    ::std::ostream* os);
+#endif
+
+// This overload prints a (const) char16_t array compactly.
+GTEST_API_ void UniversalPrintArray(const char16_t* begin, size_t len,
+                                    ::std::ostream* os);
+
+// This overload prints a (const) char32_t array compactly.
+GTEST_API_ void UniversalPrintArray(const char32_t* begin, size_t len,
+                                    ::std::ostream* os);
+
+// This overload prints a (const) wchar_t array compactly.
+GTEST_API_ void UniversalPrintArray(const wchar_t* begin, size_t len,
+                                    ::std::ostream* os);
+
+// Implements printing an array type T[N].
+template <typename T, size_t N>
+class UniversalPrinter<T[N]> {
+ public:
+  // Prints the given array, omitting some elements when there are too
+  // many.
+  static void Print(const T (&a)[N], ::std::ostream* os) {
+    UniversalPrintArray(a, N, os);
+  }
+};
+
+// Implements printing a reference type T&.
+template <typename T>
+class UniversalPrinter<T&> {
+ public:
+  // MSVC warns about adding const to a function type, so we want to
+  // disable the warning.
+  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
+
+  static void Print(const T& value, ::std::ostream* os) {
+    // Prints the address of the value.  We use reinterpret_cast here
+    // as static_cast doesn't compile when T is a function type.
+    *os << "@" << reinterpret_cast<const void*>(&value) << " ";
+
+    // Then prints the value itself.
+    UniversalPrint(value, os);
+  }
+
+  GTEST_DISABLE_MSC_WARNINGS_POP_()
+};
+
+// Prints a value tersely: for a reference type, the referenced value
+// (but not the address) is printed; for a (const) char pointer, the
+// NUL-terminated string (but not the pointer) is printed.
+
+template <typename T>
+class UniversalTersePrinter {
+ public:
+  static void Print(const T& value, ::std::ostream* os) {
+    UniversalPrint(value, os);
+  }
+};
+template <typename T>
+class UniversalTersePrinter<T&> {
+ public:
+  static void Print(const T& value, ::std::ostream* os) {
+    UniversalPrint(value, os);
+  }
+};
+template <typename T, size_t N>
+class UniversalTersePrinter<T[N]> {
+ public:
+  static void Print(const T (&value)[N], ::std::ostream* os) {
+    UniversalPrinter<T[N]>::Print(value, os);
+  }
+};
+template <>
+class UniversalTersePrinter<const char*> {
+ public:
+  static void Print(const char* str, ::std::ostream* os) {
+    if (str == nullptr) {
+      *os << "NULL";
+    } else {
+      UniversalPrint(std::string(str), os);
+    }
+  }
+};
+template <>
+class UniversalTersePrinter<char*> : public UniversalTersePrinter<const char*> {
+};
+
+#ifdef __cpp_char8_t
+template <>
+class UniversalTersePrinter<const char8_t*> {
+ public:
+  static void Print(const char8_t* str, ::std::ostream* os) {
+    if (str == nullptr) {
+      *os << "NULL";
+    } else {
+      UniversalPrint(::std::u8string(str), os);
+    }
+  }
+};
+template <>
+class UniversalTersePrinter<char8_t*>
+    : public UniversalTersePrinter<const char8_t*> {};
+#endif
+
+template <>
+class UniversalTersePrinter<const char16_t*> {
+ public:
+  static void Print(const char16_t* str, ::std::ostream* os) {
+    if (str == nullptr) {
+      *os << "NULL";
+    } else {
+      UniversalPrint(::std::u16string(str), os);
+    }
+  }
+};
+template <>
+class UniversalTersePrinter<char16_t*>
+    : public UniversalTersePrinter<const char16_t*> {};
+
+template <>
+class UniversalTersePrinter<const char32_t*> {
+ public:
+  static void Print(const char32_t* str, ::std::ostream* os) {
+    if (str == nullptr) {
+      *os << "NULL";
+    } else {
+      UniversalPrint(::std::u32string(str), os);
+    }
+  }
+};
+template <>
+class UniversalTersePrinter<char32_t*>
+    : public UniversalTersePrinter<const char32_t*> {};
+
+#if GTEST_HAS_STD_WSTRING
+template <>
+class UniversalTersePrinter<const wchar_t*> {
+ public:
+  static void Print(const wchar_t* str, ::std::ostream* os) {
+    if (str == nullptr) {
+      *os << "NULL";
+    } else {
+      UniversalPrint(::std::wstring(str), os);
+    }
+  }
+};
+#endif
+
+template <>
+class UniversalTersePrinter<wchar_t*> {
+ public:
+  static void Print(wchar_t* str, ::std::ostream* os) {
+    UniversalTersePrinter<const wchar_t*>::Print(str, os);
+  }
+};
+
+template <typename T>
+void UniversalTersePrint(const T& value, ::std::ostream* os) {
+  UniversalTersePrinter<T>::Print(value, os);
+}
+
+// Prints a value using the type inferred by the compiler.  The
+// difference between this and UniversalTersePrint() is that for a
+// (const) char pointer, this prints both the pointer and the
+// NUL-terminated string.
+template <typename T>
+void UniversalPrint(const T& value, ::std::ostream* os) {
+  // A workarond for the bug in VC++ 7.1 that prevents us from instantiating
+  // UniversalPrinter with T directly.
+  typedef T T1;
+  UniversalPrinter<T1>::Print(value, os);
+}
+
+typedef ::std::vector<::std::string> Strings;
+
+// Tersely prints the first N fields of a tuple to a string vector,
+// one element for each field.
+template <typename Tuple>
+void TersePrintPrefixToStrings(const Tuple&, std::integral_constant<size_t, 0>,
+                               Strings*) {}
+template <typename Tuple, size_t I>
+void TersePrintPrefixToStrings(const Tuple& t,
+                               std::integral_constant<size_t, I>,
+                               Strings* strings) {
+  TersePrintPrefixToStrings(t, std::integral_constant<size_t, I - 1>(),
+                            strings);
+  ::std::stringstream ss;
+  UniversalTersePrint(std::get<I - 1>(t), &ss);
+  strings->push_back(ss.str());
+}
+
+// Prints the fields of a tuple tersely to a string vector, one
+// element for each field.  See the comment before
+// UniversalTersePrint() for how we define "tersely".
+template <typename Tuple>
+Strings UniversalTersePrintTupleFieldsToStrings(const Tuple& value) {
+  Strings result;
+  TersePrintPrefixToStrings(
+      value, std::integral_constant<size_t, std::tuple_size<Tuple>::value>(),
+      &result);
+  return result;
+}
+
+}  // namespace internal
+
+template <typename T>
+::std::string PrintToString(const T& value) {
+  ::std::stringstream ss;
+  internal::UniversalTersePrinter<T>::Print(value, &ss);
+  return ss.str();
+}
+
+}  // namespace testing
+
+// Include any custom printer added by the local installation.
+// We must include this header at the end to make sure it can use the
+// declarations from this file.
+#include "gtest/internal/custom/gtest-printers.h"
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
diff --git a/test/gtest/include/gtest/gtest-spi.h b/test/gtest/include/gtest/gtest-spi.h
new file mode 100644
index 0000000..bec8c48
--- /dev/null
+++ b/test/gtest/include/gtest/gtest-spi.h
@@ -0,0 +1,248 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Utilities for testing Google Test itself and code that uses Google Test
+// (e.g. frameworks built on top of Google Test).
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_SPI_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_SPI_H_
+
+#include "gtest/gtest.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+namespace testing {
+
+// This helper class can be used to mock out Google Test failure reporting
+// so that we can test Google Test or code that builds on Google Test.
+//
+// An object of this class appends a TestPartResult object to the
+// TestPartResultArray object given in the constructor whenever a Google Test
+// failure is reported. It can either intercept only failures that are
+// generated in the same thread that created this object or it can intercept
+// all generated failures. The scope of this mock object can be controlled with
+// the second argument to the two arguments constructor.
+class GTEST_API_ ScopedFakeTestPartResultReporter
+    : public TestPartResultReporterInterface {
+ public:
+  // The two possible mocking modes of this object.
+  enum InterceptMode {
+    INTERCEPT_ONLY_CURRENT_THREAD,  // Intercepts only thread local failures.
+    INTERCEPT_ALL_THREADS           // Intercepts all failures.
+  };
+
+  // The c'tor sets this object as the test part result reporter used
+  // by Google Test.  The 'result' parameter specifies where to report the
+  // results. This reporter will only catch failures generated in the current
+  // thread. DEPRECATED
+  explicit ScopedFakeTestPartResultReporter(TestPartResultArray* result);
+
+  // Same as above, but you can choose the interception scope of this object.
+  ScopedFakeTestPartResultReporter(InterceptMode intercept_mode,
+                                   TestPartResultArray* result);
+
+  // The d'tor restores the previous test part result reporter.
+  ~ScopedFakeTestPartResultReporter() override;
+
+  // Appends the TestPartResult object to the TestPartResultArray
+  // received in the constructor.
+  //
+  // This method is from the TestPartResultReporterInterface
+  // interface.
+  void ReportTestPartResult(const TestPartResult& result) override;
+
+ private:
+  void Init();
+
+  const InterceptMode intercept_mode_;
+  TestPartResultReporterInterface* old_reporter_;
+  TestPartResultArray* const result_;
+
+  ScopedFakeTestPartResultReporter(const ScopedFakeTestPartResultReporter&) =
+      delete;
+  ScopedFakeTestPartResultReporter& operator=(
+      const ScopedFakeTestPartResultReporter&) = delete;
+};
+
+namespace internal {
+
+// A helper class for implementing EXPECT_FATAL_FAILURE() and
+// EXPECT_NONFATAL_FAILURE().  Its destructor verifies that the given
+// TestPartResultArray contains exactly one failure that has the given
+// type and contains the given substring.  If that's not the case, a
+// non-fatal failure will be generated.
+class GTEST_API_ SingleFailureChecker {
+ public:
+  // The constructor remembers the arguments.
+  SingleFailureChecker(const TestPartResultArray* results,
+                       TestPartResult::Type type, const std::string& substr);
+  ~SingleFailureChecker();
+
+ private:
+  const TestPartResultArray* const results_;
+  const TestPartResult::Type type_;
+  const std::string substr_;
+
+  SingleFailureChecker(const SingleFailureChecker&) = delete;
+  SingleFailureChecker& operator=(const SingleFailureChecker&) = delete;
+};
+
+}  // namespace internal
+
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+// A set of macros for testing Google Test assertions or code that's expected
+// to generate Google Test fatal failures (e.g. a failure from an ASSERT_EQ, but
+// not a non-fatal failure, as from EXPECT_EQ).  It verifies that the given
+// statement will cause exactly one fatal Google Test failure with 'substr'
+// being part of the failure message.
+//
+// There are two different versions of this macro. EXPECT_FATAL_FAILURE only
+// affects and considers failures generated in the current thread and
+// EXPECT_FATAL_FAILURE_ON_ALL_THREADS does the same but for all threads.
+//
+// The verification of the assertion is done correctly even when the statement
+// throws an exception or aborts the current function.
+//
+// Known restrictions:
+//   - 'statement' cannot reference local non-static variables or
+//     non-static members of the current object.
+//   - 'statement' cannot return a value.
+//   - You cannot stream a failure message to this macro.
+//
+// Note that even though the implementations of the following two
+// macros are much alike, we cannot refactor them to use a common
+// helper macro, due to some peculiarity in how the preprocessor
+// works.  The AcceptsMacroThatExpandsToUnprotectedComma test in
+// gtest_unittest.cc will fail to compile if we do that.
+#define EXPECT_FATAL_FAILURE(statement, substr)                               \
+  do {                                                                        \
+    class GTestExpectFatalFailureHelper {                                     \
+     public:                                                                  \
+      static void Execute() { statement; }                                    \
+    };                                                                        \
+    ::testing::TestPartResultArray gtest_failures;                            \
+    ::testing::internal::SingleFailureChecker gtest_checker(                  \
+        &gtest_failures, ::testing::TestPartResult::kFatalFailure, (substr)); \
+    {                                                                         \
+      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(             \
+          ::testing::ScopedFakeTestPartResultReporter::                       \
+              INTERCEPT_ONLY_CURRENT_THREAD,                                  \
+          &gtest_failures);                                                   \
+      GTestExpectFatalFailureHelper::Execute();                               \
+    }                                                                         \
+  } while (::testing::internal::AlwaysFalse())
+
+#define EXPECT_FATAL_FAILURE_ON_ALL_THREADS(statement, substr)                \
+  do {                                                                        \
+    class GTestExpectFatalFailureHelper {                                     \
+     public:                                                                  \
+      static void Execute() { statement; }                                    \
+    };                                                                        \
+    ::testing::TestPartResultArray gtest_failures;                            \
+    ::testing::internal::SingleFailureChecker gtest_checker(                  \
+        &gtest_failures, ::testing::TestPartResult::kFatalFailure, (substr)); \
+    {                                                                         \
+      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(             \
+          ::testing::ScopedFakeTestPartResultReporter::INTERCEPT_ALL_THREADS, \
+          &gtest_failures);                                                   \
+      GTestExpectFatalFailureHelper::Execute();                               \
+    }                                                                         \
+  } while (::testing::internal::AlwaysFalse())
+
+// A macro for testing Google Test assertions or code that's expected to
+// generate Google Test non-fatal failures (e.g. a failure from an EXPECT_EQ,
+// but not from an ASSERT_EQ). It asserts that the given statement will cause
+// exactly one non-fatal Google Test failure with 'substr' being part of the
+// failure message.
+//
+// There are two different versions of this macro. EXPECT_NONFATAL_FAILURE only
+// affects and considers failures generated in the current thread and
+// EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS does the same but for all threads.
+//
+// 'statement' is allowed to reference local variables and members of
+// the current object.
+//
+// The verification of the assertion is done correctly even when the statement
+// throws an exception or aborts the current function.
+//
+// Known restrictions:
+//   - You cannot stream a failure message to this macro.
+//
+// Note that even though the implementations of the following two
+// macros are much alike, we cannot refactor them to use a common
+// helper macro, due to some peculiarity in how the preprocessor
+// works.  If we do that, the code won't compile when the user gives
+// EXPECT_NONFATAL_FAILURE() a statement that contains a macro that
+// expands to code containing an unprotected comma.  The
+// AcceptsMacroThatExpandsToUnprotectedComma test in gtest_unittest.cc
+// catches that.
+//
+// For the same reason, we have to write
+//   if (::testing::internal::AlwaysTrue()) { statement; }
+// instead of
+//   GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement)
+// to avoid an MSVC warning on unreachable code.
+#define EXPECT_NONFATAL_FAILURE(statement, substr)                    \
+  do {                                                                \
+    ::testing::TestPartResultArray gtest_failures;                    \
+    ::testing::internal::SingleFailureChecker gtest_checker(          \
+        &gtest_failures, ::testing::TestPartResult::kNonFatalFailure, \
+        (substr));                                                    \
+    {                                                                 \
+      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(     \
+          ::testing::ScopedFakeTestPartResultReporter::               \
+              INTERCEPT_ONLY_CURRENT_THREAD,                          \
+          &gtest_failures);                                           \
+      if (::testing::internal::AlwaysTrue()) {                        \
+        statement;                                                    \
+      }                                                               \
+    }                                                                 \
+  } while (::testing::internal::AlwaysFalse())
+
+#define EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS(statement, substr)             \
+  do {                                                                        \
+    ::testing::TestPartResultArray gtest_failures;                            \
+    ::testing::internal::SingleFailureChecker gtest_checker(                  \
+        &gtest_failures, ::testing::TestPartResult::kNonFatalFailure,         \
+        (substr));                                                            \
+    {                                                                         \
+      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(             \
+          ::testing::ScopedFakeTestPartResultReporter::INTERCEPT_ALL_THREADS, \
+          &gtest_failures);                                                   \
+      if (::testing::internal::AlwaysTrue()) {                                \
+        statement;                                                            \
+      }                                                                       \
+    }                                                                         \
+  } while (::testing::internal::AlwaysFalse())
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_SPI_H_
diff --git a/test/gtest/include/gtest/gtest-test-part.h b/test/gtest/include/gtest/gtest-test-part.h
new file mode 100644
index 0000000..09cc8c3
--- /dev/null
+++ b/test/gtest/include/gtest/gtest-test-part.h
@@ -0,0 +1,190 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_TEST_PART_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_TEST_PART_H_
+
+#include <iosfwd>
+#include <vector>
+
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-string.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+namespace testing {
+
+// A copyable object representing the result of a test part (i.e. an
+// assertion or an explicit FAIL(), ADD_FAILURE(), or SUCCESS()).
+//
+// Don't inherit from TestPartResult as its destructor is not virtual.
+class GTEST_API_ TestPartResult {
+ public:
+  // The possible outcomes of a test part (i.e. an assertion or an
+  // explicit SUCCEED(), FAIL(), or ADD_FAILURE()).
+  enum Type {
+    kSuccess,          // Succeeded.
+    kNonFatalFailure,  // Failed but the test can continue.
+    kFatalFailure,     // Failed and the test should be terminated.
+    kSkip              // Skipped.
+  };
+
+  // C'tor.  TestPartResult does NOT have a default constructor.
+  // Always use this constructor (with parameters) to create a
+  // TestPartResult object.
+  TestPartResult(Type a_type, const char* a_file_name, int a_line_number,
+                 const char* a_message)
+      : type_(a_type),
+        file_name_(a_file_name == nullptr ? "" : a_file_name),
+        line_number_(a_line_number),
+        summary_(ExtractSummary(a_message)),
+        message_(a_message) {}
+
+  // Gets the outcome of the test part.
+  Type type() const { return type_; }
+
+  // Gets the name of the source file where the test part took place, or
+  // NULL if it's unknown.
+  const char* file_name() const {
+    return file_name_.empty() ? nullptr : file_name_.c_str();
+  }
+
+  // Gets the line in the source file where the test part took place,
+  // or -1 if it's unknown.
+  int line_number() const { return line_number_; }
+
+  // Gets the summary of the failure message.
+  const char* summary() const { return summary_.c_str(); }
+
+  // Gets the message associated with the test part.
+  const char* message() const { return message_.c_str(); }
+
+  // Returns true if and only if the test part was skipped.
+  bool skipped() const { return type_ == kSkip; }
+
+  // Returns true if and only if the test part passed.
+  bool passed() const { return type_ == kSuccess; }
+
+  // Returns true if and only if the test part non-fatally failed.
+  bool nonfatally_failed() const { return type_ == kNonFatalFailure; }
+
+  // Returns true if and only if the test part fatally failed.
+  bool fatally_failed() const { return type_ == kFatalFailure; }
+
+  // Returns true if and only if the test part failed.
+  bool failed() const { return fatally_failed() || nonfatally_failed(); }
+
+ private:
+  Type type_;
+
+  // Gets the summary of the failure message by omitting the stack
+  // trace in it.
+  static std::string ExtractSummary(const char* message);
+
+  // The name of the source file where the test part took place, or
+  // "" if the source file is unknown.
+  std::string file_name_;
+  // The line in the source file where the test part took place, or -1
+  // if the line number is unknown.
+  int line_number_;
+  std::string summary_;  // The test failure summary.
+  std::string message_;  // The test failure message.
+};
+
+// Prints a TestPartResult object.
+std::ostream& operator<<(std::ostream& os, const TestPartResult& result);
+
+// An array of TestPartResult objects.
+//
+// Don't inherit from TestPartResultArray as its destructor is not
+// virtual.
+class GTEST_API_ TestPartResultArray {
+ public:
+  TestPartResultArray() {}
+
+  // Appends the given TestPartResult to the array.
+  void Append(const TestPartResult& result);
+
+  // Returns the TestPartResult at the given index (0-based).
+  const TestPartResult& GetTestPartResult(int index) const;
+
+  // Returns the number of TestPartResult objects in the array.
+  int size() const;
+
+ private:
+  std::vector<TestPartResult> array_;
+
+  TestPartResultArray(const TestPartResultArray&) = delete;
+  TestPartResultArray& operator=(const TestPartResultArray&) = delete;
+};
+
+// This interface knows how to report a test part result.
+class GTEST_API_ TestPartResultReporterInterface {
+ public:
+  virtual ~TestPartResultReporterInterface() {}
+
+  virtual void ReportTestPartResult(const TestPartResult& result) = 0;
+};
+
+namespace internal {
+
+// This helper class is used by {ASSERT|EXPECT}_NO_FATAL_FAILURE to check if a
+// statement generates new fatal failures. To do so it registers itself as the
+// current test part result reporter. Besides checking if fatal failures were
+// reported, it only delegates the reporting to the former result reporter.
+// The original result reporter is restored in the destructor.
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+class GTEST_API_ HasNewFatalFailureHelper
+    : public TestPartResultReporterInterface {
+ public:
+  HasNewFatalFailureHelper();
+  ~HasNewFatalFailureHelper() override;
+  void ReportTestPartResult(const TestPartResult& result) override;
+  bool has_new_fatal_failure() const { return has_new_fatal_failure_; }
+
+ private:
+  bool has_new_fatal_failure_;
+  TestPartResultReporterInterface* original_reporter_;
+
+  HasNewFatalFailureHelper(const HasNewFatalFailureHelper&) = delete;
+  HasNewFatalFailureHelper& operator=(const HasNewFatalFailureHelper&) = delete;
+};
+
+}  // namespace internal
+
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_TEST_PART_H_
diff --git a/test/gtest/include/gtest/gtest-typed-test.h b/test/gtest/include/gtest/gtest-typed-test.h
new file mode 100644
index 0000000..bd35a32
--- /dev/null
+++ b/test/gtest/include/gtest/gtest-typed-test.h
@@ -0,0 +1,331 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_TYPED_TEST_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_TYPED_TEST_H_
+
+// This header implements typed tests and type-parameterized tests.
+
+// Typed (aka type-driven) tests repeat the same test for types in a
+// list.  You must know which types you want to test with when writing
+// typed tests. Here's how you do it:
+
+#if 0
+
+// First, define a fixture class template.  It should be parameterized
+// by a type.  Remember to derive it from testing::Test.
+template <typename T>
+class FooTest : public testing::Test {
+ public:
+  ...
+  typedef std::list<T> List;
+  static T shared_;
+  T value_;
+};
+
+// Next, associate a list of types with the test suite, which will be
+// repeated for each type in the list.  The typedef is necessary for
+// the macro to parse correctly.
+typedef testing::Types<char, int, unsigned int> MyTypes;
+TYPED_TEST_SUITE(FooTest, MyTypes);
+
+// If the type list contains only one type, you can write that type
+// directly without Types<...>:
+//   TYPED_TEST_SUITE(FooTest, int);
+
+// Then, use TYPED_TEST() instead of TEST_F() to define as many typed
+// tests for this test suite as you want.
+TYPED_TEST(FooTest, DoesBlah) {
+  // Inside a test, refer to the special name TypeParam to get the type
+  // parameter.  Since we are inside a derived class template, C++ requires
+  // us to visit the members of FooTest via 'this'.
+  TypeParam n = this->value_;
+
+  // To visit static members of the fixture, add the TestFixture::
+  // prefix.
+  n += TestFixture::shared_;
+
+  // To refer to typedefs in the fixture, add the "typename
+  // TestFixture::" prefix.
+  typename TestFixture::List values;
+  values.push_back(n);
+  ...
+}
+
+TYPED_TEST(FooTest, HasPropertyA) { ... }
+
+// TYPED_TEST_SUITE takes an optional third argument which allows to specify a
+// class that generates custom test name suffixes based on the type. This should
+// be a class which has a static template function GetName(int index) returning
+// a string for each type. The provided integer index equals the index of the
+// type in the provided type list. In many cases the index can be ignored.
+//
+// For example:
+//   class MyTypeNames {
+//    public:
+//     template <typename T>
+//     static std::string GetName(int) {
+//       if (std::is_same<T, char>()) return "char";
+//       if (std::is_same<T, int>()) return "int";
+//       if (std::is_same<T, unsigned int>()) return "unsignedInt";
+//     }
+//   };
+//   TYPED_TEST_SUITE(FooTest, MyTypes, MyTypeNames);
+
+#endif  // 0
+
+// Type-parameterized tests are abstract test patterns parameterized
+// by a type.  Compared with typed tests, type-parameterized tests
+// allow you to define the test pattern without knowing what the type
+// parameters are.  The defined pattern can be instantiated with
+// different types any number of times, in any number of translation
+// units.
+//
+// If you are designing an interface or concept, you can define a
+// suite of type-parameterized tests to verify properties that any
+// valid implementation of the interface/concept should have.  Then,
+// each implementation can easily instantiate the test suite to verify
+// that it conforms to the requirements, without having to write
+// similar tests repeatedly.  Here's an example:
+
+#if 0
+
+// First, define a fixture class template.  It should be parameterized
+// by a type.  Remember to derive it from testing::Test.
+template <typename T>
+class FooTest : public testing::Test {
+  ...
+};
+
+// Next, declare that you will define a type-parameterized test suite
+// (the _P suffix is for "parameterized" or "pattern", whichever you
+// prefer):
+TYPED_TEST_SUITE_P(FooTest);
+
+// Then, use TYPED_TEST_P() to define as many type-parameterized tests
+// for this type-parameterized test suite as you want.
+TYPED_TEST_P(FooTest, DoesBlah) {
+  // Inside a test, refer to TypeParam to get the type parameter.
+  TypeParam n = 0;
+  ...
+}
+
+TYPED_TEST_P(FooTest, HasPropertyA) { ... }
+
+// Now the tricky part: you need to register all test patterns before
+// you can instantiate them.  The first argument of the macro is the
+// test suite name; the rest are the names of the tests in this test
+// case.
+REGISTER_TYPED_TEST_SUITE_P(FooTest,
+                            DoesBlah, HasPropertyA);
+
+// Finally, you are free to instantiate the pattern with the types you
+// want.  If you put the above code in a header file, you can #include
+// it in multiple C++ source files and instantiate it multiple times.
+//
+// To distinguish different instances of the pattern, the first
+// argument to the INSTANTIATE_* macro is a prefix that will be added
+// to the actual test suite name.  Remember to pick unique prefixes for
+// different instances.
+typedef testing::Types<char, int, unsigned int> MyTypes;
+INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, MyTypes);
+
+// If the type list contains only one type, you can write that type
+// directly without Types<...>:
+//   INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, int);
+//
+// Similar to the optional argument of TYPED_TEST_SUITE above,
+// INSTANTIATE_TEST_SUITE_P takes an optional fourth argument which allows to
+// generate custom names.
+//   INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, MyTypes, MyTypeNames);
+
+#endif  // 0
+
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-port.h"
+#include "gtest/internal/gtest-type-util.h"
+
+// Implements typed tests.
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Expands to the name of the typedef for the type parameters of the
+// given test suite.
+#define GTEST_TYPE_PARAMS_(TestSuiteName) gtest_type_params_##TestSuiteName##_
+
+// Expands to the name of the typedef for the NameGenerator, responsible for
+// creating the suffixes of the name.
+#define GTEST_NAME_GENERATOR_(TestSuiteName) \
+  gtest_type_params_##TestSuiteName##_NameGenerator
+
+#define TYPED_TEST_SUITE(CaseName, Types, ...)                          \
+  typedef ::testing::internal::GenerateTypeList<Types>::type            \
+      GTEST_TYPE_PARAMS_(CaseName);                                     \
+  typedef ::testing::internal::NameGeneratorSelector<__VA_ARGS__>::type \
+  GTEST_NAME_GENERATOR_(CaseName)
+
+#define TYPED_TEST(CaseName, TestName)                                        \
+  static_assert(sizeof(GTEST_STRINGIFY_(TestName)) > 1,                       \
+                "test-name must not be empty");                               \
+  template <typename gtest_TypeParam_>                                        \
+  class GTEST_TEST_CLASS_NAME_(CaseName, TestName)                            \
+      : public CaseName<gtest_TypeParam_> {                                   \
+   private:                                                                   \
+    typedef CaseName<gtest_TypeParam_> TestFixture;                           \
+    typedef gtest_TypeParam_ TypeParam;                                       \
+    void TestBody() override;                                                 \
+  };                                                                          \
+  static bool gtest_##CaseName##_##TestName##_registered_                     \
+      GTEST_ATTRIBUTE_UNUSED_ = ::testing::internal::TypeParameterizedTest<   \
+          CaseName,                                                           \
+          ::testing::internal::TemplateSel<GTEST_TEST_CLASS_NAME_(CaseName,   \
+                                                                  TestName)>, \
+          GTEST_TYPE_PARAMS_(                                                 \
+              CaseName)>::Register("",                                        \
+                                   ::testing::internal::CodeLocation(         \
+                                       __FILE__, __LINE__),                   \
+                                   GTEST_STRINGIFY_(CaseName),                \
+                                   GTEST_STRINGIFY_(TestName), 0,             \
+                                   ::testing::internal::GenerateNames<        \
+                                       GTEST_NAME_GENERATOR_(CaseName),       \
+                                       GTEST_TYPE_PARAMS_(CaseName)>());      \
+  template <typename gtest_TypeParam_>                                        \
+  void GTEST_TEST_CLASS_NAME_(CaseName,                                       \
+                              TestName)<gtest_TypeParam_>::TestBody()
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+#define TYPED_TEST_CASE                                                \
+  static_assert(::testing::internal::TypedTestCaseIsDeprecated(), ""); \
+  TYPED_TEST_SUITE
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+// Implements type-parameterized tests.
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Expands to the namespace name that the type-parameterized tests for
+// the given type-parameterized test suite are defined in.  The exact
+// name of the namespace is subject to change without notice.
+#define GTEST_SUITE_NAMESPACE_(TestSuiteName) gtest_suite_##TestSuiteName##_
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Expands to the name of the variable used to remember the names of
+// the defined tests in the given test suite.
+#define GTEST_TYPED_TEST_SUITE_P_STATE_(TestSuiteName) \
+  gtest_typed_test_suite_p_state_##TestSuiteName##_
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE DIRECTLY.
+//
+// Expands to the name of the variable used to remember the names of
+// the registered tests in the given test suite.
+#define GTEST_REGISTERED_TEST_NAMES_(TestSuiteName) \
+  gtest_registered_test_names_##TestSuiteName##_
+
+// The variables defined in the type-parameterized test macros are
+// static as typically these macros are used in a .h file that can be
+// #included in multiple translation units linked together.
+#define TYPED_TEST_SUITE_P(SuiteName)              \
+  static ::testing::internal::TypedTestSuitePState \
+  GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName)
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+#define TYPED_TEST_CASE_P                                                 \
+  static_assert(::testing::internal::TypedTestCase_P_IsDeprecated(), ""); \
+  TYPED_TEST_SUITE_P
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+#define TYPED_TEST_P(SuiteName, TestName)                             \
+  namespace GTEST_SUITE_NAMESPACE_(SuiteName) {                       \
+    template <typename gtest_TypeParam_>                              \
+    class TestName : public SuiteName<gtest_TypeParam_> {             \
+     private:                                                         \
+      typedef SuiteName<gtest_TypeParam_> TestFixture;                \
+      typedef gtest_TypeParam_ TypeParam;                             \
+      void TestBody() override;                                       \
+    };                                                                \
+    static bool gtest_##TestName##_defined_ GTEST_ATTRIBUTE_UNUSED_ = \
+        GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName).AddTestName(       \
+            __FILE__, __LINE__, GTEST_STRINGIFY_(SuiteName),          \
+            GTEST_STRINGIFY_(TestName));                              \
+  }                                                                   \
+  template <typename gtest_TypeParam_>                                \
+  void GTEST_SUITE_NAMESPACE_(                                        \
+      SuiteName)::TestName<gtest_TypeParam_>::TestBody()
+
+// Note: this won't work correctly if the trailing arguments are macros.
+#define REGISTER_TYPED_TEST_SUITE_P(SuiteName, ...)                         \
+  namespace GTEST_SUITE_NAMESPACE_(SuiteName) {                             \
+    typedef ::testing::internal::Templates<__VA_ARGS__> gtest_AllTests_;    \
+  }                                                                         \
+  static const char* const GTEST_REGISTERED_TEST_NAMES_(                    \
+      SuiteName) GTEST_ATTRIBUTE_UNUSED_ =                                  \
+      GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName).VerifyRegisteredTestNames( \
+          GTEST_STRINGIFY_(SuiteName), __FILE__, __LINE__, #__VA_ARGS__)
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+#define REGISTER_TYPED_TEST_CASE_P                                           \
+  static_assert(::testing::internal::RegisterTypedTestCase_P_IsDeprecated(), \
+                "");                                                         \
+  REGISTER_TYPED_TEST_SUITE_P
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+#define INSTANTIATE_TYPED_TEST_SUITE_P(Prefix, SuiteName, Types, ...)     \
+  static_assert(sizeof(GTEST_STRINGIFY_(Prefix)) > 1,                     \
+                "test-suit-prefix must not be empty");                    \
+  static bool gtest_##Prefix##_##SuiteName GTEST_ATTRIBUTE_UNUSED_ =      \
+      ::testing::internal::TypeParameterizedTestSuite<                    \
+          SuiteName, GTEST_SUITE_NAMESPACE_(SuiteName)::gtest_AllTests_,  \
+          ::testing::internal::GenerateTypeList<Types>::type>::           \
+          Register(GTEST_STRINGIFY_(Prefix),                              \
+                   ::testing::internal::CodeLocation(__FILE__, __LINE__), \
+                   &GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName),           \
+                   GTEST_STRINGIFY_(SuiteName),                           \
+                   GTEST_REGISTERED_TEST_NAMES_(SuiteName),               \
+                   ::testing::internal::GenerateNames<                    \
+                       ::testing::internal::NameGeneratorSelector<        \
+                           __VA_ARGS__>::type,                            \
+                       ::testing::internal::GenerateTypeList<Types>::type>())
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+#define INSTANTIATE_TYPED_TEST_CASE_P                                      \
+  static_assert(                                                           \
+      ::testing::internal::InstantiateTypedTestCase_P_IsDeprecated(), ""); \
+  INSTANTIATE_TYPED_TEST_SUITE_P
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_TYPED_TEST_H_
diff --git a/test/gtest/include/gtest/gtest.h b/test/gtest/include/gtest/gtest.h
new file mode 100644
index 0000000..d19a587
--- /dev/null
+++ b/test/gtest/include/gtest/gtest.h
@@ -0,0 +1,2297 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file defines the public API for Google Test.  It should be
+// included by any test program that uses Google Test.
+//
+// IMPORTANT NOTE: Due to limitation of the C++ language, we have to
+// leave some internal implementation details in this header file.
+// They are clearly marked by comments like this:
+//
+//   // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+//
+// Such code is NOT meant to be used by a user directly, and is subject
+// to CHANGE WITHOUT NOTICE.  Therefore DO NOT DEPEND ON IT in a user
+// program!
+//
+// Acknowledgment: Google Test borrowed the idea of automatic test
+// registration from Barthelemy Dagenais' (barthelemy@prologique.com)
+// easyUnit framework.
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_H_
+
+#include <cstddef>
+#include <limits>
+#include <memory>
+#include <ostream>
+#include <type_traits>
+#include <vector>
+
+#include "gtest/gtest-assertion-result.h"
+#include "gtest/gtest-death-test.h"
+#include "gtest/gtest-matchers.h"
+#include "gtest/gtest-message.h"
+#include "gtest/gtest-param-test.h"
+#include "gtest/gtest-printers.h"
+#include "gtest/gtest-test-part.h"
+#include "gtest/gtest-typed-test.h"
+#include "gtest/gtest_pred_impl.h"
+#include "gtest/gtest_prod.h"
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-string.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+// Declares the flags.
+
+// This flag temporary enables the disabled tests.
+GTEST_DECLARE_bool_(also_run_disabled_tests);
+
+// This flag brings the debugger on an assertion failure.
+GTEST_DECLARE_bool_(break_on_failure);
+
+// This flag controls whether Google Test catches all test-thrown exceptions
+// and logs them as failures.
+GTEST_DECLARE_bool_(catch_exceptions);
+
+// This flag enables using colors in terminal output. Available values are
+// "yes" to enable colors, "no" (disable colors), or "auto" (the default)
+// to let Google Test decide.
+GTEST_DECLARE_string_(color);
+
+// This flag controls whether the test runner should continue execution past
+// first failure.
+GTEST_DECLARE_bool_(fail_fast);
+
+// This flag sets up the filter to select by name using a glob pattern
+// the tests to run. If the filter is not given all tests are executed.
+GTEST_DECLARE_string_(filter);
+
+// This flag controls whether Google Test installs a signal handler that dumps
+// debugging information when fatal signals are raised.
+GTEST_DECLARE_bool_(install_failure_signal_handler);
+
+// This flag causes the Google Test to list tests. None of the tests listed
+// are actually run if the flag is provided.
+GTEST_DECLARE_bool_(list_tests);
+
+// This flag controls whether Google Test emits a detailed XML report to a file
+// in addition to its normal textual output.
+GTEST_DECLARE_string_(output);
+
+// This flags control whether Google Test prints only test failures.
+GTEST_DECLARE_bool_(brief);
+
+// This flags control whether Google Test prints the elapsed time for each
+// test.
+GTEST_DECLARE_bool_(print_time);
+
+// This flags control whether Google Test prints UTF8 characters as text.
+GTEST_DECLARE_bool_(print_utf8);
+
+// This flag specifies the random number seed.
+GTEST_DECLARE_int32_(random_seed);
+
+// This flag sets how many times the tests are repeated. The default value
+// is 1. If the value is -1 the tests are repeating forever.
+GTEST_DECLARE_int32_(repeat);
+
+// This flag controls whether Google Test Environments are recreated for each
+// repeat of the tests. The default value is true. If set to false the global
+// test Environment objects are only set up once, for the first iteration, and
+// only torn down once, for the last.
+GTEST_DECLARE_bool_(recreate_environments_when_repeating);
+
+// This flag controls whether Google Test includes Google Test internal
+// stack frames in failure stack traces.
+GTEST_DECLARE_bool_(show_internal_stack_frames);
+
+// When this flag is specified, tests' order is randomized on every iteration.
+GTEST_DECLARE_bool_(shuffle);
+
+// This flag specifies the maximum number of stack frames to be
+// printed in a failure message.
+GTEST_DECLARE_int32_(stack_trace_depth);
+
+// When this flag is specified, a failed assertion will throw an
+// exception if exceptions are enabled, or exit the program with a
+// non-zero code otherwise. For use with an external test framework.
+GTEST_DECLARE_bool_(throw_on_failure);
+
+// When this flag is set with a "host:port" string, on supported
+// platforms test results are streamed to the specified port on
+// the specified host machine.
+GTEST_DECLARE_string_(stream_result_to);
+
+#if GTEST_USE_OWN_FLAGFILE_FLAG_
+GTEST_DECLARE_string_(flagfile);
+#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
+
+namespace testing {
+
+// Silence C4100 (unreferenced formal parameter) and 4805
+// unsafe mix of type 'const int' and type 'const bool'
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable : 4805)
+#pragma warning(disable : 4100)
+#endif
+
+// The upper limit for valid stack trace depths.
+const int kMaxStackTraceDepth = 100;
+
+namespace internal {
+
+class AssertHelper;
+class DefaultGlobalTestPartResultReporter;
+class ExecDeathTest;
+class NoExecDeathTest;
+class FinalSuccessChecker;
+class GTestFlagSaver;
+class StreamingListenerTest;
+class TestResultAccessor;
+class TestEventListenersAccessor;
+class TestEventRepeater;
+class UnitTestRecordPropertyTestHelper;
+class WindowsDeathTest;
+class FuchsiaDeathTest;
+class UnitTestImpl* GetUnitTestImpl();
+void ReportFailureInUnknownLocation(TestPartResult::Type result_type,
+                                    const std::string& message);
+std::set<std::string>* GetIgnoredParameterizedTestSuites();
+
+}  // namespace internal
+
+// The friend relationship of some of these classes is cyclic.
+// If we don't forward declare them the compiler might confuse the classes
+// in friendship clauses with same named classes on the scope.
+class Test;
+class TestSuite;
+
+// Old API is still available but deprecated
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+using TestCase = TestSuite;
+#endif
+class TestInfo;
+class UnitTest;
+
+// The abstract class that all tests inherit from.
+//
+// In Google Test, a unit test program contains one or many TestSuites, and
+// each TestSuite contains one or many Tests.
+//
+// When you define a test using the TEST macro, you don't need to
+// explicitly derive from Test - the TEST macro automatically does
+// this for you.
+//
+// The only time you derive from Test is when defining a test fixture
+// to be used in a TEST_F.  For example:
+//
+//   class FooTest : public testing::Test {
+//    protected:
+//     void SetUp() override { ... }
+//     void TearDown() override { ... }
+//     ...
+//   };
+//
+//   TEST_F(FooTest, Bar) { ... }
+//   TEST_F(FooTest, Baz) { ... }
+//
+// Test is not copyable.
+class GTEST_API_ Test {
+ public:
+  friend class TestInfo;
+
+  // The d'tor is virtual as we intend to inherit from Test.
+  virtual ~Test();
+
+  // Sets up the stuff shared by all tests in this test suite.
+  //
+  // Google Test will call Foo::SetUpTestSuite() before running the first
+  // test in test suite Foo.  Hence a sub-class can define its own
+  // SetUpTestSuite() method to shadow the one defined in the super
+  // class.
+  static void SetUpTestSuite() {}
+
+  // Tears down the stuff shared by all tests in this test suite.
+  //
+  // Google Test will call Foo::TearDownTestSuite() after running the last
+  // test in test suite Foo.  Hence a sub-class can define its own
+  // TearDownTestSuite() method to shadow the one defined in the super
+  // class.
+  static void TearDownTestSuite() {}
+
+  // Legacy API is deprecated but still available. Use SetUpTestSuite and
+  // TearDownTestSuite instead.
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  static void TearDownTestCase() {}
+  static void SetUpTestCase() {}
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Returns true if and only if the current test has a fatal failure.
+  static bool HasFatalFailure();
+
+  // Returns true if and only if the current test has a non-fatal failure.
+  static bool HasNonfatalFailure();
+
+  // Returns true if and only if the current test was skipped.
+  static bool IsSkipped();
+
+  // Returns true if and only if the current test has a (either fatal or
+  // non-fatal) failure.
+  static bool HasFailure() { return HasFatalFailure() || HasNonfatalFailure(); }
+
+  // Logs a property for the current test, test suite, or for the entire
+  // invocation of the test program when used outside of the context of a
+  // test suite.  Only the last value for a given key is remembered.  These
+  // are public static so they can be called from utility functions that are
+  // not members of the test fixture.  Calls to RecordProperty made during
+  // lifespan of the test (from the moment its constructor starts to the
+  // moment its destructor finishes) will be output in XML as attributes of
+  // the <testcase> element.  Properties recorded from fixture's
+  // SetUpTestSuite or TearDownTestSuite are logged as attributes of the
+  // corresponding <testsuite> element.  Calls to RecordProperty made in the
+  // global context (before or after invocation of RUN_ALL_TESTS and from
+  // SetUp/TearDown method of Environment objects registered with Google
+  // Test) will be output as attributes of the <testsuites> element.
+  static void RecordProperty(const std::string& key, const std::string& value);
+  static void RecordProperty(const std::string& key, int value);
+
+ protected:
+  // Creates a Test object.
+  Test();
+
+  // Sets up the test fixture.
+  virtual void SetUp();
+
+  // Tears down the test fixture.
+  virtual void TearDown();
+
+ private:
+  // Returns true if and only if the current test has the same fixture class
+  // as the first test in the current test suite.
+  static bool HasSameFixtureClass();
+
+  // Runs the test after the test fixture has been set up.
+  //
+  // A sub-class must implement this to define the test logic.
+  //
+  // DO NOT OVERRIDE THIS FUNCTION DIRECTLY IN A USER PROGRAM.
+  // Instead, use the TEST or TEST_F macro.
+  virtual void TestBody() = 0;
+
+  // Sets up, executes, and tears down the test.
+  void Run();
+
+  // Deletes self.  We deliberately pick an unusual name for this
+  // internal method to avoid clashing with names used in user TESTs.
+  void DeleteSelf_() { delete this; }
+
+  const std::unique_ptr<GTEST_FLAG_SAVER_> gtest_flag_saver_;
+
+  // Often a user misspells SetUp() as Setup() and spends a long time
+  // wondering why it is never called by Google Test.  The declaration of
+  // the following method is solely for catching such an error at
+  // compile time:
+  //
+  //   - The return type is deliberately chosen to be not void, so it
+  //   will be a conflict if void Setup() is declared in the user's
+  //   test fixture.
+  //
+  //   - This method is private, so it will be another compiler error
+  //   if the method is called from the user's test fixture.
+  //
+  // DO NOT OVERRIDE THIS FUNCTION.
+  //
+  // If you see an error about overriding the following function or
+  // about it being private, you have mis-spelled SetUp() as Setup().
+  struct Setup_should_be_spelled_SetUp {};
+  virtual Setup_should_be_spelled_SetUp* Setup() { return nullptr; }
+
+  // We disallow copying Tests.
+  Test(const Test&) = delete;
+  Test& operator=(const Test&) = delete;
+};
+
+typedef internal::TimeInMillis TimeInMillis;
+
+// A copyable object representing a user specified test property which can be
+// output as a key/value string pair.
+//
+// Don't inherit from TestProperty as its destructor is not virtual.
+class TestProperty {
+ public:
+  // C'tor.  TestProperty does NOT have a default constructor.
+  // Always use this constructor (with parameters) to create a
+  // TestProperty object.
+  TestProperty(const std::string& a_key, const std::string& a_value)
+      : key_(a_key), value_(a_value) {}
+
+  // Gets the user supplied key.
+  const char* key() const { return key_.c_str(); }
+
+  // Gets the user supplied value.
+  const char* value() const { return value_.c_str(); }
+
+  // Sets a new value, overriding the one supplied in the constructor.
+  void SetValue(const std::string& new_value) { value_ = new_value; }
+
+ private:
+  // The key supplied by the user.
+  std::string key_;
+  // The value supplied by the user.
+  std::string value_;
+};
+
+// The result of a single Test.  This includes a list of
+// TestPartResults, a list of TestProperties, a count of how many
+// death tests there are in the Test, and how much time it took to run
+// the Test.
+//
+// TestResult is not copyable.
+class GTEST_API_ TestResult {
+ public:
+  // Creates an empty TestResult.
+  TestResult();
+
+  // D'tor.  Do not inherit from TestResult.
+  ~TestResult();
+
+  // Gets the number of all test parts.  This is the sum of the number
+  // of successful test parts and the number of failed test parts.
+  int total_part_count() const;
+
+  // Returns the number of the test properties.
+  int test_property_count() const;
+
+  // Returns true if and only if the test passed (i.e. no test part failed).
+  bool Passed() const { return !Skipped() && !Failed(); }
+
+  // Returns true if and only if the test was skipped.
+  bool Skipped() const;
+
+  // Returns true if and only if the test failed.
+  bool Failed() const;
+
+  // Returns true if and only if the test fatally failed.
+  bool HasFatalFailure() const;
+
+  // Returns true if and only if the test has a non-fatal failure.
+  bool HasNonfatalFailure() const;
+
+  // Returns the elapsed time, in milliseconds.
+  TimeInMillis elapsed_time() const { return elapsed_time_; }
+
+  // Gets the time of the test case start, in ms from the start of the
+  // UNIX epoch.
+  TimeInMillis start_timestamp() const { return start_timestamp_; }
+
+  // Returns the i-th test part result among all the results. i can range from 0
+  // to total_part_count() - 1. If i is not in that range, aborts the program.
+  const TestPartResult& GetTestPartResult(int i) const;
+
+  // Returns the i-th test property. i can range from 0 to
+  // test_property_count() - 1. If i is not in that range, aborts the
+  // program.
+  const TestProperty& GetTestProperty(int i) const;
+
+ private:
+  friend class TestInfo;
+  friend class TestSuite;
+  friend class UnitTest;
+  friend class internal::DefaultGlobalTestPartResultReporter;
+  friend class internal::ExecDeathTest;
+  friend class internal::TestResultAccessor;
+  friend class internal::UnitTestImpl;
+  friend class internal::WindowsDeathTest;
+  friend class internal::FuchsiaDeathTest;
+
+  // Gets the vector of TestPartResults.
+  const std::vector<TestPartResult>& test_part_results() const {
+    return test_part_results_;
+  }
+
+  // Gets the vector of TestProperties.
+  const std::vector<TestProperty>& test_properties() const {
+    return test_properties_;
+  }
+
+  // Sets the start time.
+  void set_start_timestamp(TimeInMillis start) { start_timestamp_ = start; }
+
+  // Sets the elapsed time.
+  void set_elapsed_time(TimeInMillis elapsed) { elapsed_time_ = elapsed; }
+
+  // Adds a test property to the list. The property is validated and may add
+  // a non-fatal failure if invalid (e.g., if it conflicts with reserved
+  // key names). If a property is already recorded for the same key, the
+  // value will be updated, rather than storing multiple values for the same
+  // key.  xml_element specifies the element for which the property is being
+  // recorded and is used for validation.
+  void RecordProperty(const std::string& xml_element,
+                      const TestProperty& test_property);
+
+  // Adds a failure if the key is a reserved attribute of Google Test
+  // testsuite tags.  Returns true if the property is valid.
+  // FIXME: Validate attribute names are legal and human readable.
+  static bool ValidateTestProperty(const std::string& xml_element,
+                                   const TestProperty& test_property);
+
+  // Adds a test part result to the list.
+  void AddTestPartResult(const TestPartResult& test_part_result);
+
+  // Returns the death test count.
+  int death_test_count() const { return death_test_count_; }
+
+  // Increments the death test count, returning the new count.
+  int increment_death_test_count() { return ++death_test_count_; }
+
+  // Clears the test part results.
+  void ClearTestPartResults();
+
+  // Clears the object.
+  void Clear();
+
+  // Protects mutable state of the property vector and of owned
+  // properties, whose values may be updated.
+  internal::Mutex test_properties_mutex_;
+
+  // The vector of TestPartResults
+  std::vector<TestPartResult> test_part_results_;
+  // The vector of TestProperties
+  std::vector<TestProperty> test_properties_;
+  // Running count of death tests.
+  int death_test_count_;
+  // The start time, in milliseconds since UNIX Epoch.
+  TimeInMillis start_timestamp_;
+  // The elapsed time, in milliseconds.
+  TimeInMillis elapsed_time_;
+
+  // We disallow copying TestResult.
+  TestResult(const TestResult&) = delete;
+  TestResult& operator=(const TestResult&) = delete;
+};  // class TestResult
+
+// A TestInfo object stores the following information about a test:
+//
+//   Test suite name
+//   Test name
+//   Whether the test should be run
+//   A function pointer that creates the test object when invoked
+//   Test result
+//
+// The constructor of TestInfo registers itself with the UnitTest
+// singleton such that the RUN_ALL_TESTS() macro knows which tests to
+// run.
+class GTEST_API_ TestInfo {
+ public:
+  // Destructs a TestInfo object.  This function is not virtual, so
+  // don't inherit from TestInfo.
+  ~TestInfo();
+
+  // Returns the test suite name.
+  const char* test_suite_name() const { return test_suite_name_.c_str(); }
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  const char* test_case_name() const { return test_suite_name(); }
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Returns the test name.
+  const char* name() const { return name_.c_str(); }
+
+  // Returns the name of the parameter type, or NULL if this is not a typed
+  // or a type-parameterized test.
+  const char* type_param() const {
+    if (type_param_.get() != nullptr) return type_param_->c_str();
+    return nullptr;
+  }
+
+  // Returns the text representation of the value parameter, or NULL if this
+  // is not a value-parameterized test.
+  const char* value_param() const {
+    if (value_param_.get() != nullptr) return value_param_->c_str();
+    return nullptr;
+  }
+
+  // Returns the file name where this test is defined.
+  const char* file() const { return location_.file.c_str(); }
+
+  // Returns the line where this test is defined.
+  int line() const { return location_.line; }
+
+  // Return true if this test should not be run because it's in another shard.
+  bool is_in_another_shard() const { return is_in_another_shard_; }
+
+  // Returns true if this test should run, that is if the test is not
+  // disabled (or it is disabled but the also_run_disabled_tests flag has
+  // been specified) and its full name matches the user-specified filter.
+  //
+  // Google Test allows the user to filter the tests by their full names.
+  // The full name of a test Bar in test suite Foo is defined as
+  // "Foo.Bar".  Only the tests that match the filter will run.
+  //
+  // A filter is a colon-separated list of glob (not regex) patterns,
+  // optionally followed by a '-' and a colon-separated list of
+  // negative patterns (tests to exclude).  A test is run if it
+  // matches one of the positive patterns and does not match any of
+  // the negative patterns.
+  //
+  // For example, *A*:Foo.* is a filter that matches any string that
+  // contains the character 'A' or starts with "Foo.".
+  bool should_run() const { return should_run_; }
+
+  // Returns true if and only if this test will appear in the XML report.
+  bool is_reportable() const {
+    // The XML report includes tests matching the filter, excluding those
+    // run in other shards.
+    return matches_filter_ && !is_in_another_shard_;
+  }
+
+  // Returns the result of the test.
+  const TestResult* result() const { return &result_; }
+
+ private:
+#if GTEST_HAS_DEATH_TEST
+  friend class internal::DefaultDeathTestFactory;
+#endif  // GTEST_HAS_DEATH_TEST
+  friend class Test;
+  friend class TestSuite;
+  friend class internal::UnitTestImpl;
+  friend class internal::StreamingListenerTest;
+  friend TestInfo* internal::MakeAndRegisterTestInfo(
+      const char* test_suite_name, const char* name, const char* type_param,
+      const char* value_param, internal::CodeLocation code_location,
+      internal::TypeId fixture_class_id, internal::SetUpTestSuiteFunc set_up_tc,
+      internal::TearDownTestSuiteFunc tear_down_tc,
+      internal::TestFactoryBase* factory);
+
+  // Constructs a TestInfo object. The newly constructed instance assumes
+  // ownership of the factory object.
+  TestInfo(const std::string& test_suite_name, const std::string& name,
+           const char* a_type_param,   // NULL if not a type-parameterized test
+           const char* a_value_param,  // NULL if not a value-parameterized test
+           internal::CodeLocation a_code_location,
+           internal::TypeId fixture_class_id,
+           internal::TestFactoryBase* factory);
+
+  // Increments the number of death tests encountered in this test so
+  // far.
+  int increment_death_test_count() {
+    return result_.increment_death_test_count();
+  }
+
+  // Creates the test object, runs it, records its result, and then
+  // deletes it.
+  void Run();
+
+  // Skip and records the test result for this object.
+  void Skip();
+
+  static void ClearTestResult(TestInfo* test_info) {
+    test_info->result_.Clear();
+  }
+
+  // These fields are immutable properties of the test.
+  const std::string test_suite_name_;  // test suite name
+  const std::string name_;             // Test name
+  // Name of the parameter type, or NULL if this is not a typed or a
+  // type-parameterized test.
+  const std::unique_ptr<const ::std::string> type_param_;
+  // Text representation of the value parameter, or NULL if this is not a
+  // value-parameterized test.
+  const std::unique_ptr<const ::std::string> value_param_;
+  internal::CodeLocation location_;
+  const internal::TypeId fixture_class_id_;  // ID of the test fixture class
+  bool should_run_;           // True if and only if this test should run
+  bool is_disabled_;          // True if and only if this test is disabled
+  bool matches_filter_;       // True if this test matches the
+                              // user-specified filter.
+  bool is_in_another_shard_;  // Will be run in another shard.
+  internal::TestFactoryBase* const factory_;  // The factory that creates
+                                              // the test object
+
+  // This field is mutable and needs to be reset before running the
+  // test for the second time.
+  TestResult result_;
+
+  TestInfo(const TestInfo&) = delete;
+  TestInfo& operator=(const TestInfo&) = delete;
+};
+
+// A test suite, which consists of a vector of TestInfos.
+//
+// TestSuite is not copyable.
+class GTEST_API_ TestSuite {
+ public:
+  // Creates a TestSuite with the given name.
+  //
+  // TestSuite does NOT have a default constructor.  Always use this
+  // constructor to create a TestSuite object.
+  //
+  // Arguments:
+  //
+  //   name:         name of the test suite
+  //   a_type_param: the name of the test's type parameter, or NULL if
+  //                 this is not a type-parameterized test.
+  //   set_up_tc:    pointer to the function that sets up the test suite
+  //   tear_down_tc: pointer to the function that tears down the test suite
+  TestSuite(const char* name, const char* a_type_param,
+            internal::SetUpTestSuiteFunc set_up_tc,
+            internal::TearDownTestSuiteFunc tear_down_tc);
+
+  // Destructor of TestSuite.
+  virtual ~TestSuite();
+
+  // Gets the name of the TestSuite.
+  const char* name() const { return name_.c_str(); }
+
+  // Returns the name of the parameter type, or NULL if this is not a
+  // type-parameterized test suite.
+  const char* type_param() const {
+    if (type_param_.get() != nullptr) return type_param_->c_str();
+    return nullptr;
+  }
+
+  // Returns true if any test in this test suite should run.
+  bool should_run() const { return should_run_; }
+
+  // Gets the number of successful tests in this test suite.
+  int successful_test_count() const;
+
+  // Gets the number of skipped tests in this test suite.
+  int skipped_test_count() const;
+
+  // Gets the number of failed tests in this test suite.
+  int failed_test_count() const;
+
+  // Gets the number of disabled tests that will be reported in the XML report.
+  int reportable_disabled_test_count() const;
+
+  // Gets the number of disabled tests in this test suite.
+  int disabled_test_count() const;
+
+  // Gets the number of tests to be printed in the XML report.
+  int reportable_test_count() const;
+
+  // Get the number of tests in this test suite that should run.
+  int test_to_run_count() const;
+
+  // Gets the number of all tests in this test suite.
+  int total_test_count() const;
+
+  // Returns true if and only if the test suite passed.
+  bool Passed() const { return !Failed(); }
+
+  // Returns true if and only if the test suite failed.
+  bool Failed() const {
+    return failed_test_count() > 0 || ad_hoc_test_result().Failed();
+  }
+
+  // Returns the elapsed time, in milliseconds.
+  TimeInMillis elapsed_time() const { return elapsed_time_; }
+
+  // Gets the time of the test suite start, in ms from the start of the
+  // UNIX epoch.
+  TimeInMillis start_timestamp() const { return start_timestamp_; }
+
+  // Returns the i-th test among all the tests. i can range from 0 to
+  // total_test_count() - 1. If i is not in that range, returns NULL.
+  const TestInfo* GetTestInfo(int i) const;
+
+  // Returns the TestResult that holds test properties recorded during
+  // execution of SetUpTestSuite and TearDownTestSuite.
+  const TestResult& ad_hoc_test_result() const { return ad_hoc_test_result_; }
+
+ private:
+  friend class Test;
+  friend class internal::UnitTestImpl;
+
+  // Gets the (mutable) vector of TestInfos in this TestSuite.
+  std::vector<TestInfo*>& test_info_list() { return test_info_list_; }
+
+  // Gets the (immutable) vector of TestInfos in this TestSuite.
+  const std::vector<TestInfo*>& test_info_list() const {
+    return test_info_list_;
+  }
+
+  // Returns the i-th test among all the tests. i can range from 0 to
+  // total_test_count() - 1. If i is not in that range, returns NULL.
+  TestInfo* GetMutableTestInfo(int i);
+
+  // Sets the should_run member.
+  void set_should_run(bool should) { should_run_ = should; }
+
+  // Adds a TestInfo to this test suite.  Will delete the TestInfo upon
+  // destruction of the TestSuite object.
+  void AddTestInfo(TestInfo* test_info);
+
+  // Clears the results of all tests in this test suite.
+  void ClearResult();
+
+  // Clears the results of all tests in the given test suite.
+  static void ClearTestSuiteResult(TestSuite* test_suite) {
+    test_suite->ClearResult();
+  }
+
+  // Runs every test in this TestSuite.
+  void Run();
+
+  // Skips the execution of tests under this TestSuite
+  void Skip();
+
+  // Runs SetUpTestSuite() for this TestSuite.  This wrapper is needed
+  // for catching exceptions thrown from SetUpTestSuite().
+  void RunSetUpTestSuite() {
+    if (set_up_tc_ != nullptr) {
+      (*set_up_tc_)();
+    }
+  }
+
+  // Runs TearDownTestSuite() for this TestSuite.  This wrapper is
+  // needed for catching exceptions thrown from TearDownTestSuite().
+  void RunTearDownTestSuite() {
+    if (tear_down_tc_ != nullptr) {
+      (*tear_down_tc_)();
+    }
+  }
+
+  // Returns true if and only if test passed.
+  static bool TestPassed(const TestInfo* test_info) {
+    return test_info->should_run() && test_info->result()->Passed();
+  }
+
+  // Returns true if and only if test skipped.
+  static bool TestSkipped(const TestInfo* test_info) {
+    return test_info->should_run() && test_info->result()->Skipped();
+  }
+
+  // Returns true if and only if test failed.
+  static bool TestFailed(const TestInfo* test_info) {
+    return test_info->should_run() && test_info->result()->Failed();
+  }
+
+  // Returns true if and only if the test is disabled and will be reported in
+  // the XML report.
+  static bool TestReportableDisabled(const TestInfo* test_info) {
+    return test_info->is_reportable() && test_info->is_disabled_;
+  }
+
+  // Returns true if and only if test is disabled.
+  static bool TestDisabled(const TestInfo* test_info) {
+    return test_info->is_disabled_;
+  }
+
+  // Returns true if and only if this test will appear in the XML report.
+  static bool TestReportable(const TestInfo* test_info) {
+    return test_info->is_reportable();
+  }
+
+  // Returns true if the given test should run.
+  static bool ShouldRunTest(const TestInfo* test_info) {
+    return test_info->should_run();
+  }
+
+  // Shuffles the tests in this test suite.
+  void ShuffleTests(internal::Random* random);
+
+  // Restores the test order to before the first shuffle.
+  void UnshuffleTests();
+
+  // Name of the test suite.
+  std::string name_;
+  // Name of the parameter type, or NULL if this is not a typed or a
+  // type-parameterized test.
+  const std::unique_ptr<const ::std::string> type_param_;
+  // The vector of TestInfos in their original order.  It owns the
+  // elements in the vector.
+  std::vector<TestInfo*> test_info_list_;
+  // Provides a level of indirection for the test list to allow easy
+  // shuffling and restoring the test order.  The i-th element in this
+  // vector is the index of the i-th test in the shuffled test list.
+  std::vector<int> test_indices_;
+  // Pointer to the function that sets up the test suite.
+  internal::SetUpTestSuiteFunc set_up_tc_;
+  // Pointer to the function that tears down the test suite.
+  internal::TearDownTestSuiteFunc tear_down_tc_;
+  // True if and only if any test in this test suite should run.
+  bool should_run_;
+  // The start time, in milliseconds since UNIX Epoch.
+  TimeInMillis start_timestamp_;
+  // Elapsed time, in milliseconds.
+  TimeInMillis elapsed_time_;
+  // Holds test properties recorded during execution of SetUpTestSuite and
+  // TearDownTestSuite.
+  TestResult ad_hoc_test_result_;
+
+  // We disallow copying TestSuites.
+  TestSuite(const TestSuite&) = delete;
+  TestSuite& operator=(const TestSuite&) = delete;
+};
+
+// An Environment object is capable of setting up and tearing down an
+// environment.  You should subclass this to define your own
+// environment(s).
+//
+// An Environment object does the set-up and tear-down in virtual
+// methods SetUp() and TearDown() instead of the constructor and the
+// destructor, as:
+//
+//   1. You cannot safely throw from a destructor.  This is a problem
+//      as in some cases Google Test is used where exceptions are enabled, and
+//      we may want to implement ASSERT_* using exceptions where they are
+//      available.
+//   2. You cannot use ASSERT_* directly in a constructor or
+//      destructor.
+class Environment {
+ public:
+  // The d'tor is virtual as we need to subclass Environment.
+  virtual ~Environment() {}
+
+  // Override this to define how to set up the environment.
+  virtual void SetUp() {}
+
+  // Override this to define how to tear down the environment.
+  virtual void TearDown() {}
+
+ private:
+  // If you see an error about overriding the following function or
+  // about it being private, you have mis-spelled SetUp() as Setup().
+  struct Setup_should_be_spelled_SetUp {};
+  virtual Setup_should_be_spelled_SetUp* Setup() { return nullptr; }
+};
+
+#if GTEST_HAS_EXCEPTIONS
+
+// Exception which can be thrown from TestEventListener::OnTestPartResult.
+class GTEST_API_ AssertionException
+    : public internal::GoogleTestFailureException {
+ public:
+  explicit AssertionException(const TestPartResult& result)
+      : GoogleTestFailureException(result) {}
+};
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// The interface for tracing execution of tests. The methods are organized in
+// the order the corresponding events are fired.
+class TestEventListener {
+ public:
+  virtual ~TestEventListener() {}
+
+  // Fired before any test activity starts.
+  virtual void OnTestProgramStart(const UnitTest& unit_test) = 0;
+
+  // Fired before each iteration of tests starts.  There may be more than
+  // one iteration if GTEST_FLAG(repeat) is set. iteration is the iteration
+  // index, starting from 0.
+  virtual void OnTestIterationStart(const UnitTest& unit_test,
+                                    int iteration) = 0;
+
+  // Fired before environment set-up for each iteration of tests starts.
+  virtual void OnEnvironmentsSetUpStart(const UnitTest& unit_test) = 0;
+
+  // Fired after environment set-up for each iteration of tests ends.
+  virtual void OnEnvironmentsSetUpEnd(const UnitTest& unit_test) = 0;
+
+  // Fired before the test suite starts.
+  virtual void OnTestSuiteStart(const TestSuite& /*test_suite*/) {}
+
+  //  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  virtual void OnTestCaseStart(const TestCase& /*test_case*/) {}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Fired before the test starts.
+  virtual void OnTestStart(const TestInfo& test_info) = 0;
+
+  // Fired when a test is disabled
+  virtual void OnTestDisabled(const TestInfo& /*test_info*/) {}
+
+  // Fired after a failed assertion or a SUCCEED() invocation.
+  // If you want to throw an exception from this function to skip to the next
+  // TEST, it must be AssertionException defined above, or inherited from it.
+  virtual void OnTestPartResult(const TestPartResult& test_part_result) = 0;
+
+  // Fired after the test ends.
+  virtual void OnTestEnd(const TestInfo& test_info) = 0;
+
+  // Fired after the test suite ends.
+  virtual void OnTestSuiteEnd(const TestSuite& /*test_suite*/) {}
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  virtual void OnTestCaseEnd(const TestCase& /*test_case*/) {}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Fired before environment tear-down for each iteration of tests starts.
+  virtual void OnEnvironmentsTearDownStart(const UnitTest& unit_test) = 0;
+
+  // Fired after environment tear-down for each iteration of tests ends.
+  virtual void OnEnvironmentsTearDownEnd(const UnitTest& unit_test) = 0;
+
+  // Fired after each iteration of tests finishes.
+  virtual void OnTestIterationEnd(const UnitTest& unit_test, int iteration) = 0;
+
+  // Fired after all test activities have ended.
+  virtual void OnTestProgramEnd(const UnitTest& unit_test) = 0;
+};
+
+// The convenience class for users who need to override just one or two
+// methods and are not concerned that a possible change to a signature of
+// the methods they override will not be caught during the build.  For
+// comments about each method please see the definition of TestEventListener
+// above.
+class EmptyTestEventListener : public TestEventListener {
+ public:
+  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {}
+  void OnTestIterationStart(const UnitTest& /*unit_test*/,
+                            int /*iteration*/) override {}
+  void OnEnvironmentsSetUpStart(const UnitTest& /*unit_test*/) override {}
+  void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {}
+  void OnTestSuiteStart(const TestSuite& /*test_suite*/) override {}
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseStart(const TestCase& /*test_case*/) override {}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  void OnTestStart(const TestInfo& /*test_info*/) override {}
+  void OnTestDisabled(const TestInfo& /*test_info*/) override {}
+  void OnTestPartResult(const TestPartResult& /*test_part_result*/) override {}
+  void OnTestEnd(const TestInfo& /*test_info*/) override {}
+  void OnTestSuiteEnd(const TestSuite& /*test_suite*/) override {}
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseEnd(const TestCase& /*test_case*/) override {}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  void OnEnvironmentsTearDownStart(const UnitTest& /*unit_test*/) override {}
+  void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {}
+  void OnTestIterationEnd(const UnitTest& /*unit_test*/,
+                          int /*iteration*/) override {}
+  void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {}
+};
+
+// TestEventListeners lets users add listeners to track events in Google Test.
+class GTEST_API_ TestEventListeners {
+ public:
+  TestEventListeners();
+  ~TestEventListeners();
+
+  // Appends an event listener to the end of the list. Google Test assumes
+  // the ownership of the listener (i.e. it will delete the listener when
+  // the test program finishes).
+  void Append(TestEventListener* listener);
+
+  // Removes the given event listener from the list and returns it.  It then
+  // becomes the caller's responsibility to delete the listener. Returns
+  // NULL if the listener is not found in the list.
+  TestEventListener* Release(TestEventListener* listener);
+
+  // Returns the standard listener responsible for the default console
+  // output.  Can be removed from the listeners list to shut down default
+  // console output.  Note that removing this object from the listener list
+  // with Release transfers its ownership to the caller and makes this
+  // function return NULL the next time.
+  TestEventListener* default_result_printer() const {
+    return default_result_printer_;
+  }
+
+  // Returns the standard listener responsible for the default XML output
+  // controlled by the --gtest_output=xml flag.  Can be removed from the
+  // listeners list by users who want to shut down the default XML output
+  // controlled by this flag and substitute it with custom one.  Note that
+  // removing this object from the listener list with Release transfers its
+  // ownership to the caller and makes this function return NULL the next
+  // time.
+  TestEventListener* default_xml_generator() const {
+    return default_xml_generator_;
+  }
+
+ private:
+  friend class TestSuite;
+  friend class TestInfo;
+  friend class internal::DefaultGlobalTestPartResultReporter;
+  friend class internal::NoExecDeathTest;
+  friend class internal::TestEventListenersAccessor;
+  friend class internal::UnitTestImpl;
+
+  // Returns repeater that broadcasts the TestEventListener events to all
+  // subscribers.
+  TestEventListener* repeater();
+
+  // Sets the default_result_printer attribute to the provided listener.
+  // The listener is also added to the listener list and previous
+  // default_result_printer is removed from it and deleted. The listener can
+  // also be NULL in which case it will not be added to the list. Does
+  // nothing if the previous and the current listener objects are the same.
+  void SetDefaultResultPrinter(TestEventListener* listener);
+
+  // Sets the default_xml_generator attribute to the provided listener.  The
+  // listener is also added to the listener list and previous
+  // default_xml_generator is removed from it and deleted. The listener can
+  // also be NULL in which case it will not be added to the list. Does
+  // nothing if the previous and the current listener objects are the same.
+  void SetDefaultXmlGenerator(TestEventListener* listener);
+
+  // Controls whether events will be forwarded by the repeater to the
+  // listeners in the list.
+  bool EventForwardingEnabled() const;
+  void SuppressEventForwarding();
+
+  // The actual list of listeners.
+  internal::TestEventRepeater* repeater_;
+  // Listener responsible for the standard result output.
+  TestEventListener* default_result_printer_;
+  // Listener responsible for the creation of the XML output file.
+  TestEventListener* default_xml_generator_;
+
+  // We disallow copying TestEventListeners.
+  TestEventListeners(const TestEventListeners&) = delete;
+  TestEventListeners& operator=(const TestEventListeners&) = delete;
+};
+
+// A UnitTest consists of a vector of TestSuites.
+//
+// This is a singleton class.  The only instance of UnitTest is
+// created when UnitTest::GetInstance() is first called.  This
+// instance is never deleted.
+//
+// UnitTest is not copyable.
+//
+// This class is thread-safe as long as the methods are called
+// according to their specification.
+class GTEST_API_ UnitTest {
+ public:
+  // Gets the singleton UnitTest object.  The first time this method
+  // is called, a UnitTest object is constructed and returned.
+  // Consecutive calls will return the same object.
+  static UnitTest* GetInstance();
+
+  // Runs all tests in this UnitTest object and prints the result.
+  // Returns 0 if successful, or 1 otherwise.
+  //
+  // This method can only be called from the main thread.
+  //
+  // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+  int Run() GTEST_MUST_USE_RESULT_;
+
+  // Returns the working directory when the first TEST() or TEST_F()
+  // was executed.  The UnitTest object owns the string.
+  const char* original_working_dir() const;
+
+  // Returns the TestSuite object for the test that's currently running,
+  // or NULL if no test is running.
+  const TestSuite* current_test_suite() const GTEST_LOCK_EXCLUDED_(mutex_);
+
+// Legacy API is still available but deprecated
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  const TestCase* current_test_case() const GTEST_LOCK_EXCLUDED_(mutex_);
+#endif
+
+  // Returns the TestInfo object for the test that's currently running,
+  // or NULL if no test is running.
+  const TestInfo* current_test_info() const GTEST_LOCK_EXCLUDED_(mutex_);
+
+  // Returns the random seed used at the start of the current test run.
+  int random_seed() const;
+
+  // Returns the ParameterizedTestSuiteRegistry object used to keep track of
+  // value-parameterized tests and instantiate and register them.
+  //
+  // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+  internal::ParameterizedTestSuiteRegistry& parameterized_test_registry()
+      GTEST_LOCK_EXCLUDED_(mutex_);
+
+  // Gets the number of successful test suites.
+  int successful_test_suite_count() const;
+
+  // Gets the number of failed test suites.
+  int failed_test_suite_count() const;
+
+  // Gets the number of all test suites.
+  int total_test_suite_count() const;
+
+  // Gets the number of all test suites that contain at least one test
+  // that should run.
+  int test_suite_to_run_count() const;
+
+  //  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  int successful_test_case_count() const;
+  int failed_test_case_count() const;
+  int total_test_case_count() const;
+  int test_case_to_run_count() const;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Gets the number of successful tests.
+  int successful_test_count() const;
+
+  // Gets the number of skipped tests.
+  int skipped_test_count() const;
+
+  // Gets the number of failed tests.
+  int failed_test_count() const;
+
+  // Gets the number of disabled tests that will be reported in the XML report.
+  int reportable_disabled_test_count() const;
+
+  // Gets the number of disabled tests.
+  int disabled_test_count() const;
+
+  // Gets the number of tests to be printed in the XML report.
+  int reportable_test_count() const;
+
+  // Gets the number of all tests.
+  int total_test_count() const;
+
+  // Gets the number of tests that should run.
+  int test_to_run_count() const;
+
+  // Gets the time of the test program start, in ms from the start of the
+  // UNIX epoch.
+  TimeInMillis start_timestamp() const;
+
+  // Gets the elapsed time, in milliseconds.
+  TimeInMillis elapsed_time() const;
+
+  // Returns true if and only if the unit test passed (i.e. all test suites
+  // passed).
+  bool Passed() const;
+
+  // Returns true if and only if the unit test failed (i.e. some test suite
+  // failed or something outside of all tests failed).
+  bool Failed() const;
+
+  // Gets the i-th test suite among all the test suites. i can range from 0 to
+  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
+  const TestSuite* GetTestSuite(int i) const;
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  const TestCase* GetTestCase(int i) const;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Returns the TestResult containing information on test failures and
+  // properties logged outside of individual test suites.
+  const TestResult& ad_hoc_test_result() const;
+
+  // Returns the list of event listeners that can be used to track events
+  // inside Google Test.
+  TestEventListeners& listeners();
+
+ private:
+  // Registers and returns a global test environment.  When a test
+  // program is run, all global test environments will be set-up in
+  // the order they were registered.  After all tests in the program
+  // have finished, all global test environments will be torn-down in
+  // the *reverse* order they were registered.
+  //
+  // The UnitTest object takes ownership of the given environment.
+  //
+  // This method can only be called from the main thread.
+  Environment* AddEnvironment(Environment* env);
+
+  // Adds a TestPartResult to the current TestResult object.  All
+  // Google Test assertion macros (e.g. ASSERT_TRUE, EXPECT_EQ, etc)
+  // eventually call this to report their results.  The user code
+  // should use the assertion macros instead of calling this directly.
+  void AddTestPartResult(TestPartResult::Type result_type,
+                         const char* file_name, int line_number,
+                         const std::string& message,
+                         const std::string& os_stack_trace)
+      GTEST_LOCK_EXCLUDED_(mutex_);
+
+  // Adds a TestProperty to the current TestResult object when invoked from
+  // inside a test, to current TestSuite's ad_hoc_test_result_ when invoked
+  // from SetUpTestSuite or TearDownTestSuite, or to the global property set
+  // when invoked elsewhere.  If the result already contains a property with
+  // the same key, the value will be updated.
+  void RecordProperty(const std::string& key, const std::string& value);
+
+  // Gets the i-th test suite among all the test suites. i can range from 0 to
+  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
+  TestSuite* GetMutableTestSuite(int i);
+
+  // Accessors for the implementation object.
+  internal::UnitTestImpl* impl() { return impl_; }
+  const internal::UnitTestImpl* impl() const { return impl_; }
+
+  // These classes and functions are friends as they need to access private
+  // members of UnitTest.
+  friend class ScopedTrace;
+  friend class Test;
+  friend class internal::AssertHelper;
+  friend class internal::StreamingListenerTest;
+  friend class internal::UnitTestRecordPropertyTestHelper;
+  friend Environment* AddGlobalTestEnvironment(Environment* env);
+  friend std::set<std::string>* internal::GetIgnoredParameterizedTestSuites();
+  friend internal::UnitTestImpl* internal::GetUnitTestImpl();
+  friend void internal::ReportFailureInUnknownLocation(
+      TestPartResult::Type result_type, const std::string& message);
+
+  // Creates an empty UnitTest.
+  UnitTest();
+
+  // D'tor
+  virtual ~UnitTest();
+
+  // Pushes a trace defined by SCOPED_TRACE() on to the per-thread
+  // Google Test trace stack.
+  void PushGTestTrace(const internal::TraceInfo& trace)
+      GTEST_LOCK_EXCLUDED_(mutex_);
+
+  // Pops a trace from the per-thread Google Test trace stack.
+  void PopGTestTrace() GTEST_LOCK_EXCLUDED_(mutex_);
+
+  // Protects mutable state in *impl_.  This is mutable as some const
+  // methods need to lock it too.
+  mutable internal::Mutex mutex_;
+
+  // Opaque implementation object.  This field is never changed once
+  // the object is constructed.  We don't mark it as const here, as
+  // doing so will cause a warning in the constructor of UnitTest.
+  // Mutable state in *impl_ is protected by mutex_.
+  internal::UnitTestImpl* impl_;
+
+  // We disallow copying UnitTest.
+  UnitTest(const UnitTest&) = delete;
+  UnitTest& operator=(const UnitTest&) = delete;
+};
+
+// A convenient wrapper for adding an environment for the test
+// program.
+//
+// You should call this before RUN_ALL_TESTS() is called, probably in
+// main().  If you use gtest_main, you need to call this before main()
+// starts for it to take effect.  For example, you can define a global
+// variable like this:
+//
+//   testing::Environment* const foo_env =
+//       testing::AddGlobalTestEnvironment(new FooEnvironment);
+//
+// However, we strongly recommend you to write your own main() and
+// call AddGlobalTestEnvironment() there, as relying on initialization
+// of global variables makes the code harder to read and may cause
+// problems when you register multiple environments from different
+// translation units and the environments have dependencies among them
+// (remember that the compiler doesn't guarantee the order in which
+// global variables from different translation units are initialized).
+inline Environment* AddGlobalTestEnvironment(Environment* env) {
+  return UnitTest::GetInstance()->AddEnvironment(env);
+}
+
+// Initializes Google Test.  This must be called before calling
+// RUN_ALL_TESTS().  In particular, it parses a command line for the
+// flags that Google Test recognizes.  Whenever a Google Test flag is
+// seen, it is removed from argv, and *argc is decremented.
+//
+// No value is returned.  Instead, the Google Test flag variables are
+// updated.
+//
+// Calling the function for the second time has no user-visible effect.
+GTEST_API_ void InitGoogleTest(int* argc, char** argv);
+
+// This overloaded version can be used in Windows programs compiled in
+// UNICODE mode.
+GTEST_API_ void InitGoogleTest(int* argc, wchar_t** argv);
+
+// This overloaded version can be used on Arduino/embedded platforms where
+// there is no argc/argv.
+GTEST_API_ void InitGoogleTest();
+
+namespace internal {
+
+// Separate the error generating code from the code path to reduce the stack
+// frame size of CmpHelperEQ. This helps reduce the overhead of some sanitizers
+// when calling EXPECT_* in a tight loop.
+template <typename T1, typename T2>
+AssertionResult CmpHelperEQFailure(const char* lhs_expression,
+                                   const char* rhs_expression, const T1& lhs,
+                                   const T2& rhs) {
+  return EqFailure(lhs_expression, rhs_expression,
+                   FormatForComparisonFailureMessage(lhs, rhs),
+                   FormatForComparisonFailureMessage(rhs, lhs), false);
+}
+
+// This block of code defines operator==/!=
+// to block lexical scope lookup.
+// It prevents using invalid operator==/!= defined at namespace scope.
+struct faketype {};
+inline bool operator==(faketype, faketype) { return true; }
+inline bool operator!=(faketype, faketype) { return false; }
+
+// The helper function for {ASSERT|EXPECT}_EQ.
+template <typename T1, typename T2>
+AssertionResult CmpHelperEQ(const char* lhs_expression,
+                            const char* rhs_expression, const T1& lhs,
+                            const T2& rhs) {
+  if (lhs == rhs) {
+    return AssertionSuccess();
+  }
+
+  return CmpHelperEQFailure(lhs_expression, rhs_expression, lhs, rhs);
+}
+
+class EqHelper {
+ public:
+  // This templatized version is for the general case.
+  template <
+      typename T1, typename T2,
+      // Disable this overload for cases where one argument is a pointer
+      // and the other is the null pointer constant.
+      typename std::enable_if<!std::is_integral<T1>::value ||
+                              !std::is_pointer<T2>::value>::type* = nullptr>
+  static AssertionResult Compare(const char* lhs_expression,
+                                 const char* rhs_expression, const T1& lhs,
+                                 const T2& rhs) {
+    return CmpHelperEQ(lhs_expression, rhs_expression, lhs, rhs);
+  }
+
+  // With this overloaded version, we allow anonymous enums to be used
+  // in {ASSERT|EXPECT}_EQ when compiled with gcc 4, as anonymous
+  // enums can be implicitly cast to BiggestInt.
+  //
+  // Even though its body looks the same as the above version, we
+  // cannot merge the two, as it will make anonymous enums unhappy.
+  static AssertionResult Compare(const char* lhs_expression,
+                                 const char* rhs_expression, BiggestInt lhs,
+                                 BiggestInt rhs) {
+    return CmpHelperEQ(lhs_expression, rhs_expression, lhs, rhs);
+  }
+
+  template <typename T>
+  static AssertionResult Compare(
+      const char* lhs_expression, const char* rhs_expression,
+      // Handle cases where '0' is used as a null pointer literal.
+      std::nullptr_t /* lhs */, T* rhs) {
+    // We already know that 'lhs' is a null pointer.
+    return CmpHelperEQ(lhs_expression, rhs_expression, static_cast<T*>(nullptr),
+                       rhs);
+  }
+};
+
+// Separate the error generating code from the code path to reduce the stack
+// frame size of CmpHelperOP. This helps reduce the overhead of some sanitizers
+// when calling EXPECT_OP in a tight loop.
+template <typename T1, typename T2>
+AssertionResult CmpHelperOpFailure(const char* expr1, const char* expr2,
+                                   const T1& val1, const T2& val2,
+                                   const char* op) {
+  return AssertionFailure()
+         << "Expected: (" << expr1 << ") " << op << " (" << expr2
+         << "), actual: " << FormatForComparisonFailureMessage(val1, val2)
+         << " vs " << FormatForComparisonFailureMessage(val2, val1);
+}
+
+// A macro for implementing the helper functions needed to implement
+// ASSERT_?? and EXPECT_??.  It is here just to avoid copy-and-paste
+// of similar code.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+
+#define GTEST_IMPL_CMP_HELPER_(op_name, op)                                \
+  template <typename T1, typename T2>                                      \
+  AssertionResult CmpHelper##op_name(const char* expr1, const char* expr2, \
+                                     const T1& val1, const T2& val2) {     \
+    if (val1 op val2) {                                                    \
+      return AssertionSuccess();                                           \
+    } else {                                                               \
+      return CmpHelperOpFailure(expr1, expr2, val1, val2, #op);            \
+    }                                                                      \
+  }
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+
+// Implements the helper function for {ASSERT|EXPECT}_NE
+GTEST_IMPL_CMP_HELPER_(NE, !=)
+// Implements the helper function for {ASSERT|EXPECT}_LE
+GTEST_IMPL_CMP_HELPER_(LE, <=)
+// Implements the helper function for {ASSERT|EXPECT}_LT
+GTEST_IMPL_CMP_HELPER_(LT, <)
+// Implements the helper function for {ASSERT|EXPECT}_GE
+GTEST_IMPL_CMP_HELPER_(GE, >=)
+// Implements the helper function for {ASSERT|EXPECT}_GT
+GTEST_IMPL_CMP_HELPER_(GT, >)
+
+#undef GTEST_IMPL_CMP_HELPER_
+
+// The helper function for {ASSERT|EXPECT}_STREQ.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTREQ(const char* s1_expression,
+                                          const char* s2_expression,
+                                          const char* s1, const char* s2);
+
+// The helper function for {ASSERT|EXPECT}_STRCASEEQ.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTRCASEEQ(const char* s1_expression,
+                                              const char* s2_expression,
+                                              const char* s1, const char* s2);
+
+// The helper function for {ASSERT|EXPECT}_STRNE.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTRNE(const char* s1_expression,
+                                          const char* s2_expression,
+                                          const char* s1, const char* s2);
+
+// The helper function for {ASSERT|EXPECT}_STRCASENE.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTRCASENE(const char* s1_expression,
+                                              const char* s2_expression,
+                                              const char* s1, const char* s2);
+
+// Helper function for *_STREQ on wide strings.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTREQ(const char* s1_expression,
+                                          const char* s2_expression,
+                                          const wchar_t* s1, const wchar_t* s2);
+
+// Helper function for *_STRNE on wide strings.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTRNE(const char* s1_expression,
+                                          const char* s2_expression,
+                                          const wchar_t* s1, const wchar_t* s2);
+
+}  // namespace internal
+
+// IsSubstring() and IsNotSubstring() are intended to be used as the
+// first argument to {EXPECT,ASSERT}_PRED_FORMAT2(), not by
+// themselves.  They check whether needle is a substring of haystack
+// (NULL is considered a substring of itself only), and return an
+// appropriate error message when they fail.
+//
+// The {needle,haystack}_expr arguments are the stringified
+// expressions that generated the two real arguments.
+GTEST_API_ AssertionResult IsSubstring(const char* needle_expr,
+                                       const char* haystack_expr,
+                                       const char* needle,
+                                       const char* haystack);
+GTEST_API_ AssertionResult IsSubstring(const char* needle_expr,
+                                       const char* haystack_expr,
+                                       const wchar_t* needle,
+                                       const wchar_t* haystack);
+GTEST_API_ AssertionResult IsNotSubstring(const char* needle_expr,
+                                          const char* haystack_expr,
+                                          const char* needle,
+                                          const char* haystack);
+GTEST_API_ AssertionResult IsNotSubstring(const char* needle_expr,
+                                          const char* haystack_expr,
+                                          const wchar_t* needle,
+                                          const wchar_t* haystack);
+GTEST_API_ AssertionResult IsSubstring(const char* needle_expr,
+                                       const char* haystack_expr,
+                                       const ::std::string& needle,
+                                       const ::std::string& haystack);
+GTEST_API_ AssertionResult IsNotSubstring(const char* needle_expr,
+                                          const char* haystack_expr,
+                                          const ::std::string& needle,
+                                          const ::std::string& haystack);
+
+#if GTEST_HAS_STD_WSTRING
+GTEST_API_ AssertionResult IsSubstring(const char* needle_expr,
+                                       const char* haystack_expr,
+                                       const ::std::wstring& needle,
+                                       const ::std::wstring& haystack);
+GTEST_API_ AssertionResult IsNotSubstring(const char* needle_expr,
+                                          const char* haystack_expr,
+                                          const ::std::wstring& needle,
+                                          const ::std::wstring& haystack);
+#endif  // GTEST_HAS_STD_WSTRING
+
+namespace internal {
+
+// Helper template function for comparing floating-points.
+//
+// Template parameter:
+//
+//   RawType: the raw floating-point type (either float or double)
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+template <typename RawType>
+AssertionResult CmpHelperFloatingPointEQ(const char* lhs_expression,
+                                         const char* rhs_expression,
+                                         RawType lhs_value, RawType rhs_value) {
+  const FloatingPoint<RawType> lhs(lhs_value), rhs(rhs_value);
+
+  if (lhs.AlmostEquals(rhs)) {
+    return AssertionSuccess();
+  }
+
+  ::std::stringstream lhs_ss;
+  lhs_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
+         << lhs_value;
+
+  ::std::stringstream rhs_ss;
+  rhs_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
+         << rhs_value;
+
+  return EqFailure(lhs_expression, rhs_expression,
+                   StringStreamToString(&lhs_ss), StringStreamToString(&rhs_ss),
+                   false);
+}
+
+// Helper function for implementing ASSERT_NEAR.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult DoubleNearPredFormat(const char* expr1,
+                                                const char* expr2,
+                                                const char* abs_error_expr,
+                                                double val1, double val2,
+                                                double abs_error);
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+// A class that enables one to stream messages to assertion macros
+class GTEST_API_ AssertHelper {
+ public:
+  // Constructor.
+  AssertHelper(TestPartResult::Type type, const char* file, int line,
+               const char* message);
+  ~AssertHelper();
+
+  // Message assignment is a semantic trick to enable assertion
+  // streaming; see the GTEST_MESSAGE_ macro below.
+  void operator=(const Message& message) const;
+
+ private:
+  // We put our data in a struct so that the size of the AssertHelper class can
+  // be as small as possible.  This is important because gcc is incapable of
+  // re-using stack space even for temporary variables, so every EXPECT_EQ
+  // reserves stack space for another AssertHelper.
+  struct AssertHelperData {
+    AssertHelperData(TestPartResult::Type t, const char* srcfile, int line_num,
+                     const char* msg)
+        : type(t), file(srcfile), line(line_num), message(msg) {}
+
+    TestPartResult::Type const type;
+    const char* const file;
+    int const line;
+    std::string const message;
+
+   private:
+    AssertHelperData(const AssertHelperData&) = delete;
+    AssertHelperData& operator=(const AssertHelperData&) = delete;
+  };
+
+  AssertHelperData* const data_;
+
+  AssertHelper(const AssertHelper&) = delete;
+  AssertHelper& operator=(const AssertHelper&) = delete;
+};
+
+}  // namespace internal
+
+// The pure interface class that all value-parameterized tests inherit from.
+// A value-parameterized class must inherit from both ::testing::Test and
+// ::testing::WithParamInterface. In most cases that just means inheriting
+// from ::testing::TestWithParam, but more complicated test hierarchies
+// may need to inherit from Test and WithParamInterface at different levels.
+//
+// This interface has support for accessing the test parameter value via
+// the GetParam() method.
+//
+// Use it with one of the parameter generator defining functions, like Range(),
+// Values(), ValuesIn(), Bool(), and Combine().
+//
+// class FooTest : public ::testing::TestWithParam<int> {
+//  protected:
+//   FooTest() {
+//     // Can use GetParam() here.
+//   }
+//   ~FooTest() override {
+//     // Can use GetParam() here.
+//   }
+//   void SetUp() override {
+//     // Can use GetParam() here.
+//   }
+//   void TearDown override {
+//     // Can use GetParam() here.
+//   }
+// };
+// TEST_P(FooTest, DoesBar) {
+//   // Can use GetParam() method here.
+//   Foo foo;
+//   ASSERT_TRUE(foo.DoesBar(GetParam()));
+// }
+// INSTANTIATE_TEST_SUITE_P(OneToTenRange, FooTest, ::testing::Range(1, 10));
+
+template <typename T>
+class WithParamInterface {
+ public:
+  typedef T ParamType;
+  virtual ~WithParamInterface() {}
+
+  // The current parameter value. Is also available in the test fixture's
+  // constructor.
+  static const ParamType& GetParam() {
+    GTEST_CHECK_(parameter_ != nullptr)
+        << "GetParam() can only be called inside a value-parameterized test "
+        << "-- did you intend to write TEST_P instead of TEST_F?";
+    return *parameter_;
+  }
+
+ private:
+  // Sets parameter value. The caller is responsible for making sure the value
+  // remains alive and unchanged throughout the current test.
+  static void SetParam(const ParamType* parameter) { parameter_ = parameter; }
+
+  // Static value used for accessing parameter during a test lifetime.
+  static const ParamType* parameter_;
+
+  // TestClass must be a subclass of WithParamInterface<T> and Test.
+  template <class TestClass>
+  friend class internal::ParameterizedTestFactory;
+};
+
+template <typename T>
+const T* WithParamInterface<T>::parameter_ = nullptr;
+
+// Most value-parameterized classes can ignore the existence of
+// WithParamInterface, and can just inherit from ::testing::TestWithParam.
+
+template <typename T>
+class TestWithParam : public Test, public WithParamInterface<T> {};
+
+// Macros for indicating success/failure in test code.
+
+// Skips test in runtime.
+// Skipping test aborts current function.
+// Skipped tests are neither successful nor failed.
+#define GTEST_SKIP() GTEST_SKIP_("")
+
+// ADD_FAILURE unconditionally adds a failure to the current test.
+// SUCCEED generates a success - it doesn't automatically make the
+// current test successful, as a test is only successful when it has
+// no failure.
+//
+// EXPECT_* verifies that a certain condition is satisfied.  If not,
+// it behaves like ADD_FAILURE.  In particular:
+//
+//   EXPECT_TRUE  verifies that a Boolean condition is true.
+//   EXPECT_FALSE verifies that a Boolean condition is false.
+//
+// FAIL and ASSERT_* are similar to ADD_FAILURE and EXPECT_*, except
+// that they will also abort the current function on failure.  People
+// usually want the fail-fast behavior of FAIL and ASSERT_*, but those
+// writing data-driven tests often find themselves using ADD_FAILURE
+// and EXPECT_* more.
+
+// Generates a nonfatal failure with a generic message.
+#define ADD_FAILURE() GTEST_NONFATAL_FAILURE_("Failed")
+
+// Generates a nonfatal failure at the given source file location with
+// a generic message.
+#define ADD_FAILURE_AT(file, line)        \
+  GTEST_MESSAGE_AT_(file, line, "Failed", \
+                    ::testing::TestPartResult::kNonFatalFailure)
+
+// Generates a fatal failure with a generic message.
+#define GTEST_FAIL() GTEST_FATAL_FAILURE_("Failed")
+
+// Like GTEST_FAIL(), but at the given source file location.
+#define GTEST_FAIL_AT(file, line)         \
+  GTEST_MESSAGE_AT_(file, line, "Failed", \
+                    ::testing::TestPartResult::kFatalFailure)
+
+// Define this macro to 1 to omit the definition of FAIL(), which is a
+// generic name and clashes with some other libraries.
+#if !GTEST_DONT_DEFINE_FAIL
+#define FAIL() GTEST_FAIL()
+#endif
+
+// Generates a success with a generic message.
+#define GTEST_SUCCEED() GTEST_SUCCESS_("Succeeded")
+
+// Define this macro to 1 to omit the definition of SUCCEED(), which
+// is a generic name and clashes with some other libraries.
+#if !GTEST_DONT_DEFINE_SUCCEED
+#define SUCCEED() GTEST_SUCCEED()
+#endif
+
+// Macros for testing exceptions.
+//
+//    * {ASSERT|EXPECT}_THROW(statement, expected_exception):
+//         Tests that the statement throws the expected exception.
+//    * {ASSERT|EXPECT}_NO_THROW(statement):
+//         Tests that the statement doesn't throw any exception.
+//    * {ASSERT|EXPECT}_ANY_THROW(statement):
+//         Tests that the statement throws an exception.
+
+#define EXPECT_THROW(statement, expected_exception) \
+  GTEST_TEST_THROW_(statement, expected_exception, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_NO_THROW(statement) \
+  GTEST_TEST_NO_THROW_(statement, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_ANY_THROW(statement) \
+  GTEST_TEST_ANY_THROW_(statement, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_THROW(statement, expected_exception) \
+  GTEST_TEST_THROW_(statement, expected_exception, GTEST_FATAL_FAILURE_)
+#define ASSERT_NO_THROW(statement) \
+  GTEST_TEST_NO_THROW_(statement, GTEST_FATAL_FAILURE_)
+#define ASSERT_ANY_THROW(statement) \
+  GTEST_TEST_ANY_THROW_(statement, GTEST_FATAL_FAILURE_)
+
+// Boolean assertions. Condition can be either a Boolean expression or an
+// AssertionResult. For more information on how to use AssertionResult with
+// these macros see comments on that class.
+#define GTEST_EXPECT_TRUE(condition)                      \
+  GTEST_TEST_BOOLEAN_(condition, #condition, false, true, \
+                      GTEST_NONFATAL_FAILURE_)
+#define GTEST_EXPECT_FALSE(condition)                        \
+  GTEST_TEST_BOOLEAN_(!(condition), #condition, true, false, \
+                      GTEST_NONFATAL_FAILURE_)
+#define GTEST_ASSERT_TRUE(condition) \
+  GTEST_TEST_BOOLEAN_(condition, #condition, false, true, GTEST_FATAL_FAILURE_)
+#define GTEST_ASSERT_FALSE(condition)                        \
+  GTEST_TEST_BOOLEAN_(!(condition), #condition, true, false, \
+                      GTEST_FATAL_FAILURE_)
+
+// Define these macros to 1 to omit the definition of the corresponding
+// EXPECT or ASSERT, which clashes with some users' own code.
+
+#if !GTEST_DONT_DEFINE_EXPECT_TRUE
+#define EXPECT_TRUE(condition) GTEST_EXPECT_TRUE(condition)
+#endif
+
+#if !GTEST_DONT_DEFINE_EXPECT_FALSE
+#define EXPECT_FALSE(condition) GTEST_EXPECT_FALSE(condition)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_TRUE
+#define ASSERT_TRUE(condition) GTEST_ASSERT_TRUE(condition)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_FALSE
+#define ASSERT_FALSE(condition) GTEST_ASSERT_FALSE(condition)
+#endif
+
+// Macros for testing equalities and inequalities.
+//
+//    * {ASSERT|EXPECT}_EQ(v1, v2): Tests that v1 == v2
+//    * {ASSERT|EXPECT}_NE(v1, v2): Tests that v1 != v2
+//    * {ASSERT|EXPECT}_LT(v1, v2): Tests that v1 < v2
+//    * {ASSERT|EXPECT}_LE(v1, v2): Tests that v1 <= v2
+//    * {ASSERT|EXPECT}_GT(v1, v2): Tests that v1 > v2
+//    * {ASSERT|EXPECT}_GE(v1, v2): Tests that v1 >= v2
+//
+// When they are not, Google Test prints both the tested expressions and
+// their actual values.  The values must be compatible built-in types,
+// or you will get a compiler error.  By "compatible" we mean that the
+// values can be compared by the respective operator.
+//
+// Note:
+//
+//   1. It is possible to make a user-defined type work with
+//   {ASSERT|EXPECT}_??(), but that requires overloading the
+//   comparison operators and is thus discouraged by the Google C++
+//   Usage Guide.  Therefore, you are advised to use the
+//   {ASSERT|EXPECT}_TRUE() macro to assert that two objects are
+//   equal.
+//
+//   2. The {ASSERT|EXPECT}_??() macros do pointer comparisons on
+//   pointers (in particular, C strings).  Therefore, if you use it
+//   with two C strings, you are testing how their locations in memory
+//   are related, not how their content is related.  To compare two C
+//   strings by content, use {ASSERT|EXPECT}_STR*().
+//
+//   3. {ASSERT|EXPECT}_EQ(v1, v2) is preferred to
+//   {ASSERT|EXPECT}_TRUE(v1 == v2), as the former tells you
+//   what the actual value is when it fails, and similarly for the
+//   other comparisons.
+//
+//   4. Do not depend on the order in which {ASSERT|EXPECT}_??()
+//   evaluate their arguments, which is undefined.
+//
+//   5. These macros evaluate their arguments exactly once.
+//
+// Examples:
+//
+//   EXPECT_NE(Foo(), 5);
+//   EXPECT_EQ(a_pointer, NULL);
+//   ASSERT_LT(i, array_size);
+//   ASSERT_GT(records.size(), 0) << "There is no record left.";
+
+#define EXPECT_EQ(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::EqHelper::Compare, val1, val2)
+#define EXPECT_NE(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperNE, val1, val2)
+#define EXPECT_LE(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperLE, val1, val2)
+#define EXPECT_LT(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperLT, val1, val2)
+#define EXPECT_GE(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperGE, val1, val2)
+#define EXPECT_GT(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperGT, val1, val2)
+
+#define GTEST_ASSERT_EQ(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::EqHelper::Compare, val1, val2)
+#define GTEST_ASSERT_NE(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperNE, val1, val2)
+#define GTEST_ASSERT_LE(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperLE, val1, val2)
+#define GTEST_ASSERT_LT(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperLT, val1, val2)
+#define GTEST_ASSERT_GE(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperGE, val1, val2)
+#define GTEST_ASSERT_GT(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperGT, val1, val2)
+
+// Define macro GTEST_DONT_DEFINE_ASSERT_XY to 1 to omit the definition of
+// ASSERT_XY(), which clashes with some users' own code.
+
+#if !GTEST_DONT_DEFINE_ASSERT_EQ
+#define ASSERT_EQ(val1, val2) GTEST_ASSERT_EQ(val1, val2)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_NE
+#define ASSERT_NE(val1, val2) GTEST_ASSERT_NE(val1, val2)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_LE
+#define ASSERT_LE(val1, val2) GTEST_ASSERT_LE(val1, val2)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_LT
+#define ASSERT_LT(val1, val2) GTEST_ASSERT_LT(val1, val2)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_GE
+#define ASSERT_GE(val1, val2) GTEST_ASSERT_GE(val1, val2)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_GT
+#define ASSERT_GT(val1, val2) GTEST_ASSERT_GT(val1, val2)
+#endif
+
+// C-string Comparisons.  All tests treat NULL and any non-NULL string
+// as different.  Two NULLs are equal.
+//
+//    * {ASSERT|EXPECT}_STREQ(s1, s2):     Tests that s1 == s2
+//    * {ASSERT|EXPECT}_STRNE(s1, s2):     Tests that s1 != s2
+//    * {ASSERT|EXPECT}_STRCASEEQ(s1, s2): Tests that s1 == s2, ignoring case
+//    * {ASSERT|EXPECT}_STRCASENE(s1, s2): Tests that s1 != s2, ignoring case
+//
+// For wide or narrow string objects, you can use the
+// {ASSERT|EXPECT}_??() macros.
+//
+// Don't depend on the order in which the arguments are evaluated,
+// which is undefined.
+//
+// These macros evaluate their arguments exactly once.
+
+#define EXPECT_STREQ(s1, s2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTREQ, s1, s2)
+#define EXPECT_STRNE(s1, s2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRNE, s1, s2)
+#define EXPECT_STRCASEEQ(s1, s2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASEEQ, s1, s2)
+#define EXPECT_STRCASENE(s1, s2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASENE, s1, s2)
+
+#define ASSERT_STREQ(s1, s2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTREQ, s1, s2)
+#define ASSERT_STRNE(s1, s2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRNE, s1, s2)
+#define ASSERT_STRCASEEQ(s1, s2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASEEQ, s1, s2)
+#define ASSERT_STRCASENE(s1, s2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASENE, s1, s2)
+
+// Macros for comparing floating-point numbers.
+//
+//    * {ASSERT|EXPECT}_FLOAT_EQ(val1, val2):
+//         Tests that two float values are almost equal.
+//    * {ASSERT|EXPECT}_DOUBLE_EQ(val1, val2):
+//         Tests that two double values are almost equal.
+//    * {ASSERT|EXPECT}_NEAR(v1, v2, abs_error):
+//         Tests that v1 and v2 are within the given distance to each other.
+//
+// Google Test uses ULP-based comparison to automatically pick a default
+// error bound that is appropriate for the operands.  See the
+// FloatingPoint template class in gtest-internal.h if you are
+// interested in the implementation details.
+
+#define EXPECT_FLOAT_EQ(val1, val2)                                         \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<float>, \
+                      val1, val2)
+
+#define EXPECT_DOUBLE_EQ(val1, val2)                                         \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<double>, \
+                      val1, val2)
+
+#define ASSERT_FLOAT_EQ(val1, val2)                                         \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<float>, \
+                      val1, val2)
+
+#define ASSERT_DOUBLE_EQ(val1, val2)                                         \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<double>, \
+                      val1, val2)
+
+#define EXPECT_NEAR(val1, val2, abs_error)                                   \
+  EXPECT_PRED_FORMAT3(::testing::internal::DoubleNearPredFormat, val1, val2, \
+                      abs_error)
+
+#define ASSERT_NEAR(val1, val2, abs_error)                                   \
+  ASSERT_PRED_FORMAT3(::testing::internal::DoubleNearPredFormat, val1, val2, \
+                      abs_error)
+
+// These predicate format functions work on floating-point values, and
+// can be used in {ASSERT|EXPECT}_PRED_FORMAT2*(), e.g.
+//
+//   EXPECT_PRED_FORMAT2(testing::DoubleLE, Foo(), 5.0);
+
+// Asserts that val1 is less than, or almost equal to, val2.  Fails
+// otherwise.  In particular, it fails if either val1 or val2 is NaN.
+GTEST_API_ AssertionResult FloatLE(const char* expr1, const char* expr2,
+                                   float val1, float val2);
+GTEST_API_ AssertionResult DoubleLE(const char* expr1, const char* expr2,
+                                    double val1, double val2);
+
+#if GTEST_OS_WINDOWS
+
+// Macros that test for HRESULT failure and success, these are only useful
+// on Windows, and rely on Windows SDK macros and APIs to compile.
+//
+//    * {ASSERT|EXPECT}_HRESULT_{SUCCEEDED|FAILED}(expr)
+//
+// When expr unexpectedly fails or succeeds, Google Test prints the
+// expected result and the actual result with both a human-readable
+// string representation of the error, if available, as well as the
+// hex result code.
+#define EXPECT_HRESULT_SUCCEEDED(expr) \
+  EXPECT_PRED_FORMAT1(::testing::internal::IsHRESULTSuccess, (expr))
+
+#define ASSERT_HRESULT_SUCCEEDED(expr) \
+  ASSERT_PRED_FORMAT1(::testing::internal::IsHRESULTSuccess, (expr))
+
+#define EXPECT_HRESULT_FAILED(expr) \
+  EXPECT_PRED_FORMAT1(::testing::internal::IsHRESULTFailure, (expr))
+
+#define ASSERT_HRESULT_FAILED(expr) \
+  ASSERT_PRED_FORMAT1(::testing::internal::IsHRESULTFailure, (expr))
+
+#endif  // GTEST_OS_WINDOWS
+
+// Macros that execute statement and check that it doesn't generate new fatal
+// failures in the current thread.
+//
+//   * {ASSERT|EXPECT}_NO_FATAL_FAILURE(statement);
+//
+// Examples:
+//
+//   EXPECT_NO_FATAL_FAILURE(Process());
+//   ASSERT_NO_FATAL_FAILURE(Process()) << "Process() failed";
+//
+#define ASSERT_NO_FATAL_FAILURE(statement) \
+  GTEST_TEST_NO_FATAL_FAILURE_(statement, GTEST_FATAL_FAILURE_)
+#define EXPECT_NO_FATAL_FAILURE(statement) \
+  GTEST_TEST_NO_FATAL_FAILURE_(statement, GTEST_NONFATAL_FAILURE_)
+
+// Causes a trace (including the given source file path and line number,
+// and the given message) to be included in every test failure message generated
+// by code in the scope of the lifetime of an instance of this class. The effect
+// is undone with the destruction of the instance.
+//
+// The message argument can be anything streamable to std::ostream.
+//
+// Example:
+//   testing::ScopedTrace trace("file.cc", 123, "message");
+//
+class GTEST_API_ ScopedTrace {
+ public:
+  // The c'tor pushes the given source file location and message onto
+  // a trace stack maintained by Google Test.
+
+  // Template version. Uses Message() to convert the values into strings.
+  // Slow, but flexible.
+  template <typename T>
+  ScopedTrace(const char* file, int line, const T& message) {
+    PushTrace(file, line, (Message() << message).GetString());
+  }
+
+  // Optimize for some known types.
+  ScopedTrace(const char* file, int line, const char* message) {
+    PushTrace(file, line, message ? message : "(null)");
+  }
+
+  ScopedTrace(const char* file, int line, const std::string& message) {
+    PushTrace(file, line, message);
+  }
+
+  // The d'tor pops the info pushed by the c'tor.
+  //
+  // Note that the d'tor is not virtual in order to be efficient.
+  // Don't inherit from ScopedTrace!
+  ~ScopedTrace();
+
+ private:
+  void PushTrace(const char* file, int line, std::string message);
+
+  ScopedTrace(const ScopedTrace&) = delete;
+  ScopedTrace& operator=(const ScopedTrace&) = delete;
+} GTEST_ATTRIBUTE_UNUSED_;  // A ScopedTrace object does its job in its
+                            // c'tor and d'tor.  Therefore it doesn't
+                            // need to be used otherwise.
+
+// Causes a trace (including the source file path, the current line
+// number, and the given message) to be included in every test failure
+// message generated by code in the current scope.  The effect is
+// undone when the control leaves the current scope.
+//
+// The message argument can be anything streamable to std::ostream.
+//
+// In the implementation, we include the current line number as part
+// of the dummy variable name, thus allowing multiple SCOPED_TRACE()s
+// to appear in the same block - as long as they are on different
+// lines.
+//
+// Assuming that each thread maintains its own stack of traces.
+// Therefore, a SCOPED_TRACE() would (correctly) only affect the
+// assertions in its own thread.
+#define SCOPED_TRACE(message)                                         \
+  ::testing::ScopedTrace GTEST_CONCAT_TOKEN_(gtest_trace_, __LINE__)( \
+      __FILE__, __LINE__, (message))
+
+// Compile-time assertion for type equality.
+// StaticAssertTypeEq<type1, type2>() compiles if and only if type1 and type2
+// are the same type.  The value it returns is not interesting.
+//
+// Instead of making StaticAssertTypeEq a class template, we make it a
+// function template that invokes a helper class template.  This
+// prevents a user from misusing StaticAssertTypeEq<T1, T2> by
+// defining objects of that type.
+//
+// CAVEAT:
+//
+// When used inside a method of a class template,
+// StaticAssertTypeEq<T1, T2>() is effective ONLY IF the method is
+// instantiated.  For example, given:
+//
+//   template <typename T> class Foo {
+//    public:
+//     void Bar() { testing::StaticAssertTypeEq<int, T>(); }
+//   };
+//
+// the code:
+//
+//   void Test1() { Foo<bool> foo; }
+//
+// will NOT generate a compiler error, as Foo<bool>::Bar() is never
+// actually instantiated.  Instead, you need:
+//
+//   void Test2() { Foo<bool> foo; foo.Bar(); }
+//
+// to cause a compiler error.
+template <typename T1, typename T2>
+constexpr bool StaticAssertTypeEq() noexcept {
+  static_assert(std::is_same<T1, T2>::value, "T1 and T2 are not the same type");
+  return true;
+}
+
+// Defines a test.
+//
+// The first parameter is the name of the test suite, and the second
+// parameter is the name of the test within the test suite.
+//
+// The convention is to end the test suite name with "Test".  For
+// example, a test suite for the Foo class can be named FooTest.
+//
+// Test code should appear between braces after an invocation of
+// this macro.  Example:
+//
+//   TEST(FooTest, InitializesCorrectly) {
+//     Foo foo;
+//     EXPECT_TRUE(foo.StatusIsOK());
+//   }
+
+// Note that we call GetTestTypeId() instead of GetTypeId<
+// ::testing::Test>() here to get the type ID of testing::Test.  This
+// is to work around a suspected linker bug when using Google Test as
+// a framework on Mac OS X.  The bug causes GetTypeId<
+// ::testing::Test>() to return different values depending on whether
+// the call is from the Google Test framework itself or from user test
+// code.  GetTestTypeId() is guaranteed to always return the same
+// value, as it always calls GetTypeId<>() from the Google Test
+// framework.
+#define GTEST_TEST(test_suite_name, test_name)             \
+  GTEST_TEST_(test_suite_name, test_name, ::testing::Test, \
+              ::testing::internal::GetTestTypeId())
+
+// Define this macro to 1 to omit the definition of TEST(), which
+// is a generic name and clashes with some other libraries.
+#if !GTEST_DONT_DEFINE_TEST
+#define TEST(test_suite_name, test_name) GTEST_TEST(test_suite_name, test_name)
+#endif
+
+// Defines a test that uses a test fixture.
+//
+// The first parameter is the name of the test fixture class, which
+// also doubles as the test suite name.  The second parameter is the
+// name of the test within the test suite.
+//
+// A test fixture class must be declared earlier.  The user should put
+// the test code between braces after using this macro.  Example:
+//
+//   class FooTest : public testing::Test {
+//    protected:
+//     void SetUp() override { b_.AddElement(3); }
+//
+//     Foo a_;
+//     Foo b_;
+//   };
+//
+//   TEST_F(FooTest, InitializesCorrectly) {
+//     EXPECT_TRUE(a_.StatusIsOK());
+//   }
+//
+//   TEST_F(FooTest, ReturnsElementCountCorrectly) {
+//     EXPECT_EQ(a_.size(), 0);
+//     EXPECT_EQ(b_.size(), 1);
+//   }
+#define GTEST_TEST_F(test_fixture, test_name)        \
+  GTEST_TEST_(test_fixture, test_name, test_fixture, \
+              ::testing::internal::GetTypeId<test_fixture>())
+#if !GTEST_DONT_DEFINE_TEST_F
+#define TEST_F(test_fixture, test_name) GTEST_TEST_F(test_fixture, test_name)
+#endif
+
+// Returns a path to temporary directory.
+// Tries to determine an appropriate directory for the platform.
+GTEST_API_ std::string TempDir();
+
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+// Dynamically registers a test with the framework.
+//
+// This is an advanced API only to be used when the `TEST` macros are
+// insufficient. The macros should be preferred when possible, as they avoid
+// most of the complexity of calling this function.
+//
+// The `factory` argument is a factory callable (move-constructible) object or
+// function pointer that creates a new instance of the Test object. It
+// handles ownership to the caller. The signature of the callable is
+// `Fixture*()`, where `Fixture` is the test fixture class for the test. All
+// tests registered with the same `test_suite_name` must return the same
+// fixture type. This is checked at runtime.
+//
+// The framework will infer the fixture class from the factory and will call
+// the `SetUpTestSuite` and `TearDownTestSuite` for it.
+//
+// Must be called before `RUN_ALL_TESTS()` is invoked, otherwise behavior is
+// undefined.
+//
+// Use case example:
+//
+// class MyFixture : public ::testing::Test {
+//  public:
+//   // All of these optional, just like in regular macro usage.
+//   static void SetUpTestSuite() { ... }
+//   static void TearDownTestSuite() { ... }
+//   void SetUp() override { ... }
+//   void TearDown() override { ... }
+// };
+//
+// class MyTest : public MyFixture {
+//  public:
+//   explicit MyTest(int data) : data_(data) {}
+//   void TestBody() override { ... }
+//
+//  private:
+//   int data_;
+// };
+//
+// void RegisterMyTests(const std::vector<int>& values) {
+//   for (int v : values) {
+//     ::testing::RegisterTest(
+//         "MyFixture", ("Test" + std::to_string(v)).c_str(), nullptr,
+//         std::to_string(v).c_str(),
+//         __FILE__, __LINE__,
+//         // Important to use the fixture type as the return type here.
+//         [=]() -> MyFixture* { return new MyTest(v); });
+//   }
+// }
+// ...
+// int main(int argc, char** argv) {
+//   ::testing::InitGoogleTest(&argc, argv);
+//   std::vector<int> values_to_test = LoadValuesFromConfig();
+//   RegisterMyTests(values_to_test);
+//   ...
+//   return RUN_ALL_TESTS();
+// }
+//
+template <int&... ExplicitParameterBarrier, typename Factory>
+TestInfo* RegisterTest(const char* test_suite_name, const char* test_name,
+                       const char* type_param, const char* value_param,
+                       const char* file, int line, Factory factory) {
+  using TestT = typename std::remove_pointer<decltype(factory())>::type;
+
+  class FactoryImpl : public internal::TestFactoryBase {
+   public:
+    explicit FactoryImpl(Factory f) : factory_(std::move(f)) {}
+    Test* CreateTest() override { return factory_(); }
+
+   private:
+    Factory factory_;
+  };
+
+  return internal::MakeAndRegisterTestInfo(
+      test_suite_name, test_name, type_param, value_param,
+      internal::CodeLocation(file, line), internal::GetTypeId<TestT>(),
+      internal::SuiteApiResolver<TestT>::GetSetUpCaseOrSuite(file, line),
+      internal::SuiteApiResolver<TestT>::GetTearDownCaseOrSuite(file, line),
+      new FactoryImpl{std::move(factory)});
+}
+
+}  // namespace testing
+
+// Use this function in main() to run all tests.  It returns 0 if all
+// tests are successful, or 1 otherwise.
+//
+// RUN_ALL_TESTS() should be invoked after the command line has been
+// parsed by InitGoogleTest().
+//
+// This function was formerly a macro; thus, it is in the global
+// namespace and has an all-caps name.
+int RUN_ALL_TESTS() GTEST_MUST_USE_RESULT_;
+
+inline int RUN_ALL_TESTS() { return ::testing::UnitTest::GetInstance()->Run(); }
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_H_
diff --git a/test/gtest/include/gtest/gtest_pred_impl.h b/test/gtest/include/gtest/gtest_pred_impl.h
new file mode 100644
index 0000000..47a24aa
--- /dev/null
+++ b/test/gtest/include/gtest/gtest_pred_impl.h
@@ -0,0 +1,279 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Implements a family of generic predicate assertion macros.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
+
+#include "gtest/gtest-assertion-result.h"
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-port.h"
+
+namespace testing {
+
+// This header implements a family of generic predicate assertion
+// macros:
+//
+//   ASSERT_PRED_FORMAT1(pred_format, v1)
+//   ASSERT_PRED_FORMAT2(pred_format, v1, v2)
+//   ...
+//
+// where pred_format is a function or functor that takes n (in the
+// case of ASSERT_PRED_FORMATn) values and their source expression
+// text, and returns a testing::AssertionResult.  See the definition
+// of ASSERT_EQ in gtest.h for an example.
+//
+// If you don't care about formatting, you can use the more
+// restrictive version:
+//
+//   ASSERT_PRED1(pred, v1)
+//   ASSERT_PRED2(pred, v1, v2)
+//   ...
+//
+// where pred is an n-ary function or functor that returns bool,
+// and the values v1, v2, ..., must support the << operator for
+// streaming to std::ostream.
+//
+// We also define the EXPECT_* variations.
+//
+// For now we only support predicates whose arity is at most 5.
+// Please email googletestframework@googlegroups.com if you need
+// support for higher arities.
+
+// GTEST_ASSERT_ is the basic statement to which all of the assertions
+// in this file reduce.  Don't use this in your code.
+
+#define GTEST_ASSERT_(expression, on_failure)                   \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                 \
+  if (const ::testing::AssertionResult gtest_ar = (expression)) \
+    ;                                                           \
+  else                                                          \
+    on_failure(gtest_ar.failure_message())
+
+// Helper function for implementing {EXPECT|ASSERT}_PRED1.  Don't use
+// this in your code.
+template <typename Pred, typename T1>
+AssertionResult AssertPred1Helper(const char* pred_text, const char* e1,
+                                  Pred pred, const T1& v1) {
+  if (pred(v1)) return AssertionSuccess();
+
+  return AssertionFailure()
+         << pred_text << "(" << e1 << ") evaluates to false, where"
+         << "\n"
+         << e1 << " evaluates to " << ::testing::PrintToString(v1);
+}
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT1.
+// Don't use this in your code.
+#define GTEST_PRED_FORMAT1_(pred_format, v1, on_failure) \
+  GTEST_ASSERT_(pred_format(#v1, v1), on_failure)
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED1.  Don't use
+// this in your code.
+#define GTEST_PRED1_(pred, v1, on_failure) \
+  GTEST_ASSERT_(::testing::AssertPred1Helper(#pred, #v1, pred, v1), on_failure)
+
+// Unary predicate assertion macros.
+#define EXPECT_PRED_FORMAT1(pred_format, v1) \
+  GTEST_PRED_FORMAT1_(pred_format, v1, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_PRED1(pred, v1) GTEST_PRED1_(pred, v1, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_PRED_FORMAT1(pred_format, v1) \
+  GTEST_PRED_FORMAT1_(pred_format, v1, GTEST_FATAL_FAILURE_)
+#define ASSERT_PRED1(pred, v1) GTEST_PRED1_(pred, v1, GTEST_FATAL_FAILURE_)
+
+// Helper function for implementing {EXPECT|ASSERT}_PRED2.  Don't use
+// this in your code.
+template <typename Pred, typename T1, typename T2>
+AssertionResult AssertPred2Helper(const char* pred_text, const char* e1,
+                                  const char* e2, Pred pred, const T1& v1,
+                                  const T2& v2) {
+  if (pred(v1, v2)) return AssertionSuccess();
+
+  return AssertionFailure()
+         << pred_text << "(" << e1 << ", " << e2
+         << ") evaluates to false, where"
+         << "\n"
+         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
+         << e2 << " evaluates to " << ::testing::PrintToString(v2);
+}
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT2.
+// Don't use this in your code.
+#define GTEST_PRED_FORMAT2_(pred_format, v1, v2, on_failure) \
+  GTEST_ASSERT_(pred_format(#v1, #v2, v1, v2), on_failure)
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED2.  Don't use
+// this in your code.
+#define GTEST_PRED2_(pred, v1, v2, on_failure)                               \
+  GTEST_ASSERT_(::testing::AssertPred2Helper(#pred, #v1, #v2, pred, v1, v2), \
+                on_failure)
+
+// Binary predicate assertion macros.
+#define EXPECT_PRED_FORMAT2(pred_format, v1, v2) \
+  GTEST_PRED_FORMAT2_(pred_format, v1, v2, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_PRED2(pred, v1, v2) \
+  GTEST_PRED2_(pred, v1, v2, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_PRED_FORMAT2(pred_format, v1, v2) \
+  GTEST_PRED_FORMAT2_(pred_format, v1, v2, GTEST_FATAL_FAILURE_)
+#define ASSERT_PRED2(pred, v1, v2) \
+  GTEST_PRED2_(pred, v1, v2, GTEST_FATAL_FAILURE_)
+
+// Helper function for implementing {EXPECT|ASSERT}_PRED3.  Don't use
+// this in your code.
+template <typename Pred, typename T1, typename T2, typename T3>
+AssertionResult AssertPred3Helper(const char* pred_text, const char* e1,
+                                  const char* e2, const char* e3, Pred pred,
+                                  const T1& v1, const T2& v2, const T3& v3) {
+  if (pred(v1, v2, v3)) return AssertionSuccess();
+
+  return AssertionFailure()
+         << pred_text << "(" << e1 << ", " << e2 << ", " << e3
+         << ") evaluates to false, where"
+         << "\n"
+         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
+         << e2 << " evaluates to " << ::testing::PrintToString(v2) << "\n"
+         << e3 << " evaluates to " << ::testing::PrintToString(v3);
+}
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT3.
+// Don't use this in your code.
+#define GTEST_PRED_FORMAT3_(pred_format, v1, v2, v3, on_failure) \
+  GTEST_ASSERT_(pred_format(#v1, #v2, #v3, v1, v2, v3), on_failure)
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED3.  Don't use
+// this in your code.
+#define GTEST_PRED3_(pred, v1, v2, v3, on_failure)                          \
+  GTEST_ASSERT_(                                                            \
+      ::testing::AssertPred3Helper(#pred, #v1, #v2, #v3, pred, v1, v2, v3), \
+      on_failure)
+
+// Ternary predicate assertion macros.
+#define EXPECT_PRED_FORMAT3(pred_format, v1, v2, v3) \
+  GTEST_PRED_FORMAT3_(pred_format, v1, v2, v3, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_PRED3(pred, v1, v2, v3) \
+  GTEST_PRED3_(pred, v1, v2, v3, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_PRED_FORMAT3(pred_format, v1, v2, v3) \
+  GTEST_PRED_FORMAT3_(pred_format, v1, v2, v3, GTEST_FATAL_FAILURE_)
+#define ASSERT_PRED3(pred, v1, v2, v3) \
+  GTEST_PRED3_(pred, v1, v2, v3, GTEST_FATAL_FAILURE_)
+
+// Helper function for implementing {EXPECT|ASSERT}_PRED4.  Don't use
+// this in your code.
+template <typename Pred, typename T1, typename T2, typename T3, typename T4>
+AssertionResult AssertPred4Helper(const char* pred_text, const char* e1,
+                                  const char* e2, const char* e3,
+                                  const char* e4, Pred pred, const T1& v1,
+                                  const T2& v2, const T3& v3, const T4& v4) {
+  if (pred(v1, v2, v3, v4)) return AssertionSuccess();
+
+  return AssertionFailure()
+         << pred_text << "(" << e1 << ", " << e2 << ", " << e3 << ", " << e4
+         << ") evaluates to false, where"
+         << "\n"
+         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
+         << e2 << " evaluates to " << ::testing::PrintToString(v2) << "\n"
+         << e3 << " evaluates to " << ::testing::PrintToString(v3) << "\n"
+         << e4 << " evaluates to " << ::testing::PrintToString(v4);
+}
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT4.
+// Don't use this in your code.
+#define GTEST_PRED_FORMAT4_(pred_format, v1, v2, v3, v4, on_failure) \
+  GTEST_ASSERT_(pred_format(#v1, #v2, #v3, #v4, v1, v2, v3, v4), on_failure)
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED4.  Don't use
+// this in your code.
+#define GTEST_PRED4_(pred, v1, v2, v3, v4, on_failure)                        \
+  GTEST_ASSERT_(::testing::AssertPred4Helper(#pred, #v1, #v2, #v3, #v4, pred, \
+                                             v1, v2, v3, v4),                 \
+                on_failure)
+
+// 4-ary predicate assertion macros.
+#define EXPECT_PRED_FORMAT4(pred_format, v1, v2, v3, v4) \
+  GTEST_PRED_FORMAT4_(pred_format, v1, v2, v3, v4, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_PRED4(pred, v1, v2, v3, v4) \
+  GTEST_PRED4_(pred, v1, v2, v3, v4, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_PRED_FORMAT4(pred_format, v1, v2, v3, v4) \
+  GTEST_PRED_FORMAT4_(pred_format, v1, v2, v3, v4, GTEST_FATAL_FAILURE_)
+#define ASSERT_PRED4(pred, v1, v2, v3, v4) \
+  GTEST_PRED4_(pred, v1, v2, v3, v4, GTEST_FATAL_FAILURE_)
+
+// Helper function for implementing {EXPECT|ASSERT}_PRED5.  Don't use
+// this in your code.
+template <typename Pred, typename T1, typename T2, typename T3, typename T4,
+          typename T5>
+AssertionResult AssertPred5Helper(const char* pred_text, const char* e1,
+                                  const char* e2, const char* e3,
+                                  const char* e4, const char* e5, Pred pred,
+                                  const T1& v1, const T2& v2, const T3& v3,
+                                  const T4& v4, const T5& v5) {
+  if (pred(v1, v2, v3, v4, v5)) return AssertionSuccess();
+
+  return AssertionFailure()
+         << pred_text << "(" << e1 << ", " << e2 << ", " << e3 << ", " << e4
+         << ", " << e5 << ") evaluates to false, where"
+         << "\n"
+         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
+         << e2 << " evaluates to " << ::testing::PrintToString(v2) << "\n"
+         << e3 << " evaluates to " << ::testing::PrintToString(v3) << "\n"
+         << e4 << " evaluates to " << ::testing::PrintToString(v4) << "\n"
+         << e5 << " evaluates to " << ::testing::PrintToString(v5);
+}
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT5.
+// Don't use this in your code.
+#define GTEST_PRED_FORMAT5_(pred_format, v1, v2, v3, v4, v5, on_failure)  \
+  GTEST_ASSERT_(pred_format(#v1, #v2, #v3, #v4, #v5, v1, v2, v3, v4, v5), \
+                on_failure)
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED5.  Don't use
+// this in your code.
+#define GTEST_PRED5_(pred, v1, v2, v3, v4, v5, on_failure)                   \
+  GTEST_ASSERT_(::testing::AssertPred5Helper(#pred, #v1, #v2, #v3, #v4, #v5, \
+                                             pred, v1, v2, v3, v4, v5),      \
+                on_failure)
+
+// 5-ary predicate assertion macros.
+#define EXPECT_PRED_FORMAT5(pred_format, v1, v2, v3, v4, v5) \
+  GTEST_PRED_FORMAT5_(pred_format, v1, v2, v3, v4, v5, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_PRED5(pred, v1, v2, v3, v4, v5) \
+  GTEST_PRED5_(pred, v1, v2, v3, v4, v5, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_PRED_FORMAT5(pred_format, v1, v2, v3, v4, v5) \
+  GTEST_PRED_FORMAT5_(pred_format, v1, v2, v3, v4, v5, GTEST_FATAL_FAILURE_)
+#define ASSERT_PRED5(pred, v1, v2, v3, v4, v5) \
+  GTEST_PRED5_(pred, v1, v2, v3, v4, v5, GTEST_FATAL_FAILURE_)
+
+}  // namespace testing
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
diff --git a/test/gtest/include/gtest/gtest_prod.h b/test/gtest/include/gtest/gtest_prod.h
new file mode 100644
index 0000000..1f37dc3
--- /dev/null
+++ b/test/gtest/include/gtest/gtest_prod.h
@@ -0,0 +1,60 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google C++ Testing and Mocking Framework definitions useful in production
+// code.
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PROD_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_PROD_H_
+
+// When you need to test the private or protected members of a class,
+// use the FRIEND_TEST macro to declare your tests as friends of the
+// class.  For example:
+//
+// class MyClass {
+//  private:
+//   void PrivateMethod();
+//   FRIEND_TEST(MyClassTest, PrivateMethodWorks);
+// };
+//
+// class MyClassTest : public testing::Test {
+//   // ...
+// };
+//
+// TEST_F(MyClassTest, PrivateMethodWorks) {
+//   // Can call MyClass::PrivateMethod() here.
+// }
+//
+// Note: The test class must be in the same namespace as the class being tested.
+// For example, putting MyClassTest in an anonymous namespace will not work.
+
+#define FRIEND_TEST(test_case_name, test_name) \
+  friend class test_case_name##_##test_name##_Test
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_PROD_H_
diff --git a/test/gtest/include/gtest/internal/custom/README.md b/test/gtest/include/gtest/internal/custom/README.md
new file mode 100644
index 0000000..cb49e2c
--- /dev/null
+++ b/test/gtest/include/gtest/internal/custom/README.md
@@ -0,0 +1,44 @@
+# Customization Points
+
+The custom directory is an injection point for custom user configurations.
+
+## Header `gtest.h`
+
+### The following macros can be defined:
+
+*   `GTEST_OS_STACK_TRACE_GETTER_` - The name of an implementation of
+    `OsStackTraceGetterInterface`.
+*   `GTEST_CUSTOM_TEMPDIR_FUNCTION_` - An override for `testing::TempDir()`. See
+    `testing::TempDir` for semantics and signature.
+
+## Header `gtest-port.h`
+
+The following macros can be defined:
+
+### Logging:
+
+*   `GTEST_LOG_(severity)`
+*   `GTEST_CHECK_(condition)`
+*   Functions `LogToStderr()` and `FlushInfoLog()` have to be provided too.
+
+### Threading:
+
+*   `GTEST_HAS_NOTIFICATION_` - Enabled if Notification is already provided.
+*   `GTEST_HAS_MUTEX_AND_THREAD_LOCAL_` - Enabled if `Mutex` and `ThreadLocal`
+    are already provided. Must also provide `GTEST_DECLARE_STATIC_MUTEX_(mutex)`
+    and `GTEST_DEFINE_STATIC_MUTEX_(mutex)`
+*   `GTEST_EXCLUSIVE_LOCK_REQUIRED_(locks)`
+*   `GTEST_LOCK_EXCLUDED_(locks)`
+
+### Underlying library support features
+
+*   `GTEST_HAS_CXXABI_H_`
+
+### Exporting API symbols:
+
+*   `GTEST_API_` - Specifier for exported symbols.
+
+## Header `gtest-printers.h`
+
+*   See documentation at `gtest/gtest-printers.h` for details on how to define a
+    custom printer.
diff --git a/test/gtest/include/gtest/internal/custom/gtest-port.h b/test/gtest/include/gtest/internal/custom/gtest-port.h
new file mode 100644
index 0000000..db02881
--- /dev/null
+++ b/test/gtest/include/gtest/internal/custom/gtest-port.h
@@ -0,0 +1,37 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Injection point for custom user configurations. See README for details
+//
+// ** Custom implementation starts here **
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PORT_H_
+#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PORT_H_
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PORT_H_
diff --git a/test/gtest/include/gtest/internal/custom/gtest-printers.h b/test/gtest/include/gtest/internal/custom/gtest-printers.h
new file mode 100644
index 0000000..b9495d8
--- /dev/null
+++ b/test/gtest/include/gtest/internal/custom/gtest-printers.h
@@ -0,0 +1,42 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// This file provides an injection point for custom printers in a local
+// installation of gTest.
+// It will be included from gtest-printers.h and the overrides in this file
+// will be visible to everyone.
+//
+// Injection point for custom user configurations. See README for details
+//
+// ** Custom implementation starts here **
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PRINTERS_H_
+#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PRINTERS_H_
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PRINTERS_H_
diff --git a/test/gtest/include/gtest/internal/custom/gtest.h b/test/gtest/include/gtest/internal/custom/gtest.h
new file mode 100644
index 0000000..afaaf17
--- /dev/null
+++ b/test/gtest/include/gtest/internal/custom/gtest.h
@@ -0,0 +1,37 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Injection point for custom user configurations. See README for details
+//
+// ** Custom implementation starts here **
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_H_
+#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_H_
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_H_
diff --git a/test/gtest/include/gtest/internal/gtest-death-test-internal.h b/test/gtest/include/gtest/internal/gtest-death-test-internal.h
new file mode 100644
index 0000000..45580ae
--- /dev/null
+++ b/test/gtest/include/gtest/internal/gtest-death-test-internal.h
@@ -0,0 +1,306 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file defines internal utilities needed for implementing
+// death tests.  They are subject to change without notice.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
+#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
+
+#include <stdio.h>
+
+#include <memory>
+
+#include "gtest/gtest-matchers.h"
+#include "gtest/internal/gtest-internal.h"
+
+GTEST_DECLARE_string_(internal_run_death_test);
+
+namespace testing {
+namespace internal {
+
+// Names of the flags (needed for parsing Google Test flags).
+const char kDeathTestStyleFlag[] = "death_test_style";
+const char kDeathTestUseFork[] = "death_test_use_fork";
+const char kInternalRunDeathTestFlag[] = "internal_run_death_test";
+
+#if GTEST_HAS_DEATH_TEST
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+// DeathTest is a class that hides much of the complexity of the
+// GTEST_DEATH_TEST_ macro.  It is abstract; its static Create method
+// returns a concrete class that depends on the prevailing death test
+// style, as defined by the --gtest_death_test_style and/or
+// --gtest_internal_run_death_test flags.
+
+// In describing the results of death tests, these terms are used with
+// the corresponding definitions:
+//
+// exit status:  The integer exit information in the format specified
+//               by wait(2)
+// exit code:    The integer code passed to exit(3), _exit(2), or
+//               returned from main()
+class GTEST_API_ DeathTest {
+ public:
+  // Create returns false if there was an error determining the
+  // appropriate action to take for the current death test; for example,
+  // if the gtest_death_test_style flag is set to an invalid value.
+  // The LastMessage method will return a more detailed message in that
+  // case.  Otherwise, the DeathTest pointer pointed to by the "test"
+  // argument is set.  If the death test should be skipped, the pointer
+  // is set to NULL; otherwise, it is set to the address of a new concrete
+  // DeathTest object that controls the execution of the current test.
+  static bool Create(const char* statement, Matcher<const std::string&> matcher,
+                     const char* file, int line, DeathTest** test);
+  DeathTest();
+  virtual ~DeathTest() {}
+
+  // A helper class that aborts a death test when it's deleted.
+  class ReturnSentinel {
+   public:
+    explicit ReturnSentinel(DeathTest* test) : test_(test) {}
+    ~ReturnSentinel() { test_->Abort(TEST_ENCOUNTERED_RETURN_STATEMENT); }
+
+   private:
+    DeathTest* const test_;
+    ReturnSentinel(const ReturnSentinel&) = delete;
+    ReturnSentinel& operator=(const ReturnSentinel&) = delete;
+  } GTEST_ATTRIBUTE_UNUSED_;
+
+  // An enumeration of possible roles that may be taken when a death
+  // test is encountered.  EXECUTE means that the death test logic should
+  // be executed immediately.  OVERSEE means that the program should prepare
+  // the appropriate environment for a child process to execute the death
+  // test, then wait for it to complete.
+  enum TestRole { OVERSEE_TEST, EXECUTE_TEST };
+
+  // An enumeration of the three reasons that a test might be aborted.
+  enum AbortReason {
+    TEST_ENCOUNTERED_RETURN_STATEMENT,
+    TEST_THREW_EXCEPTION,
+    TEST_DID_NOT_DIE
+  };
+
+  // Assumes one of the above roles.
+  virtual TestRole AssumeRole() = 0;
+
+  // Waits for the death test to finish and returns its status.
+  virtual int Wait() = 0;
+
+  // Returns true if the death test passed; that is, the test process
+  // exited during the test, its exit status matches a user-supplied
+  // predicate, and its stderr output matches a user-supplied regular
+  // expression.
+  // The user-supplied predicate may be a macro expression rather
+  // than a function pointer or functor, or else Wait and Passed could
+  // be combined.
+  virtual bool Passed(bool exit_status_ok) = 0;
+
+  // Signals that the death test did not die as expected.
+  virtual void Abort(AbortReason reason) = 0;
+
+  // Returns a human-readable outcome message regarding the outcome of
+  // the last death test.
+  static const char* LastMessage();
+
+  static void set_last_death_test_message(const std::string& message);
+
+ private:
+  // A string containing a description of the outcome of the last death test.
+  static std::string last_death_test_message_;
+
+  DeathTest(const DeathTest&) = delete;
+  DeathTest& operator=(const DeathTest&) = delete;
+};
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+// Factory interface for death tests.  May be mocked out for testing.
+class DeathTestFactory {
+ public:
+  virtual ~DeathTestFactory() {}
+  virtual bool Create(const char* statement,
+                      Matcher<const std::string&> matcher, const char* file,
+                      int line, DeathTest** test) = 0;
+};
+
+// A concrete DeathTestFactory implementation for normal use.
+class DefaultDeathTestFactory : public DeathTestFactory {
+ public:
+  bool Create(const char* statement, Matcher<const std::string&> matcher,
+              const char* file, int line, DeathTest** test) override;
+};
+
+// Returns true if exit_status describes a process that was terminated
+// by a signal, or exited normally with a nonzero exit code.
+GTEST_API_ bool ExitedUnsuccessfully(int exit_status);
+
+// A string passed to EXPECT_DEATH (etc.) is caught by one of these overloads
+// and interpreted as a regex (rather than an Eq matcher) for legacy
+// compatibility.
+inline Matcher<const ::std::string&> MakeDeathTestMatcher(
+    ::testing::internal::RE regex) {
+  return ContainsRegex(regex.pattern());
+}
+inline Matcher<const ::std::string&> MakeDeathTestMatcher(const char* regex) {
+  return ContainsRegex(regex);
+}
+inline Matcher<const ::std::string&> MakeDeathTestMatcher(
+    const ::std::string& regex) {
+  return ContainsRegex(regex);
+}
+
+// If a Matcher<const ::std::string&> is passed to EXPECT_DEATH (etc.), it's
+// used directly.
+inline Matcher<const ::std::string&> MakeDeathTestMatcher(
+    Matcher<const ::std::string&> matcher) {
+  return matcher;
+}
+
+// Traps C++ exceptions escaping statement and reports them as test
+// failures. Note that trapping SEH exceptions is not implemented here.
+#if GTEST_HAS_EXCEPTIONS
+#define GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, death_test)           \
+  try {                                                                      \
+    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement);               \
+  } catch (const ::std::exception& gtest_exception) {                        \
+    fprintf(                                                                 \
+        stderr,                                                              \
+        "\n%s: Caught std::exception-derived exception escaping the "        \
+        "death test statement. Exception message: %s\n",                     \
+        ::testing::internal::FormatFileLocation(__FILE__, __LINE__).c_str(), \
+        gtest_exception.what());                                             \
+    fflush(stderr);                                                          \
+    death_test->Abort(::testing::internal::DeathTest::TEST_THREW_EXCEPTION); \
+  } catch (...) {                                                            \
+    death_test->Abort(::testing::internal::DeathTest::TEST_THREW_EXCEPTION); \
+  }
+
+#else
+#define GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, death_test) \
+  GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement)
+
+#endif
+
+// This macro is for implementing ASSERT_DEATH*, EXPECT_DEATH*,
+// ASSERT_EXIT*, and EXPECT_EXIT*.
+#define GTEST_DEATH_TEST_(statement, predicate, regex_or_matcher, fail)        \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                                \
+  if (::testing::internal::AlwaysTrue()) {                                     \
+    ::testing::internal::DeathTest* gtest_dt;                                  \
+    if (!::testing::internal::DeathTest::Create(                               \
+            #statement,                                                        \
+            ::testing::internal::MakeDeathTestMatcher(regex_or_matcher),       \
+            __FILE__, __LINE__, &gtest_dt)) {                                  \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__);                        \
+    }                                                                          \
+    if (gtest_dt != nullptr) {                                                 \
+      std::unique_ptr< ::testing::internal::DeathTest> gtest_dt_ptr(gtest_dt); \
+      switch (gtest_dt->AssumeRole()) {                                        \
+        case ::testing::internal::DeathTest::OVERSEE_TEST:                     \
+          if (!gtest_dt->Passed(predicate(gtest_dt->Wait()))) {                \
+            goto GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__);                  \
+          }                                                                    \
+          break;                                                               \
+        case ::testing::internal::DeathTest::EXECUTE_TEST: {                   \
+          ::testing::internal::DeathTest::ReturnSentinel gtest_sentinel(       \
+              gtest_dt);                                                       \
+          GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, gtest_dt);            \
+          gtest_dt->Abort(::testing::internal::DeathTest::TEST_DID_NOT_DIE);   \
+          break;                                                               \
+        }                                                                      \
+      }                                                                        \
+    }                                                                          \
+  } else                                                                       \
+    GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__)                                \
+        : fail(::testing::internal::DeathTest::LastMessage())
+// The symbol "fail" here expands to something into which a message
+// can be streamed.
+
+// This macro is for implementing ASSERT/EXPECT_DEBUG_DEATH when compiled in
+// NDEBUG mode. In this case we need the statements to be executed and the macro
+// must accept a streamed message even though the message is never printed.
+// The regex object is not evaluated, but it is used to prevent "unused"
+// warnings and to avoid an expression that doesn't compile in debug mode.
+#define GTEST_EXECUTE_STATEMENT_(statement, regex_or_matcher)    \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                  \
+  if (::testing::internal::AlwaysTrue()) {                       \
+    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement);   \
+  } else if (!::testing::internal::AlwaysTrue()) {               \
+    ::testing::internal::MakeDeathTestMatcher(regex_or_matcher); \
+  } else                                                         \
+    ::testing::Message()
+
+// A class representing the parsed contents of the
+// --gtest_internal_run_death_test flag, as it existed when
+// RUN_ALL_TESTS was called.
+class InternalRunDeathTestFlag {
+ public:
+  InternalRunDeathTestFlag(const std::string& a_file, int a_line, int an_index,
+                           int a_write_fd)
+      : file_(a_file), line_(a_line), index_(an_index), write_fd_(a_write_fd) {}
+
+  ~InternalRunDeathTestFlag() {
+    if (write_fd_ >= 0) posix::Close(write_fd_);
+  }
+
+  const std::string& file() const { return file_; }
+  int line() const { return line_; }
+  int index() const { return index_; }
+  int write_fd() const { return write_fd_; }
+
+ private:
+  std::string file_;
+  int line_;
+  int index_;
+  int write_fd_;
+
+  InternalRunDeathTestFlag(const InternalRunDeathTestFlag&) = delete;
+  InternalRunDeathTestFlag& operator=(const InternalRunDeathTestFlag&) = delete;
+};
+
+// Returns a newly created InternalRunDeathTestFlag object with fields
+// initialized from the GTEST_FLAG(internal_run_death_test) flag if
+// the flag is specified; otherwise returns NULL.
+InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag();
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+}  // namespace internal
+}  // namespace testing
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
diff --git a/test/gtest/include/gtest/internal/gtest-filepath.h b/test/gtest/include/gtest/internal/gtest-filepath.h
new file mode 100644
index 0000000..a2a60a9
--- /dev/null
+++ b/test/gtest/include/gtest/internal/gtest-filepath.h
@@ -0,0 +1,210 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Test filepath utilities
+//
+// This header file declares classes and functions used internally by
+// Google Test.  They are subject to change without notice.
+//
+// This file is #included in gtest/internal/gtest-internal.h.
+// Do not include this header file separately!
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_FILEPATH_H_
+#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_FILEPATH_H_
+
+#include "gtest/internal/gtest-string.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+namespace testing {
+namespace internal {
+
+// FilePath - a class for file and directory pathname manipulation which
+// handles platform-specific conventions (like the pathname separator).
+// Used for helper functions for naming files in a directory for xml output.
+// Except for Set methods, all methods are const or static, which provides an
+// "immutable value object" -- useful for peace of mind.
+// A FilePath with a value ending in a path separator ("like/this/") represents
+// a directory, otherwise it is assumed to represent a file. In either case,
+// it may or may not represent an actual file or directory in the file system.
+// Names are NOT checked for syntax correctness -- no checking for illegal
+// characters, malformed paths, etc.
+
+class GTEST_API_ FilePath {
+ public:
+  FilePath() : pathname_("") {}
+  FilePath(const FilePath& rhs) : pathname_(rhs.pathname_) {}
+
+  explicit FilePath(const std::string& pathname) : pathname_(pathname) {
+    Normalize();
+  }
+
+  FilePath& operator=(const FilePath& rhs) {
+    Set(rhs);
+    return *this;
+  }
+
+  void Set(const FilePath& rhs) { pathname_ = rhs.pathname_; }
+
+  const std::string& string() const { return pathname_; }
+  const char* c_str() const { return pathname_.c_str(); }
+
+  // Returns the current working directory, or "" if unsuccessful.
+  static FilePath GetCurrentDir();
+
+  // Given directory = "dir", base_name = "test", number = 0,
+  // extension = "xml", returns "dir/test.xml". If number is greater
+  // than zero (e.g., 12), returns "dir/test_12.xml".
+  // On Windows platform, uses \ as the separator rather than /.
+  static FilePath MakeFileName(const FilePath& directory,
+                               const FilePath& base_name, int number,
+                               const char* extension);
+
+  // Given directory = "dir", relative_path = "test.xml",
+  // returns "dir/test.xml".
+  // On Windows, uses \ as the separator rather than /.
+  static FilePath ConcatPaths(const FilePath& directory,
+                              const FilePath& relative_path);
+
+  // Returns a pathname for a file that does not currently exist. The pathname
+  // will be directory/base_name.extension or
+  // directory/base_name_<number>.extension if directory/base_name.extension
+  // already exists. The number will be incremented until a pathname is found
+  // that does not already exist.
+  // Examples: 'dir/foo_test.xml' or 'dir/foo_test_1.xml'.
+  // There could be a race condition if two or more processes are calling this
+  // function at the same time -- they could both pick the same filename.
+  static FilePath GenerateUniqueFileName(const FilePath& directory,
+                                         const FilePath& base_name,
+                                         const char* extension);
+
+  // Returns true if and only if the path is "".
+  bool IsEmpty() const { return pathname_.empty(); }
+
+  // If input name has a trailing separator character, removes it and returns
+  // the name, otherwise return the name string unmodified.
+  // On Windows platform, uses \ as the separator, other platforms use /.
+  FilePath RemoveTrailingPathSeparator() const;
+
+  // Returns a copy of the FilePath with the directory part removed.
+  // Example: FilePath("path/to/file").RemoveDirectoryName() returns
+  // FilePath("file"). If there is no directory part ("just_a_file"), it returns
+  // the FilePath unmodified. If there is no file part ("just_a_dir/") it
+  // returns an empty FilePath ("").
+  // On Windows platform, '\' is the path separator, otherwise it is '/'.
+  FilePath RemoveDirectoryName() const;
+
+  // RemoveFileName returns the directory path with the filename removed.
+  // Example: FilePath("path/to/file").RemoveFileName() returns "path/to/".
+  // If the FilePath is "a_file" or "/a_file", RemoveFileName returns
+  // FilePath("./") or, on Windows, FilePath(".\\"). If the filepath does
+  // not have a file, like "just/a/dir/", it returns the FilePath unmodified.
+  // On Windows platform, '\' is the path separator, otherwise it is '/'.
+  FilePath RemoveFileName() const;
+
+  // Returns a copy of the FilePath with the case-insensitive extension removed.
+  // Example: FilePath("dir/file.exe").RemoveExtension("EXE") returns
+  // FilePath("dir/file"). If a case-insensitive extension is not
+  // found, returns a copy of the original FilePath.
+  FilePath RemoveExtension(const char* extension) const;
+
+  // Creates directories so that path exists. Returns true if successful or if
+  // the directories already exist; returns false if unable to create
+  // directories for any reason. Will also return false if the FilePath does
+  // not represent a directory (that is, it doesn't end with a path separator).
+  bool CreateDirectoriesRecursively() const;
+
+  // Create the directory so that path exists. Returns true if successful or
+  // if the directory already exists; returns false if unable to create the
+  // directory for any reason, including if the parent directory does not
+  // exist. Not named "CreateDirectory" because that's a macro on Windows.
+  bool CreateFolder() const;
+
+  // Returns true if FilePath describes something in the file-system,
+  // either a file, directory, or whatever, and that something exists.
+  bool FileOrDirectoryExists() const;
+
+  // Returns true if pathname describes a directory in the file-system
+  // that exists.
+  bool DirectoryExists() const;
+
+  // Returns true if FilePath ends with a path separator, which indicates that
+  // it is intended to represent a directory. Returns false otherwise.
+  // This does NOT check that a directory (or file) actually exists.
+  bool IsDirectory() const;
+
+  // Returns true if pathname describes a root directory. (Windows has one
+  // root directory per disk drive.)
+  bool IsRootDirectory() const;
+
+  // Returns true if pathname describes an absolute path.
+  bool IsAbsolutePath() const;
+
+ private:
+  // Replaces multiple consecutive separators with a single separator.
+  // For example, "bar///foo" becomes "bar/foo". Does not eliminate other
+  // redundancies that might be in a pathname involving "." or "..".
+  //
+  // A pathname with multiple consecutive separators may occur either through
+  // user error or as a result of some scripts or APIs that generate a pathname
+  // with a trailing separator. On other platforms the same API or script
+  // may NOT generate a pathname with a trailing "/". Then elsewhere that
+  // pathname may have another "/" and pathname components added to it,
+  // without checking for the separator already being there.
+  // The script language and operating system may allow paths like "foo//bar"
+  // but some of the functions in FilePath will not handle that correctly. In
+  // particular, RemoveTrailingPathSeparator() only removes one separator, and
+  // it is called in CreateDirectoriesRecursively() assuming that it will change
+  // a pathname from directory syntax (trailing separator) to filename syntax.
+  //
+  // On Windows this method also replaces the alternate path separator '/' with
+  // the primary path separator '\\', so that for example "bar\\/\\foo" becomes
+  // "bar\\foo".
+
+  void Normalize();
+
+  // Returns a pointer to the last occurrence of a valid path separator in
+  // the FilePath. On Windows, for example, both '/' and '\' are valid path
+  // separators. Returns NULL if no path separator was found.
+  const char* FindLastPathSeparator() const;
+
+  std::string pathname_;
+};  // class FilePath
+
+}  // namespace internal
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_FILEPATH_H_
diff --git a/test/gtest/include/gtest/internal/gtest-internal.h b/test/gtest/include/gtest/internal/gtest-internal.h
new file mode 100644
index 0000000..9b04e4c
--- /dev/null
+++ b/test/gtest/include/gtest/internal/gtest-internal.h
@@ -0,0 +1,1570 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file declares functions and macros used internally by
+// Google Test.  They are subject to change without notice.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
+#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
+
+#include "gtest/internal/gtest-port.h"
+
+#if GTEST_OS_LINUX
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#endif  // GTEST_OS_LINUX
+
+#if GTEST_HAS_EXCEPTIONS
+#include <stdexcept>
+#endif
+
+#include <ctype.h>
+#include <float.h>
+#include <string.h>
+
+#include <cstdint>
+#include <iomanip>
+#include <limits>
+#include <map>
+#include <set>
+#include <string>
+#include <type_traits>
+#include <vector>
+
+#include "gtest/gtest-message.h"
+#include "gtest/internal/gtest-filepath.h"
+#include "gtest/internal/gtest-string.h"
+#include "gtest/internal/gtest-type-util.h"
+
+// Due to C++ preprocessor weirdness, we need double indirection to
+// concatenate two tokens when one of them is __LINE__.  Writing
+//
+//   foo ## __LINE__
+//
+// will result in the token foo__LINE__, instead of foo followed by
+// the current line number.  For more details, see
+// http://www.parashift.com/c++-faq-lite/misc-technical-issues.html#faq-39.6
+#define GTEST_CONCAT_TOKEN_(foo, bar) GTEST_CONCAT_TOKEN_IMPL_(foo, bar)
+#define GTEST_CONCAT_TOKEN_IMPL_(foo, bar) foo##bar
+
+// Stringifies its argument.
+// Work around a bug in visual studio which doesn't accept code like this:
+//
+//   #define GTEST_STRINGIFY_(name) #name
+//   #define MACRO(a, b, c) ... GTEST_STRINGIFY_(a) ...
+//   MACRO(, x, y)
+//
+// Complaining about the argument to GTEST_STRINGIFY_ being empty.
+// This is allowed by the spec.
+#define GTEST_STRINGIFY_HELPER_(name, ...) #name
+#define GTEST_STRINGIFY_(...) GTEST_STRINGIFY_HELPER_(__VA_ARGS__, )
+
+namespace proto2 {
+class MessageLite;
+}
+
+namespace testing {
+
+// Forward declarations.
+
+class AssertionResult;  // Result of an assertion.
+class Message;          // Represents a failure message.
+class Test;             // Represents a test.
+class TestInfo;         // Information about a test.
+class TestPartResult;   // Result of a test part.
+class UnitTest;         // A collection of test suites.
+
+template <typename T>
+::std::string PrintToString(const T& value);
+
+namespace internal {
+
+struct TraceInfo;    // Information about a trace point.
+class TestInfoImpl;  // Opaque implementation of TestInfo
+class UnitTestImpl;  // Opaque implementation of UnitTest
+
+// The text used in failure messages to indicate the start of the
+// stack trace.
+GTEST_API_ extern const char kStackTraceMarker[];
+
+// An IgnoredValue object can be implicitly constructed from ANY value.
+class IgnoredValue {
+  struct Sink {};
+
+ public:
+  // This constructor template allows any value to be implicitly
+  // converted to IgnoredValue.  The object has no data member and
+  // doesn't try to remember anything about the argument.  We
+  // deliberately omit the 'explicit' keyword in order to allow the
+  // conversion to be implicit.
+  // Disable the conversion if T already has a magical conversion operator.
+  // Otherwise we get ambiguity.
+  template <typename T,
+            typename std::enable_if<!std::is_convertible<T, Sink>::value,
+                                    int>::type = 0>
+  IgnoredValue(const T& /* ignored */) {}  // NOLINT(runtime/explicit)
+};
+
+// Appends the user-supplied message to the Google-Test-generated message.
+GTEST_API_ std::string AppendUserMessage(const std::string& gtest_msg,
+                                         const Message& user_msg);
+
+#if GTEST_HAS_EXCEPTIONS
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(
+    4275 /* an exported class was derived from a class that was not exported */)
+
+// This exception is thrown by (and only by) a failed Google Test
+// assertion when GTEST_FLAG(throw_on_failure) is true (if exceptions
+// are enabled).  We derive it from std::runtime_error, which is for
+// errors presumably detectable only at run time.  Since
+// std::runtime_error inherits from std::exception, many testing
+// frameworks know how to extract and print the message inside it.
+class GTEST_API_ GoogleTestFailureException : public ::std::runtime_error {
+ public:
+  explicit GoogleTestFailureException(const TestPartResult& failure);
+};
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4275
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+namespace edit_distance {
+// Returns the optimal edits to go from 'left' to 'right'.
+// All edits cost the same, with replace having lower priority than
+// add/remove.
+// Simple implementation of the Wagner-Fischer algorithm.
+// See http://en.wikipedia.org/wiki/Wagner-Fischer_algorithm
+enum EditType { kMatch, kAdd, kRemove, kReplace };
+GTEST_API_ std::vector<EditType> CalculateOptimalEdits(
+    const std::vector<size_t>& left, const std::vector<size_t>& right);
+
+// Same as above, but the input is represented as strings.
+GTEST_API_ std::vector<EditType> CalculateOptimalEdits(
+    const std::vector<std::string>& left,
+    const std::vector<std::string>& right);
+
+// Create a diff of the input strings in Unified diff format.
+GTEST_API_ std::string CreateUnifiedDiff(const std::vector<std::string>& left,
+                                         const std::vector<std::string>& right,
+                                         size_t context = 2);
+
+}  // namespace edit_distance
+
+// Constructs and returns the message for an equality assertion
+// (e.g. ASSERT_EQ, EXPECT_STREQ, etc) failure.
+//
+// The first four parameters are the expressions used in the assertion
+// and their values, as strings.  For example, for ASSERT_EQ(foo, bar)
+// where foo is 5 and bar is 6, we have:
+//
+//   expected_expression: "foo"
+//   actual_expression:   "bar"
+//   expected_value:      "5"
+//   actual_value:        "6"
+//
+// The ignoring_case parameter is true if and only if the assertion is a
+// *_STRCASEEQ*.  When it's true, the string " (ignoring case)" will
+// be inserted into the message.
+GTEST_API_ AssertionResult EqFailure(const char* expected_expression,
+                                     const char* actual_expression,
+                                     const std::string& expected_value,
+                                     const std::string& actual_value,
+                                     bool ignoring_case);
+
+// Constructs a failure message for Boolean assertions such as EXPECT_TRUE.
+GTEST_API_ std::string GetBoolAssertionFailureMessage(
+    const AssertionResult& assertion_result, const char* expression_text,
+    const char* actual_predicate_value, const char* expected_predicate_value);
+
+// This template class represents an IEEE floating-point number
+// (either single-precision or double-precision, depending on the
+// template parameters).
+//
+// The purpose of this class is to do more sophisticated number
+// comparison.  (Due to round-off error, etc, it's very unlikely that
+// two floating-points will be equal exactly.  Hence a naive
+// comparison by the == operation often doesn't work.)
+//
+// Format of IEEE floating-point:
+//
+//   The most-significant bit being the leftmost, an IEEE
+//   floating-point looks like
+//
+//     sign_bit exponent_bits fraction_bits
+//
+//   Here, sign_bit is a single bit that designates the sign of the
+//   number.
+//
+//   For float, there are 8 exponent bits and 23 fraction bits.
+//
+//   For double, there are 11 exponent bits and 52 fraction bits.
+//
+//   More details can be found at
+//   http://en.wikipedia.org/wiki/IEEE_floating-point_standard.
+//
+// Template parameter:
+//
+//   RawType: the raw floating-point type (either float or double)
+template <typename RawType>
+class FloatingPoint {
+ public:
+  // Defines the unsigned integer type that has the same size as the
+  // floating point number.
+  typedef typename TypeWithSize<sizeof(RawType)>::UInt Bits;
+
+  // Constants.
+
+  // # of bits in a number.
+  static const size_t kBitCount = 8 * sizeof(RawType);
+
+  // # of fraction bits in a number.
+  static const size_t kFractionBitCount =
+      std::numeric_limits<RawType>::digits - 1;
+
+  // # of exponent bits in a number.
+  static const size_t kExponentBitCount = kBitCount - 1 - kFractionBitCount;
+
+  // The mask for the sign bit.
+  static const Bits kSignBitMask = static_cast<Bits>(1) << (kBitCount - 1);
+
+  // The mask for the fraction bits.
+  static const Bits kFractionBitMask = ~static_cast<Bits>(0) >>
+                                       (kExponentBitCount + 1);
+
+  // The mask for the exponent bits.
+  static const Bits kExponentBitMask = ~(kSignBitMask | kFractionBitMask);
+
+  // How many ULP's (Units in the Last Place) we want to tolerate when
+  // comparing two numbers.  The larger the value, the more error we
+  // allow.  A 0 value means that two numbers must be exactly the same
+  // to be considered equal.
+  //
+  // The maximum error of a single floating-point operation is 0.5
+  // units in the last place.  On Intel CPU's, all floating-point
+  // calculations are done with 80-bit precision, while double has 64
+  // bits.  Therefore, 4 should be enough for ordinary use.
+  //
+  // See the following article for more details on ULP:
+  // http://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/
+  static const uint32_t kMaxUlps = 4;
+
+  // Constructs a FloatingPoint from a raw floating-point number.
+  //
+  // On an Intel CPU, passing a non-normalized NAN (Not a Number)
+  // around may change its bits, although the new value is guaranteed
+  // to be also a NAN.  Therefore, don't expect this constructor to
+  // preserve the bits in x when x is a NAN.
+  explicit FloatingPoint(const RawType& x) { u_.value_ = x; }
+
+  // Static methods
+
+  // Reinterprets a bit pattern as a floating-point number.
+  //
+  // This function is needed to test the AlmostEquals() method.
+  static RawType ReinterpretBits(const Bits bits) {
+    FloatingPoint fp(0);
+    fp.u_.bits_ = bits;
+    return fp.u_.value_;
+  }
+
+  // Returns the floating-point number that represent positive infinity.
+  static RawType Infinity() { return ReinterpretBits(kExponentBitMask); }
+
+  // Returns the maximum representable finite floating-point number.
+  static RawType Max();
+
+  // Non-static methods
+
+  // Returns the bits that represents this number.
+  const Bits& bits() const { return u_.bits_; }
+
+  // Returns the exponent bits of this number.
+  Bits exponent_bits() const { return kExponentBitMask & u_.bits_; }
+
+  // Returns the fraction bits of this number.
+  Bits fraction_bits() const { return kFractionBitMask & u_.bits_; }
+
+  // Returns the sign bit of this number.
+  Bits sign_bit() const { return kSignBitMask & u_.bits_; }
+
+  // Returns true if and only if this is NAN (not a number).
+  bool is_nan() const {
+    // It's a NAN if the exponent bits are all ones and the fraction
+    // bits are not entirely zeros.
+    return (exponent_bits() == kExponentBitMask) && (fraction_bits() != 0);
+  }
+
+  // Returns true if and only if this number is at most kMaxUlps ULP's away
+  // from rhs.  In particular, this function:
+  //
+  //   - returns false if either number is (or both are) NAN.
+  //   - treats really large numbers as almost equal to infinity.
+  //   - thinks +0.0 and -0.0 are 0 DLP's apart.
+  bool AlmostEquals(const FloatingPoint& rhs) const {
+    // The IEEE standard says that any comparison operation involving
+    // a NAN must return false.
+    if (is_nan() || rhs.is_nan()) return false;
+
+    return DistanceBetweenSignAndMagnitudeNumbers(u_.bits_, rhs.u_.bits_) <=
+           kMaxUlps;
+  }
+
+ private:
+  // The data type used to store the actual floating-point number.
+  union FloatingPointUnion {
+    RawType value_;  // The raw floating-point number.
+    Bits bits_;      // The bits that represent the number.
+  };
+
+  // Converts an integer from the sign-and-magnitude representation to
+  // the biased representation.  More precisely, let N be 2 to the
+  // power of (kBitCount - 1), an integer x is represented by the
+  // unsigned number x + N.
+  //
+  // For instance,
+  //
+  //   -N + 1 (the most negative number representable using
+  //          sign-and-magnitude) is represented by 1;
+  //   0      is represented by N; and
+  //   N - 1  (the biggest number representable using
+  //          sign-and-magnitude) is represented by 2N - 1.
+  //
+  // Read http://en.wikipedia.org/wiki/Signed_number_representations
+  // for more details on signed number representations.
+  static Bits SignAndMagnitudeToBiased(const Bits& sam) {
+    if (kSignBitMask & sam) {
+      // sam represents a negative number.
+      return ~sam + 1;
+    } else {
+      // sam represents a positive number.
+      return kSignBitMask | sam;
+    }
+  }
+
+  // Given two numbers in the sign-and-magnitude representation,
+  // returns the distance between them as an unsigned number.
+  static Bits DistanceBetweenSignAndMagnitudeNumbers(const Bits& sam1,
+                                                     const Bits& sam2) {
+    const Bits biased1 = SignAndMagnitudeToBiased(sam1);
+    const Bits biased2 = SignAndMagnitudeToBiased(sam2);
+    return (biased1 >= biased2) ? (biased1 - biased2) : (biased2 - biased1);
+  }
+
+  FloatingPointUnion u_;
+};
+
+// We cannot use std::numeric_limits<T>::max() as it clashes with the max()
+// macro defined by <windows.h>.
+template <>
+inline float FloatingPoint<float>::Max() {
+  return FLT_MAX;
+}
+template <>
+inline double FloatingPoint<double>::Max() {
+  return DBL_MAX;
+}
+
+// Typedefs the instances of the FloatingPoint template class that we
+// care to use.
+typedef FloatingPoint<float> Float;
+typedef FloatingPoint<double> Double;
+
+// In order to catch the mistake of putting tests that use different
+// test fixture classes in the same test suite, we need to assign
+// unique IDs to fixture classes and compare them.  The TypeId type is
+// used to hold such IDs.  The user should treat TypeId as an opaque
+// type: the only operation allowed on TypeId values is to compare
+// them for equality using the == operator.
+typedef const void* TypeId;
+
+template <typename T>
+class TypeIdHelper {
+ public:
+  // dummy_ must not have a const type.  Otherwise an overly eager
+  // compiler (e.g. MSVC 7.1 & 8.0) may try to merge
+  // TypeIdHelper<T>::dummy_ for different Ts as an "optimization".
+  static bool dummy_;
+};
+
+template <typename T>
+bool TypeIdHelper<T>::dummy_ = false;
+
+// GetTypeId<T>() returns the ID of type T.  Different values will be
+// returned for different types.  Calling the function twice with the
+// same type argument is guaranteed to return the same ID.
+template <typename T>
+TypeId GetTypeId() {
+  // The compiler is required to allocate a different
+  // TypeIdHelper<T>::dummy_ variable for each T used to instantiate
+  // the template.  Therefore, the address of dummy_ is guaranteed to
+  // be unique.
+  return &(TypeIdHelper<T>::dummy_);
+}
+
+// Returns the type ID of ::testing::Test.  Always call this instead
+// of GetTypeId< ::testing::Test>() to get the type ID of
+// ::testing::Test, as the latter may give the wrong result due to a
+// suspected linker bug when compiling Google Test as a Mac OS X
+// framework.
+GTEST_API_ TypeId GetTestTypeId();
+
+// Defines the abstract factory interface that creates instances
+// of a Test object.
+class TestFactoryBase {
+ public:
+  virtual ~TestFactoryBase() {}
+
+  // Creates a test instance to run. The instance is both created and destroyed
+  // within TestInfoImpl::Run()
+  virtual Test* CreateTest() = 0;
+
+ protected:
+  TestFactoryBase() {}
+
+ private:
+  TestFactoryBase(const TestFactoryBase&) = delete;
+  TestFactoryBase& operator=(const TestFactoryBase&) = delete;
+};
+
+// This class provides implementation of TeastFactoryBase interface.
+// It is used in TEST and TEST_F macros.
+template <class TestClass>
+class TestFactoryImpl : public TestFactoryBase {
+ public:
+  Test* CreateTest() override { return new TestClass; }
+};
+
+#if GTEST_OS_WINDOWS
+
+// Predicate-formatters for implementing the HRESULT checking macros
+// {ASSERT|EXPECT}_HRESULT_{SUCCEEDED|FAILED}
+// We pass a long instead of HRESULT to avoid causing an
+// include dependency for the HRESULT type.
+GTEST_API_ AssertionResult IsHRESULTSuccess(const char* expr,
+                                            long hr);  // NOLINT
+GTEST_API_ AssertionResult IsHRESULTFailure(const char* expr,
+                                            long hr);  // NOLINT
+
+#endif  // GTEST_OS_WINDOWS
+
+// Types of SetUpTestSuite() and TearDownTestSuite() functions.
+using SetUpTestSuiteFunc = void (*)();
+using TearDownTestSuiteFunc = void (*)();
+
+struct CodeLocation {
+  CodeLocation(const std::string& a_file, int a_line)
+      : file(a_file), line(a_line) {}
+
+  std::string file;
+  int line;
+};
+
+//  Helper to identify which setup function for TestCase / TestSuite to call.
+//  Only one function is allowed, either TestCase or TestSute but not both.
+
+// Utility functions to help SuiteApiResolver
+using SetUpTearDownSuiteFuncType = void (*)();
+
+inline SetUpTearDownSuiteFuncType GetNotDefaultOrNull(
+    SetUpTearDownSuiteFuncType a, SetUpTearDownSuiteFuncType def) {
+  return a == def ? nullptr : a;
+}
+
+template <typename T>
+//  Note that SuiteApiResolver inherits from T because
+//  SetUpTestSuite()/TearDownTestSuite() could be protected. This way
+//  SuiteApiResolver can access them.
+struct SuiteApiResolver : T {
+  // testing::Test is only forward declared at this point. So we make it a
+  // dependent class for the compiler to be OK with it.
+  using Test =
+      typename std::conditional<sizeof(T) != 0, ::testing::Test, void>::type;
+
+  static SetUpTearDownSuiteFuncType GetSetUpCaseOrSuite(const char* filename,
+                                                        int line_num) {
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+    SetUpTearDownSuiteFuncType test_case_fp =
+        GetNotDefaultOrNull(&T::SetUpTestCase, &Test::SetUpTestCase);
+    SetUpTearDownSuiteFuncType test_suite_fp =
+        GetNotDefaultOrNull(&T::SetUpTestSuite, &Test::SetUpTestSuite);
+
+    GTEST_CHECK_(!test_case_fp || !test_suite_fp)
+        << "Test can not provide both SetUpTestSuite and SetUpTestCase, please "
+           "make sure there is only one present at "
+        << filename << ":" << line_num;
+
+    return test_case_fp != nullptr ? test_case_fp : test_suite_fp;
+#else
+    (void)(filename);
+    (void)(line_num);
+    return &T::SetUpTestSuite;
+#endif
+  }
+
+  static SetUpTearDownSuiteFuncType GetTearDownCaseOrSuite(const char* filename,
+                                                           int line_num) {
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+    SetUpTearDownSuiteFuncType test_case_fp =
+        GetNotDefaultOrNull(&T::TearDownTestCase, &Test::TearDownTestCase);
+    SetUpTearDownSuiteFuncType test_suite_fp =
+        GetNotDefaultOrNull(&T::TearDownTestSuite, &Test::TearDownTestSuite);
+
+    GTEST_CHECK_(!test_case_fp || !test_suite_fp)
+        << "Test can not provide both TearDownTestSuite and TearDownTestCase,"
+           " please make sure there is only one present at"
+        << filename << ":" << line_num;
+
+    return test_case_fp != nullptr ? test_case_fp : test_suite_fp;
+#else
+    (void)(filename);
+    (void)(line_num);
+    return &T::TearDownTestSuite;
+#endif
+  }
+};
+
+// Creates a new TestInfo object and registers it with Google Test;
+// returns the created object.
+//
+// Arguments:
+//
+//   test_suite_name:  name of the test suite
+//   name:             name of the test
+//   type_param:       the name of the test's type parameter, or NULL if
+//                     this is not a typed or a type-parameterized test.
+//   value_param:      text representation of the test's value parameter,
+//                     or NULL if this is not a type-parameterized test.
+//   code_location:    code location where the test is defined
+//   fixture_class_id: ID of the test fixture class
+//   set_up_tc:        pointer to the function that sets up the test suite
+//   tear_down_tc:     pointer to the function that tears down the test suite
+//   factory:          pointer to the factory that creates a test object.
+//                     The newly created TestInfo instance will assume
+//                     ownership of the factory object.
+GTEST_API_ TestInfo* MakeAndRegisterTestInfo(
+    const char* test_suite_name, const char* name, const char* type_param,
+    const char* value_param, CodeLocation code_location,
+    TypeId fixture_class_id, SetUpTestSuiteFunc set_up_tc,
+    TearDownTestSuiteFunc tear_down_tc, TestFactoryBase* factory);
+
+// If *pstr starts with the given prefix, modifies *pstr to be right
+// past the prefix and returns true; otherwise leaves *pstr unchanged
+// and returns false.  None of pstr, *pstr, and prefix can be NULL.
+GTEST_API_ bool SkipPrefix(const char* prefix, const char** pstr);
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+// State of the definition of a type-parameterized test suite.
+class GTEST_API_ TypedTestSuitePState {
+ public:
+  TypedTestSuitePState() : registered_(false) {}
+
+  // Adds the given test name to defined_test_names_ and return true
+  // if the test suite hasn't been registered; otherwise aborts the
+  // program.
+  bool AddTestName(const char* file, int line, const char* case_name,
+                   const char* test_name) {
+    if (registered_) {
+      fprintf(stderr,
+              "%s Test %s must be defined before "
+              "REGISTER_TYPED_TEST_SUITE_P(%s, ...).\n",
+              FormatFileLocation(file, line).c_str(), test_name, case_name);
+      fflush(stderr);
+      posix::Abort();
+    }
+    registered_tests_.insert(
+        ::std::make_pair(test_name, CodeLocation(file, line)));
+    return true;
+  }
+
+  bool TestExists(const std::string& test_name) const {
+    return registered_tests_.count(test_name) > 0;
+  }
+
+  const CodeLocation& GetCodeLocation(const std::string& test_name) const {
+    RegisteredTestsMap::const_iterator it = registered_tests_.find(test_name);
+    GTEST_CHECK_(it != registered_tests_.end());
+    return it->second;
+  }
+
+  // Verifies that registered_tests match the test names in
+  // defined_test_names_; returns registered_tests if successful, or
+  // aborts the program otherwise.
+  const char* VerifyRegisteredTestNames(const char* test_suite_name,
+                                        const char* file, int line,
+                                        const char* registered_tests);
+
+ private:
+  typedef ::std::map<std::string, CodeLocation> RegisteredTestsMap;
+
+  bool registered_;
+  RegisteredTestsMap registered_tests_;
+};
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+using TypedTestCasePState = TypedTestSuitePState;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+// Skips to the first non-space char after the first comma in 'str';
+// returns NULL if no comma is found in 'str'.
+inline const char* SkipComma(const char* str) {
+  const char* comma = strchr(str, ',');
+  if (comma == nullptr) {
+    return nullptr;
+  }
+  while (IsSpace(*(++comma))) {
+  }
+  return comma;
+}
+
+// Returns the prefix of 'str' before the first comma in it; returns
+// the entire string if it contains no comma.
+inline std::string GetPrefixUntilComma(const char* str) {
+  const char* comma = strchr(str, ',');
+  return comma == nullptr ? str : std::string(str, comma);
+}
+
+// Splits a given string on a given delimiter, populating a given
+// vector with the fields.
+void SplitString(const ::std::string& str, char delimiter,
+                 ::std::vector<::std::string>* dest);
+
+// The default argument to the template below for the case when the user does
+// not provide a name generator.
+struct DefaultNameGenerator {
+  template <typename T>
+  static std::string GetName(int i) {
+    return StreamableToString(i);
+  }
+};
+
+template <typename Provided = DefaultNameGenerator>
+struct NameGeneratorSelector {
+  typedef Provided type;
+};
+
+template <typename NameGenerator>
+void GenerateNamesRecursively(internal::None, std::vector<std::string>*, int) {}
+
+template <typename NameGenerator, typename Types>
+void GenerateNamesRecursively(Types, std::vector<std::string>* result, int i) {
+  result->push_back(NameGenerator::template GetName<typename Types::Head>(i));
+  GenerateNamesRecursively<NameGenerator>(typename Types::Tail(), result,
+                                          i + 1);
+}
+
+template <typename NameGenerator, typename Types>
+std::vector<std::string> GenerateNames() {
+  std::vector<std::string> result;
+  GenerateNamesRecursively<NameGenerator>(Types(), &result, 0);
+  return result;
+}
+
+// TypeParameterizedTest<Fixture, TestSel, Types>::Register()
+// registers a list of type-parameterized tests with Google Test.  The
+// return value is insignificant - we just need to return something
+// such that we can call this function in a namespace scope.
+//
+// Implementation note: The GTEST_TEMPLATE_ macro declares a template
+// template parameter.  It's defined in gtest-type-util.h.
+template <GTEST_TEMPLATE_ Fixture, class TestSel, typename Types>
+class TypeParameterizedTest {
+ public:
+  // 'index' is the index of the test in the type list 'Types'
+  // specified in INSTANTIATE_TYPED_TEST_SUITE_P(Prefix, TestSuite,
+  // Types).  Valid values for 'index' are [0, N - 1] where N is the
+  // length of Types.
+  static bool Register(const char* prefix, const CodeLocation& code_location,
+                       const char* case_name, const char* test_names, int index,
+                       const std::vector<std::string>& type_names =
+                           GenerateNames<DefaultNameGenerator, Types>()) {
+    typedef typename Types::Head Type;
+    typedef Fixture<Type> FixtureClass;
+    typedef typename GTEST_BIND_(TestSel, Type) TestClass;
+
+    // First, registers the first type-parameterized test in the type
+    // list.
+    MakeAndRegisterTestInfo(
+        (std::string(prefix) + (prefix[0] == '\0' ? "" : "/") + case_name +
+         "/" + type_names[static_cast<size_t>(index)])
+            .c_str(),
+        StripTrailingSpaces(GetPrefixUntilComma(test_names)).c_str(),
+        GetTypeName<Type>().c_str(),
+        nullptr,  // No value parameter.
+        code_location, GetTypeId<FixtureClass>(),
+        SuiteApiResolver<TestClass>::GetSetUpCaseOrSuite(
+            code_location.file.c_str(), code_location.line),
+        SuiteApiResolver<TestClass>::GetTearDownCaseOrSuite(
+            code_location.file.c_str(), code_location.line),
+        new TestFactoryImpl<TestClass>);
+
+    // Next, recurses (at compile time) with the tail of the type list.
+    return TypeParameterizedTest<Fixture, TestSel,
+                                 typename Types::Tail>::Register(prefix,
+                                                                 code_location,
+                                                                 case_name,
+                                                                 test_names,
+                                                                 index + 1,
+                                                                 type_names);
+  }
+};
+
+// The base case for the compile time recursion.
+template <GTEST_TEMPLATE_ Fixture, class TestSel>
+class TypeParameterizedTest<Fixture, TestSel, internal::None> {
+ public:
+  static bool Register(const char* /*prefix*/, const CodeLocation&,
+                       const char* /*case_name*/, const char* /*test_names*/,
+                       int /*index*/,
+                       const std::vector<std::string>& =
+                           std::vector<std::string>() /*type_names*/) {
+    return true;
+  }
+};
+
+GTEST_API_ void RegisterTypeParameterizedTestSuite(const char* test_suite_name,
+                                                   CodeLocation code_location);
+GTEST_API_ void RegisterTypeParameterizedTestSuiteInstantiation(
+    const char* case_name);
+
+// TypeParameterizedTestSuite<Fixture, Tests, Types>::Register()
+// registers *all combinations* of 'Tests' and 'Types' with Google
+// Test.  The return value is insignificant - we just need to return
+// something such that we can call this function in a namespace scope.
+template <GTEST_TEMPLATE_ Fixture, typename Tests, typename Types>
+class TypeParameterizedTestSuite {
+ public:
+  static bool Register(const char* prefix, CodeLocation code_location,
+                       const TypedTestSuitePState* state, const char* case_name,
+                       const char* test_names,
+                       const std::vector<std::string>& type_names =
+                           GenerateNames<DefaultNameGenerator, Types>()) {
+    RegisterTypeParameterizedTestSuiteInstantiation(case_name);
+    std::string test_name =
+        StripTrailingSpaces(GetPrefixUntilComma(test_names));
+    if (!state->TestExists(test_name)) {
+      fprintf(stderr, "Failed to get code location for test %s.%s at %s.",
+              case_name, test_name.c_str(),
+              FormatFileLocation(code_location.file.c_str(), code_location.line)
+                  .c_str());
+      fflush(stderr);
+      posix::Abort();
+    }
+    const CodeLocation& test_location = state->GetCodeLocation(test_name);
+
+    typedef typename Tests::Head Head;
+
+    // First, register the first test in 'Test' for each type in 'Types'.
+    TypeParameterizedTest<Fixture, Head, Types>::Register(
+        prefix, test_location, case_name, test_names, 0, type_names);
+
+    // Next, recurses (at compile time) with the tail of the test list.
+    return TypeParameterizedTestSuite<Fixture, typename Tests::Tail,
+                                      Types>::Register(prefix, code_location,
+                                                       state, case_name,
+                                                       SkipComma(test_names),
+                                                       type_names);
+  }
+};
+
+// The base case for the compile time recursion.
+template <GTEST_TEMPLATE_ Fixture, typename Types>
+class TypeParameterizedTestSuite<Fixture, internal::None, Types> {
+ public:
+  static bool Register(const char* /*prefix*/, const CodeLocation&,
+                       const TypedTestSuitePState* /*state*/,
+                       const char* /*case_name*/, const char* /*test_names*/,
+                       const std::vector<std::string>& =
+                           std::vector<std::string>() /*type_names*/) {
+    return true;
+  }
+};
+
+// Returns the current OS stack trace as an std::string.
+//
+// The maximum number of stack frames to be included is specified by
+// the gtest_stack_trace_depth flag.  The skip_count parameter
+// specifies the number of top frames to be skipped, which doesn't
+// count against the number of frames to be included.
+//
+// For example, if Foo() calls Bar(), which in turn calls
+// GetCurrentOsStackTraceExceptTop(..., 1), Foo() will be included in
+// the trace but Bar() and GetCurrentOsStackTraceExceptTop() won't.
+GTEST_API_ std::string GetCurrentOsStackTraceExceptTop(UnitTest* unit_test,
+                                                       int skip_count);
+
+// Helpers for suppressing warnings on unreachable code or constant
+// condition.
+
+// Always returns true.
+GTEST_API_ bool AlwaysTrue();
+
+// Always returns false.
+inline bool AlwaysFalse() { return !AlwaysTrue(); }
+
+// Helper for suppressing false warning from Clang on a const char*
+// variable declared in a conditional expression always being NULL in
+// the else branch.
+struct GTEST_API_ ConstCharPtr {
+  ConstCharPtr(const char* str) : value(str) {}
+  operator bool() const { return true; }
+  const char* value;
+};
+
+// Helper for declaring std::string within 'if' statement
+// in pre C++17 build environment.
+struct TrueWithString {
+  TrueWithString() = default;
+  explicit TrueWithString(const char* str) : value(str) {}
+  explicit TrueWithString(const std::string& str) : value(str) {}
+  explicit operator bool() const { return true; }
+  std::string value;
+};
+
+// A simple Linear Congruential Generator for generating random
+// numbers with a uniform distribution.  Unlike rand() and srand(), it
+// doesn't use global state (and therefore can't interfere with user
+// code).  Unlike rand_r(), it's portable.  An LCG isn't very random,
+// but it's good enough for our purposes.
+class GTEST_API_ Random {
+ public:
+  static const uint32_t kMaxRange = 1u << 31;
+
+  explicit Random(uint32_t seed) : state_(seed) {}
+
+  void Reseed(uint32_t seed) { state_ = seed; }
+
+  // Generates a random number from [0, range).  Crashes if 'range' is
+  // 0 or greater than kMaxRange.
+  uint32_t Generate(uint32_t range);
+
+ private:
+  uint32_t state_;
+  Random(const Random&) = delete;
+  Random& operator=(const Random&) = delete;
+};
+
+// Turns const U&, U&, const U, and U all into U.
+#define GTEST_REMOVE_REFERENCE_AND_CONST_(T) \
+  typename std::remove_const<typename std::remove_reference<T>::type>::type
+
+// HasDebugStringAndShortDebugString<T>::value is a compile-time bool constant
+// that's true if and only if T has methods DebugString() and ShortDebugString()
+// that return std::string.
+template <typename T>
+class HasDebugStringAndShortDebugString {
+ private:
+  template <typename C>
+  static auto CheckDebugString(C*) -> typename std::is_same<
+      std::string, decltype(std::declval<const C>().DebugString())>::type;
+  template <typename>
+  static std::false_type CheckDebugString(...);
+
+  template <typename C>
+  static auto CheckShortDebugString(C*) -> typename std::is_same<
+      std::string, decltype(std::declval<const C>().ShortDebugString())>::type;
+  template <typename>
+  static std::false_type CheckShortDebugString(...);
+
+  using HasDebugStringType = decltype(CheckDebugString<T>(nullptr));
+  using HasShortDebugStringType = decltype(CheckShortDebugString<T>(nullptr));
+
+ public:
+  static constexpr bool value =
+      HasDebugStringType::value && HasShortDebugStringType::value;
+};
+
+template <typename T>
+constexpr bool HasDebugStringAndShortDebugString<T>::value;
+
+// When the compiler sees expression IsContainerTest<C>(0), if C is an
+// STL-style container class, the first overload of IsContainerTest
+// will be viable (since both C::iterator* and C::const_iterator* are
+// valid types and NULL can be implicitly converted to them).  It will
+// be picked over the second overload as 'int' is a perfect match for
+// the type of argument 0.  If C::iterator or C::const_iterator is not
+// a valid type, the first overload is not viable, and the second
+// overload will be picked.  Therefore, we can determine whether C is
+// a container class by checking the type of IsContainerTest<C>(0).
+// The value of the expression is insignificant.
+//
+// In C++11 mode we check the existence of a const_iterator and that an
+// iterator is properly implemented for the container.
+//
+// For pre-C++11 that we look for both C::iterator and C::const_iterator.
+// The reason is that C++ injects the name of a class as a member of the
+// class itself (e.g. you can refer to class iterator as either
+// 'iterator' or 'iterator::iterator').  If we look for C::iterator
+// only, for example, we would mistakenly think that a class named
+// iterator is an STL container.
+//
+// Also note that the simpler approach of overloading
+// IsContainerTest(typename C::const_iterator*) and
+// IsContainerTest(...) doesn't work with Visual Age C++ and Sun C++.
+typedef int IsContainer;
+template <class C,
+          class Iterator = decltype(::std::declval<const C&>().begin()),
+          class = decltype(::std::declval<const C&>().end()),
+          class = decltype(++::std::declval<Iterator&>()),
+          class = decltype(*::std::declval<Iterator>()),
+          class = typename C::const_iterator>
+IsContainer IsContainerTest(int /* dummy */) {
+  return 0;
+}
+
+typedef char IsNotContainer;
+template <class C>
+IsNotContainer IsContainerTest(long /* dummy */) {
+  return '\0';
+}
+
+// Trait to detect whether a type T is a hash table.
+// The heuristic used is that the type contains an inner type `hasher` and does
+// not contain an inner type `reverse_iterator`.
+// If the container is iterable in reverse, then order might actually matter.
+template <typename T>
+struct IsHashTable {
+ private:
+  template <typename U>
+  static char test(typename U::hasher*, typename U::reverse_iterator*);
+  template <typename U>
+  static int test(typename U::hasher*, ...);
+  template <typename U>
+  static char test(...);
+
+ public:
+  static const bool value = sizeof(test<T>(nullptr, nullptr)) == sizeof(int);
+};
+
+template <typename T>
+const bool IsHashTable<T>::value;
+
+template <typename C,
+          bool = sizeof(IsContainerTest<C>(0)) == sizeof(IsContainer)>
+struct IsRecursiveContainerImpl;
+
+template <typename C>
+struct IsRecursiveContainerImpl<C, false> : public std::false_type {};
+
+// Since the IsRecursiveContainerImpl depends on the IsContainerTest we need to
+// obey the same inconsistencies as the IsContainerTest, namely check if
+// something is a container is relying on only const_iterator in C++11 and
+// is relying on both const_iterator and iterator otherwise
+template <typename C>
+struct IsRecursiveContainerImpl<C, true> {
+  using value_type = decltype(*std::declval<typename C::const_iterator>());
+  using type =
+      std::is_same<typename std::remove_const<
+                       typename std::remove_reference<value_type>::type>::type,
+                   C>;
+};
+
+// IsRecursiveContainer<Type> is a unary compile-time predicate that
+// evaluates whether C is a recursive container type. A recursive container
+// type is a container type whose value_type is equal to the container type
+// itself. An example for a recursive container type is
+// boost::filesystem::path, whose iterator has a value_type that is equal to
+// boost::filesystem::path.
+template <typename C>
+struct IsRecursiveContainer : public IsRecursiveContainerImpl<C>::type {};
+
+// Utilities for native arrays.
+
+// ArrayEq() compares two k-dimensional native arrays using the
+// elements' operator==, where k can be any integer >= 0.  When k is
+// 0, ArrayEq() degenerates into comparing a single pair of values.
+
+template <typename T, typename U>
+bool ArrayEq(const T* lhs, size_t size, const U* rhs);
+
+// This generic version is used when k is 0.
+template <typename T, typename U>
+inline bool ArrayEq(const T& lhs, const U& rhs) {
+  return lhs == rhs;
+}
+
+// This overload is used when k >= 1.
+template <typename T, typename U, size_t N>
+inline bool ArrayEq(const T (&lhs)[N], const U (&rhs)[N]) {
+  return internal::ArrayEq(lhs, N, rhs);
+}
+
+// This helper reduces code bloat.  If we instead put its logic inside
+// the previous ArrayEq() function, arrays with different sizes would
+// lead to different copies of the template code.
+template <typename T, typename U>
+bool ArrayEq(const T* lhs, size_t size, const U* rhs) {
+  for (size_t i = 0; i != size; i++) {
+    if (!internal::ArrayEq(lhs[i], rhs[i])) return false;
+  }
+  return true;
+}
+
+// Finds the first element in the iterator range [begin, end) that
+// equals elem.  Element may be a native array type itself.
+template <typename Iter, typename Element>
+Iter ArrayAwareFind(Iter begin, Iter end, const Element& elem) {
+  for (Iter it = begin; it != end; ++it) {
+    if (internal::ArrayEq(*it, elem)) return it;
+  }
+  return end;
+}
+
+// CopyArray() copies a k-dimensional native array using the elements'
+// operator=, where k can be any integer >= 0.  When k is 0,
+// CopyArray() degenerates into copying a single value.
+
+template <typename T, typename U>
+void CopyArray(const T* from, size_t size, U* to);
+
+// This generic version is used when k is 0.
+template <typename T, typename U>
+inline void CopyArray(const T& from, U* to) {
+  *to = from;
+}
+
+// This overload is used when k >= 1.
+template <typename T, typename U, size_t N>
+inline void CopyArray(const T (&from)[N], U (*to)[N]) {
+  internal::CopyArray(from, N, *to);
+}
+
+// This helper reduces code bloat.  If we instead put its logic inside
+// the previous CopyArray() function, arrays with different sizes
+// would lead to different copies of the template code.
+template <typename T, typename U>
+void CopyArray(const T* from, size_t size, U* to) {
+  for (size_t i = 0; i != size; i++) {
+    internal::CopyArray(from[i], to + i);
+  }
+}
+
+// The relation between an NativeArray object (see below) and the
+// native array it represents.
+// We use 2 different structs to allow non-copyable types to be used, as long
+// as RelationToSourceReference() is passed.
+struct RelationToSourceReference {};
+struct RelationToSourceCopy {};
+
+// Adapts a native array to a read-only STL-style container.  Instead
+// of the complete STL container concept, this adaptor only implements
+// members useful for Google Mock's container matchers.  New members
+// should be added as needed.  To simplify the implementation, we only
+// support Element being a raw type (i.e. having no top-level const or
+// reference modifier).  It's the client's responsibility to satisfy
+// this requirement.  Element can be an array type itself (hence
+// multi-dimensional arrays are supported).
+template <typename Element>
+class NativeArray {
+ public:
+  // STL-style container typedefs.
+  typedef Element value_type;
+  typedef Element* iterator;
+  typedef const Element* const_iterator;
+
+  // Constructs from a native array. References the source.
+  NativeArray(const Element* array, size_t count, RelationToSourceReference) {
+    InitRef(array, count);
+  }
+
+  // Constructs from a native array. Copies the source.
+  NativeArray(const Element* array, size_t count, RelationToSourceCopy) {
+    InitCopy(array, count);
+  }
+
+  // Copy constructor.
+  NativeArray(const NativeArray& rhs) {
+    (this->*rhs.clone_)(rhs.array_, rhs.size_);
+  }
+
+  ~NativeArray() {
+    if (clone_ != &NativeArray::InitRef) delete[] array_;
+  }
+
+  // STL-style container methods.
+  size_t size() const { return size_; }
+  const_iterator begin() const { return array_; }
+  const_iterator end() const { return array_ + size_; }
+  bool operator==(const NativeArray& rhs) const {
+    return size() == rhs.size() && ArrayEq(begin(), size(), rhs.begin());
+  }
+
+ private:
+  static_assert(!std::is_const<Element>::value, "Type must not be const");
+  static_assert(!std::is_reference<Element>::value,
+                "Type must not be a reference");
+
+  // Initializes this object with a copy of the input.
+  void InitCopy(const Element* array, size_t a_size) {
+    Element* const copy = new Element[a_size];
+    CopyArray(array, a_size, copy);
+    array_ = copy;
+    size_ = a_size;
+    clone_ = &NativeArray::InitCopy;
+  }
+
+  // Initializes this object with a reference of the input.
+  void InitRef(const Element* array, size_t a_size) {
+    array_ = array;
+    size_ = a_size;
+    clone_ = &NativeArray::InitRef;
+  }
+
+  const Element* array_;
+  size_t size_;
+  void (NativeArray::*clone_)(const Element*, size_t);
+};
+
+// Backport of std::index_sequence.
+template <size_t... Is>
+struct IndexSequence {
+  using type = IndexSequence;
+};
+
+// Double the IndexSequence, and one if plus_one is true.
+template <bool plus_one, typename T, size_t sizeofT>
+struct DoubleSequence;
+template <size_t... I, size_t sizeofT>
+struct DoubleSequence<true, IndexSequence<I...>, sizeofT> {
+  using type = IndexSequence<I..., (sizeofT + I)..., 2 * sizeofT>;
+};
+template <size_t... I, size_t sizeofT>
+struct DoubleSequence<false, IndexSequence<I...>, sizeofT> {
+  using type = IndexSequence<I..., (sizeofT + I)...>;
+};
+
+// Backport of std::make_index_sequence.
+// It uses O(ln(N)) instantiation depth.
+template <size_t N>
+struct MakeIndexSequenceImpl
+    : DoubleSequence<N % 2 == 1, typename MakeIndexSequenceImpl<N / 2>::type,
+                     N / 2>::type {};
+
+template <>
+struct MakeIndexSequenceImpl<0> : IndexSequence<> {};
+
+template <size_t N>
+using MakeIndexSequence = typename MakeIndexSequenceImpl<N>::type;
+
+template <typename... T>
+using IndexSequenceFor = typename MakeIndexSequence<sizeof...(T)>::type;
+
+template <size_t>
+struct Ignore {
+  Ignore(...);  // NOLINT
+};
+
+template <typename>
+struct ElemFromListImpl;
+template <size_t... I>
+struct ElemFromListImpl<IndexSequence<I...>> {
+  // We make Ignore a template to solve a problem with MSVC.
+  // A non-template Ignore would work fine with `decltype(Ignore(I))...`, but
+  // MSVC doesn't understand how to deal with that pack expansion.
+  // Use `0 * I` to have a single instantiation of Ignore.
+  template <typename R>
+  static R Apply(Ignore<0 * I>..., R (*)(), ...);
+};
+
+template <size_t N, typename... T>
+struct ElemFromList {
+  using type =
+      decltype(ElemFromListImpl<typename MakeIndexSequence<N>::type>::Apply(
+          static_cast<T (*)()>(nullptr)...));
+};
+
+struct FlatTupleConstructTag {};
+
+template <typename... T>
+class FlatTuple;
+
+template <typename Derived, size_t I>
+struct FlatTupleElemBase;
+
+template <typename... T, size_t I>
+struct FlatTupleElemBase<FlatTuple<T...>, I> {
+  using value_type = typename ElemFromList<I, T...>::type;
+  FlatTupleElemBase() = default;
+  template <typename Arg>
+  explicit FlatTupleElemBase(FlatTupleConstructTag, Arg&& t)
+      : value(std::forward<Arg>(t)) {}
+  value_type value;
+};
+
+template <typename Derived, typename Idx>
+struct FlatTupleBase;
+
+template <size_t... Idx, typename... T>
+struct FlatTupleBase<FlatTuple<T...>, IndexSequence<Idx...>>
+    : FlatTupleElemBase<FlatTuple<T...>, Idx>... {
+  using Indices = IndexSequence<Idx...>;
+  FlatTupleBase() = default;
+  template <typename... Args>
+  explicit FlatTupleBase(FlatTupleConstructTag, Args&&... args)
+      : FlatTupleElemBase<FlatTuple<T...>, Idx>(FlatTupleConstructTag{},
+                                                std::forward<Args>(args))... {}
+
+  template <size_t I>
+  const typename ElemFromList<I, T...>::type& Get() const {
+    return FlatTupleElemBase<FlatTuple<T...>, I>::value;
+  }
+
+  template <size_t I>
+  typename ElemFromList<I, T...>::type& Get() {
+    return FlatTupleElemBase<FlatTuple<T...>, I>::value;
+  }
+
+  template <typename F>
+  auto Apply(F&& f) -> decltype(std::forward<F>(f)(this->Get<Idx>()...)) {
+    return std::forward<F>(f)(Get<Idx>()...);
+  }
+
+  template <typename F>
+  auto Apply(F&& f) const -> decltype(std::forward<F>(f)(this->Get<Idx>()...)) {
+    return std::forward<F>(f)(Get<Idx>()...);
+  }
+};
+
+// Analog to std::tuple but with different tradeoffs.
+// This class minimizes the template instantiation depth, thus allowing more
+// elements than std::tuple would. std::tuple has been seen to require an
+// instantiation depth of more than 10x the number of elements in some
+// implementations.
+// FlatTuple and ElemFromList are not recursive and have a fixed depth
+// regardless of T...
+// MakeIndexSequence, on the other hand, it is recursive but with an
+// instantiation depth of O(ln(N)).
+template <typename... T>
+class FlatTuple
+    : private FlatTupleBase<FlatTuple<T...>,
+                            typename MakeIndexSequence<sizeof...(T)>::type> {
+  using Indices = typename FlatTupleBase<
+      FlatTuple<T...>, typename MakeIndexSequence<sizeof...(T)>::type>::Indices;
+
+ public:
+  FlatTuple() = default;
+  template <typename... Args>
+  explicit FlatTuple(FlatTupleConstructTag tag, Args&&... args)
+      : FlatTuple::FlatTupleBase(tag, std::forward<Args>(args)...) {}
+
+  using FlatTuple::FlatTupleBase::Apply;
+  using FlatTuple::FlatTupleBase::Get;
+};
+
+// Utility functions to be called with static_assert to induce deprecation
+// warnings.
+GTEST_INTERNAL_DEPRECATED(
+    "INSTANTIATE_TEST_CASE_P is deprecated, please use "
+    "INSTANTIATE_TEST_SUITE_P")
+constexpr bool InstantiateTestCase_P_IsDeprecated() { return true; }
+
+GTEST_INTERNAL_DEPRECATED(
+    "TYPED_TEST_CASE_P is deprecated, please use "
+    "TYPED_TEST_SUITE_P")
+constexpr bool TypedTestCase_P_IsDeprecated() { return true; }
+
+GTEST_INTERNAL_DEPRECATED(
+    "TYPED_TEST_CASE is deprecated, please use "
+    "TYPED_TEST_SUITE")
+constexpr bool TypedTestCaseIsDeprecated() { return true; }
+
+GTEST_INTERNAL_DEPRECATED(
+    "REGISTER_TYPED_TEST_CASE_P is deprecated, please use "
+    "REGISTER_TYPED_TEST_SUITE_P")
+constexpr bool RegisterTypedTestCase_P_IsDeprecated() { return true; }
+
+GTEST_INTERNAL_DEPRECATED(
+    "INSTANTIATE_TYPED_TEST_CASE_P is deprecated, please use "
+    "INSTANTIATE_TYPED_TEST_SUITE_P")
+constexpr bool InstantiateTypedTestCase_P_IsDeprecated() { return true; }
+
+}  // namespace internal
+}  // namespace testing
+
+namespace std {
+// Some standard library implementations use `struct tuple_size` and some use
+// `class tuple_size`. Clang warns about the mismatch.
+// https://reviews.llvm.org/D55466
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wmismatched-tags"
+#endif
+template <typename... Ts>
+struct tuple_size<testing::internal::FlatTuple<Ts...>>
+    : std::integral_constant<size_t, sizeof...(Ts)> {};
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+}  // namespace std
+
+#define GTEST_MESSAGE_AT_(file, line, message, result_type)             \
+  ::testing::internal::AssertHelper(result_type, file, line, message) = \
+      ::testing::Message()
+
+#define GTEST_MESSAGE_(message, result_type) \
+  GTEST_MESSAGE_AT_(__FILE__, __LINE__, message, result_type)
+
+#define GTEST_FATAL_FAILURE_(message) \
+  return GTEST_MESSAGE_(message, ::testing::TestPartResult::kFatalFailure)
+
+#define GTEST_NONFATAL_FAILURE_(message) \
+  GTEST_MESSAGE_(message, ::testing::TestPartResult::kNonFatalFailure)
+
+#define GTEST_SUCCESS_(message) \
+  GTEST_MESSAGE_(message, ::testing::TestPartResult::kSuccess)
+
+#define GTEST_SKIP_(message) \
+  return GTEST_MESSAGE_(message, ::testing::TestPartResult::kSkip)
+
+// Suppress MSVC warning 4072 (unreachable code) for the code following
+// statement if it returns or throws (or doesn't return or throw in some
+// situations).
+// NOTE: The "else" is important to keep this expansion to prevent a top-level
+// "else" from attaching to our "if".
+#define GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement) \
+  if (::testing::internal::AlwaysTrue()) {                        \
+    statement;                                                    \
+  } else                     /* NOLINT */                         \
+    static_assert(true, "")  // User must have a semicolon after expansion.
+
+#if GTEST_HAS_EXCEPTIONS
+
+namespace testing {
+namespace internal {
+
+class NeverThrown {
+ public:
+  const char* what() const noexcept {
+    return "this exception should never be thrown";
+  }
+};
+
+}  // namespace internal
+}  // namespace testing
+
+#if GTEST_HAS_RTTI
+
+#define GTEST_EXCEPTION_TYPE_(e) ::testing::internal::GetTypeName(typeid(e))
+
+#else  // GTEST_HAS_RTTI
+
+#define GTEST_EXCEPTION_TYPE_(e) \
+  std::string { "an std::exception-derived error" }
+
+#endif  // GTEST_HAS_RTTI
+
+#define GTEST_TEST_THROW_CATCH_STD_EXCEPTION_(statement, expected_exception)   \
+  catch (typename std::conditional<                                            \
+         std::is_same<typename std::remove_cv<typename std::remove_reference<  \
+                          expected_exception>::type>::type,                    \
+                      std::exception>::value,                                  \
+         const ::testing::internal::NeverThrown&, const std::exception&>::type \
+             e) {                                                              \
+    gtest_msg.value = "Expected: " #statement                                  \
+                      " throws an exception of type " #expected_exception      \
+                      ".\n  Actual: it throws ";                               \
+    gtest_msg.value += GTEST_EXCEPTION_TYPE_(e);                               \
+    gtest_msg.value += " with description \"";                                 \
+    gtest_msg.value += e.what();                                               \
+    gtest_msg.value += "\".";                                                  \
+    goto GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__);                \
+  }
+
+#else  // GTEST_HAS_EXCEPTIONS
+
+#define GTEST_TEST_THROW_CATCH_STD_EXCEPTION_(statement, expected_exception)
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+#define GTEST_TEST_THROW_(statement, expected_exception, fail)              \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                             \
+  if (::testing::internal::TrueWithString gtest_msg{}) {                    \
+    bool gtest_caught_expected = false;                                     \
+    try {                                                                   \
+      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement);            \
+    } catch (expected_exception const&) {                                   \
+      gtest_caught_expected = true;                                         \
+    }                                                                       \
+    GTEST_TEST_THROW_CATCH_STD_EXCEPTION_(statement, expected_exception)    \
+    catch (...) {                                                           \
+      gtest_msg.value = "Expected: " #statement                             \
+                        " throws an exception of type " #expected_exception \
+                        ".\n  Actual: it throws a different type.";         \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__);           \
+    }                                                                       \
+    if (!gtest_caught_expected) {                                           \
+      gtest_msg.value = "Expected: " #statement                             \
+                        " throws an exception of type " #expected_exception \
+                        ".\n  Actual: it throws nothing.";                  \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__);           \
+    }                                                                       \
+  } else /*NOLINT*/                                                         \
+    GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__)                   \
+        : fail(gtest_msg.value.c_str())
+
+#if GTEST_HAS_EXCEPTIONS
+
+#define GTEST_TEST_NO_THROW_CATCH_STD_EXCEPTION_()                \
+  catch (std::exception const& e) {                               \
+    gtest_msg.value = "it throws ";                               \
+    gtest_msg.value += GTEST_EXCEPTION_TYPE_(e);                  \
+    gtest_msg.value += " with description \"";                    \
+    gtest_msg.value += e.what();                                  \
+    gtest_msg.value += "\".";                                     \
+    goto GTEST_CONCAT_TOKEN_(gtest_label_testnothrow_, __LINE__); \
+  }
+
+#else  // GTEST_HAS_EXCEPTIONS
+
+#define GTEST_TEST_NO_THROW_CATCH_STD_EXCEPTION_()
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+#define GTEST_TEST_NO_THROW_(statement, fail)                            \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                          \
+  if (::testing::internal::TrueWithString gtest_msg{}) {                 \
+    try {                                                                \
+      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement);         \
+    }                                                                    \
+    GTEST_TEST_NO_THROW_CATCH_STD_EXCEPTION_()                           \
+    catch (...) {                                                        \
+      gtest_msg.value = "it throws.";                                    \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_testnothrow_, __LINE__);      \
+    }                                                                    \
+  } else                                                                 \
+    GTEST_CONCAT_TOKEN_(gtest_label_testnothrow_, __LINE__)              \
+        : fail(("Expected: " #statement " doesn't throw an exception.\n" \
+                "  Actual: " +                                           \
+                gtest_msg.value)                                         \
+                   .c_str())
+
+#define GTEST_TEST_ANY_THROW_(statement, fail)                       \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                      \
+  if (::testing::internal::AlwaysTrue()) {                           \
+    bool gtest_caught_any = false;                                   \
+    try {                                                            \
+      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement);     \
+    } catch (...) {                                                  \
+      gtest_caught_any = true;                                       \
+    }                                                                \
+    if (!gtest_caught_any) {                                         \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_testanythrow_, __LINE__); \
+    }                                                                \
+  } else                                                             \
+    GTEST_CONCAT_TOKEN_(gtest_label_testanythrow_, __LINE__)         \
+        : fail("Expected: " #statement                               \
+               " throws an exception.\n"                             \
+               "  Actual: it doesn't.")
+
+// Implements Boolean test assertions such as EXPECT_TRUE. expression can be
+// either a boolean expression or an AssertionResult. text is a textual
+// representation of expression as it was passed into the EXPECT_TRUE.
+#define GTEST_TEST_BOOLEAN_(expression, text, actual, expected, fail) \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                       \
+  if (const ::testing::AssertionResult gtest_ar_ =                    \
+          ::testing::AssertionResult(expression))                     \
+    ;                                                                 \
+  else                                                                \
+    fail(::testing::internal::GetBoolAssertionFailureMessage(         \
+             gtest_ar_, text, #actual, #expected)                     \
+             .c_str())
+
+#define GTEST_TEST_NO_FATAL_FAILURE_(statement, fail)                          \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                                \
+  if (::testing::internal::AlwaysTrue()) {                                     \
+    ::testing::internal::HasNewFatalFailureHelper gtest_fatal_failure_checker; \
+    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement);                 \
+    if (gtest_fatal_failure_checker.has_new_fatal_failure()) {                 \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_testnofatal_, __LINE__);            \
+    }                                                                          \
+  } else                                                                       \
+    GTEST_CONCAT_TOKEN_(gtest_label_testnofatal_, __LINE__)                    \
+        : fail("Expected: " #statement                                         \
+               " doesn't generate new fatal "                                  \
+               "failures in the current thread.\n"                             \
+               "  Actual: it does.")
+
+// Expands to the name of the class that implements the given test.
+#define GTEST_TEST_CLASS_NAME_(test_suite_name, test_name) \
+  test_suite_name##_##test_name##_Test
+
+// Helper macro for defining tests.
+#define GTEST_TEST_(test_suite_name, test_name, parent_class, parent_id)       \
+  static_assert(sizeof(GTEST_STRINGIFY_(test_suite_name)) > 1,                 \
+                "test_suite_name must not be empty");                          \
+  static_assert(sizeof(GTEST_STRINGIFY_(test_name)) > 1,                       \
+                "test_name must not be empty");                                \
+  class GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)                     \
+      : public parent_class {                                                  \
+   public:                                                                     \
+    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)() = default;            \
+    ~GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)() override = default;  \
+    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)                         \
+    (const GTEST_TEST_CLASS_NAME_(test_suite_name, test_name) &) = delete;     \
+    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name) & operator=(            \
+        const GTEST_TEST_CLASS_NAME_(test_suite_name,                          \
+                                     test_name) &) = delete; /* NOLINT */      \
+    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)                         \
+    (GTEST_TEST_CLASS_NAME_(test_suite_name, test_name) &&) noexcept = delete; \
+    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name) & operator=(            \
+        GTEST_TEST_CLASS_NAME_(test_suite_name,                                \
+                               test_name) &&) noexcept = delete; /* NOLINT */  \
+                                                                               \
+   private:                                                                    \
+    void TestBody() override;                                                  \
+    static ::testing::TestInfo* const test_info_ GTEST_ATTRIBUTE_UNUSED_;      \
+  };                                                                           \
+                                                                               \
+  ::testing::TestInfo* const GTEST_TEST_CLASS_NAME_(test_suite_name,           \
+                                                    test_name)::test_info_ =   \
+      ::testing::internal::MakeAndRegisterTestInfo(                            \
+          #test_suite_name, #test_name, nullptr, nullptr,                      \
+          ::testing::internal::CodeLocation(__FILE__, __LINE__), (parent_id),  \
+          ::testing::internal::SuiteApiResolver<                               \
+              parent_class>::GetSetUpCaseOrSuite(__FILE__, __LINE__),          \
+          ::testing::internal::SuiteApiResolver<                               \
+              parent_class>::GetTearDownCaseOrSuite(__FILE__, __LINE__),       \
+          new ::testing::internal::TestFactoryImpl<GTEST_TEST_CLASS_NAME_(     \
+              test_suite_name, test_name)>);                                   \
+  void GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)::TestBody()
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
diff --git a/test/gtest/include/gtest/internal/gtest-param-util.h b/test/gtest/include/gtest/internal/gtest-param-util.h
new file mode 100644
index 0000000..e7af2f9
--- /dev/null
+++ b/test/gtest/include/gtest/internal/gtest-param-util.h
@@ -0,0 +1,956 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Type and function utilities for implementing parameterized tests.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
+#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
+
+#include <ctype.h>
+
+#include <cassert>
+#include <iterator>
+#include <memory>
+#include <set>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#include "gtest/gtest-printers.h"
+#include "gtest/gtest-test-part.h"
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-port.h"
+
+namespace testing {
+// Input to a parameterized test name generator, describing a test parameter.
+// Consists of the parameter value and the integer parameter index.
+template <class ParamType>
+struct TestParamInfo {
+  TestParamInfo(const ParamType& a_param, size_t an_index)
+      : param(a_param), index(an_index) {}
+  ParamType param;
+  size_t index;
+};
+
+// A builtin parameterized test name generator which returns the result of
+// testing::PrintToString.
+struct PrintToStringParamName {
+  template <class ParamType>
+  std::string operator()(const TestParamInfo<ParamType>& info) const {
+    return PrintToString(info.param);
+  }
+};
+
+namespace internal {
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+// Utility Functions
+
+// Outputs a message explaining invalid registration of different
+// fixture class for the same test suite. This may happen when
+// TEST_P macro is used to define two tests with the same name
+// but in different namespaces.
+GTEST_API_ void ReportInvalidTestSuiteType(const char* test_suite_name,
+                                           CodeLocation code_location);
+
+template <typename>
+class ParamGeneratorInterface;
+template <typename>
+class ParamGenerator;
+
+// Interface for iterating over elements provided by an implementation
+// of ParamGeneratorInterface<T>.
+template <typename T>
+class ParamIteratorInterface {
+ public:
+  virtual ~ParamIteratorInterface() {}
+  // A pointer to the base generator instance.
+  // Used only for the purposes of iterator comparison
+  // to make sure that two iterators belong to the same generator.
+  virtual const ParamGeneratorInterface<T>* BaseGenerator() const = 0;
+  // Advances iterator to point to the next element
+  // provided by the generator. The caller is responsible
+  // for not calling Advance() on an iterator equal to
+  // BaseGenerator()->End().
+  virtual void Advance() = 0;
+  // Clones the iterator object. Used for implementing copy semantics
+  // of ParamIterator<T>.
+  virtual ParamIteratorInterface* Clone() const = 0;
+  // Dereferences the current iterator and provides (read-only) access
+  // to the pointed value. It is the caller's responsibility not to call
+  // Current() on an iterator equal to BaseGenerator()->End().
+  // Used for implementing ParamGenerator<T>::operator*().
+  virtual const T* Current() const = 0;
+  // Determines whether the given iterator and other point to the same
+  // element in the sequence generated by the generator.
+  // Used for implementing ParamGenerator<T>::operator==().
+  virtual bool Equals(const ParamIteratorInterface& other) const = 0;
+};
+
+// Class iterating over elements provided by an implementation of
+// ParamGeneratorInterface<T>. It wraps ParamIteratorInterface<T>
+// and implements the const forward iterator concept.
+template <typename T>
+class ParamIterator {
+ public:
+  typedef T value_type;
+  typedef const T& reference;
+  typedef ptrdiff_t difference_type;
+
+  // ParamIterator assumes ownership of the impl_ pointer.
+  ParamIterator(const ParamIterator& other) : impl_(other.impl_->Clone()) {}
+  ParamIterator& operator=(const ParamIterator& other) {
+    if (this != &other) impl_.reset(other.impl_->Clone());
+    return *this;
+  }
+
+  const T& operator*() const { return *impl_->Current(); }
+  const T* operator->() const { return impl_->Current(); }
+  // Prefix version of operator++.
+  ParamIterator& operator++() {
+    impl_->Advance();
+    return *this;
+  }
+  // Postfix version of operator++.
+  ParamIterator operator++(int /*unused*/) {
+    ParamIteratorInterface<T>* clone = impl_->Clone();
+    impl_->Advance();
+    return ParamIterator(clone);
+  }
+  bool operator==(const ParamIterator& other) const {
+    return impl_.get() == other.impl_.get() || impl_->Equals(*other.impl_);
+  }
+  bool operator!=(const ParamIterator& other) const {
+    return !(*this == other);
+  }
+
+ private:
+  friend class ParamGenerator<T>;
+  explicit ParamIterator(ParamIteratorInterface<T>* impl) : impl_(impl) {}
+  std::unique_ptr<ParamIteratorInterface<T>> impl_;
+};
+
+// ParamGeneratorInterface<T> is the binary interface to access generators
+// defined in other translation units.
+template <typename T>
+class ParamGeneratorInterface {
+ public:
+  typedef T ParamType;
+
+  virtual ~ParamGeneratorInterface() {}
+
+  // Generator interface definition
+  virtual ParamIteratorInterface<T>* Begin() const = 0;
+  virtual ParamIteratorInterface<T>* End() const = 0;
+};
+
+// Wraps ParamGeneratorInterface<T> and provides general generator syntax
+// compatible with the STL Container concept.
+// This class implements copy initialization semantics and the contained
+// ParamGeneratorInterface<T> instance is shared among all copies
+// of the original object. This is possible because that instance is immutable.
+template <typename T>
+class ParamGenerator {
+ public:
+  typedef ParamIterator<T> iterator;
+
+  explicit ParamGenerator(ParamGeneratorInterface<T>* impl) : impl_(impl) {}
+  ParamGenerator(const ParamGenerator& other) : impl_(other.impl_) {}
+
+  ParamGenerator& operator=(const ParamGenerator& other) {
+    impl_ = other.impl_;
+    return *this;
+  }
+
+  iterator begin() const { return iterator(impl_->Begin()); }
+  iterator end() const { return iterator(impl_->End()); }
+
+ private:
+  std::shared_ptr<const ParamGeneratorInterface<T>> impl_;
+};
+
+// Generates values from a range of two comparable values. Can be used to
+// generate sequences of user-defined types that implement operator+() and
+// operator<().
+// This class is used in the Range() function.
+template <typename T, typename IncrementT>
+class RangeGenerator : public ParamGeneratorInterface<T> {
+ public:
+  RangeGenerator(T begin, T end, IncrementT step)
+      : begin_(begin),
+        end_(end),
+        step_(step),
+        end_index_(CalculateEndIndex(begin, end, step)) {}
+  ~RangeGenerator() override {}
+
+  ParamIteratorInterface<T>* Begin() const override {
+    return new Iterator(this, begin_, 0, step_);
+  }
+  ParamIteratorInterface<T>* End() const override {
+    return new Iterator(this, end_, end_index_, step_);
+  }
+
+ private:
+  class Iterator : public ParamIteratorInterface<T> {
+   public:
+    Iterator(const ParamGeneratorInterface<T>* base, T value, int index,
+             IncrementT step)
+        : base_(base), value_(value), index_(index), step_(step) {}
+    ~Iterator() override {}
+
+    const ParamGeneratorInterface<T>* BaseGenerator() const override {
+      return base_;
+    }
+    void Advance() override {
+      value_ = static_cast<T>(value_ + step_);
+      index_++;
+    }
+    ParamIteratorInterface<T>* Clone() const override {
+      return new Iterator(*this);
+    }
+    const T* Current() const override { return &value_; }
+    bool Equals(const ParamIteratorInterface<T>& other) const override {
+      // Having the same base generator guarantees that the other
+      // iterator is of the same type and we can downcast.
+      GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
+          << "The program attempted to compare iterators "
+          << "from different generators." << std::endl;
+      const int other_index =
+          CheckedDowncastToActualType<const Iterator>(&other)->index_;
+      return index_ == other_index;
+    }
+
+   private:
+    Iterator(const Iterator& other)
+        : ParamIteratorInterface<T>(),
+          base_(other.base_),
+          value_(other.value_),
+          index_(other.index_),
+          step_(other.step_) {}
+
+    // No implementation - assignment is unsupported.
+    void operator=(const Iterator& other);
+
+    const ParamGeneratorInterface<T>* const base_;
+    T value_;
+    int index_;
+    const IncrementT step_;
+  };  // class RangeGenerator::Iterator
+
+  static int CalculateEndIndex(const T& begin, const T& end,
+                               const IncrementT& step) {
+    int end_index = 0;
+    for (T i = begin; i < end; i = static_cast<T>(i + step)) end_index++;
+    return end_index;
+  }
+
+  // No implementation - assignment is unsupported.
+  void operator=(const RangeGenerator& other);
+
+  const T begin_;
+  const T end_;
+  const IncrementT step_;
+  // The index for the end() iterator. All the elements in the generated
+  // sequence are indexed (0-based) to aid iterator comparison.
+  const int end_index_;
+};  // class RangeGenerator
+
+// Generates values from a pair of STL-style iterators. Used in the
+// ValuesIn() function. The elements are copied from the source range
+// since the source can be located on the stack, and the generator
+// is likely to persist beyond that stack frame.
+template <typename T>
+class ValuesInIteratorRangeGenerator : public ParamGeneratorInterface<T> {
+ public:
+  template <typename ForwardIterator>
+  ValuesInIteratorRangeGenerator(ForwardIterator begin, ForwardIterator end)
+      : container_(begin, end) {}
+  ~ValuesInIteratorRangeGenerator() override {}
+
+  ParamIteratorInterface<T>* Begin() const override {
+    return new Iterator(this, container_.begin());
+  }
+  ParamIteratorInterface<T>* End() const override {
+    return new Iterator(this, container_.end());
+  }
+
+ private:
+  typedef typename ::std::vector<T> ContainerType;
+
+  class Iterator : public ParamIteratorInterface<T> {
+   public:
+    Iterator(const ParamGeneratorInterface<T>* base,
+             typename ContainerType::const_iterator iterator)
+        : base_(base), iterator_(iterator) {}
+    ~Iterator() override {}
+
+    const ParamGeneratorInterface<T>* BaseGenerator() const override {
+      return base_;
+    }
+    void Advance() override {
+      ++iterator_;
+      value_.reset();
+    }
+    ParamIteratorInterface<T>* Clone() const override {
+      return new Iterator(*this);
+    }
+    // We need to use cached value referenced by iterator_ because *iterator_
+    // can return a temporary object (and of type other then T), so just
+    // having "return &*iterator_;" doesn't work.
+    // value_ is updated here and not in Advance() because Advance()
+    // can advance iterator_ beyond the end of the range, and we cannot
+    // detect that fact. The client code, on the other hand, is
+    // responsible for not calling Current() on an out-of-range iterator.
+    const T* Current() const override {
+      if (value_.get() == nullptr) value_.reset(new T(*iterator_));
+      return value_.get();
+    }
+    bool Equals(const ParamIteratorInterface<T>& other) const override {
+      // Having the same base generator guarantees that the other
+      // iterator is of the same type and we can downcast.
+      GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
+          << "The program attempted to compare iterators "
+          << "from different generators." << std::endl;
+      return iterator_ ==
+             CheckedDowncastToActualType<const Iterator>(&other)->iterator_;
+    }
+
+   private:
+    Iterator(const Iterator& other)
+        // The explicit constructor call suppresses a false warning
+        // emitted by gcc when supplied with the -Wextra option.
+        : ParamIteratorInterface<T>(),
+          base_(other.base_),
+          iterator_(other.iterator_) {}
+
+    const ParamGeneratorInterface<T>* const base_;
+    typename ContainerType::const_iterator iterator_;
+    // A cached value of *iterator_. We keep it here to allow access by
+    // pointer in the wrapping iterator's operator->().
+    // value_ needs to be mutable to be accessed in Current().
+    // Use of std::unique_ptr helps manage cached value's lifetime,
+    // which is bound by the lifespan of the iterator itself.
+    mutable std::unique_ptr<const T> value_;
+  };  // class ValuesInIteratorRangeGenerator::Iterator
+
+  // No implementation - assignment is unsupported.
+  void operator=(const ValuesInIteratorRangeGenerator& other);
+
+  const ContainerType container_;
+};  // class ValuesInIteratorRangeGenerator
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Default parameterized test name generator, returns a string containing the
+// integer test parameter index.
+template <class ParamType>
+std::string DefaultParamName(const TestParamInfo<ParamType>& info) {
+  Message name_stream;
+  name_stream << info.index;
+  return name_stream.GetString();
+}
+
+template <typename T = int>
+void TestNotEmpty() {
+  static_assert(sizeof(T) == 0, "Empty arguments are not allowed.");
+}
+template <typename T = int>
+void TestNotEmpty(const T&) {}
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Stores a parameter value and later creates tests parameterized with that
+// value.
+template <class TestClass>
+class ParameterizedTestFactory : public TestFactoryBase {
+ public:
+  typedef typename TestClass::ParamType ParamType;
+  explicit ParameterizedTestFactory(ParamType parameter)
+      : parameter_(parameter) {}
+  Test* CreateTest() override {
+    TestClass::SetParam(&parameter_);
+    return new TestClass();
+  }
+
+ private:
+  const ParamType parameter_;
+
+  ParameterizedTestFactory(const ParameterizedTestFactory&) = delete;
+  ParameterizedTestFactory& operator=(const ParameterizedTestFactory&) = delete;
+};
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// TestMetaFactoryBase is a base class for meta-factories that create
+// test factories for passing into MakeAndRegisterTestInfo function.
+template <class ParamType>
+class TestMetaFactoryBase {
+ public:
+  virtual ~TestMetaFactoryBase() {}
+
+  virtual TestFactoryBase* CreateTestFactory(ParamType parameter) = 0;
+};
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// TestMetaFactory creates test factories for passing into
+// MakeAndRegisterTestInfo function. Since MakeAndRegisterTestInfo receives
+// ownership of test factory pointer, same factory object cannot be passed
+// into that method twice. But ParameterizedTestSuiteInfo is going to call
+// it for each Test/Parameter value combination. Thus it needs meta factory
+// creator class.
+template <class TestSuite>
+class TestMetaFactory
+    : public TestMetaFactoryBase<typename TestSuite::ParamType> {
+ public:
+  using ParamType = typename TestSuite::ParamType;
+
+  TestMetaFactory() {}
+
+  TestFactoryBase* CreateTestFactory(ParamType parameter) override {
+    return new ParameterizedTestFactory<TestSuite>(parameter);
+  }
+
+ private:
+  TestMetaFactory(const TestMetaFactory&) = delete;
+  TestMetaFactory& operator=(const TestMetaFactory&) = delete;
+};
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// ParameterizedTestSuiteInfoBase is a generic interface
+// to ParameterizedTestSuiteInfo classes. ParameterizedTestSuiteInfoBase
+// accumulates test information provided by TEST_P macro invocations
+// and generators provided by INSTANTIATE_TEST_SUITE_P macro invocations
+// and uses that information to register all resulting test instances
+// in RegisterTests method. The ParameterizeTestSuiteRegistry class holds
+// a collection of pointers to the ParameterizedTestSuiteInfo objects
+// and calls RegisterTests() on each of them when asked.
+class ParameterizedTestSuiteInfoBase {
+ public:
+  virtual ~ParameterizedTestSuiteInfoBase() {}
+
+  // Base part of test suite name for display purposes.
+  virtual const std::string& GetTestSuiteName() const = 0;
+  // Test suite id to verify identity.
+  virtual TypeId GetTestSuiteTypeId() const = 0;
+  // UnitTest class invokes this method to register tests in this
+  // test suite right before running them in RUN_ALL_TESTS macro.
+  // This method should not be called more than once on any single
+  // instance of a ParameterizedTestSuiteInfoBase derived class.
+  virtual void RegisterTests() = 0;
+
+ protected:
+  ParameterizedTestSuiteInfoBase() {}
+
+ private:
+  ParameterizedTestSuiteInfoBase(const ParameterizedTestSuiteInfoBase&) =
+      delete;
+  ParameterizedTestSuiteInfoBase& operator=(
+      const ParameterizedTestSuiteInfoBase&) = delete;
+};
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Report a the name of a test_suit as safe to ignore
+// as the side effect of construction of this type.
+struct GTEST_API_ MarkAsIgnored {
+  explicit MarkAsIgnored(const char* test_suite);
+};
+
+GTEST_API_ void InsertSyntheticTestCase(const std::string& name,
+                                        CodeLocation location, bool has_test_p);
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// ParameterizedTestSuiteInfo accumulates tests obtained from TEST_P
+// macro invocations for a particular test suite and generators
+// obtained from INSTANTIATE_TEST_SUITE_P macro invocations for that
+// test suite. It registers tests with all values generated by all
+// generators when asked.
+template <class TestSuite>
+class ParameterizedTestSuiteInfo : public ParameterizedTestSuiteInfoBase {
+ public:
+  // ParamType and GeneratorCreationFunc are private types but are required
+  // for declarations of public methods AddTestPattern() and
+  // AddTestSuiteInstantiation().
+  using ParamType = typename TestSuite::ParamType;
+  // A function that returns an instance of appropriate generator type.
+  typedef ParamGenerator<ParamType>(GeneratorCreationFunc)();
+  using ParamNameGeneratorFunc = std::string(const TestParamInfo<ParamType>&);
+
+  explicit ParameterizedTestSuiteInfo(const char* name,
+                                      CodeLocation code_location)
+      : test_suite_name_(name), code_location_(code_location) {}
+
+  // Test suite base name for display purposes.
+  const std::string& GetTestSuiteName() const override {
+    return test_suite_name_;
+  }
+  // Test suite id to verify identity.
+  TypeId GetTestSuiteTypeId() const override { return GetTypeId<TestSuite>(); }
+  // TEST_P macro uses AddTestPattern() to record information
+  // about a single test in a LocalTestInfo structure.
+  // test_suite_name is the base name of the test suite (without invocation
+  // prefix). test_base_name is the name of an individual test without
+  // parameter index. For the test SequenceA/FooTest.DoBar/1 FooTest is
+  // test suite base name and DoBar is test base name.
+  void AddTestPattern(const char* test_suite_name, const char* test_base_name,
+                      TestMetaFactoryBase<ParamType>* meta_factory,
+                      CodeLocation code_location) {
+    tests_.push_back(std::shared_ptr<TestInfo>(new TestInfo(
+        test_suite_name, test_base_name, meta_factory, code_location)));
+  }
+  // INSTANTIATE_TEST_SUITE_P macro uses AddGenerator() to record information
+  // about a generator.
+  int AddTestSuiteInstantiation(const std::string& instantiation_name,
+                                GeneratorCreationFunc* func,
+                                ParamNameGeneratorFunc* name_func,
+                                const char* file, int line) {
+    instantiations_.push_back(
+        InstantiationInfo(instantiation_name, func, name_func, file, line));
+    return 0;  // Return value used only to run this method in namespace scope.
+  }
+  // UnitTest class invokes this method to register tests in this test suite
+  // right before running tests in RUN_ALL_TESTS macro.
+  // This method should not be called more than once on any single
+  // instance of a ParameterizedTestSuiteInfoBase derived class.
+  // UnitTest has a guard to prevent from calling this method more than once.
+  void RegisterTests() override {
+    bool generated_instantiations = false;
+
+    for (typename TestInfoContainer::iterator test_it = tests_.begin();
+         test_it != tests_.end(); ++test_it) {
+      std::shared_ptr<TestInfo> test_info = *test_it;
+      for (typename InstantiationContainer::iterator gen_it =
+               instantiations_.begin();
+           gen_it != instantiations_.end(); ++gen_it) {
+        const std::string& instantiation_name = gen_it->name;
+        ParamGenerator<ParamType> generator((*gen_it->generator)());
+        ParamNameGeneratorFunc* name_func = gen_it->name_func;
+        const char* file = gen_it->file;
+        int line = gen_it->line;
+
+        std::string test_suite_name;
+        if (!instantiation_name.empty())
+          test_suite_name = instantiation_name + "/";
+        test_suite_name += test_info->test_suite_base_name;
+
+        size_t i = 0;
+        std::set<std::string> test_param_names;
+        for (typename ParamGenerator<ParamType>::iterator param_it =
+                 generator.begin();
+             param_it != generator.end(); ++param_it, ++i) {
+          generated_instantiations = true;
+
+          Message test_name_stream;
+
+          std::string param_name =
+              name_func(TestParamInfo<ParamType>(*param_it, i));
+
+          GTEST_CHECK_(IsValidParamName(param_name))
+              << "Parameterized test name '" << param_name
+              << "' is invalid, in " << file << " line " << line << std::endl;
+
+          GTEST_CHECK_(test_param_names.count(param_name) == 0)
+              << "Duplicate parameterized test name '" << param_name << "', in "
+              << file << " line " << line << std::endl;
+
+          test_param_names.insert(param_name);
+
+          if (!test_info->test_base_name.empty()) {
+            test_name_stream << test_info->test_base_name << "/";
+          }
+          test_name_stream << param_name;
+          MakeAndRegisterTestInfo(
+              test_suite_name.c_str(), test_name_stream.GetString().c_str(),
+              nullptr,  // No type parameter.
+              PrintToString(*param_it).c_str(), test_info->code_location,
+              GetTestSuiteTypeId(),
+              SuiteApiResolver<TestSuite>::GetSetUpCaseOrSuite(file, line),
+              SuiteApiResolver<TestSuite>::GetTearDownCaseOrSuite(file, line),
+              test_info->test_meta_factory->CreateTestFactory(*param_it));
+        }  // for param_it
+      }    // for gen_it
+    }      // for test_it
+
+    if (!generated_instantiations) {
+      // There are no generaotrs, or they all generate nothing ...
+      InsertSyntheticTestCase(GetTestSuiteName(), code_location_,
+                              !tests_.empty());
+    }
+  }  // RegisterTests
+
+ private:
+  // LocalTestInfo structure keeps information about a single test registered
+  // with TEST_P macro.
+  struct TestInfo {
+    TestInfo(const char* a_test_suite_base_name, const char* a_test_base_name,
+             TestMetaFactoryBase<ParamType>* a_test_meta_factory,
+             CodeLocation a_code_location)
+        : test_suite_base_name(a_test_suite_base_name),
+          test_base_name(a_test_base_name),
+          test_meta_factory(a_test_meta_factory),
+          code_location(a_code_location) {}
+
+    const std::string test_suite_base_name;
+    const std::string test_base_name;
+    const std::unique_ptr<TestMetaFactoryBase<ParamType>> test_meta_factory;
+    const CodeLocation code_location;
+  };
+  using TestInfoContainer = ::std::vector<std::shared_ptr<TestInfo>>;
+  // Records data received from INSTANTIATE_TEST_SUITE_P macros:
+  //  <Instantiation name, Sequence generator creation function,
+  //     Name generator function, Source file, Source line>
+  struct InstantiationInfo {
+    InstantiationInfo(const std::string& name_in,
+                      GeneratorCreationFunc* generator_in,
+                      ParamNameGeneratorFunc* name_func_in, const char* file_in,
+                      int line_in)
+        : name(name_in),
+          generator(generator_in),
+          name_func(name_func_in),
+          file(file_in),
+          line(line_in) {}
+
+    std::string name;
+    GeneratorCreationFunc* generator;
+    ParamNameGeneratorFunc* name_func;
+    const char* file;
+    int line;
+  };
+  typedef ::std::vector<InstantiationInfo> InstantiationContainer;
+
+  static bool IsValidParamName(const std::string& name) {
+    // Check for empty string
+    if (name.empty()) return false;
+
+    // Check for invalid characters
+    for (std::string::size_type index = 0; index < name.size(); ++index) {
+      if (!IsAlNum(name[index]) && name[index] != '_') return false;
+    }
+
+    return true;
+  }
+
+  const std::string test_suite_name_;
+  CodeLocation code_location_;
+  TestInfoContainer tests_;
+  InstantiationContainer instantiations_;
+
+  ParameterizedTestSuiteInfo(const ParameterizedTestSuiteInfo&) = delete;
+  ParameterizedTestSuiteInfo& operator=(const ParameterizedTestSuiteInfo&) =
+      delete;
+};  // class ParameterizedTestSuiteInfo
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+template <class TestCase>
+using ParameterizedTestCaseInfo = ParameterizedTestSuiteInfo<TestCase>;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// ParameterizedTestSuiteRegistry contains a map of
+// ParameterizedTestSuiteInfoBase classes accessed by test suite names. TEST_P
+// and INSTANTIATE_TEST_SUITE_P macros use it to locate their corresponding
+// ParameterizedTestSuiteInfo descriptors.
+class ParameterizedTestSuiteRegistry {
+ public:
+  ParameterizedTestSuiteRegistry() {}
+  ~ParameterizedTestSuiteRegistry() {
+    for (auto& test_suite_info : test_suite_infos_) {
+      delete test_suite_info;
+    }
+  }
+
+  // Looks up or creates and returns a structure containing information about
+  // tests and instantiations of a particular test suite.
+  template <class TestSuite>
+  ParameterizedTestSuiteInfo<TestSuite>* GetTestSuitePatternHolder(
+      const char* test_suite_name, CodeLocation code_location) {
+    ParameterizedTestSuiteInfo<TestSuite>* typed_test_info = nullptr;
+    for (auto& test_suite_info : test_suite_infos_) {
+      if (test_suite_info->GetTestSuiteName() == test_suite_name) {
+        if (test_suite_info->GetTestSuiteTypeId() != GetTypeId<TestSuite>()) {
+          // Complain about incorrect usage of Google Test facilities
+          // and terminate the program since we cannot guaranty correct
+          // test suite setup and tear-down in this case.
+          ReportInvalidTestSuiteType(test_suite_name, code_location);
+          posix::Abort();
+        } else {
+          // At this point we are sure that the object we found is of the same
+          // type we are looking for, so we downcast it to that type
+          // without further checks.
+          typed_test_info = CheckedDowncastToActualType<
+              ParameterizedTestSuiteInfo<TestSuite>>(test_suite_info);
+        }
+        break;
+      }
+    }
+    if (typed_test_info == nullptr) {
+      typed_test_info = new ParameterizedTestSuiteInfo<TestSuite>(
+          test_suite_name, code_location);
+      test_suite_infos_.push_back(typed_test_info);
+    }
+    return typed_test_info;
+  }
+  void RegisterTests() {
+    for (auto& test_suite_info : test_suite_infos_) {
+      test_suite_info->RegisterTests();
+    }
+  }
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  template <class TestCase>
+  ParameterizedTestCaseInfo<TestCase>* GetTestCasePatternHolder(
+      const char* test_case_name, CodeLocation code_location) {
+    return GetTestSuitePatternHolder<TestCase>(test_case_name, code_location);
+  }
+
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+ private:
+  using TestSuiteInfoContainer = ::std::vector<ParameterizedTestSuiteInfoBase*>;
+
+  TestSuiteInfoContainer test_suite_infos_;
+
+  ParameterizedTestSuiteRegistry(const ParameterizedTestSuiteRegistry&) =
+      delete;
+  ParameterizedTestSuiteRegistry& operator=(
+      const ParameterizedTestSuiteRegistry&) = delete;
+};
+
+// Keep track of what type-parameterized test suite are defined and
+// where as well as which are intatiated. This allows susequently
+// identifying suits that are defined but never used.
+class TypeParameterizedTestSuiteRegistry {
+ public:
+  // Add a suite definition
+  void RegisterTestSuite(const char* test_suite_name,
+                         CodeLocation code_location);
+
+  // Add an instantiation of a suit.
+  void RegisterInstantiation(const char* test_suite_name);
+
+  // For each suit repored as defined but not reported as instantiation,
+  // emit a test that reports that fact (configurably, as an error).
+  void CheckForInstantiations();
+
+ private:
+  struct TypeParameterizedTestSuiteInfo {
+    explicit TypeParameterizedTestSuiteInfo(CodeLocation c)
+        : code_location(c), instantiated(false) {}
+
+    CodeLocation code_location;
+    bool instantiated;
+  };
+
+  std::map<std::string, TypeParameterizedTestSuiteInfo> suites_;
+};
+
+}  // namespace internal
+
+// Forward declarations of ValuesIn(), which is implemented in
+// include/gtest/gtest-param-test.h.
+template <class Container>
+internal::ParamGenerator<typename Container::value_type> ValuesIn(
+    const Container& container);
+
+namespace internal {
+// Used in the Values() function to provide polymorphic capabilities.
+
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable : 4100)
+#endif
+
+template <typename... Ts>
+class ValueArray {
+ public:
+  explicit ValueArray(Ts... v) : v_(FlatTupleConstructTag{}, std::move(v)...) {}
+
+  template <typename T>
+  operator ParamGenerator<T>() const {  // NOLINT
+    return ValuesIn(MakeVector<T>(MakeIndexSequence<sizeof...(Ts)>()));
+  }
+
+ private:
+  template <typename T, size_t... I>
+  std::vector<T> MakeVector(IndexSequence<I...>) const {
+    return std::vector<T>{static_cast<T>(v_.template Get<I>())...};
+  }
+
+  FlatTuple<Ts...> v_;
+};
+
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+template <typename... T>
+class CartesianProductGenerator
+    : public ParamGeneratorInterface<::std::tuple<T...>> {
+ public:
+  typedef ::std::tuple<T...> ParamType;
+
+  CartesianProductGenerator(const std::tuple<ParamGenerator<T>...>& g)
+      : generators_(g) {}
+  ~CartesianProductGenerator() override {}
+
+  ParamIteratorInterface<ParamType>* Begin() const override {
+    return new Iterator(this, generators_, false);
+  }
+  ParamIteratorInterface<ParamType>* End() const override {
+    return new Iterator(this, generators_, true);
+  }
+
+ private:
+  template <class I>
+  class IteratorImpl;
+  template <size_t... I>
+  class IteratorImpl<IndexSequence<I...>>
+      : public ParamIteratorInterface<ParamType> {
+   public:
+    IteratorImpl(const ParamGeneratorInterface<ParamType>* base,
+                 const std::tuple<ParamGenerator<T>...>& generators,
+                 bool is_end)
+        : base_(base),
+          begin_(std::get<I>(generators).begin()...),
+          end_(std::get<I>(generators).end()...),
+          current_(is_end ? end_ : begin_) {
+      ComputeCurrentValue();
+    }
+    ~IteratorImpl() override {}
+
+    const ParamGeneratorInterface<ParamType>* BaseGenerator() const override {
+      return base_;
+    }
+    // Advance should not be called on beyond-of-range iterators
+    // so no component iterators must be beyond end of range, either.
+    void Advance() override {
+      assert(!AtEnd());
+      // Advance the last iterator.
+      ++std::get<sizeof...(T) - 1>(current_);
+      // if that reaches end, propagate that up.
+      AdvanceIfEnd<sizeof...(T) - 1>();
+      ComputeCurrentValue();
+    }
+    ParamIteratorInterface<ParamType>* Clone() const override {
+      return new IteratorImpl(*this);
+    }
+
+    const ParamType* Current() const override { return current_value_.get(); }
+
+    bool Equals(const ParamIteratorInterface<ParamType>& other) const override {
+      // Having the same base generator guarantees that the other
+      // iterator is of the same type and we can downcast.
+      GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
+          << "The program attempted to compare iterators "
+          << "from different generators." << std::endl;
+      const IteratorImpl* typed_other =
+          CheckedDowncastToActualType<const IteratorImpl>(&other);
+
+      // We must report iterators equal if they both point beyond their
+      // respective ranges. That can happen in a variety of fashions,
+      // so we have to consult AtEnd().
+      if (AtEnd() && typed_other->AtEnd()) return true;
+
+      bool same = true;
+      bool dummy[] = {
+          (same = same && std::get<I>(current_) ==
+                              std::get<I>(typed_other->current_))...};
+      (void)dummy;
+      return same;
+    }
+
+   private:
+    template <size_t ThisI>
+    void AdvanceIfEnd() {
+      if (std::get<ThisI>(current_) != std::get<ThisI>(end_)) return;
+
+      bool last = ThisI == 0;
+      if (last) {
+        // We are done. Nothing else to propagate.
+        return;
+      }
+
+      constexpr size_t NextI = ThisI - (ThisI != 0);
+      std::get<ThisI>(current_) = std::get<ThisI>(begin_);
+      ++std::get<NextI>(current_);
+      AdvanceIfEnd<NextI>();
+    }
+
+    void ComputeCurrentValue() {
+      if (!AtEnd())
+        current_value_ = std::make_shared<ParamType>(*std::get<I>(current_)...);
+    }
+    bool AtEnd() const {
+      bool at_end = false;
+      bool dummy[] = {
+          (at_end = at_end || std::get<I>(current_) == std::get<I>(end_))...};
+      (void)dummy;
+      return at_end;
+    }
+
+    const ParamGeneratorInterface<ParamType>* const base_;
+    std::tuple<typename ParamGenerator<T>::iterator...> begin_;
+    std::tuple<typename ParamGenerator<T>::iterator...> end_;
+    std::tuple<typename ParamGenerator<T>::iterator...> current_;
+    std::shared_ptr<ParamType> current_value_;
+  };
+
+  using Iterator = IteratorImpl<typename MakeIndexSequence<sizeof...(T)>::type>;
+
+  std::tuple<ParamGenerator<T>...> generators_;
+};
+
+template <class... Gen>
+class CartesianProductHolder {
+ public:
+  CartesianProductHolder(const Gen&... g) : generators_(g...) {}
+  template <typename... T>
+  operator ParamGenerator<::std::tuple<T...>>() const {
+    return ParamGenerator<::std::tuple<T...>>(
+        new CartesianProductGenerator<T...>(generators_));
+  }
+
+ private:
+  std::tuple<Gen...> generators_;
+};
+
+}  // namespace internal
+}  // namespace testing
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
diff --git a/test/gtest/include/gtest/internal/gtest-port-arch.h b/test/gtest/include/gtest/internal/gtest-port-arch.h
new file mode 100644
index 0000000..f025db7
--- /dev/null
+++ b/test/gtest/include/gtest/internal/gtest-port-arch.h
@@ -0,0 +1,116 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file defines the GTEST_OS_* macro.
+// It is separate from gtest-port.h so that custom/gtest-port.h can include it.
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_ARCH_H_
+#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_ARCH_H_
+
+// Determines the platform on which Google Test is compiled.
+#ifdef __CYGWIN__
+#define GTEST_OS_CYGWIN 1
+#elif defined(__MINGW__) || defined(__MINGW32__) || defined(__MINGW64__)
+#define GTEST_OS_WINDOWS_MINGW 1
+#define GTEST_OS_WINDOWS 1
+#elif defined _WIN32
+#define GTEST_OS_WINDOWS 1
+#ifdef _WIN32_WCE
+#define GTEST_OS_WINDOWS_MOBILE 1
+#elif defined(WINAPI_FAMILY)
+#include <winapifamily.h>
+#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
+#define GTEST_OS_WINDOWS_DESKTOP 1
+#elif WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_PHONE_APP)
+#define GTEST_OS_WINDOWS_PHONE 1
+#elif WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP)
+#define GTEST_OS_WINDOWS_RT 1
+#elif WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_TV_TITLE)
+#define GTEST_OS_WINDOWS_PHONE 1
+#define GTEST_OS_WINDOWS_TV_TITLE 1
+#else
+// WINAPI_FAMILY defined but no known partition matched.
+// Default to desktop.
+#define GTEST_OS_WINDOWS_DESKTOP 1
+#endif
+#else
+#define GTEST_OS_WINDOWS_DESKTOP 1
+#endif  // _WIN32_WCE
+#elif defined __OS2__
+#define GTEST_OS_OS2 1
+#elif defined __APPLE__
+#define GTEST_OS_MAC 1
+#include <TargetConditionals.h>
+#if TARGET_OS_IPHONE
+#define GTEST_OS_IOS 1
+#endif
+#elif defined __DragonFly__
+#define GTEST_OS_DRAGONFLY 1
+#elif defined __FreeBSD__
+#define GTEST_OS_FREEBSD 1
+#elif defined __Fuchsia__
+#define GTEST_OS_FUCHSIA 1
+#elif defined(__GNU__)
+#define GTEST_OS_GNU_HURD 1
+#elif defined(__GLIBC__) && defined(__FreeBSD_kernel__)
+#define GTEST_OS_GNU_KFREEBSD 1
+#elif defined __linux__
+#define GTEST_OS_LINUX 1
+#if defined __ANDROID__
+#define GTEST_OS_LINUX_ANDROID 1
+#endif
+#elif defined __MVS__
+#define GTEST_OS_ZOS 1
+#elif defined(__sun) && defined(__SVR4)
+#define GTEST_OS_SOLARIS 1
+#elif defined(_AIX)
+#define GTEST_OS_AIX 1
+#elif defined(__hpux)
+#define GTEST_OS_HPUX 1
+#elif defined __native_client__
+#define GTEST_OS_NACL 1
+#elif defined __NetBSD__
+#define GTEST_OS_NETBSD 1
+#elif defined __OpenBSD__
+#define GTEST_OS_OPENBSD 1
+#elif defined __QNX__
+#define GTEST_OS_QNX 1
+#elif defined(__HAIKU__)
+#define GTEST_OS_HAIKU 1
+#elif defined ESP8266
+#define GTEST_OS_ESP8266 1
+#elif defined ESP32
+#define GTEST_OS_ESP32 1
+#elif defined(__XTENSA__)
+#define GTEST_OS_XTENSA 1
+#endif  // __CYGWIN__
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_ARCH_H_
diff --git a/test/gtest/include/gtest/internal/gtest-port.h b/test/gtest/include/gtest/internal/gtest-port.h
new file mode 100644
index 0000000..0003d27
--- /dev/null
+++ b/test/gtest/include/gtest/internal/gtest-port.h
@@ -0,0 +1,2413 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Low-level types and utilities for porting Google Test to various
+// platforms.  All macros ending with _ and symbols defined in an
+// internal namespace are subject to change without notice.  Code
+// outside Google Test MUST NOT USE THEM DIRECTLY.  Macros that don't
+// end with _ are part of Google Test's public API and can be used by
+// code outside Google Test.
+//
+// This file is fundamental to Google Test.  All other Google Test source
+// files are expected to #include this.  Therefore, it cannot #include
+// any other Google Test header.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_
+#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_
+
+// Environment-describing macros
+// -----------------------------
+//
+// Google Test can be used in many different environments.  Macros in
+// this section tell Google Test what kind of environment it is being
+// used in, such that Google Test can provide environment-specific
+// features and implementations.
+//
+// Google Test tries to automatically detect the properties of its
+// environment, so users usually don't need to worry about these
+// macros.  However, the automatic detection is not perfect.
+// Sometimes it's necessary for a user to define some of the following
+// macros in the build script to override Google Test's decisions.
+//
+// If the user doesn't define a macro in the list, Google Test will
+// provide a default definition.  After this header is #included, all
+// macros in this list will be defined to either 1 or 0.
+//
+// Notes to maintainers:
+//   - Each macro here is a user-tweakable knob; do not grow the list
+//     lightly.
+//   - Use #if to key off these macros.  Don't use #ifdef or "#if
+//     defined(...)", which will not work as these macros are ALWAYS
+//     defined.
+//
+//   GTEST_HAS_CLONE          - Define it to 1/0 to indicate that clone(2)
+//                              is/isn't available.
+//   GTEST_HAS_EXCEPTIONS     - Define it to 1/0 to indicate that exceptions
+//                              are enabled.
+//   GTEST_HAS_POSIX_RE       - Define it to 1/0 to indicate that POSIX regular
+//                              expressions are/aren't available.
+//   GTEST_HAS_PTHREAD        - Define it to 1/0 to indicate that <pthread.h>
+//                              is/isn't available.
+//   GTEST_HAS_RTTI           - Define it to 1/0 to indicate that RTTI is/isn't
+//                              enabled.
+//   GTEST_HAS_STD_WSTRING    - Define it to 1/0 to indicate that
+//                              std::wstring does/doesn't work (Google Test can
+//                              be used where std::wstring is unavailable).
+//   GTEST_HAS_SEH            - Define it to 1/0 to indicate whether the
+//                              compiler supports Microsoft's "Structured
+//                              Exception Handling".
+//   GTEST_HAS_STREAM_REDIRECTION
+//                            - Define it to 1/0 to indicate whether the
+//                              platform supports I/O stream redirection using
+//                              dup() and dup2().
+//   GTEST_LINKED_AS_SHARED_LIBRARY
+//                            - Define to 1 when compiling tests that use
+//                              Google Test as a shared library (known as
+//                              DLL on Windows).
+//   GTEST_CREATE_SHARED_LIBRARY
+//                            - Define to 1 when compiling Google Test itself
+//                              as a shared library.
+//   GTEST_DEFAULT_DEATH_TEST_STYLE
+//                            - The default value of --gtest_death_test_style.
+//                              The legacy default has been "fast" in the open
+//                              source version since 2008. The recommended value
+//                              is "threadsafe", and can be set in
+//                              custom/gtest-port.h.
+
+// Platform-indicating macros
+// --------------------------
+//
+// Macros indicating the platform on which Google Test is being used
+// (a macro is defined to 1 if compiled on the given platform;
+// otherwise UNDEFINED -- it's never defined to 0.).  Google Test
+// defines these macros automatically.  Code outside Google Test MUST
+// NOT define them.
+//
+//   GTEST_OS_AIX      - IBM AIX
+//   GTEST_OS_CYGWIN   - Cygwin
+//   GTEST_OS_DRAGONFLY - DragonFlyBSD
+//   GTEST_OS_FREEBSD  - FreeBSD
+//   GTEST_OS_FUCHSIA  - Fuchsia
+//   GTEST_OS_GNU_HURD - GNU/Hurd
+//   GTEST_OS_GNU_KFREEBSD - GNU/kFreeBSD
+//   GTEST_OS_HAIKU    - Haiku
+//   GTEST_OS_HPUX     - HP-UX
+//   GTEST_OS_LINUX    - Linux
+//     GTEST_OS_LINUX_ANDROID - Google Android
+//   GTEST_OS_MAC      - Mac OS X
+//     GTEST_OS_IOS    - iOS
+//   GTEST_OS_NACL     - Google Native Client (NaCl)
+//   GTEST_OS_NETBSD   - NetBSD
+//   GTEST_OS_OPENBSD  - OpenBSD
+//   GTEST_OS_OS2      - OS/2
+//   GTEST_OS_QNX      - QNX
+//   GTEST_OS_SOLARIS  - Sun Solaris
+//   GTEST_OS_WINDOWS  - Windows (Desktop, MinGW, or Mobile)
+//     GTEST_OS_WINDOWS_DESKTOP  - Windows Desktop
+//     GTEST_OS_WINDOWS_MINGW    - MinGW
+//     GTEST_OS_WINDOWS_MOBILE   - Windows Mobile
+//     GTEST_OS_WINDOWS_PHONE    - Windows Phone
+//     GTEST_OS_WINDOWS_RT       - Windows Store App/WinRT
+//   GTEST_OS_ZOS      - z/OS
+//
+// Among the platforms, Cygwin, Linux, Mac OS X, and Windows have the
+// most stable support.  Since core members of the Google Test project
+// don't have access to other platforms, support for them may be less
+// stable.  If you notice any problems on your platform, please notify
+// googletestframework@googlegroups.com (patches for fixing them are
+// even more welcome!).
+//
+// It is possible that none of the GTEST_OS_* macros are defined.
+
+// Feature-indicating macros
+// -------------------------
+//
+// Macros indicating which Google Test features are available (a macro
+// is defined to 1 if the corresponding feature is supported;
+// otherwise UNDEFINED -- it's never defined to 0.).  Google Test
+// defines these macros automatically.  Code outside Google Test MUST
+// NOT define them.
+//
+// These macros are public so that portable tests can be written.
+// Such tests typically surround code using a feature with an #if
+// which controls that code.  For example:
+//
+// #if GTEST_HAS_DEATH_TEST
+//   EXPECT_DEATH(DoSomethingDeadly());
+// #endif
+//
+//   GTEST_HAS_DEATH_TEST   - death tests
+//   GTEST_HAS_TYPED_TEST   - typed tests
+//   GTEST_HAS_TYPED_TEST_P - type-parameterized tests
+//   GTEST_IS_THREADSAFE    - Google Test is thread-safe.
+//   GTEST_USES_RE2         - the RE2 regular expression library is used
+//   GTEST_USES_POSIX_RE    - enhanced POSIX regex is used. Do not confuse with
+//                            GTEST_HAS_POSIX_RE (see above) which users can
+//                            define themselves.
+//   GTEST_USES_SIMPLE_RE   - our own simple regex is used;
+//                            the above RE\b(s) are mutually exclusive.
+
+// Misc public macros
+// ------------------
+//
+//   GTEST_FLAG(flag_name)  - references the variable corresponding to
+//                            the given Google Test flag.
+
+// Internal utilities
+// ------------------
+//
+// The following macros and utilities are for Google Test's INTERNAL
+// use only.  Code outside Google Test MUST NOT USE THEM DIRECTLY.
+//
+// Macros for basic C++ coding:
+//   GTEST_AMBIGUOUS_ELSE_BLOCKER_ - for disabling a gcc warning.
+//   GTEST_ATTRIBUTE_UNUSED_  - declares that a class' instances or a
+//                              variable don't have to be used.
+//   GTEST_MUST_USE_RESULT_   - declares that a function's result must be used.
+//   GTEST_INTENTIONAL_CONST_COND_PUSH_ - start code section where MSVC C4127 is
+//                                        suppressed (constant conditional).
+//   GTEST_INTENTIONAL_CONST_COND_POP_  - finish code section where MSVC C4127
+//                                        is suppressed.
+//   GTEST_INTERNAL_HAS_ANY - for enabling UniversalPrinter<std::any> or
+//                            UniversalPrinter<absl::any> specializations.
+//   GTEST_INTERNAL_HAS_OPTIONAL - for enabling UniversalPrinter<std::optional>
+//   or
+//                                 UniversalPrinter<absl::optional>
+//                                 specializations.
+//   GTEST_INTERNAL_HAS_STRING_VIEW - for enabling Matcher<std::string_view> or
+//                                    Matcher<absl::string_view>
+//                                    specializations.
+//   GTEST_INTERNAL_HAS_VARIANT - for enabling UniversalPrinter<std::variant> or
+//                                UniversalPrinter<absl::variant>
+//                                specializations.
+//
+// Synchronization:
+//   Mutex, MutexLock, ThreadLocal, GetThreadCount()
+//                            - synchronization primitives.
+//
+// Regular expressions:
+//   RE             - a simple regular expression class using
+//                     1) the RE2 syntax on all platforms when built with RE2
+//                        and Abseil as dependencies
+//                     2) the POSIX Extended Regular Expression syntax on
+//                        UNIX-like platforms,
+//                     3) A reduced regular exception syntax on other platforms,
+//                        including Windows.
+// Logging:
+//   GTEST_LOG_()   - logs messages at the specified severity level.
+//   LogToStderr()  - directs all log messages to stderr.
+//   FlushInfoLog() - flushes informational log messages.
+//
+// Stdout and stderr capturing:
+//   CaptureStdout()     - starts capturing stdout.
+//   GetCapturedStdout() - stops capturing stdout and returns the captured
+//                         string.
+//   CaptureStderr()     - starts capturing stderr.
+//   GetCapturedStderr() - stops capturing stderr and returns the captured
+//                         string.
+//
+// Integer types:
+//   TypeWithSize   - maps an integer to a int type.
+//   TimeInMillis   - integers of known sizes.
+//   BiggestInt     - the biggest signed integer type.
+//
+// Command-line utilities:
+//   GetInjectableArgvs() - returns the command line as a vector of strings.
+//
+// Environment variable utilities:
+//   GetEnv()             - gets the value of an environment variable.
+//   BoolFromGTestEnv()   - parses a bool environment variable.
+//   Int32FromGTestEnv()  - parses an int32_t environment variable.
+//   StringFromGTestEnv() - parses a string environment variable.
+//
+// Deprecation warnings:
+//   GTEST_INTERNAL_DEPRECATED(message) - attribute marking a function as
+//                                        deprecated; calling a marked function
+//                                        should generate a compiler warning
+
+#include <ctype.h>   // for isspace, etc
+#include <stddef.h>  // for ptrdiff_t
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <cerrno>
+// #include <condition_variable>  // Guarded by GTEST_IS_THREADSAFE below
+#include <cstdint>
+#include <iostream>
+#include <limits>
+#include <locale>
+#include <memory>
+#include <string>
+// #include <mutex>  // Guarded by GTEST_IS_THREADSAFE below
+#include <tuple>
+#include <type_traits>
+#include <vector>
+
+#ifndef _WIN32_WCE
+#include <sys/stat.h>
+#include <sys/types.h>
+#endif  // !_WIN32_WCE
+
+#if defined __APPLE__
+#include <AvailabilityMacros.h>
+#include <TargetConditionals.h>
+#endif
+
+#include "gtest/internal/custom/gtest-port.h"
+#include "gtest/internal/gtest-port-arch.h"
+
+#if GTEST_HAS_ABSL
+#include "absl/flags/declare.h"
+#include "absl/flags/flag.h"
+#include "absl/flags/reflection.h"
+#endif
+
+#if !defined(GTEST_DEV_EMAIL_)
+#define GTEST_DEV_EMAIL_ "googletestframework@@googlegroups.com"
+#define GTEST_FLAG_PREFIX_ "gtest_"
+#define GTEST_FLAG_PREFIX_DASH_ "gtest-"
+#define GTEST_FLAG_PREFIX_UPPER_ "GTEST_"
+#define GTEST_NAME_ "Google Test"
+#define GTEST_PROJECT_URL_ "https://github.com/google/googletest/"
+#endif  // !defined(GTEST_DEV_EMAIL_)
+
+#if !defined(GTEST_INIT_GOOGLE_TEST_NAME_)
+#define GTEST_INIT_GOOGLE_TEST_NAME_ "testing::InitGoogleTest"
+#endif  // !defined(GTEST_INIT_GOOGLE_TEST_NAME_)
+
+// Determines the version of gcc that is used to compile this.
+#ifdef __GNUC__
+// 40302 means version 4.3.2.
+#define GTEST_GCC_VER_ \
+  (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
+#endif  // __GNUC__
+
+// Macros for disabling Microsoft Visual C++ warnings.
+//
+//   GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800 4385)
+//   /* code that triggers warnings C4800 and C4385 */
+//   GTEST_DISABLE_MSC_WARNINGS_POP_()
+#if defined(_MSC_VER)
+#define GTEST_DISABLE_MSC_WARNINGS_PUSH_(warnings) \
+  __pragma(warning(push)) __pragma(warning(disable : warnings))
+#define GTEST_DISABLE_MSC_WARNINGS_POP_() __pragma(warning(pop))
+#else
+// Not all compilers are MSVC
+#define GTEST_DISABLE_MSC_WARNINGS_PUSH_(warnings)
+#define GTEST_DISABLE_MSC_WARNINGS_POP_()
+#endif
+
+// Clang on Windows does not understand MSVC's pragma warning.
+// We need clang-specific way to disable function deprecation warning.
+#ifdef __clang__
+#define GTEST_DISABLE_MSC_DEPRECATED_PUSH_()                            \
+  _Pragma("clang diagnostic push")                                      \
+      _Pragma("clang diagnostic ignored \"-Wdeprecated-declarations\"") \
+          _Pragma("clang diagnostic ignored \"-Wdeprecated-implementations\"")
+#define GTEST_DISABLE_MSC_DEPRECATED_POP_() _Pragma("clang diagnostic pop")
+#else
+#define GTEST_DISABLE_MSC_DEPRECATED_PUSH_() \
+  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4996)
+#define GTEST_DISABLE_MSC_DEPRECATED_POP_() GTEST_DISABLE_MSC_WARNINGS_POP_()
+#endif
+
+// Brings in definitions for functions used in the testing::internal::posix
+// namespace (read, write, close, chdir, isatty, stat). We do not currently
+// use them on Windows Mobile.
+#if GTEST_OS_WINDOWS
+#if !GTEST_OS_WINDOWS_MOBILE
+#include <direct.h>
+#include <io.h>
+#endif
+// In order to avoid having to include <windows.h>, use forward declaration
+#if GTEST_OS_WINDOWS_MINGW && !defined(__MINGW64_VERSION_MAJOR)
+// MinGW defined _CRITICAL_SECTION and _RTL_CRITICAL_SECTION as two
+// separate (equivalent) structs, instead of using typedef
+typedef struct _CRITICAL_SECTION GTEST_CRITICAL_SECTION;
+#else
+// Assume CRITICAL_SECTION is a typedef of _RTL_CRITICAL_SECTION.
+// This assumption is verified by
+// WindowsTypesTest.CRITICAL_SECTIONIs_RTL_CRITICAL_SECTION.
+typedef struct _RTL_CRITICAL_SECTION GTEST_CRITICAL_SECTION;
+#endif
+#elif GTEST_OS_XTENSA
+#include <unistd.h>
+// Xtensa toolchains define strcasecmp in the string.h header instead of
+// strings.h. string.h is already included.
+#else
+// This assumes that non-Windows OSes provide unistd.h. For OSes where this
+// is not the case, we need to include headers that provide the functions
+// mentioned above.
+#include <strings.h>
+#include <unistd.h>
+#endif  // GTEST_OS_WINDOWS
+
+#if GTEST_OS_LINUX_ANDROID
+// Used to define __ANDROID_API__ matching the target NDK API level.
+#include <android/api-level.h>  // NOLINT
+#endif
+
+// Defines this to true if and only if Google Test can use POSIX regular
+// expressions.
+#ifndef GTEST_HAS_POSIX_RE
+#if GTEST_OS_LINUX_ANDROID
+// On Android, <regex.h> is only available starting with Gingerbread.
+#define GTEST_HAS_POSIX_RE (__ANDROID_API__ >= 9)
+#else
+#define GTEST_HAS_POSIX_RE (!GTEST_OS_WINDOWS && !GTEST_OS_XTENSA)
+#endif
+#endif
+
+// Select the regular expression implementation.
+#if GTEST_HAS_ABSL
+// When using Abseil, RE2 is required.
+#include "absl/strings/string_view.h"
+#include "re2/re2.h"
+#define GTEST_USES_RE2 1
+#elif GTEST_HAS_POSIX_RE
+#include <regex.h>  // NOLINT
+#define GTEST_USES_POSIX_RE 1
+#else
+// Use our own simple regex implementation.
+#define GTEST_USES_SIMPLE_RE 1
+#endif
+
+#ifndef GTEST_HAS_EXCEPTIONS
+// The user didn't tell us whether exceptions are enabled, so we need
+// to figure it out.
+#if defined(_MSC_VER) && defined(_CPPUNWIND)
+// MSVC defines _CPPUNWIND to 1 if and only if exceptions are enabled.
+#define GTEST_HAS_EXCEPTIONS 1
+#elif defined(__BORLANDC__)
+// C++Builder's implementation of the STL uses the _HAS_EXCEPTIONS
+// macro to enable exceptions, so we'll do the same.
+// Assumes that exceptions are enabled by default.
+#ifndef _HAS_EXCEPTIONS
+#define _HAS_EXCEPTIONS 1
+#endif  // _HAS_EXCEPTIONS
+#define GTEST_HAS_EXCEPTIONS _HAS_EXCEPTIONS
+#elif defined(__clang__)
+// clang defines __EXCEPTIONS if and only if exceptions are enabled before clang
+// 220714, but if and only if cleanups are enabled after that. In Obj-C++ files,
+// there can be cleanups for ObjC exceptions which also need cleanups, even if
+// C++ exceptions are disabled. clang has __has_feature(cxx_exceptions) which
+// checks for C++ exceptions starting at clang r206352, but which checked for
+// cleanups prior to that. To reliably check for C++ exception availability with
+// clang, check for
+// __EXCEPTIONS && __has_feature(cxx_exceptions).
+#define GTEST_HAS_EXCEPTIONS (__EXCEPTIONS && __has_feature(cxx_exceptions))
+#elif defined(__GNUC__) && __EXCEPTIONS
+// gcc defines __EXCEPTIONS to 1 if and only if exceptions are enabled.
+#define GTEST_HAS_EXCEPTIONS 1
+#elif defined(__SUNPRO_CC)
+// Sun Pro CC supports exceptions.  However, there is no compile-time way of
+// detecting whether they are enabled or not.  Therefore, we assume that
+// they are enabled unless the user tells us otherwise.
+#define GTEST_HAS_EXCEPTIONS 1
+#elif defined(__IBMCPP__) && __EXCEPTIONS
+// xlC defines __EXCEPTIONS to 1 if and only if exceptions are enabled.
+#define GTEST_HAS_EXCEPTIONS 1
+#elif defined(__HP_aCC)
+// Exception handling is in effect by default in HP aCC compiler. It has to
+// be turned of by +noeh compiler option if desired.
+#define GTEST_HAS_EXCEPTIONS 1
+#else
+// For other compilers, we assume exceptions are disabled to be
+// conservative.
+#define GTEST_HAS_EXCEPTIONS 0
+#endif  // defined(_MSC_VER) || defined(__BORLANDC__)
+#endif  // GTEST_HAS_EXCEPTIONS
+
+#ifndef GTEST_HAS_STD_WSTRING
+// The user didn't tell us whether ::std::wstring is available, so we need
+// to figure it out.
+// Cygwin 1.7 and below doesn't support ::std::wstring.
+// Solaris' libc++ doesn't support it either.  Android has
+// no support for it at least as recent as Froyo (2.2).
+#define GTEST_HAS_STD_WSTRING                                         \
+  (!(GTEST_OS_LINUX_ANDROID || GTEST_OS_CYGWIN || GTEST_OS_SOLARIS || \
+     GTEST_OS_HAIKU || GTEST_OS_ESP32 || GTEST_OS_ESP8266 || GTEST_OS_XTENSA))
+
+#endif  // GTEST_HAS_STD_WSTRING
+
+// Determines whether RTTI is available.
+#ifndef GTEST_HAS_RTTI
+// The user didn't tell us whether RTTI is enabled, so we need to
+// figure it out.
+
+#ifdef _MSC_VER
+
+#ifdef _CPPRTTI  // MSVC defines this macro if and only if RTTI is enabled.
+#define GTEST_HAS_RTTI 1
+#else
+#define GTEST_HAS_RTTI 0
+#endif
+
+// Starting with version 4.3.2, gcc defines __GXX_RTTI if and only if RTTI is
+// enabled.
+#elif defined(__GNUC__)
+
+#ifdef __GXX_RTTI
+// When building against STLport with the Android NDK and with
+// -frtti -fno-exceptions, the build fails at link time with undefined
+// references to __cxa_bad_typeid. Note sure if STL or toolchain bug,
+// so disable RTTI when detected.
+#if GTEST_OS_LINUX_ANDROID && defined(_STLPORT_MAJOR) && !defined(__EXCEPTIONS)
+#define GTEST_HAS_RTTI 0
+#else
+#define GTEST_HAS_RTTI 1
+#endif  // GTEST_OS_LINUX_ANDROID && __STLPORT_MAJOR && !__EXCEPTIONS
+#else
+#define GTEST_HAS_RTTI 0
+#endif  // __GXX_RTTI
+
+// Clang defines __GXX_RTTI starting with version 3.0, but its manual recommends
+// using has_feature instead. has_feature(cxx_rtti) is supported since 2.7, the
+// first version with C++ support.
+#elif defined(__clang__)
+
+#define GTEST_HAS_RTTI __has_feature(cxx_rtti)
+
+// Starting with version 9.0 IBM Visual Age defines __RTTI_ALL__ to 1 if
+// both the typeid and dynamic_cast features are present.
+#elif defined(__IBMCPP__) && (__IBMCPP__ >= 900)
+
+#ifdef __RTTI_ALL__
+#define GTEST_HAS_RTTI 1
+#else
+#define GTEST_HAS_RTTI 0
+#endif
+
+#else
+
+// For all other compilers, we assume RTTI is enabled.
+#define GTEST_HAS_RTTI 1
+
+#endif  // _MSC_VER
+
+#endif  // GTEST_HAS_RTTI
+
+// It's this header's responsibility to #include <typeinfo> when RTTI
+// is enabled.
+#if GTEST_HAS_RTTI
+#include <typeinfo>
+#endif
+
+// Determines whether Google Test can use the pthreads library.
+#ifndef GTEST_HAS_PTHREAD
+// The user didn't tell us explicitly, so we make reasonable assumptions about
+// which platforms have pthreads support.
+//
+// To disable threading support in Google Test, add -DGTEST_HAS_PTHREAD=0
+// to your compiler flags.
+#define GTEST_HAS_PTHREAD                                                      \
+  (GTEST_OS_LINUX || GTEST_OS_MAC || GTEST_OS_HPUX || GTEST_OS_QNX ||          \
+   GTEST_OS_FREEBSD || GTEST_OS_NACL || GTEST_OS_NETBSD || GTEST_OS_FUCHSIA || \
+   GTEST_OS_DRAGONFLY || GTEST_OS_GNU_KFREEBSD || GTEST_OS_OPENBSD ||          \
+   GTEST_OS_HAIKU || GTEST_OS_GNU_HURD)
+#endif  // GTEST_HAS_PTHREAD
+
+#if GTEST_HAS_PTHREAD
+// gtest-port.h guarantees to #include <pthread.h> when GTEST_HAS_PTHREAD is
+// true.
+#include <pthread.h>  // NOLINT
+
+// For timespec and nanosleep, used below.
+#include <time.h>  // NOLINT
+#endif
+
+// Determines whether clone(2) is supported.
+// Usually it will only be available on Linux, excluding
+// Linux on the Itanium architecture.
+// Also see http://linux.die.net/man/2/clone.
+#ifndef GTEST_HAS_CLONE
+// The user didn't tell us, so we need to figure it out.
+
+#if GTEST_OS_LINUX && !defined(__ia64__)
+#if GTEST_OS_LINUX_ANDROID
+// On Android, clone() became available at different API levels for each 32-bit
+// architecture.
+#if defined(__LP64__) || (defined(__arm__) && __ANDROID_API__ >= 9) || \
+    (defined(__mips__) && __ANDROID_API__ >= 12) ||                    \
+    (defined(__i386__) && __ANDROID_API__ >= 17)
+#define GTEST_HAS_CLONE 1
+#else
+#define GTEST_HAS_CLONE 0
+#endif
+#else
+#define GTEST_HAS_CLONE 1
+#endif
+#else
+#define GTEST_HAS_CLONE 0
+#endif  // GTEST_OS_LINUX && !defined(__ia64__)
+
+#endif  // GTEST_HAS_CLONE
+
+// Determines whether to support stream redirection. This is used to test
+// output correctness and to implement death tests.
+#ifndef GTEST_HAS_STREAM_REDIRECTION
+// By default, we assume that stream redirection is supported on all
+// platforms except known mobile ones.
+#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_PHONE || \
+    GTEST_OS_WINDOWS_RT || GTEST_OS_ESP8266 || GTEST_OS_XTENSA
+#define GTEST_HAS_STREAM_REDIRECTION 0
+#else
+#define GTEST_HAS_STREAM_REDIRECTION 1
+#endif  // !GTEST_OS_WINDOWS_MOBILE
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+
+// Determines whether to support death tests.
+// pops up a dialog window that cannot be suppressed programmatically.
+#if (GTEST_OS_LINUX || GTEST_OS_CYGWIN || GTEST_OS_SOLARIS ||             \
+     (GTEST_OS_MAC && !GTEST_OS_IOS) ||                                   \
+     (GTEST_OS_WINDOWS_DESKTOP && _MSC_VER) || GTEST_OS_WINDOWS_MINGW ||  \
+     GTEST_OS_AIX || GTEST_OS_HPUX || GTEST_OS_OPENBSD || GTEST_OS_QNX || \
+     GTEST_OS_FREEBSD || GTEST_OS_NETBSD || GTEST_OS_FUCHSIA ||           \
+     GTEST_OS_DRAGONFLY || GTEST_OS_GNU_KFREEBSD || GTEST_OS_HAIKU ||     \
+     GTEST_OS_GNU_HURD)
+#define GTEST_HAS_DEATH_TEST 1
+#endif
+
+// Determines whether to support type-driven tests.
+
+// Typed tests need <typeinfo> and variadic macros, which GCC, VC++ 8.0,
+// Sun Pro CC, IBM Visual Age, and HP aCC support.
+#if defined(__GNUC__) || defined(_MSC_VER) || defined(__SUNPRO_CC) || \
+    defined(__IBMCPP__) || defined(__HP_aCC)
+#define GTEST_HAS_TYPED_TEST 1
+#define GTEST_HAS_TYPED_TEST_P 1
+#endif
+
+// Determines whether the system compiler uses UTF-16 for encoding wide strings.
+#define GTEST_WIDE_STRING_USES_UTF16_ \
+  (GTEST_OS_WINDOWS || GTEST_OS_CYGWIN || GTEST_OS_AIX || GTEST_OS_OS2)
+
+// Determines whether test results can be streamed to a socket.
+#if GTEST_OS_LINUX || GTEST_OS_GNU_KFREEBSD || GTEST_OS_DRAGONFLY || \
+    GTEST_OS_FREEBSD || GTEST_OS_NETBSD || GTEST_OS_OPENBSD ||       \
+    GTEST_OS_GNU_HURD
+#define GTEST_CAN_STREAM_RESULTS_ 1
+#endif
+
+// Defines some utility macros.
+
+// The GNU compiler emits a warning if nested "if" statements are followed by
+// an "else" statement and braces are not used to explicitly disambiguate the
+// "else" binding.  This leads to problems with code like:
+//
+//   if (gate)
+//     ASSERT_*(condition) << "Some message";
+//
+// The "switch (0) case 0:" idiom is used to suppress this.
+#ifdef __INTEL_COMPILER
+#define GTEST_AMBIGUOUS_ELSE_BLOCKER_
+#else
+#define GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
+  switch (0)                          \
+  case 0:                             \
+  default:  // NOLINT
+#endif
+
+// Use this annotation at the end of a struct/class definition to
+// prevent the compiler from optimizing away instances that are never
+// used.  This is useful when all interesting logic happens inside the
+// c'tor and / or d'tor.  Example:
+//
+//   struct Foo {
+//     Foo() { ... }
+//   } GTEST_ATTRIBUTE_UNUSED_;
+//
+// Also use it after a variable or parameter declaration to tell the
+// compiler the variable/parameter does not have to be used.
+#if defined(__GNUC__) && !defined(COMPILER_ICC)
+#define GTEST_ATTRIBUTE_UNUSED_ __attribute__((unused))
+#elif defined(__clang__)
+#if __has_attribute(unused)
+#define GTEST_ATTRIBUTE_UNUSED_ __attribute__((unused))
+#endif
+#endif
+#ifndef GTEST_ATTRIBUTE_UNUSED_
+#define GTEST_ATTRIBUTE_UNUSED_
+#endif
+
+// Use this annotation before a function that takes a printf format string.
+#if (defined(__GNUC__) || defined(__clang__)) && !defined(COMPILER_ICC)
+#if defined(__MINGW_PRINTF_FORMAT)
+// MinGW has two different printf implementations. Ensure the format macro
+// matches the selected implementation. See
+// https://sourceforge.net/p/mingw-w64/wiki2/gnu%20printf/.
+#define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check) \
+  __attribute__((                                             \
+      __format__(__MINGW_PRINTF_FORMAT, string_index, first_to_check)))
+#else
+#define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check) \
+  __attribute__((__format__(__printf__, string_index, first_to_check)))
+#endif
+#else
+#define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check)
+#endif
+
+// Tell the compiler to warn about unused return values for functions declared
+// with this macro.  The macro should be used on function declarations
+// following the argument list:
+//
+//   Sprocket* AllocateSprocket() GTEST_MUST_USE_RESULT_;
+#if defined(__GNUC__) && !defined(COMPILER_ICC)
+#define GTEST_MUST_USE_RESULT_ __attribute__((warn_unused_result))
+#else
+#define GTEST_MUST_USE_RESULT_
+#endif  // __GNUC__ && !COMPILER_ICC
+
+// MS C++ compiler emits warning when a conditional expression is compile time
+// constant. In some contexts this warning is false positive and needs to be
+// suppressed. Use the following two macros in such cases:
+//
+// GTEST_INTENTIONAL_CONST_COND_PUSH_()
+// while (true) {
+// GTEST_INTENTIONAL_CONST_COND_POP_()
+// }
+#define GTEST_INTENTIONAL_CONST_COND_PUSH_() \
+  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4127)
+#define GTEST_INTENTIONAL_CONST_COND_POP_() GTEST_DISABLE_MSC_WARNINGS_POP_()
+
+// Determine whether the compiler supports Microsoft's Structured Exception
+// Handling.  This is supported by several Windows compilers but generally
+// does not exist on any other system.
+#ifndef GTEST_HAS_SEH
+// The user didn't tell us, so we need to figure it out.
+
+#if defined(_MSC_VER) || defined(__BORLANDC__)
+// These two compilers are known to support SEH.
+#define GTEST_HAS_SEH 1
+#else
+// Assume no SEH.
+#define GTEST_HAS_SEH 0
+#endif
+
+#endif  // GTEST_HAS_SEH
+
+#ifndef GTEST_IS_THREADSAFE
+
+#define GTEST_IS_THREADSAFE                                                 \
+  (GTEST_HAS_MUTEX_AND_THREAD_LOCAL_ ||                                     \
+   (GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT) || \
+   GTEST_HAS_PTHREAD)
+
+#endif  // GTEST_IS_THREADSAFE
+
+#if GTEST_IS_THREADSAFE
+// Some platforms don't support including these threading related headers.
+#include <condition_variable>  // NOLINT
+#include <mutex>               // NOLINT
+#endif                         // GTEST_IS_THREADSAFE
+
+// GTEST_API_ qualifies all symbols that must be exported. The definitions below
+// are guarded by #ifndef to give embedders a chance to define GTEST_API_ in
+// gtest/internal/custom/gtest-port.h
+#ifndef GTEST_API_
+
+#ifdef _MSC_VER
+#if GTEST_LINKED_AS_SHARED_LIBRARY
+#define GTEST_API_ __declspec(dllimport)
+#elif GTEST_CREATE_SHARED_LIBRARY
+#define GTEST_API_ __declspec(dllexport)
+#endif
+#elif __GNUC__ >= 4 || defined(__clang__)
+#define GTEST_API_ __attribute__((visibility("default")))
+#endif  // _MSC_VER
+
+#endif  // GTEST_API_
+
+#ifndef GTEST_API_
+#define GTEST_API_
+#endif  // GTEST_API_
+
+#ifndef GTEST_DEFAULT_DEATH_TEST_STYLE
+#define GTEST_DEFAULT_DEATH_TEST_STYLE "fast"
+#endif  // GTEST_DEFAULT_DEATH_TEST_STYLE
+
+#ifdef __GNUC__
+// Ask the compiler to never inline a given function.
+#define GTEST_NO_INLINE_ __attribute__((noinline))
+#else
+#define GTEST_NO_INLINE_
+#endif
+
+#if defined(__clang__)
+// Nested ifs to avoid triggering MSVC warning.
+#if __has_attribute(disable_tail_calls)
+// Ask the compiler not to perform tail call optimization inside
+// the marked function.
+#define GTEST_NO_TAIL_CALL_ __attribute__((disable_tail_calls))
+#endif
+#elif __GNUC__
+#define GTEST_NO_TAIL_CALL_ \
+  __attribute__((optimize("no-optimize-sibling-calls")))
+#else
+#define GTEST_NO_TAIL_CALL_
+#endif
+
+// _LIBCPP_VERSION is defined by the libc++ library from the LLVM project.
+#if !defined(GTEST_HAS_CXXABI_H_)
+#if defined(__GLIBCXX__) || (defined(_LIBCPP_VERSION) && !defined(_MSC_VER))
+#define GTEST_HAS_CXXABI_H_ 1
+#else
+#define GTEST_HAS_CXXABI_H_ 0
+#endif
+#endif
+
+// A function level attribute to disable checking for use of uninitialized
+// memory when built with MemorySanitizer.
+#if defined(__clang__)
+#if __has_feature(memory_sanitizer)
+#define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_ __attribute__((no_sanitize_memory))
+#else
+#define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
+#endif  // __has_feature(memory_sanitizer)
+#else
+#define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
+#endif  // __clang__
+
+// A function level attribute to disable AddressSanitizer instrumentation.
+#if defined(__clang__)
+#if __has_feature(address_sanitizer)
+#define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_ \
+  __attribute__((no_sanitize_address))
+#else
+#define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+#endif  // __has_feature(address_sanitizer)
+#else
+#define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+#endif  // __clang__
+
+// A function level attribute to disable HWAddressSanitizer instrumentation.
+#if defined(__clang__)
+#if __has_feature(hwaddress_sanitizer)
+#define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_ \
+  __attribute__((no_sanitize("hwaddress")))
+#else
+#define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+#endif  // __has_feature(hwaddress_sanitizer)
+#else
+#define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+#endif  // __clang__
+
+// A function level attribute to disable ThreadSanitizer instrumentation.
+#if defined(__clang__)
+#if __has_feature(thread_sanitizer)
+#define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_ __attribute__((no_sanitize_thread))
+#else
+#define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
+#endif  // __has_feature(thread_sanitizer)
+#else
+#define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
+#endif  // __clang__
+
+namespace testing {
+
+class Message;
+
+// Legacy imports for backwards compatibility.
+// New code should use std:: names directly.
+using std::get;
+using std::make_tuple;
+using std::tuple;
+using std::tuple_element;
+using std::tuple_size;
+
+namespace internal {
+
+// A secret type that Google Test users don't know about.  It has no
+// definition on purpose.  Therefore it's impossible to create a
+// Secret object, which is what we want.
+class Secret;
+
+// A helper for suppressing warnings on constant condition.  It just
+// returns 'condition'.
+GTEST_API_ bool IsTrue(bool condition);
+
+// Defines RE.
+
+#if GTEST_USES_RE2
+
+// This is almost `using RE = ::RE2`, except it is copy-constructible, and it
+// needs to disambiguate the `std::string`, `absl::string_view`, and `const
+// char*` constructors.
+class GTEST_API_ RE {
+ public:
+  RE(absl::string_view regex) : regex_(regex) {}                  // NOLINT
+  RE(const char* regex) : RE(absl::string_view(regex)) {}         // NOLINT
+  RE(const std::string& regex) : RE(absl::string_view(regex)) {}  // NOLINT
+  RE(const RE& other) : RE(other.pattern()) {}
+
+  const std::string& pattern() const { return regex_.pattern(); }
+
+  static bool FullMatch(absl::string_view str, const RE& re) {
+    return RE2::FullMatch(str, re.regex_);
+  }
+  static bool PartialMatch(absl::string_view str, const RE& re) {
+    return RE2::PartialMatch(str, re.regex_);
+  }
+
+ private:
+  RE2 regex_;
+};
+
+#elif GTEST_USES_POSIX_RE || GTEST_USES_SIMPLE_RE
+
+// A simple C++ wrapper for <regex.h>.  It uses the POSIX Extended
+// Regular Expression syntax.
+class GTEST_API_ RE {
+ public:
+  // A copy constructor is required by the Standard to initialize object
+  // references from r-values.
+  RE(const RE& other) { Init(other.pattern()); }
+
+  // Constructs an RE from a string.
+  RE(const ::std::string& regex) { Init(regex.c_str()); }  // NOLINT
+
+  RE(const char* regex) { Init(regex); }  // NOLINT
+  ~RE();
+
+  // Returns the string representation of the regex.
+  const char* pattern() const { return pattern_; }
+
+  // FullMatch(str, re) returns true if and only if regular expression re
+  // matches the entire str.
+  // PartialMatch(str, re) returns true if and only if regular expression re
+  // matches a substring of str (including str itself).
+  static bool FullMatch(const ::std::string& str, const RE& re) {
+    return FullMatch(str.c_str(), re);
+  }
+  static bool PartialMatch(const ::std::string& str, const RE& re) {
+    return PartialMatch(str.c_str(), re);
+  }
+
+  static bool FullMatch(const char* str, const RE& re);
+  static bool PartialMatch(const char* str, const RE& re);
+
+ private:
+  void Init(const char* regex);
+  const char* pattern_;
+  bool is_valid_;
+
+#if GTEST_USES_POSIX_RE
+
+  regex_t full_regex_;     // For FullMatch().
+  regex_t partial_regex_;  // For PartialMatch().
+
+#else  // GTEST_USES_SIMPLE_RE
+
+  const char* full_pattern_;  // For FullMatch();
+
+#endif
+};
+
+#endif  // ::testing::internal::RE implementation
+
+// Formats a source file path and a line number as they would appear
+// in an error message from the compiler used to compile this code.
+GTEST_API_ ::std::string FormatFileLocation(const char* file, int line);
+
+// Formats a file location for compiler-independent XML output.
+// Although this function is not platform dependent, we put it next to
+// FormatFileLocation in order to contrast the two functions.
+GTEST_API_ ::std::string FormatCompilerIndependentFileLocation(const char* file,
+                                                               int line);
+
+// Defines logging utilities:
+//   GTEST_LOG_(severity) - logs messages at the specified severity level. The
+//                          message itself is streamed into the macro.
+//   LogToStderr()  - directs all log messages to stderr.
+//   FlushInfoLog() - flushes informational log messages.
+
+enum GTestLogSeverity { GTEST_INFO, GTEST_WARNING, GTEST_ERROR, GTEST_FATAL };
+
+// Formats log entry severity, provides a stream object for streaming the
+// log message, and terminates the message with a newline when going out of
+// scope.
+class GTEST_API_ GTestLog {
+ public:
+  GTestLog(GTestLogSeverity severity, const char* file, int line);
+
+  // Flushes the buffers and, if severity is GTEST_FATAL, aborts the program.
+  ~GTestLog();
+
+  ::std::ostream& GetStream() { return ::std::cerr; }
+
+ private:
+  const GTestLogSeverity severity_;
+
+  GTestLog(const GTestLog&) = delete;
+  GTestLog& operator=(const GTestLog&) = delete;
+};
+
+#if !defined(GTEST_LOG_)
+
+#define GTEST_LOG_(severity)                                           \
+  ::testing::internal::GTestLog(::testing::internal::GTEST_##severity, \
+                                __FILE__, __LINE__)                    \
+      .GetStream()
+
+inline void LogToStderr() {}
+inline void FlushInfoLog() { fflush(nullptr); }
+
+#endif  // !defined(GTEST_LOG_)
+
+#if !defined(GTEST_CHECK_)
+// INTERNAL IMPLEMENTATION - DO NOT USE.
+//
+// GTEST_CHECK_ is an all-mode assert. It aborts the program if the condition
+// is not satisfied.
+//  Synopsis:
+//    GTEST_CHECK_(boolean_condition);
+//     or
+//    GTEST_CHECK_(boolean_condition) << "Additional message";
+//
+//    This checks the condition and if the condition is not satisfied
+//    it prints message about the condition violation, including the
+//    condition itself, plus additional message streamed into it, if any,
+//    and then it aborts the program. It aborts the program irrespective of
+//    whether it is built in the debug mode or not.
+#define GTEST_CHECK_(condition)               \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_               \
+  if (::testing::internal::IsTrue(condition)) \
+    ;                                         \
+  else                                        \
+    GTEST_LOG_(FATAL) << "Condition " #condition " failed. "
+#endif  // !defined(GTEST_CHECK_)
+
+// An all-mode assert to verify that the given POSIX-style function
+// call returns 0 (indicating success).  Known limitation: this
+// doesn't expand to a balanced 'if' statement, so enclose the macro
+// in {} if you need to use it as the only statement in an 'if'
+// branch.
+#define GTEST_CHECK_POSIX_SUCCESS_(posix_call) \
+  if (const int gtest_error = (posix_call))    \
+  GTEST_LOG_(FATAL) << #posix_call << "failed with error " << gtest_error
+
+// Transforms "T" into "const T&" according to standard reference collapsing
+// rules (this is only needed as a backport for C++98 compilers that do not
+// support reference collapsing). Specifically, it transforms:
+//
+//   char         ==> const char&
+//   const char   ==> const char&
+//   char&        ==> char&
+//   const char&  ==> const char&
+//
+// Note that the non-const reference will not have "const" added. This is
+// standard, and necessary so that "T" can always bind to "const T&".
+template <typename T>
+struct ConstRef {
+  typedef const T& type;
+};
+template <typename T>
+struct ConstRef<T&> {
+  typedef T& type;
+};
+
+// The argument T must depend on some template parameters.
+#define GTEST_REFERENCE_TO_CONST_(T) \
+  typename ::testing::internal::ConstRef<T>::type
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Use ImplicitCast_ as a safe version of static_cast for upcasting in
+// the type hierarchy (e.g. casting a Foo* to a SuperclassOfFoo* or a
+// const Foo*).  When you use ImplicitCast_, the compiler checks that
+// the cast is safe.  Such explicit ImplicitCast_s are necessary in
+// surprisingly many situations where C++ demands an exact type match
+// instead of an argument type convertible to a target type.
+//
+// The syntax for using ImplicitCast_ is the same as for static_cast:
+//
+//   ImplicitCast_<ToType>(expr)
+//
+// ImplicitCast_ would have been part of the C++ standard library,
+// but the proposal was submitted too late.  It will probably make
+// its way into the language in the future.
+//
+// This relatively ugly name is intentional. It prevents clashes with
+// similar functions users may have (e.g., implicit_cast). The internal
+// namespace alone is not enough because the function can be found by ADL.
+template <typename To>
+inline To ImplicitCast_(To x) {
+  return x;
+}
+
+// When you upcast (that is, cast a pointer from type Foo to type
+// SuperclassOfFoo), it's fine to use ImplicitCast_<>, since upcasts
+// always succeed.  When you downcast (that is, cast a pointer from
+// type Foo to type SubclassOfFoo), static_cast<> isn't safe, because
+// how do you know the pointer is really of type SubclassOfFoo?  It
+// could be a bare Foo, or of type DifferentSubclassOfFoo.  Thus,
+// when you downcast, you should use this macro.  In debug mode, we
+// use dynamic_cast<> to double-check the downcast is legal (we die
+// if it's not).  In normal mode, we do the efficient static_cast<>
+// instead.  Thus, it's important to test in debug mode to make sure
+// the cast is legal!
+//    This is the only place in the code we should use dynamic_cast<>.
+// In particular, you SHOULDN'T be using dynamic_cast<> in order to
+// do RTTI (eg code like this:
+//    if (dynamic_cast<Subclass1>(foo)) HandleASubclass1Object(foo);
+//    if (dynamic_cast<Subclass2>(foo)) HandleASubclass2Object(foo);
+// You should design the code some other way not to need this.
+//
+// This relatively ugly name is intentional. It prevents clashes with
+// similar functions users may have (e.g., down_cast). The internal
+// namespace alone is not enough because the function can be found by ADL.
+template <typename To, typename From>  // use like this: DownCast_<T*>(foo);
+inline To DownCast_(From* f) {         // so we only accept pointers
+  // Ensures that To is a sub-type of From *.  This test is here only
+  // for compile-time type checking, and has no overhead in an
+  // optimized build at run-time, as it will be optimized away
+  // completely.
+  GTEST_INTENTIONAL_CONST_COND_PUSH_()
+  if (false) {
+    GTEST_INTENTIONAL_CONST_COND_POP_()
+    const To to = nullptr;
+    ::testing::internal::ImplicitCast_<From*>(to);
+  }
+
+#if GTEST_HAS_RTTI
+  // RTTI: debug mode only!
+  GTEST_CHECK_(f == nullptr || dynamic_cast<To>(f) != nullptr);
+#endif
+  return static_cast<To>(f);
+}
+
+// Downcasts the pointer of type Base to Derived.
+// Derived must be a subclass of Base. The parameter MUST
+// point to a class of type Derived, not any subclass of it.
+// When RTTI is available, the function performs a runtime
+// check to enforce this.
+template <class Derived, class Base>
+Derived* CheckedDowncastToActualType(Base* base) {
+#if GTEST_HAS_RTTI
+  GTEST_CHECK_(typeid(*base) == typeid(Derived));
+#endif
+
+#if GTEST_HAS_DOWNCAST_
+  return ::down_cast<Derived*>(base);
+#elif GTEST_HAS_RTTI
+  return dynamic_cast<Derived*>(base);  // NOLINT
+#else
+  return static_cast<Derived*>(base);  // Poor man's downcast.
+#endif
+}
+
+#if GTEST_HAS_STREAM_REDIRECTION
+
+// Defines the stderr capturer:
+//   CaptureStdout     - starts capturing stdout.
+//   GetCapturedStdout - stops capturing stdout and returns the captured string.
+//   CaptureStderr     - starts capturing stderr.
+//   GetCapturedStderr - stops capturing stderr and returns the captured string.
+//
+GTEST_API_ void CaptureStdout();
+GTEST_API_ std::string GetCapturedStdout();
+GTEST_API_ void CaptureStderr();
+GTEST_API_ std::string GetCapturedStderr();
+
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+// Returns the size (in bytes) of a file.
+GTEST_API_ size_t GetFileSize(FILE* file);
+
+// Reads the entire content of a file as a string.
+GTEST_API_ std::string ReadEntireFile(FILE* file);
+
+// All command line arguments.
+GTEST_API_ std::vector<std::string> GetArgvs();
+
+#if GTEST_HAS_DEATH_TEST
+
+std::vector<std::string> GetInjectableArgvs();
+// Deprecated: pass the args vector by value instead.
+void SetInjectableArgvs(const std::vector<std::string>* new_argvs);
+void SetInjectableArgvs(const std::vector<std::string>& new_argvs);
+void ClearInjectableArgvs();
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+// Defines synchronization primitives.
+#if GTEST_IS_THREADSAFE
+
+#if GTEST_OS_WINDOWS
+// Provides leak-safe Windows kernel handle ownership.
+// Used in death tests and in threading support.
+class GTEST_API_ AutoHandle {
+ public:
+  // Assume that Win32 HANDLE type is equivalent to void*. Doing so allows us to
+  // avoid including <windows.h> in this header file. Including <windows.h> is
+  // undesirable because it defines a lot of symbols and macros that tend to
+  // conflict with client code. This assumption is verified by
+  // WindowsTypesTest.HANDLEIsVoidStar.
+  typedef void* Handle;
+  AutoHandle();
+  explicit AutoHandle(Handle handle);
+
+  ~AutoHandle();
+
+  Handle Get() const;
+  void Reset();
+  void Reset(Handle handle);
+
+ private:
+  // Returns true if and only if the handle is a valid handle object that can be
+  // closed.
+  bool IsCloseable() const;
+
+  Handle handle_;
+
+  AutoHandle(const AutoHandle&) = delete;
+  AutoHandle& operator=(const AutoHandle&) = delete;
+};
+#endif
+
+#if GTEST_HAS_NOTIFICATION_
+// Notification has already been imported into the namespace.
+// Nothing to do here.
+
+#else
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+// Allows a controller thread to pause execution of newly created
+// threads until notified.  Instances of this class must be created
+// and destroyed in the controller thread.
+//
+// This class is only for testing Google Test's own constructs. Do not
+// use it in user tests, either directly or indirectly.
+// TODO(b/203539622): Replace unconditionally with absl::Notification.
+class GTEST_API_ Notification {
+ public:
+  Notification() : notified_(false) {}
+  Notification(const Notification&) = delete;
+  Notification& operator=(const Notification&) = delete;
+
+  // Notifies all threads created with this notification to start. Must
+  // be called from the controller thread.
+  void Notify() {
+    std::lock_guard<std::mutex> lock(mu_);
+    notified_ = true;
+    cv_.notify_all();
+  }
+
+  // Blocks until the controller thread notifies. Must be called from a test
+  // thread.
+  void WaitForNotification() {
+    std::unique_lock<std::mutex> lock(mu_);
+    cv_.wait(lock, [this]() { return notified_; });
+  }
+
+ private:
+  std::mutex mu_;
+  std::condition_variable cv_;
+  bool notified_;
+};
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4251
+#endif  // GTEST_HAS_NOTIFICATION_
+
+// On MinGW, we can have both GTEST_OS_WINDOWS and GTEST_HAS_PTHREAD
+// defined, but we don't want to use MinGW's pthreads implementation, which
+// has conformance problems with some versions of the POSIX standard.
+#if GTEST_HAS_PTHREAD && !GTEST_OS_WINDOWS_MINGW
+
+// As a C-function, ThreadFuncWithCLinkage cannot be templated itself.
+// Consequently, it cannot select a correct instantiation of ThreadWithParam
+// in order to call its Run(). Introducing ThreadWithParamBase as a
+// non-templated base class for ThreadWithParam allows us to bypass this
+// problem.
+class ThreadWithParamBase {
+ public:
+  virtual ~ThreadWithParamBase() {}
+  virtual void Run() = 0;
+};
+
+// pthread_create() accepts a pointer to a function type with the C linkage.
+// According to the Standard (7.5/1), function types with different linkages
+// are different even if they are otherwise identical.  Some compilers (for
+// example, SunStudio) treat them as different types.  Since class methods
+// cannot be defined with C-linkage we need to define a free C-function to
+// pass into pthread_create().
+extern "C" inline void* ThreadFuncWithCLinkage(void* thread) {
+  static_cast<ThreadWithParamBase*>(thread)->Run();
+  return nullptr;
+}
+
+// Helper class for testing Google Test's multi-threading constructs.
+// To use it, write:
+//
+//   void ThreadFunc(int param) { /* Do things with param */ }
+//   Notification thread_can_start;
+//   ...
+//   // The thread_can_start parameter is optional; you can supply NULL.
+//   ThreadWithParam<int> thread(&ThreadFunc, 5, &thread_can_start);
+//   thread_can_start.Notify();
+//
+// These classes are only for testing Google Test's own constructs. Do
+// not use them in user tests, either directly or indirectly.
+template <typename T>
+class ThreadWithParam : public ThreadWithParamBase {
+ public:
+  typedef void UserThreadFunc(T);
+
+  ThreadWithParam(UserThreadFunc* func, T param, Notification* thread_can_start)
+      : func_(func),
+        param_(param),
+        thread_can_start_(thread_can_start),
+        finished_(false) {
+    ThreadWithParamBase* const base = this;
+    // The thread can be created only after all fields except thread_
+    // have been initialized.
+    GTEST_CHECK_POSIX_SUCCESS_(
+        pthread_create(&thread_, nullptr, &ThreadFuncWithCLinkage, base));
+  }
+  ~ThreadWithParam() override { Join(); }
+
+  void Join() {
+    if (!finished_) {
+      GTEST_CHECK_POSIX_SUCCESS_(pthread_join(thread_, nullptr));
+      finished_ = true;
+    }
+  }
+
+  void Run() override {
+    if (thread_can_start_ != nullptr) thread_can_start_->WaitForNotification();
+    func_(param_);
+  }
+
+ private:
+  UserThreadFunc* const func_;  // User-supplied thread function.
+  const T param_;  // User-supplied parameter to the thread function.
+  // When non-NULL, used to block execution until the controller thread
+  // notifies.
+  Notification* const thread_can_start_;
+  bool finished_;  // true if and only if we know that the thread function has
+                   // finished.
+  pthread_t thread_;  // The native thread object.
+
+  ThreadWithParam(const ThreadWithParam&) = delete;
+  ThreadWithParam& operator=(const ThreadWithParam&) = delete;
+};
+#endif  // !GTEST_OS_WINDOWS && GTEST_HAS_PTHREAD ||
+        // GTEST_HAS_MUTEX_AND_THREAD_LOCAL_
+
+#if GTEST_HAS_MUTEX_AND_THREAD_LOCAL_
+// Mutex and ThreadLocal have already been imported into the namespace.
+// Nothing to do here.
+
+#elif GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
+
+// Mutex implements mutex on Windows platforms.  It is used in conjunction
+// with class MutexLock:
+//
+//   Mutex mutex;
+//   ...
+//   MutexLock lock(&mutex);  // Acquires the mutex and releases it at the
+//                            // end of the current scope.
+//
+// A static Mutex *must* be defined or declared using one of the following
+// macros:
+//   GTEST_DEFINE_STATIC_MUTEX_(g_some_mutex);
+//   GTEST_DECLARE_STATIC_MUTEX_(g_some_mutex);
+//
+// (A non-static Mutex is defined/declared in the usual way).
+class GTEST_API_ Mutex {
+ public:
+  enum MutexType { kStatic = 0, kDynamic = 1 };
+  // We rely on kStaticMutex being 0 as it is to what the linker initializes
+  // type_ in static mutexes.  critical_section_ will be initialized lazily
+  // in ThreadSafeLazyInit().
+  enum StaticConstructorSelector { kStaticMutex = 0 };
+
+  // This constructor intentionally does nothing.  It relies on type_ being
+  // statically initialized to 0 (effectively setting it to kStatic) and on
+  // ThreadSafeLazyInit() to lazily initialize the rest of the members.
+  explicit Mutex(StaticConstructorSelector /*dummy*/) {}
+
+  Mutex();
+  ~Mutex();
+
+  void Lock();
+
+  void Unlock();
+
+  // Does nothing if the current thread holds the mutex. Otherwise, crashes
+  // with high probability.
+  void AssertHeld();
+
+ private:
+  // Initializes owner_thread_id_ and critical_section_ in static mutexes.
+  void ThreadSafeLazyInit();
+
+  // Per https://blogs.msdn.microsoft.com/oldnewthing/20040223-00/?p=40503,
+  // we assume that 0 is an invalid value for thread IDs.
+  unsigned int owner_thread_id_;
+
+  // For static mutexes, we rely on these members being initialized to zeros
+  // by the linker.
+  MutexType type_;
+  long critical_section_init_phase_;  // NOLINT
+  GTEST_CRITICAL_SECTION* critical_section_;
+
+  Mutex(const Mutex&) = delete;
+  Mutex& operator=(const Mutex&) = delete;
+};
+
+#define GTEST_DECLARE_STATIC_MUTEX_(mutex) \
+  extern ::testing::internal::Mutex mutex
+
+#define GTEST_DEFINE_STATIC_MUTEX_(mutex) \
+  ::testing::internal::Mutex mutex(::testing::internal::Mutex::kStaticMutex)
+
+// We cannot name this class MutexLock because the ctor declaration would
+// conflict with a macro named MutexLock, which is defined on some
+// platforms. That macro is used as a defensive measure to prevent against
+// inadvertent misuses of MutexLock like "MutexLock(&mu)" rather than
+// "MutexLock l(&mu)".  Hence the typedef trick below.
+class GTestMutexLock {
+ public:
+  explicit GTestMutexLock(Mutex* mutex) : mutex_(mutex) { mutex_->Lock(); }
+
+  ~GTestMutexLock() { mutex_->Unlock(); }
+
+ private:
+  Mutex* const mutex_;
+
+  GTestMutexLock(const GTestMutexLock&) = delete;
+  GTestMutexLock& operator=(const GTestMutexLock&) = delete;
+};
+
+typedef GTestMutexLock MutexLock;
+
+// Base class for ValueHolder<T>.  Allows a caller to hold and delete a value
+// without knowing its type.
+class ThreadLocalValueHolderBase {
+ public:
+  virtual ~ThreadLocalValueHolderBase() {}
+};
+
+// Provides a way for a thread to send notifications to a ThreadLocal
+// regardless of its parameter type.
+class ThreadLocalBase {
+ public:
+  // Creates a new ValueHolder<T> object holding a default value passed to
+  // this ThreadLocal<T>'s constructor and returns it.  It is the caller's
+  // responsibility not to call this when the ThreadLocal<T> instance already
+  // has a value on the current thread.
+  virtual ThreadLocalValueHolderBase* NewValueForCurrentThread() const = 0;
+
+ protected:
+  ThreadLocalBase() {}
+  virtual ~ThreadLocalBase() {}
+
+ private:
+  ThreadLocalBase(const ThreadLocalBase&) = delete;
+  ThreadLocalBase& operator=(const ThreadLocalBase&) = delete;
+};
+
+// Maps a thread to a set of ThreadLocals that have values instantiated on that
+// thread and notifies them when the thread exits.  A ThreadLocal instance is
+// expected to persist until all threads it has values on have terminated.
+class GTEST_API_ ThreadLocalRegistry {
+ public:
+  // Registers thread_local_instance as having value on the current thread.
+  // Returns a value that can be used to identify the thread from other threads.
+  static ThreadLocalValueHolderBase* GetValueOnCurrentThread(
+      const ThreadLocalBase* thread_local_instance);
+
+  // Invoked when a ThreadLocal instance is destroyed.
+  static void OnThreadLocalDestroyed(
+      const ThreadLocalBase* thread_local_instance);
+};
+
+class GTEST_API_ ThreadWithParamBase {
+ public:
+  void Join();
+
+ protected:
+  class Runnable {
+   public:
+    virtual ~Runnable() {}
+    virtual void Run() = 0;
+  };
+
+  ThreadWithParamBase(Runnable* runnable, Notification* thread_can_start);
+  virtual ~ThreadWithParamBase();
+
+ private:
+  AutoHandle thread_;
+};
+
+// Helper class for testing Google Test's multi-threading constructs.
+template <typename T>
+class ThreadWithParam : public ThreadWithParamBase {
+ public:
+  typedef void UserThreadFunc(T);
+
+  ThreadWithParam(UserThreadFunc* func, T param, Notification* thread_can_start)
+      : ThreadWithParamBase(new RunnableImpl(func, param), thread_can_start) {}
+  virtual ~ThreadWithParam() {}
+
+ private:
+  class RunnableImpl : public Runnable {
+   public:
+    RunnableImpl(UserThreadFunc* func, T param) : func_(func), param_(param) {}
+    virtual ~RunnableImpl() {}
+    virtual void Run() { func_(param_); }
+
+   private:
+    UserThreadFunc* const func_;
+    const T param_;
+
+    RunnableImpl(const RunnableImpl&) = delete;
+    RunnableImpl& operator=(const RunnableImpl&) = delete;
+  };
+
+  ThreadWithParam(const ThreadWithParam&) = delete;
+  ThreadWithParam& operator=(const ThreadWithParam&) = delete;
+};
+
+// Implements thread-local storage on Windows systems.
+//
+//   // Thread 1
+//   ThreadLocal<int> tl(100);  // 100 is the default value for each thread.
+//
+//   // Thread 2
+//   tl.set(150);  // Changes the value for thread 2 only.
+//   EXPECT_EQ(150, tl.get());
+//
+//   // Thread 1
+//   EXPECT_EQ(100, tl.get());  // In thread 1, tl has the original value.
+//   tl.set(200);
+//   EXPECT_EQ(200, tl.get());
+//
+// The template type argument T must have a public copy constructor.
+// In addition, the default ThreadLocal constructor requires T to have
+// a public default constructor.
+//
+// The users of a TheadLocal instance have to make sure that all but one
+// threads (including the main one) using that instance have exited before
+// destroying it. Otherwise, the per-thread objects managed for them by the
+// ThreadLocal instance are not guaranteed to be destroyed on all platforms.
+//
+// Google Test only uses global ThreadLocal objects.  That means they
+// will die after main() has returned.  Therefore, no per-thread
+// object managed by Google Test will be leaked as long as all threads
+// using Google Test have exited when main() returns.
+template <typename T>
+class ThreadLocal : public ThreadLocalBase {
+ public:
+  ThreadLocal() : default_factory_(new DefaultValueHolderFactory()) {}
+  explicit ThreadLocal(const T& value)
+      : default_factory_(new InstanceValueHolderFactory(value)) {}
+
+  ~ThreadLocal() override { ThreadLocalRegistry::OnThreadLocalDestroyed(this); }
+
+  T* pointer() { return GetOrCreateValue(); }
+  const T* pointer() const { return GetOrCreateValue(); }
+  const T& get() const { return *pointer(); }
+  void set(const T& value) { *pointer() = value; }
+
+ private:
+  // Holds a value of T.  Can be deleted via its base class without the caller
+  // knowing the type of T.
+  class ValueHolder : public ThreadLocalValueHolderBase {
+   public:
+    ValueHolder() : value_() {}
+    explicit ValueHolder(const T& value) : value_(value) {}
+
+    T* pointer() { return &value_; }
+
+   private:
+    T value_;
+    ValueHolder(const ValueHolder&) = delete;
+    ValueHolder& operator=(const ValueHolder&) = delete;
+  };
+
+  T* GetOrCreateValue() const {
+    return static_cast<ValueHolder*>(
+               ThreadLocalRegistry::GetValueOnCurrentThread(this))
+        ->pointer();
+  }
+
+  ThreadLocalValueHolderBase* NewValueForCurrentThread() const override {
+    return default_factory_->MakeNewHolder();
+  }
+
+  class ValueHolderFactory {
+   public:
+    ValueHolderFactory() {}
+    virtual ~ValueHolderFactory() {}
+    virtual ValueHolder* MakeNewHolder() const = 0;
+
+   private:
+    ValueHolderFactory(const ValueHolderFactory&) = delete;
+    ValueHolderFactory& operator=(const ValueHolderFactory&) = delete;
+  };
+
+  class DefaultValueHolderFactory : public ValueHolderFactory {
+   public:
+    DefaultValueHolderFactory() {}
+    ValueHolder* MakeNewHolder() const override { return new ValueHolder(); }
+
+   private:
+    DefaultValueHolderFactory(const DefaultValueHolderFactory&) = delete;
+    DefaultValueHolderFactory& operator=(const DefaultValueHolderFactory&) =
+        delete;
+  };
+
+  class InstanceValueHolderFactory : public ValueHolderFactory {
+   public:
+    explicit InstanceValueHolderFactory(const T& value) : value_(value) {}
+    ValueHolder* MakeNewHolder() const override {
+      return new ValueHolder(value_);
+    }
+
+   private:
+    const T value_;  // The value for each thread.
+
+    InstanceValueHolderFactory(const InstanceValueHolderFactory&) = delete;
+    InstanceValueHolderFactory& operator=(const InstanceValueHolderFactory&) =
+        delete;
+  };
+
+  std::unique_ptr<ValueHolderFactory> default_factory_;
+
+  ThreadLocal(const ThreadLocal&) = delete;
+  ThreadLocal& operator=(const ThreadLocal&) = delete;
+};
+
+#elif GTEST_HAS_PTHREAD
+
+// MutexBase and Mutex implement mutex on pthreads-based platforms.
+class MutexBase {
+ public:
+  // Acquires this mutex.
+  void Lock() {
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_lock(&mutex_));
+    owner_ = pthread_self();
+    has_owner_ = true;
+  }
+
+  // Releases this mutex.
+  void Unlock() {
+    // Since the lock is being released the owner_ field should no longer be
+    // considered valid. We don't protect writing to has_owner_ here, as it's
+    // the caller's responsibility to ensure that the current thread holds the
+    // mutex when this is called.
+    has_owner_ = false;
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_unlock(&mutex_));
+  }
+
+  // Does nothing if the current thread holds the mutex. Otherwise, crashes
+  // with high probability.
+  void AssertHeld() const {
+    GTEST_CHECK_(has_owner_ && pthread_equal(owner_, pthread_self()))
+        << "The current thread is not holding the mutex @" << this;
+  }
+
+  // A static mutex may be used before main() is entered.  It may even
+  // be used before the dynamic initialization stage.  Therefore we
+  // must be able to initialize a static mutex object at link time.
+  // This means MutexBase has to be a POD and its member variables
+  // have to be public.
+ public:
+  pthread_mutex_t mutex_;  // The underlying pthread mutex.
+  // has_owner_ indicates whether the owner_ field below contains a valid thread
+  // ID and is therefore safe to inspect (e.g., to use in pthread_equal()). All
+  // accesses to the owner_ field should be protected by a check of this field.
+  // An alternative might be to memset() owner_ to all zeros, but there's no
+  // guarantee that a zero'd pthread_t is necessarily invalid or even different
+  // from pthread_self().
+  bool has_owner_;
+  pthread_t owner_;  // The thread holding the mutex.
+};
+
+// Forward-declares a static mutex.
+#define GTEST_DECLARE_STATIC_MUTEX_(mutex) \
+  extern ::testing::internal::MutexBase mutex
+
+// Defines and statically (i.e. at link time) initializes a static mutex.
+// The initialization list here does not explicitly initialize each field,
+// instead relying on default initialization for the unspecified fields. In
+// particular, the owner_ field (a pthread_t) is not explicitly initialized.
+// This allows initialization to work whether pthread_t is a scalar or struct.
+// The flag -Wmissing-field-initializers must not be specified for this to work.
+#define GTEST_DEFINE_STATIC_MUTEX_(mutex) \
+  ::testing::internal::MutexBase mutex = {PTHREAD_MUTEX_INITIALIZER, false, 0}
+
+// The Mutex class can only be used for mutexes created at runtime. It
+// shares its API with MutexBase otherwise.
+class Mutex : public MutexBase {
+ public:
+  Mutex() {
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_init(&mutex_, nullptr));
+    has_owner_ = false;
+  }
+  ~Mutex() { GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_destroy(&mutex_)); }
+
+ private:
+  Mutex(const Mutex&) = delete;
+  Mutex& operator=(const Mutex&) = delete;
+};
+
+// We cannot name this class MutexLock because the ctor declaration would
+// conflict with a macro named MutexLock, which is defined on some
+// platforms. That macro is used as a defensive measure to prevent against
+// inadvertent misuses of MutexLock like "MutexLock(&mu)" rather than
+// "MutexLock l(&mu)".  Hence the typedef trick below.
+class GTestMutexLock {
+ public:
+  explicit GTestMutexLock(MutexBase* mutex) : mutex_(mutex) { mutex_->Lock(); }
+
+  ~GTestMutexLock() { mutex_->Unlock(); }
+
+ private:
+  MutexBase* const mutex_;
+
+  GTestMutexLock(const GTestMutexLock&) = delete;
+  GTestMutexLock& operator=(const GTestMutexLock&) = delete;
+};
+
+typedef GTestMutexLock MutexLock;
+
+// Helpers for ThreadLocal.
+
+// pthread_key_create() requires DeleteThreadLocalValue() to have
+// C-linkage.  Therefore it cannot be templatized to access
+// ThreadLocal<T>.  Hence the need for class
+// ThreadLocalValueHolderBase.
+class ThreadLocalValueHolderBase {
+ public:
+  virtual ~ThreadLocalValueHolderBase() {}
+};
+
+// Called by pthread to delete thread-local data stored by
+// pthread_setspecific().
+extern "C" inline void DeleteThreadLocalValue(void* value_holder) {
+  delete static_cast<ThreadLocalValueHolderBase*>(value_holder);
+}
+
+// Implements thread-local storage on pthreads-based systems.
+template <typename T>
+class GTEST_API_ ThreadLocal {
+ public:
+  ThreadLocal()
+      : key_(CreateKey()), default_factory_(new DefaultValueHolderFactory()) {}
+  explicit ThreadLocal(const T& value)
+      : key_(CreateKey()),
+        default_factory_(new InstanceValueHolderFactory(value)) {}
+
+  ~ThreadLocal() {
+    // Destroys the managed object for the current thread, if any.
+    DeleteThreadLocalValue(pthread_getspecific(key_));
+
+    // Releases resources associated with the key.  This will *not*
+    // delete managed objects for other threads.
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_key_delete(key_));
+  }
+
+  T* pointer() { return GetOrCreateValue(); }
+  const T* pointer() const { return GetOrCreateValue(); }
+  const T& get() const { return *pointer(); }
+  void set(const T& value) { *pointer() = value; }
+
+ private:
+  // Holds a value of type T.
+  class ValueHolder : public ThreadLocalValueHolderBase {
+   public:
+    ValueHolder() : value_() {}
+    explicit ValueHolder(const T& value) : value_(value) {}
+
+    T* pointer() { return &value_; }
+
+   private:
+    T value_;
+    ValueHolder(const ValueHolder&) = delete;
+    ValueHolder& operator=(const ValueHolder&) = delete;
+  };
+
+  static pthread_key_t CreateKey() {
+    pthread_key_t key;
+    // When a thread exits, DeleteThreadLocalValue() will be called on
+    // the object managed for that thread.
+    GTEST_CHECK_POSIX_SUCCESS_(
+        pthread_key_create(&key, &DeleteThreadLocalValue));
+    return key;
+  }
+
+  T* GetOrCreateValue() const {
+    ThreadLocalValueHolderBase* const holder =
+        static_cast<ThreadLocalValueHolderBase*>(pthread_getspecific(key_));
+    if (holder != nullptr) {
+      return CheckedDowncastToActualType<ValueHolder>(holder)->pointer();
+    }
+
+    ValueHolder* const new_holder = default_factory_->MakeNewHolder();
+    ThreadLocalValueHolderBase* const holder_base = new_holder;
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_setspecific(key_, holder_base));
+    return new_holder->pointer();
+  }
+
+  class ValueHolderFactory {
+   public:
+    ValueHolderFactory() {}
+    virtual ~ValueHolderFactory() {}
+    virtual ValueHolder* MakeNewHolder() const = 0;
+
+   private:
+    ValueHolderFactory(const ValueHolderFactory&) = delete;
+    ValueHolderFactory& operator=(const ValueHolderFactory&) = delete;
+  };
+
+  class DefaultValueHolderFactory : public ValueHolderFactory {
+   public:
+    DefaultValueHolderFactory() {}
+    ValueHolder* MakeNewHolder() const override { return new ValueHolder(); }
+
+   private:
+    DefaultValueHolderFactory(const DefaultValueHolderFactory&) = delete;
+    DefaultValueHolderFactory& operator=(const DefaultValueHolderFactory&) =
+        delete;
+  };
+
+  class InstanceValueHolderFactory : public ValueHolderFactory {
+   public:
+    explicit InstanceValueHolderFactory(const T& value) : value_(value) {}
+    ValueHolder* MakeNewHolder() const override {
+      return new ValueHolder(value_);
+    }
+
+   private:
+    const T value_;  // The value for each thread.
+
+    InstanceValueHolderFactory(const InstanceValueHolderFactory&) = delete;
+    InstanceValueHolderFactory& operator=(const InstanceValueHolderFactory&) =
+        delete;
+  };
+
+  // A key pthreads uses for looking up per-thread values.
+  const pthread_key_t key_;
+  std::unique_ptr<ValueHolderFactory> default_factory_;
+
+  ThreadLocal(const ThreadLocal&) = delete;
+  ThreadLocal& operator=(const ThreadLocal&) = delete;
+};
+
+#endif  // GTEST_HAS_MUTEX_AND_THREAD_LOCAL_
+
+#else  // GTEST_IS_THREADSAFE
+
+// A dummy implementation of synchronization primitives (mutex, lock,
+// and thread-local variable).  Necessary for compiling Google Test where
+// mutex is not supported - using Google Test in multiple threads is not
+// supported on such platforms.
+
+class Mutex {
+ public:
+  Mutex() {}
+  void Lock() {}
+  void Unlock() {}
+  void AssertHeld() const {}
+};
+
+#define GTEST_DECLARE_STATIC_MUTEX_(mutex) \
+  extern ::testing::internal::Mutex mutex
+
+#define GTEST_DEFINE_STATIC_MUTEX_(mutex) ::testing::internal::Mutex mutex
+
+// We cannot name this class MutexLock because the ctor declaration would
+// conflict with a macro named MutexLock, which is defined on some
+// platforms. That macro is used as a defensive measure to prevent against
+// inadvertent misuses of MutexLock like "MutexLock(&mu)" rather than
+// "MutexLock l(&mu)".  Hence the typedef trick below.
+class GTestMutexLock {
+ public:
+  explicit GTestMutexLock(Mutex*) {}  // NOLINT
+};
+
+typedef GTestMutexLock MutexLock;
+
+template <typename T>
+class GTEST_API_ ThreadLocal {
+ public:
+  ThreadLocal() : value_() {}
+  explicit ThreadLocal(const T& value) : value_(value) {}
+  T* pointer() { return &value_; }
+  const T* pointer() const { return &value_; }
+  const T& get() const { return value_; }
+  void set(const T& value) { value_ = value; }
+
+ private:
+  T value_;
+};
+
+#endif  // GTEST_IS_THREADSAFE
+
+// Returns the number of threads running in the process, or 0 to indicate that
+// we cannot detect it.
+GTEST_API_ size_t GetThreadCount();
+
+#if GTEST_OS_WINDOWS
+#define GTEST_PATH_SEP_ "\\"
+#define GTEST_HAS_ALT_PATH_SEP_ 1
+#else
+#define GTEST_PATH_SEP_ "/"
+#define GTEST_HAS_ALT_PATH_SEP_ 0
+#endif  // GTEST_OS_WINDOWS
+
+// Utilities for char.
+
+// isspace(int ch) and friends accept an unsigned char or EOF.  char
+// may be signed, depending on the compiler (or compiler flags).
+// Therefore we need to cast a char to unsigned char before calling
+// isspace(), etc.
+
+inline bool IsAlpha(char ch) {
+  return isalpha(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsAlNum(char ch) {
+  return isalnum(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsDigit(char ch) {
+  return isdigit(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsLower(char ch) {
+  return islower(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsSpace(char ch) {
+  return isspace(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsUpper(char ch) {
+  return isupper(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsXDigit(char ch) {
+  return isxdigit(static_cast<unsigned char>(ch)) != 0;
+}
+#ifdef __cpp_char8_t
+inline bool IsXDigit(char8_t ch) {
+  return isxdigit(static_cast<unsigned char>(ch)) != 0;
+}
+#endif
+inline bool IsXDigit(char16_t ch) {
+  const unsigned char low_byte = static_cast<unsigned char>(ch);
+  return ch == low_byte && isxdigit(low_byte) != 0;
+}
+inline bool IsXDigit(char32_t ch) {
+  const unsigned char low_byte = static_cast<unsigned char>(ch);
+  return ch == low_byte && isxdigit(low_byte) != 0;
+}
+inline bool IsXDigit(wchar_t ch) {
+  const unsigned char low_byte = static_cast<unsigned char>(ch);
+  return ch == low_byte && isxdigit(low_byte) != 0;
+}
+
+inline char ToLower(char ch) {
+  return static_cast<char>(tolower(static_cast<unsigned char>(ch)));
+}
+inline char ToUpper(char ch) {
+  return static_cast<char>(toupper(static_cast<unsigned char>(ch)));
+}
+
+inline std::string StripTrailingSpaces(std::string str) {
+  std::string::iterator it = str.end();
+  while (it != str.begin() && IsSpace(*--it)) it = str.erase(it);
+  return str;
+}
+
+// The testing::internal::posix namespace holds wrappers for common
+// POSIX functions.  These wrappers hide the differences between
+// Windows/MSVC and POSIX systems.  Since some compilers define these
+// standard functions as macros, the wrapper cannot have the same name
+// as the wrapped function.
+
+namespace posix {
+
+// Functions with a different name on Windows.
+
+#if GTEST_OS_WINDOWS
+
+typedef struct _stat StatStruct;
+
+#ifdef __BORLANDC__
+inline int DoIsATTY(int fd) { return isatty(fd); }
+inline int StrCaseCmp(const char* s1, const char* s2) {
+  return stricmp(s1, s2);
+}
+inline char* StrDup(const char* src) { return strdup(src); }
+#else  // !__BORLANDC__
+#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_ZOS || GTEST_OS_IOS || \
+    GTEST_OS_WINDOWS_PHONE || GTEST_OS_WINDOWS_RT || defined(ESP_PLATFORM)
+inline int DoIsATTY(int /* fd */) { return 0; }
+#else
+inline int DoIsATTY(int fd) { return _isatty(fd); }
+#endif  // GTEST_OS_WINDOWS_MOBILE
+inline int StrCaseCmp(const char* s1, const char* s2) {
+  return _stricmp(s1, s2);
+}
+inline char* StrDup(const char* src) { return _strdup(src); }
+#endif  // __BORLANDC__
+
+#if GTEST_OS_WINDOWS_MOBILE
+inline int FileNo(FILE* file) { return reinterpret_cast<int>(_fileno(file)); }
+// Stat(), RmDir(), and IsDir() are not needed on Windows CE at this
+// time and thus not defined there.
+#else
+inline int FileNo(FILE* file) { return _fileno(file); }
+inline int Stat(const char* path, StatStruct* buf) { return _stat(path, buf); }
+inline int RmDir(const char* dir) { return _rmdir(dir); }
+inline bool IsDir(const StatStruct& st) { return (_S_IFDIR & st.st_mode) != 0; }
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+#elif GTEST_OS_ESP8266
+typedef struct stat StatStruct;
+
+inline int FileNo(FILE* file) { return fileno(file); }
+inline int DoIsATTY(int fd) { return isatty(fd); }
+inline int Stat(const char* path, StatStruct* buf) {
+  // stat function not implemented on ESP8266
+  return 0;
+}
+inline int StrCaseCmp(const char* s1, const char* s2) {
+  return strcasecmp(s1, s2);
+}
+inline char* StrDup(const char* src) { return strdup(src); }
+inline int RmDir(const char* dir) { return rmdir(dir); }
+inline bool IsDir(const StatStruct& st) { return S_ISDIR(st.st_mode); }
+
+#else
+
+typedef struct stat StatStruct;
+
+inline int FileNo(FILE* file) { return fileno(file); }
+inline int DoIsATTY(int fd) { return isatty(fd); }
+inline int Stat(const char* path, StatStruct* buf) { return stat(path, buf); }
+inline int StrCaseCmp(const char* s1, const char* s2) {
+  return strcasecmp(s1, s2);
+}
+inline char* StrDup(const char* src) { return strdup(src); }
+inline int RmDir(const char* dir) { return rmdir(dir); }
+inline bool IsDir(const StatStruct& st) { return S_ISDIR(st.st_mode); }
+
+#endif  // GTEST_OS_WINDOWS
+
+inline int IsATTY(int fd) {
+  // DoIsATTY might change errno (for example ENOTTY in case you redirect stdout
+  // to a file on Linux), which is unexpected, so save the previous value, and
+  // restore it after the call.
+  int savedErrno = errno;
+  int isAttyValue = DoIsATTY(fd);
+  errno = savedErrno;
+
+  return isAttyValue;
+}
+
+// Functions deprecated by MSVC 8.0.
+
+GTEST_DISABLE_MSC_DEPRECATED_PUSH_()
+
+// ChDir(), FReopen(), FDOpen(), Read(), Write(), Close(), and
+// StrError() aren't needed on Windows CE at this time and thus not
+// defined there.
+
+#if !GTEST_OS_WINDOWS_MOBILE && !GTEST_OS_WINDOWS_PHONE && \
+    !GTEST_OS_WINDOWS_RT && !GTEST_OS_ESP8266 && !GTEST_OS_XTENSA
+inline int ChDir(const char* dir) { return chdir(dir); }
+#endif
+inline FILE* FOpen(const char* path, const char* mode) {
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
+  struct wchar_codecvt : public std::codecvt<wchar_t, char, std::mbstate_t> {};
+  std::wstring_convert<wchar_codecvt> converter;
+  std::wstring wide_path = converter.from_bytes(path);
+  std::wstring wide_mode = converter.from_bytes(mode);
+  return _wfopen(wide_path.c_str(), wide_mode.c_str());
+#else   // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
+  return fopen(path, mode);
+#endif  // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
+}
+#if !GTEST_OS_WINDOWS_MOBILE
+inline FILE* FReopen(const char* path, const char* mode, FILE* stream) {
+  return freopen(path, mode, stream);
+}
+inline FILE* FDOpen(int fd, const char* mode) { return fdopen(fd, mode); }
+#endif
+inline int FClose(FILE* fp) { return fclose(fp); }
+#if !GTEST_OS_WINDOWS_MOBILE
+inline int Read(int fd, void* buf, unsigned int count) {
+  return static_cast<int>(read(fd, buf, count));
+}
+inline int Write(int fd, const void* buf, unsigned int count) {
+  return static_cast<int>(write(fd, buf, count));
+}
+inline int Close(int fd) { return close(fd); }
+inline const char* StrError(int errnum) { return strerror(errnum); }
+#endif
+inline const char* GetEnv(const char* name) {
+#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_PHONE || \
+    GTEST_OS_WINDOWS_RT || GTEST_OS_ESP8266 || GTEST_OS_XTENSA
+  // We are on an embedded platform, which has no environment variables.
+  static_cast<void>(name);  // To prevent 'unused argument' warning.
+  return nullptr;
+#elif defined(__BORLANDC__) || defined(__SunOS_5_8) || defined(__SunOS_5_9)
+  // Environment variables which we programmatically clear will be set to the
+  // empty string rather than unset (NULL).  Handle that case.
+  const char* const env = getenv(name);
+  return (env != nullptr && env[0] != '\0') ? env : nullptr;
+#else
+  return getenv(name);
+#endif
+}
+
+GTEST_DISABLE_MSC_DEPRECATED_POP_()
+
+#if GTEST_OS_WINDOWS_MOBILE
+// Windows CE has no C library. The abort() function is used in
+// several places in Google Test. This implementation provides a reasonable
+// imitation of standard behaviour.
+[[noreturn]] void Abort();
+#else
+[[noreturn]] inline void Abort() { abort(); }
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+}  // namespace posix
+
+// MSVC "deprecates" snprintf and issues warnings wherever it is used.  In
+// order to avoid these warnings, we need to use _snprintf or _snprintf_s on
+// MSVC-based platforms.  We map the GTEST_SNPRINTF_ macro to the appropriate
+// function in order to achieve that.  We use macro definition here because
+// snprintf is a variadic function.
+#if _MSC_VER && !GTEST_OS_WINDOWS_MOBILE
+// MSVC 2005 and above support variadic macros.
+#define GTEST_SNPRINTF_(buffer, size, format, ...) \
+  _snprintf_s(buffer, size, size, format, __VA_ARGS__)
+#elif defined(_MSC_VER)
+// Windows CE does not define _snprintf_s
+#define GTEST_SNPRINTF_ _snprintf
+#else
+#define GTEST_SNPRINTF_ snprintf
+#endif
+
+// The biggest signed integer type the compiler supports.
+//
+// long long is guaranteed to be at least 64-bits in C++11.
+using BiggestInt = long long;  // NOLINT
+
+// The maximum number a BiggestInt can represent.
+constexpr BiggestInt kMaxBiggestInt = (std::numeric_limits<BiggestInt>::max)();
+
+// This template class serves as a compile-time function from size to
+// type.  It maps a size in bytes to a primitive type with that
+// size. e.g.
+//
+//   TypeWithSize<4>::UInt
+//
+// is typedef-ed to be unsigned int (unsigned integer made up of 4
+// bytes).
+//
+// Such functionality should belong to STL, but I cannot find it
+// there.
+//
+// Google Test uses this class in the implementation of floating-point
+// comparison.
+//
+// For now it only handles UInt (unsigned int) as that's all Google Test
+// needs.  Other types can be easily added in the future if need
+// arises.
+template <size_t size>
+class TypeWithSize {
+ public:
+  // This prevents the user from using TypeWithSize<N> with incorrect
+  // values of N.
+  using UInt = void;
+};
+
+// The specialization for size 4.
+template <>
+class TypeWithSize<4> {
+ public:
+  using Int = std::int32_t;
+  using UInt = std::uint32_t;
+};
+
+// The specialization for size 8.
+template <>
+class TypeWithSize<8> {
+ public:
+  using Int = std::int64_t;
+  using UInt = std::uint64_t;
+};
+
+// Integer types of known sizes.
+using TimeInMillis = int64_t;  // Represents time in milliseconds.
+
+// Utilities for command line flags and environment variables.
+
+// Macro for referencing flags.
+#if !defined(GTEST_FLAG)
+#define GTEST_FLAG_NAME_(name) gtest_##name
+#define GTEST_FLAG(name) FLAGS_gtest_##name
+#endif  // !defined(GTEST_FLAG)
+
+// Pick a command line flags implementation.
+#if GTEST_HAS_ABSL
+
+// Macros for defining flags.
+#define GTEST_DEFINE_bool_(name, default_val, doc) \
+  ABSL_FLAG(bool, GTEST_FLAG_NAME_(name), default_val, doc)
+#define GTEST_DEFINE_int32_(name, default_val, doc) \
+  ABSL_FLAG(int32_t, GTEST_FLAG_NAME_(name), default_val, doc)
+#define GTEST_DEFINE_string_(name, default_val, doc) \
+  ABSL_FLAG(std::string, GTEST_FLAG_NAME_(name), default_val, doc)
+
+// Macros for declaring flags.
+#define GTEST_DECLARE_bool_(name) \
+  ABSL_DECLARE_FLAG(bool, GTEST_FLAG_NAME_(name))
+#define GTEST_DECLARE_int32_(name) \
+  ABSL_DECLARE_FLAG(int32_t, GTEST_FLAG_NAME_(name))
+#define GTEST_DECLARE_string_(name) \
+  ABSL_DECLARE_FLAG(std::string, GTEST_FLAG_NAME_(name))
+
+#define GTEST_FLAG_SAVER_ ::absl::FlagSaver
+
+#define GTEST_FLAG_GET(name) ::absl::GetFlag(GTEST_FLAG(name))
+#define GTEST_FLAG_SET(name, value) \
+  (void)(::absl::SetFlag(&GTEST_FLAG(name), value))
+#define GTEST_USE_OWN_FLAGFILE_FLAG_ 0
+
+#else  // GTEST_HAS_ABSL
+
+// Macros for defining flags.
+#define GTEST_DEFINE_bool_(name, default_val, doc)  \
+  namespace testing {                               \
+  GTEST_API_ bool GTEST_FLAG(name) = (default_val); \
+  }                                                 \
+  static_assert(true, "no-op to require trailing semicolon")
+#define GTEST_DEFINE_int32_(name, default_val, doc)         \
+  namespace testing {                                       \
+  GTEST_API_ std::int32_t GTEST_FLAG(name) = (default_val); \
+  }                                                         \
+  static_assert(true, "no-op to require trailing semicolon")
+#define GTEST_DEFINE_string_(name, default_val, doc)         \
+  namespace testing {                                        \
+  GTEST_API_ ::std::string GTEST_FLAG(name) = (default_val); \
+  }                                                          \
+  static_assert(true, "no-op to require trailing semicolon")
+
+// Macros for declaring flags.
+#define GTEST_DECLARE_bool_(name)          \
+  namespace testing {                      \
+  GTEST_API_ extern bool GTEST_FLAG(name); \
+  }                                        \
+  static_assert(true, "no-op to require trailing semicolon")
+#define GTEST_DECLARE_int32_(name)                 \
+  namespace testing {                              \
+  GTEST_API_ extern std::int32_t GTEST_FLAG(name); \
+  }                                                \
+  static_assert(true, "no-op to require trailing semicolon")
+#define GTEST_DECLARE_string_(name)                 \
+  namespace testing {                               \
+  GTEST_API_ extern ::std::string GTEST_FLAG(name); \
+  }                                                 \
+  static_assert(true, "no-op to require trailing semicolon")
+
+#define GTEST_FLAG_SAVER_ ::testing::internal::GTestFlagSaver
+
+#define GTEST_FLAG_GET(name) ::testing::GTEST_FLAG(name)
+#define GTEST_FLAG_SET(name, value) (void)(::testing::GTEST_FLAG(name) = value)
+#define GTEST_USE_OWN_FLAGFILE_FLAG_ 1
+
+#endif  // GTEST_HAS_ABSL
+
+// Thread annotations
+#if !defined(GTEST_EXCLUSIVE_LOCK_REQUIRED_)
+#define GTEST_EXCLUSIVE_LOCK_REQUIRED_(locks)
+#define GTEST_LOCK_EXCLUDED_(locks)
+#endif  // !defined(GTEST_EXCLUSIVE_LOCK_REQUIRED_)
+
+// Parses 'str' for a 32-bit signed integer.  If successful, writes the result
+// to *value and returns true; otherwise leaves *value unchanged and returns
+// false.
+GTEST_API_ bool ParseInt32(const Message& src_text, const char* str,
+                           int32_t* value);
+
+// Parses a bool/int32_t/string from the environment variable
+// corresponding to the given Google Test flag.
+bool BoolFromGTestEnv(const char* flag, bool default_val);
+GTEST_API_ int32_t Int32FromGTestEnv(const char* flag, int32_t default_val);
+std::string OutputFlagAlsoCheckEnvVar();
+const char* StringFromGTestEnv(const char* flag, const char* default_val);
+
+}  // namespace internal
+}  // namespace testing
+
+#if !defined(GTEST_INTERNAL_DEPRECATED)
+
+// Internal Macro to mark an API deprecated, for googletest usage only
+// Usage: class GTEST_INTERNAL_DEPRECATED(message) MyClass or
+// GTEST_INTERNAL_DEPRECATED(message) <return_type> myFunction(); Every usage of
+// a deprecated entity will trigger a warning when compiled with
+// `-Wdeprecated-declarations` option (clang, gcc, any __GNUC__ compiler).
+// For msvc /W3 option will need to be used
+// Note that for 'other' compilers this macro evaluates to nothing to prevent
+// compilations errors.
+#if defined(_MSC_VER)
+#define GTEST_INTERNAL_DEPRECATED(message) __declspec(deprecated(message))
+#elif defined(__GNUC__)
+#define GTEST_INTERNAL_DEPRECATED(message) __attribute__((deprecated(message)))
+#else
+#define GTEST_INTERNAL_DEPRECATED(message)
+#endif
+
+#endif  // !defined(GTEST_INTERNAL_DEPRECATED)
+
+#if GTEST_HAS_ABSL
+// Always use absl::any for UniversalPrinter<> specializations if googletest
+// is built with absl support.
+#define GTEST_INTERNAL_HAS_ANY 1
+#include "absl/types/any.h"
+namespace testing {
+namespace internal {
+using Any = ::absl::any;
+}  // namespace internal
+}  // namespace testing
+#else
+#ifdef __has_include
+#if __has_include(<any>) && __cplusplus >= 201703L
+// Otherwise for C++17 and higher use std::any for UniversalPrinter<>
+// specializations.
+#define GTEST_INTERNAL_HAS_ANY 1
+#include <any>
+namespace testing {
+namespace internal {
+using Any = ::std::any;
+}  // namespace internal
+}  // namespace testing
+// The case where absl is configured NOT to alias std::any is not
+// supported.
+#endif  // __has_include(<any>) && __cplusplus >= 201703L
+#endif  // __has_include
+#endif  // GTEST_HAS_ABSL
+
+#if GTEST_HAS_ABSL
+// Always use absl::optional for UniversalPrinter<> specializations if
+// googletest is built with absl support.
+#define GTEST_INTERNAL_HAS_OPTIONAL 1
+#include "absl/types/optional.h"
+namespace testing {
+namespace internal {
+template <typename T>
+using Optional = ::absl::optional<T>;
+inline ::absl::nullopt_t Nullopt() { return ::absl::nullopt; }
+}  // namespace internal
+}  // namespace testing
+#else
+#ifdef __has_include
+#if __has_include(<optional>) && __cplusplus >= 201703L
+// Otherwise for C++17 and higher use std::optional for UniversalPrinter<>
+// specializations.
+#define GTEST_INTERNAL_HAS_OPTIONAL 1
+#include <optional>
+namespace testing {
+namespace internal {
+template <typename T>
+using Optional = ::std::optional<T>;
+inline ::std::nullopt_t Nullopt() { return ::std::nullopt; }
+}  // namespace internal
+}  // namespace testing
+// The case where absl is configured NOT to alias std::optional is not
+// supported.
+#endif  // __has_include(<optional>) && __cplusplus >= 201703L
+#endif  // __has_include
+#endif  // GTEST_HAS_ABSL
+
+#if GTEST_HAS_ABSL
+// Always use absl::string_view for Matcher<> specializations if googletest
+// is built with absl support.
+#define GTEST_INTERNAL_HAS_STRING_VIEW 1
+#include "absl/strings/string_view.h"
+namespace testing {
+namespace internal {
+using StringView = ::absl::string_view;
+}  // namespace internal
+}  // namespace testing
+#else
+#ifdef __has_include
+#if __has_include(<string_view>) && __cplusplus >= 201703L
+// Otherwise for C++17 and higher use std::string_view for Matcher<>
+// specializations.
+#define GTEST_INTERNAL_HAS_STRING_VIEW 1
+#include <string_view>
+namespace testing {
+namespace internal {
+using StringView = ::std::string_view;
+}  // namespace internal
+}  // namespace testing
+// The case where absl is configured NOT to alias std::string_view is not
+// supported.
+#endif  // __has_include(<string_view>) && __cplusplus >= 201703L
+#endif  // __has_include
+#endif  // GTEST_HAS_ABSL
+
+#if GTEST_HAS_ABSL
+// Always use absl::variant for UniversalPrinter<> specializations if googletest
+// is built with absl support.
+#define GTEST_INTERNAL_HAS_VARIANT 1
+#include "absl/types/variant.h"
+namespace testing {
+namespace internal {
+template <typename... T>
+using Variant = ::absl::variant<T...>;
+}  // namespace internal
+}  // namespace testing
+#else
+#ifdef __has_include
+#if __has_include(<variant>) && __cplusplus >= 201703L
+// Otherwise for C++17 and higher use std::variant for UniversalPrinter<>
+// specializations.
+#define GTEST_INTERNAL_HAS_VARIANT 1
+#include <variant>
+namespace testing {
+namespace internal {
+template <typename... T>
+using Variant = ::std::variant<T...>;
+}  // namespace internal
+}  // namespace testing
+// The case where absl is configured NOT to alias std::variant is not supported.
+#endif  // __has_include(<variant>) && __cplusplus >= 201703L
+#endif  // __has_include
+#endif  // GTEST_HAS_ABSL
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_
diff --git a/test/gtest/include/gtest/internal/gtest-string.h b/test/gtest/include/gtest/internal/gtest-string.h
new file mode 100644
index 0000000..cca2e1f
--- /dev/null
+++ b/test/gtest/include/gtest/internal/gtest-string.h
@@ -0,0 +1,177 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file declares the String class and functions used internally by
+// Google Test.  They are subject to change without notice. They should not used
+// by code external to Google Test.
+//
+// This header file is #included by gtest-internal.h.
+// It should not be #included by other files.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_STRING_H_
+#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_STRING_H_
+
+#ifdef __BORLANDC__
+// string.h is not guaranteed to provide strcpy on C++ Builder.
+#include <mem.h>
+#endif
+
+#include <string.h>
+
+#include <cstdint>
+#include <string>
+
+#include "gtest/internal/gtest-port.h"
+
+namespace testing {
+namespace internal {
+
+// String - an abstract class holding static string utilities.
+class GTEST_API_ String {
+ public:
+  // Static utility methods
+
+  // Clones a 0-terminated C string, allocating memory using new.  The
+  // caller is responsible for deleting the return value using
+  // delete[].  Returns the cloned string, or NULL if the input is
+  // NULL.
+  //
+  // This is different from strdup() in string.h, which allocates
+  // memory using malloc().
+  static const char* CloneCString(const char* c_str);
+
+#if GTEST_OS_WINDOWS_MOBILE
+  // Windows CE does not have the 'ANSI' versions of Win32 APIs. To be
+  // able to pass strings to Win32 APIs on CE we need to convert them
+  // to 'Unicode', UTF-16.
+
+  // Creates a UTF-16 wide string from the given ANSI string, allocating
+  // memory using new. The caller is responsible for deleting the return
+  // value using delete[]. Returns the wide string, or NULL if the
+  // input is NULL.
+  //
+  // The wide string is created using the ANSI codepage (CP_ACP) to
+  // match the behaviour of the ANSI versions of Win32 calls and the
+  // C runtime.
+  static LPCWSTR AnsiToUtf16(const char* c_str);
+
+  // Creates an ANSI string from the given wide string, allocating
+  // memory using new. The caller is responsible for deleting the return
+  // value using delete[]. Returns the ANSI string, or NULL if the
+  // input is NULL.
+  //
+  // The returned string is created using the ANSI codepage (CP_ACP) to
+  // match the behaviour of the ANSI versions of Win32 calls and the
+  // C runtime.
+  static const char* Utf16ToAnsi(LPCWSTR utf16_str);
+#endif
+
+  // Compares two C strings.  Returns true if and only if they have the same
+  // content.
+  //
+  // Unlike strcmp(), this function can handle NULL argument(s).  A
+  // NULL C string is considered different to any non-NULL C string,
+  // including the empty string.
+  static bool CStringEquals(const char* lhs, const char* rhs);
+
+  // Converts a wide C string to a String using the UTF-8 encoding.
+  // NULL will be converted to "(null)".  If an error occurred during
+  // the conversion, "(failed to convert from wide string)" is
+  // returned.
+  static std::string ShowWideCString(const wchar_t* wide_c_str);
+
+  // Compares two wide C strings.  Returns true if and only if they have the
+  // same content.
+  //
+  // Unlike wcscmp(), this function can handle NULL argument(s).  A
+  // NULL C string is considered different to any non-NULL C string,
+  // including the empty string.
+  static bool WideCStringEquals(const wchar_t* lhs, const wchar_t* rhs);
+
+  // Compares two C strings, ignoring case.  Returns true if and only if
+  // they have the same content.
+  //
+  // Unlike strcasecmp(), this function can handle NULL argument(s).
+  // A NULL C string is considered different to any non-NULL C string,
+  // including the empty string.
+  static bool CaseInsensitiveCStringEquals(const char* lhs, const char* rhs);
+
+  // Compares two wide C strings, ignoring case.  Returns true if and only if
+  // they have the same content.
+  //
+  // Unlike wcscasecmp(), this function can handle NULL argument(s).
+  // A NULL C string is considered different to any non-NULL wide C string,
+  // including the empty string.
+  // NB: The implementations on different platforms slightly differ.
+  // On windows, this method uses _wcsicmp which compares according to LC_CTYPE
+  // environment variable. On GNU platform this method uses wcscasecmp
+  // which compares according to LC_CTYPE category of the current locale.
+  // On MacOS X, it uses towlower, which also uses LC_CTYPE category of the
+  // current locale.
+  static bool CaseInsensitiveWideCStringEquals(const wchar_t* lhs,
+                                               const wchar_t* rhs);
+
+  // Returns true if and only if the given string ends with the given suffix,
+  // ignoring case. Any string is considered to end with an empty suffix.
+  static bool EndsWithCaseInsensitive(const std::string& str,
+                                      const std::string& suffix);
+
+  // Formats an int value as "%02d".
+  static std::string FormatIntWidth2(int value);  // "%02d" for width == 2
+
+  // Formats an int value to given width with leading zeros.
+  static std::string FormatIntWidthN(int value, int width);
+
+  // Formats an int value as "%X".
+  static std::string FormatHexInt(int value);
+
+  // Formats an int value as "%X".
+  static std::string FormatHexUInt32(uint32_t value);
+
+  // Formats a byte as "%02X".
+  static std::string FormatByte(unsigned char value);
+
+ private:
+  String();  // Not meant to be instantiated.
+};           // class String
+
+// Gets the content of the stringstream's buffer as an std::string.  Each '\0'
+// character in the buffer is replaced with "\\0".
+GTEST_API_ std::string StringStreamToString(::std::stringstream* stream);
+
+}  // namespace internal
+}  // namespace testing
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_STRING_H_
diff --git a/test/gtest/include/gtest/internal/gtest-type-util.h b/test/gtest/include/gtest/internal/gtest-type-util.h
new file mode 100644
index 0000000..6bc02a7
--- /dev/null
+++ b/test/gtest/include/gtest/internal/gtest-type-util.h
@@ -0,0 +1,186 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Type utilities needed for implementing typed and type-parameterized
+// tests.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
+#define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
+
+#include "gtest/internal/gtest-port.h"
+
+// #ifdef __GNUC__ is too general here.  It is possible to use gcc without using
+// libstdc++ (which is where cxxabi.h comes from).
+#if GTEST_HAS_CXXABI_H_
+#include <cxxabi.h>
+#elif defined(__HP_aCC)
+#include <acxx_demangle.h>
+#endif  // GTEST_HASH_CXXABI_H_
+
+namespace testing {
+namespace internal {
+
+// Canonicalizes a given name with respect to the Standard C++ Library.
+// This handles removing the inline namespace within `std` that is
+// used by various standard libraries (e.g., `std::__1`).  Names outside
+// of namespace std are returned unmodified.
+inline std::string CanonicalizeForStdLibVersioning(std::string s) {
+  static const char prefix[] = "std::__";
+  if (s.compare(0, strlen(prefix), prefix) == 0) {
+    std::string::size_type end = s.find("::", strlen(prefix));
+    if (end != s.npos) {
+      // Erase everything between the initial `std` and the second `::`.
+      s.erase(strlen("std"), end - strlen("std"));
+    }
+  }
+  return s;
+}
+
+#if GTEST_HAS_RTTI
+// GetTypeName(const std::type_info&) returns a human-readable name of type T.
+inline std::string GetTypeName(const std::type_info& type) {
+  const char* const name = type.name();
+#if GTEST_HAS_CXXABI_H_ || defined(__HP_aCC)
+  int status = 0;
+  // gcc's implementation of typeid(T).name() mangles the type name,
+  // so we have to demangle it.
+#if GTEST_HAS_CXXABI_H_
+  using abi::__cxa_demangle;
+#endif  // GTEST_HAS_CXXABI_H_
+  char* const readable_name = __cxa_demangle(name, nullptr, nullptr, &status);
+  const std::string name_str(status == 0 ? readable_name : name);
+  free(readable_name);
+  return CanonicalizeForStdLibVersioning(name_str);
+#else
+  return name;
+#endif  // GTEST_HAS_CXXABI_H_ || __HP_aCC
+}
+#endif  // GTEST_HAS_RTTI
+
+// GetTypeName<T>() returns a human-readable name of type T if and only if
+// RTTI is enabled, otherwise it returns a dummy type name.
+// NB: This function is also used in Google Mock, so don't move it inside of
+// the typed-test-only section below.
+template <typename T>
+std::string GetTypeName() {
+#if GTEST_HAS_RTTI
+  return GetTypeName(typeid(T));
+#else
+  return "<type>";
+#endif  // GTEST_HAS_RTTI
+}
+
+// A unique type indicating an empty node
+struct None {};
+
+#define GTEST_TEMPLATE_ \
+  template <typename T> \
+  class
+
+// The template "selector" struct TemplateSel<Tmpl> is used to
+// represent Tmpl, which must be a class template with one type
+// parameter, as a type.  TemplateSel<Tmpl>::Bind<T>::type is defined
+// as the type Tmpl<T>.  This allows us to actually instantiate the
+// template "selected" by TemplateSel<Tmpl>.
+//
+// This trick is necessary for simulating typedef for class templates,
+// which C++ doesn't support directly.
+template <GTEST_TEMPLATE_ Tmpl>
+struct TemplateSel {
+  template <typename T>
+  struct Bind {
+    typedef Tmpl<T> type;
+  };
+};
+
+#define GTEST_BIND_(TmplSel, T) TmplSel::template Bind<T>::type
+
+template <GTEST_TEMPLATE_ Head_, GTEST_TEMPLATE_... Tail_>
+struct Templates {
+  using Head = TemplateSel<Head_>;
+  using Tail = Templates<Tail_...>;
+};
+
+template <GTEST_TEMPLATE_ Head_>
+struct Templates<Head_> {
+  using Head = TemplateSel<Head_>;
+  using Tail = None;
+};
+
+// Tuple-like type lists
+template <typename Head_, typename... Tail_>
+struct Types {
+  using Head = Head_;
+  using Tail = Types<Tail_...>;
+};
+
+template <typename Head_>
+struct Types<Head_> {
+  using Head = Head_;
+  using Tail = None;
+};
+
+// Helper metafunctions to tell apart a single type from types
+// generated by ::testing::Types
+template <typename... Ts>
+struct ProxyTypeList {
+  using type = Types<Ts...>;
+};
+
+template <typename>
+struct is_proxy_type_list : std::false_type {};
+
+template <typename... Ts>
+struct is_proxy_type_list<ProxyTypeList<Ts...>> : std::true_type {};
+
+// Generator which conditionally creates type lists.
+// It recognizes if a requested type list should be created
+// and prevents creating a new type list nested within another one.
+template <typename T>
+struct GenerateTypeList {
+ private:
+  using proxy = typename std::conditional<is_proxy_type_list<T>::value, T,
+                                          ProxyTypeList<T>>::type;
+
+ public:
+  using type = typename proxy::type;
+};
+
+}  // namespace internal
+
+template <typename... Ts>
+using Types = internal::ProxyTypeList<Ts...>;
+
+}  // namespace testing
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
diff --git a/test/gtest/src/gtest-all.cc b/test/gtest/src/gtest-all.cc
new file mode 100644
index 0000000..2a70ed8
--- /dev/null
+++ b/test/gtest/src/gtest-all.cc
@@ -0,0 +1,49 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Google C++ Testing and Mocking Framework (Google Test)
+//
+// Sometimes it's desirable to build Google Test by compiling a single file.
+// This file serves this purpose.
+
+// This line ensures that gtest.h can be compiled on its own, even
+// when it's fused.
+#include "gtest/gtest.h"
+
+// The following lines pull in the real gtest *.cc files.
+#include "src/gtest-assertion-result.cc"
+#include "src/gtest-death-test.cc"
+#include "src/gtest-filepath.cc"
+#include "src/gtest-matchers.cc"
+#include "src/gtest-port.cc"
+#include "src/gtest-printers.cc"
+#include "src/gtest-test-part.cc"
+#include "src/gtest-typed-test.cc"
+#include "src/gtest.cc"
diff --git a/test/gtest/src/gtest-assertion-result.cc b/test/gtest/src/gtest-assertion-result.cc
new file mode 100644
index 0000000..f1c0b10
--- /dev/null
+++ b/test/gtest/src/gtest-assertion-result.cc
@@ -0,0 +1,77 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This file defines the AssertionResult type.
+
+#include "gtest/gtest-assertion-result.h"
+
+#include <string>
+#include <utility>
+
+#include "gtest/gtest-message.h"
+
+namespace testing {
+
+// AssertionResult constructors.
+// Used in EXPECT_TRUE/FALSE(assertion_result).
+AssertionResult::AssertionResult(const AssertionResult& other)
+    : success_(other.success_),
+      message_(other.message_.get() != nullptr
+                   ? new ::std::string(*other.message_)
+                   : static_cast< ::std::string*>(nullptr)) {}
+
+// Swaps two AssertionResults.
+void AssertionResult::swap(AssertionResult& other) {
+  using std::swap;
+  swap(success_, other.success_);
+  swap(message_, other.message_);
+}
+
+// Returns the assertion's negation. Used with EXPECT/ASSERT_FALSE.
+AssertionResult AssertionResult::operator!() const {
+  AssertionResult negation(!success_);
+  if (message_.get() != nullptr) negation << *message_;
+  return negation;
+}
+
+// Makes a successful assertion result.
+AssertionResult AssertionSuccess() { return AssertionResult(true); }
+
+// Makes a failed assertion result.
+AssertionResult AssertionFailure() { return AssertionResult(false); }
+
+// Makes a failed assertion result with the given failure message.
+// Deprecated; use AssertionFailure() << message.
+AssertionResult AssertionFailure(const Message& message) {
+  return AssertionFailure() << message;
+}
+
+}  // namespace testing
diff --git a/test/gtest/src/gtest-death-test.cc b/test/gtest/src/gtest-death-test.cc
new file mode 100644
index 0000000..e6abc62
--- /dev/null
+++ b/test/gtest/src/gtest-death-test.cc
@@ -0,0 +1,1620 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// This file implements death tests.
+
+#include "gtest/gtest-death-test.h"
+
+#include <functional>
+#include <utility>
+
+#include "gtest/internal/custom/gtest.h"
+#include "gtest/internal/gtest-port.h"
+
+#if GTEST_HAS_DEATH_TEST
+
+#if GTEST_OS_MAC
+#include <crt_externs.h>
+#endif  // GTEST_OS_MAC
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+
+#if GTEST_OS_LINUX
+#include <signal.h>
+#endif  // GTEST_OS_LINUX
+
+#include <stdarg.h>
+
+#if GTEST_OS_WINDOWS
+#include <windows.h>
+#else
+#include <sys/mman.h>
+#include <sys/wait.h>
+#endif  // GTEST_OS_WINDOWS
+
+#if GTEST_OS_QNX
+#include <spawn.h>
+#endif  // GTEST_OS_QNX
+
+#if GTEST_OS_FUCHSIA
+#include <lib/fdio/fd.h>
+#include <lib/fdio/io.h>
+#include <lib/fdio/spawn.h>
+#include <lib/zx/channel.h>
+#include <lib/zx/port.h>
+#include <lib/zx/process.h>
+#include <lib/zx/socket.h>
+#include <zircon/processargs.h>
+#include <zircon/syscalls.h>
+#include <zircon/syscalls/policy.h>
+#include <zircon/syscalls/port.h>
+#endif  // GTEST_OS_FUCHSIA
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+#include "gtest/gtest-message.h"
+#include "gtest/internal/gtest-string.h"
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+
+// Constants.
+
+// The default death test style.
+//
+// This is defined in internal/gtest-port.h as "fast", but can be overridden by
+// a definition in internal/custom/gtest-port.h. The recommended value, which is
+// used internally at Google, is "threadsafe".
+static const char kDefaultDeathTestStyle[] = GTEST_DEFAULT_DEATH_TEST_STYLE;
+
+}  // namespace testing
+
+GTEST_DEFINE_string_(
+    death_test_style,
+    testing::internal::StringFromGTestEnv("death_test_style",
+                                          testing::kDefaultDeathTestStyle),
+    "Indicates how to run a death test in a forked child process: "
+    "\"threadsafe\" (child process re-executes the test binary "
+    "from the beginning, running only the specific death test) or "
+    "\"fast\" (child process runs the death test immediately "
+    "after forking).");
+
+GTEST_DEFINE_bool_(
+    death_test_use_fork,
+    testing::internal::BoolFromGTestEnv("death_test_use_fork", false),
+    "Instructs to use fork()/_exit() instead of clone() in death tests. "
+    "Ignored and always uses fork() on POSIX systems where clone() is not "
+    "implemented. Useful when running under valgrind or similar tools if "
+    "those do not support clone(). Valgrind 3.3.1 will just fail if "
+    "it sees an unsupported combination of clone() flags. "
+    "It is not recommended to use this flag w/o valgrind though it will "
+    "work in 99% of the cases. Once valgrind is fixed, this flag will "
+    "most likely be removed.");
+
+GTEST_DEFINE_string_(
+    internal_run_death_test, "",
+    "Indicates the file, line number, temporal index of "
+    "the single death test to run, and a file descriptor to "
+    "which a success code may be sent, all separated by "
+    "the '|' characters.  This flag is specified if and only if the "
+    "current process is a sub-process launched for running a thread-safe "
+    "death test.  FOR INTERNAL USE ONLY.");
+
+namespace testing {
+
+#if GTEST_HAS_DEATH_TEST
+
+namespace internal {
+
+// Valid only for fast death tests. Indicates the code is running in the
+// child process of a fast style death test.
+#if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+static bool g_in_fast_death_test_child = false;
+#endif
+
+// Returns a Boolean value indicating whether the caller is currently
+// executing in the context of the death test child process.  Tools such as
+// Valgrind heap checkers may need this to modify their behavior in death
+// tests.  IMPORTANT: This is an internal utility.  Using it may break the
+// implementation of death tests.  User code MUST NOT use it.
+bool InDeathTestChild() {
+#if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+
+  // On Windows and Fuchsia, death tests are thread-safe regardless of the value
+  // of the death_test_style flag.
+  return !GTEST_FLAG_GET(internal_run_death_test).empty();
+
+#else
+
+  if (GTEST_FLAG_GET(death_test_style) == "threadsafe")
+    return !GTEST_FLAG_GET(internal_run_death_test).empty();
+  else
+    return g_in_fast_death_test_child;
+#endif
+}
+
+}  // namespace internal
+
+// ExitedWithCode constructor.
+ExitedWithCode::ExitedWithCode(int exit_code) : exit_code_(exit_code) {}
+
+// ExitedWithCode function-call operator.
+bool ExitedWithCode::operator()(int exit_status) const {
+#if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+
+  return exit_status == exit_code_;
+
+#else
+
+  return WIFEXITED(exit_status) && WEXITSTATUS(exit_status) == exit_code_;
+
+#endif  // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+}
+
+#if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+// KilledBySignal constructor.
+KilledBySignal::KilledBySignal(int signum) : signum_(signum) {}
+
+// KilledBySignal function-call operator.
+bool KilledBySignal::operator()(int exit_status) const {
+#if defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
+  {
+    bool result;
+    if (GTEST_KILLED_BY_SIGNAL_OVERRIDE_(signum_, exit_status, &result)) {
+      return result;
+    }
+  }
+#endif  // defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
+  return WIFSIGNALED(exit_status) && WTERMSIG(exit_status) == signum_;
+}
+#endif  // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+
+namespace internal {
+
+// Utilities needed for death tests.
+
+// Generates a textual description of a given exit code, in the format
+// specified by wait(2).
+static std::string ExitSummary(int exit_code) {
+  Message m;
+
+#if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+
+  m << "Exited with exit status " << exit_code;
+
+#else
+
+  if (WIFEXITED(exit_code)) {
+    m << "Exited with exit status " << WEXITSTATUS(exit_code);
+  } else if (WIFSIGNALED(exit_code)) {
+    m << "Terminated by signal " << WTERMSIG(exit_code);
+  }
+#ifdef WCOREDUMP
+  if (WCOREDUMP(exit_code)) {
+    m << " (core dumped)";
+  }
+#endif
+#endif  // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+
+  return m.GetString();
+}
+
+// Returns true if exit_status describes a process that was terminated
+// by a signal, or exited normally with a nonzero exit code.
+bool ExitedUnsuccessfully(int exit_status) {
+  return !ExitedWithCode(0)(exit_status);
+}
+
+#if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+// Generates a textual failure message when a death test finds more than
+// one thread running, or cannot determine the number of threads, prior
+// to executing the given statement.  It is the responsibility of the
+// caller not to pass a thread_count of 1.
+static std::string DeathTestThreadWarning(size_t thread_count) {
+  Message msg;
+  msg << "Death tests use fork(), which is unsafe particularly"
+      << " in a threaded context. For this test, " << GTEST_NAME_ << " ";
+  if (thread_count == 0) {
+    msg << "couldn't detect the number of threads.";
+  } else {
+    msg << "detected " << thread_count << " threads.";
+  }
+  msg << " See "
+         "https://github.com/google/googletest/blob/master/docs/"
+         "advanced.md#death-tests-and-threads"
+      << " for more explanation and suggested solutions, especially if"
+      << " this is the last message you see before your test times out.";
+  return msg.GetString();
+}
+#endif  // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+
+// Flag characters for reporting a death test that did not die.
+static const char kDeathTestLived = 'L';
+static const char kDeathTestReturned = 'R';
+static const char kDeathTestThrew = 'T';
+static const char kDeathTestInternalError = 'I';
+
+#if GTEST_OS_FUCHSIA
+
+// File descriptor used for the pipe in the child process.
+static const int kFuchsiaReadPipeFd = 3;
+
+#endif
+
+// An enumeration describing all of the possible ways that a death test can
+// conclude.  DIED means that the process died while executing the test
+// code; LIVED means that process lived beyond the end of the test code;
+// RETURNED means that the test statement attempted to execute a return
+// statement, which is not allowed; THREW means that the test statement
+// returned control by throwing an exception.  IN_PROGRESS means the test
+// has not yet concluded.
+enum DeathTestOutcome { IN_PROGRESS, DIED, LIVED, RETURNED, THREW };
+
+// Routine for aborting the program which is safe to call from an
+// exec-style death test child process, in which case the error
+// message is propagated back to the parent process.  Otherwise, the
+// message is simply printed to stderr.  In either case, the program
+// then exits with status 1.
+static void DeathTestAbort(const std::string& message) {
+  // On a POSIX system, this function may be called from a threadsafe-style
+  // death test child process, which operates on a very small stack.  Use
+  // the heap for any additional non-minuscule memory requirements.
+  const InternalRunDeathTestFlag* const flag =
+      GetUnitTestImpl()->internal_run_death_test_flag();
+  if (flag != nullptr) {
+    FILE* parent = posix::FDOpen(flag->write_fd(), "w");
+    fputc(kDeathTestInternalError, parent);
+    fprintf(parent, "%s", message.c_str());
+    fflush(parent);
+    _exit(1);
+  } else {
+    fprintf(stderr, "%s", message.c_str());
+    fflush(stderr);
+    posix::Abort();
+  }
+}
+
+// A replacement for CHECK that calls DeathTestAbort if the assertion
+// fails.
+#define GTEST_DEATH_TEST_CHECK_(expression)                              \
+  do {                                                                   \
+    if (!::testing::internal::IsTrue(expression)) {                      \
+      DeathTestAbort(::std::string("CHECK failed: File ") + __FILE__ +   \
+                     ", line " +                                         \
+                     ::testing::internal::StreamableToString(__LINE__) + \
+                     ": " + #expression);                                \
+    }                                                                    \
+  } while (::testing::internal::AlwaysFalse())
+
+// This macro is similar to GTEST_DEATH_TEST_CHECK_, but it is meant for
+// evaluating any system call that fulfills two conditions: it must return
+// -1 on failure, and set errno to EINTR when it is interrupted and
+// should be tried again.  The macro expands to a loop that repeatedly
+// evaluates the expression as long as it evaluates to -1 and sets
+// errno to EINTR.  If the expression evaluates to -1 but errno is
+// something other than EINTR, DeathTestAbort is called.
+#define GTEST_DEATH_TEST_CHECK_SYSCALL_(expression)                      \
+  do {                                                                   \
+    int gtest_retval;                                                    \
+    do {                                                                 \
+      gtest_retval = (expression);                                       \
+    } while (gtest_retval == -1 && errno == EINTR);                      \
+    if (gtest_retval == -1) {                                            \
+      DeathTestAbort(::std::string("CHECK failed: File ") + __FILE__ +   \
+                     ", line " +                                         \
+                     ::testing::internal::StreamableToString(__LINE__) + \
+                     ": " + #expression + " != -1");                     \
+    }                                                                    \
+  } while (::testing::internal::AlwaysFalse())
+
+// Returns the message describing the last system error in errno.
+std::string GetLastErrnoDescription() {
+  return errno == 0 ? "" : posix::StrError(errno);
+}
+
+// This is called from a death test parent process to read a failure
+// message from the death test child process and log it with the FATAL
+// severity. On Windows, the message is read from a pipe handle. On other
+// platforms, it is read from a file descriptor.
+static void FailFromInternalError(int fd) {
+  Message error;
+  char buffer[256];
+  int num_read;
+
+  do {
+    while ((num_read = posix::Read(fd, buffer, 255)) > 0) {
+      buffer[num_read] = '\0';
+      error << buffer;
+    }
+  } while (num_read == -1 && errno == EINTR);
+
+  if (num_read == 0) {
+    GTEST_LOG_(FATAL) << error.GetString();
+  } else {
+    const int last_error = errno;
+    GTEST_LOG_(FATAL) << "Error while reading death test internal: "
+                      << GetLastErrnoDescription() << " [" << last_error << "]";
+  }
+}
+
+// Death test constructor.  Increments the running death test count
+// for the current test.
+DeathTest::DeathTest() {
+  TestInfo* const info = GetUnitTestImpl()->current_test_info();
+  if (info == nullptr) {
+    DeathTestAbort(
+        "Cannot run a death test outside of a TEST or "
+        "TEST_F construct");
+  }
+}
+
+// Creates and returns a death test by dispatching to the current
+// death test factory.
+bool DeathTest::Create(const char* statement,
+                       Matcher<const std::string&> matcher, const char* file,
+                       int line, DeathTest** test) {
+  return GetUnitTestImpl()->death_test_factory()->Create(
+      statement, std::move(matcher), file, line, test);
+}
+
+const char* DeathTest::LastMessage() {
+  return last_death_test_message_.c_str();
+}
+
+void DeathTest::set_last_death_test_message(const std::string& message) {
+  last_death_test_message_ = message;
+}
+
+std::string DeathTest::last_death_test_message_;
+
+// Provides cross platform implementation for some death functionality.
+class DeathTestImpl : public DeathTest {
+ protected:
+  DeathTestImpl(const char* a_statement, Matcher<const std::string&> matcher)
+      : statement_(a_statement),
+        matcher_(std::move(matcher)),
+        spawned_(false),
+        status_(-1),
+        outcome_(IN_PROGRESS),
+        read_fd_(-1),
+        write_fd_(-1) {}
+
+  // read_fd_ is expected to be closed and cleared by a derived class.
+  ~DeathTestImpl() override { GTEST_DEATH_TEST_CHECK_(read_fd_ == -1); }
+
+  void Abort(AbortReason reason) override;
+  bool Passed(bool status_ok) override;
+
+  const char* statement() const { return statement_; }
+  bool spawned() const { return spawned_; }
+  void set_spawned(bool is_spawned) { spawned_ = is_spawned; }
+  int status() const { return status_; }
+  void set_status(int a_status) { status_ = a_status; }
+  DeathTestOutcome outcome() const { return outcome_; }
+  void set_outcome(DeathTestOutcome an_outcome) { outcome_ = an_outcome; }
+  int read_fd() const { return read_fd_; }
+  void set_read_fd(int fd) { read_fd_ = fd; }
+  int write_fd() const { return write_fd_; }
+  void set_write_fd(int fd) { write_fd_ = fd; }
+
+  // Called in the parent process only. Reads the result code of the death
+  // test child process via a pipe, interprets it to set the outcome_
+  // member, and closes read_fd_.  Outputs diagnostics and terminates in
+  // case of unexpected codes.
+  void ReadAndInterpretStatusByte();
+
+  // Returns stderr output from the child process.
+  virtual std::string GetErrorLogs();
+
+ private:
+  // The textual content of the code this object is testing.  This class
+  // doesn't own this string and should not attempt to delete it.
+  const char* const statement_;
+  // A matcher that's expected to match the stderr output by the child process.
+  Matcher<const std::string&> matcher_;
+  // True if the death test child process has been successfully spawned.
+  bool spawned_;
+  // The exit status of the child process.
+  int status_;
+  // How the death test concluded.
+  DeathTestOutcome outcome_;
+  // Descriptor to the read end of the pipe to the child process.  It is
+  // always -1 in the child process.  The child keeps its write end of the
+  // pipe in write_fd_.
+  int read_fd_;
+  // Descriptor to the child's write end of the pipe to the parent process.
+  // It is always -1 in the parent process.  The parent keeps its end of the
+  // pipe in read_fd_.
+  int write_fd_;
+};
+
+// Called in the parent process only. Reads the result code of the death
+// test child process via a pipe, interprets it to set the outcome_
+// member, and closes read_fd_.  Outputs diagnostics and terminates in
+// case of unexpected codes.
+void DeathTestImpl::ReadAndInterpretStatusByte() {
+  char flag;
+  int bytes_read;
+
+  // The read() here blocks until data is available (signifying the
+  // failure of the death test) or until the pipe is closed (signifying
+  // its success), so it's okay to call this in the parent before
+  // the child process has exited.
+  do {
+    bytes_read = posix::Read(read_fd(), &flag, 1);
+  } while (bytes_read == -1 && errno == EINTR);
+
+  if (bytes_read == 0) {
+    set_outcome(DIED);
+  } else if (bytes_read == 1) {
+    switch (flag) {
+      case kDeathTestReturned:
+        set_outcome(RETURNED);
+        break;
+      case kDeathTestThrew:
+        set_outcome(THREW);
+        break;
+      case kDeathTestLived:
+        set_outcome(LIVED);
+        break;
+      case kDeathTestInternalError:
+        FailFromInternalError(read_fd());  // Does not return.
+        break;
+      default:
+        GTEST_LOG_(FATAL) << "Death test child process reported "
+                          << "unexpected status byte ("
+                          << static_cast<unsigned int>(flag) << ")";
+    }
+  } else {
+    GTEST_LOG_(FATAL) << "Read from death test child process failed: "
+                      << GetLastErrnoDescription();
+  }
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Close(read_fd()));
+  set_read_fd(-1);
+}
+
+std::string DeathTestImpl::GetErrorLogs() { return GetCapturedStderr(); }
+
+// Signals that the death test code which should have exited, didn't.
+// Should be called only in a death test child process.
+// Writes a status byte to the child's status file descriptor, then
+// calls _exit(1).
+void DeathTestImpl::Abort(AbortReason reason) {
+  // The parent process considers the death test to be a failure if
+  // it finds any data in our pipe.  So, here we write a single flag byte
+  // to the pipe, then exit.
+  const char status_ch = reason == TEST_DID_NOT_DIE       ? kDeathTestLived
+                         : reason == TEST_THREW_EXCEPTION ? kDeathTestThrew
+                                                          : kDeathTestReturned;
+
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Write(write_fd(), &status_ch, 1));
+  // We are leaking the descriptor here because on some platforms (i.e.,
+  // when built as Windows DLL), destructors of global objects will still
+  // run after calling _exit(). On such systems, write_fd_ will be
+  // indirectly closed from the destructor of UnitTestImpl, causing double
+  // close if it is also closed here. On debug configurations, double close
+  // may assert. As there are no in-process buffers to flush here, we are
+  // relying on the OS to close the descriptor after the process terminates
+  // when the destructors are not run.
+  _exit(1);  // Exits w/o any normal exit hooks (we were supposed to crash)
+}
+
+// Returns an indented copy of stderr output for a death test.
+// This makes distinguishing death test output lines from regular log lines
+// much easier.
+static ::std::string FormatDeathTestOutput(const ::std::string& output) {
+  ::std::string ret;
+  for (size_t at = 0;;) {
+    const size_t line_end = output.find('\n', at);
+    ret += "[  DEATH   ] ";
+    if (line_end == ::std::string::npos) {
+      ret += output.substr(at);
+      break;
+    }
+    ret += output.substr(at, line_end + 1 - at);
+    at = line_end + 1;
+  }
+  return ret;
+}
+
+// Assesses the success or failure of a death test, using both private
+// members which have previously been set, and one argument:
+//
+// Private data members:
+//   outcome:  An enumeration describing how the death test
+//             concluded: DIED, LIVED, THREW, or RETURNED.  The death test
+//             fails in the latter three cases.
+//   status:   The exit status of the child process. On *nix, it is in the
+//             in the format specified by wait(2). On Windows, this is the
+//             value supplied to the ExitProcess() API or a numeric code
+//             of the exception that terminated the program.
+//   matcher_: A matcher that's expected to match the stderr output by the child
+//             process.
+//
+// Argument:
+//   status_ok: true if exit_status is acceptable in the context of
+//              this particular death test, which fails if it is false
+//
+// Returns true if and only if all of the above conditions are met.  Otherwise,
+// the first failing condition, in the order given above, is the one that is
+// reported. Also sets the last death test message string.
+bool DeathTestImpl::Passed(bool status_ok) {
+  if (!spawned()) return false;
+
+  const std::string error_message = GetErrorLogs();
+
+  bool success = false;
+  Message buffer;
+
+  buffer << "Death test: " << statement() << "\n";
+  switch (outcome()) {
+    case LIVED:
+      buffer << "    Result: failed to die.\n"
+             << " Error msg:\n"
+             << FormatDeathTestOutput(error_message);
+      break;
+    case THREW:
+      buffer << "    Result: threw an exception.\n"
+             << " Error msg:\n"
+             << FormatDeathTestOutput(error_message);
+      break;
+    case RETURNED:
+      buffer << "    Result: illegal return in test statement.\n"
+             << " Error msg:\n"
+             << FormatDeathTestOutput(error_message);
+      break;
+    case DIED:
+      if (status_ok) {
+        if (matcher_.Matches(error_message)) {
+          success = true;
+        } else {
+          std::ostringstream stream;
+          matcher_.DescribeTo(&stream);
+          buffer << "    Result: died but not with expected error.\n"
+                 << "  Expected: " << stream.str() << "\n"
+                 << "Actual msg:\n"
+                 << FormatDeathTestOutput(error_message);
+        }
+      } else {
+        buffer << "    Result: died but not with expected exit code:\n"
+               << "            " << ExitSummary(status()) << "\n"
+               << "Actual msg:\n"
+               << FormatDeathTestOutput(error_message);
+      }
+      break;
+    case IN_PROGRESS:
+    default:
+      GTEST_LOG_(FATAL)
+          << "DeathTest::Passed somehow called before conclusion of test";
+  }
+
+  DeathTest::set_last_death_test_message(buffer.GetString());
+  return success;
+}
+
+#if GTEST_OS_WINDOWS
+// WindowsDeathTest implements death tests on Windows. Due to the
+// specifics of starting new processes on Windows, death tests there are
+// always threadsafe, and Google Test considers the
+// --gtest_death_test_style=fast setting to be equivalent to
+// --gtest_death_test_style=threadsafe there.
+//
+// A few implementation notes:  Like the Linux version, the Windows
+// implementation uses pipes for child-to-parent communication. But due to
+// the specifics of pipes on Windows, some extra steps are required:
+//
+// 1. The parent creates a communication pipe and stores handles to both
+//    ends of it.
+// 2. The parent starts the child and provides it with the information
+//    necessary to acquire the handle to the write end of the pipe.
+// 3. The child acquires the write end of the pipe and signals the parent
+//    using a Windows event.
+// 4. Now the parent can release the write end of the pipe on its side. If
+//    this is done before step 3, the object's reference count goes down to
+//    0 and it is destroyed, preventing the child from acquiring it. The
+//    parent now has to release it, or read operations on the read end of
+//    the pipe will not return when the child terminates.
+// 5. The parent reads child's output through the pipe (outcome code and
+//    any possible error messages) from the pipe, and its stderr and then
+//    determines whether to fail the test.
+//
+// Note: to distinguish Win32 API calls from the local method and function
+// calls, the former are explicitly resolved in the global namespace.
+//
+class WindowsDeathTest : public DeathTestImpl {
+ public:
+  WindowsDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
+                   const char* file, int line)
+      : DeathTestImpl(a_statement, std::move(matcher)),
+        file_(file),
+        line_(line) {}
+
+  // All of these virtual functions are inherited from DeathTest.
+  virtual int Wait();
+  virtual TestRole AssumeRole();
+
+ private:
+  // The name of the file in which the death test is located.
+  const char* const file_;
+  // The line number on which the death test is located.
+  const int line_;
+  // Handle to the write end of the pipe to the child process.
+  AutoHandle write_handle_;
+  // Child process handle.
+  AutoHandle child_handle_;
+  // Event the child process uses to signal the parent that it has
+  // acquired the handle to the write end of the pipe. After seeing this
+  // event the parent can release its own handles to make sure its
+  // ReadFile() calls return when the child terminates.
+  AutoHandle event_handle_;
+};
+
+// Waits for the child in a death test to exit, returning its exit
+// status, or 0 if no child process exists.  As a side effect, sets the
+// outcome data member.
+int WindowsDeathTest::Wait() {
+  if (!spawned()) return 0;
+
+  // Wait until the child either signals that it has acquired the write end
+  // of the pipe or it dies.
+  const HANDLE wait_handles[2] = {child_handle_.Get(), event_handle_.Get()};
+  switch (::WaitForMultipleObjects(2, wait_handles,
+                                   FALSE,  // Waits for any of the handles.
+                                   INFINITE)) {
+    case WAIT_OBJECT_0:
+    case WAIT_OBJECT_0 + 1:
+      break;
+    default:
+      GTEST_DEATH_TEST_CHECK_(false);  // Should not get here.
+  }
+
+  // The child has acquired the write end of the pipe or exited.
+  // We release the handle on our side and continue.
+  write_handle_.Reset();
+  event_handle_.Reset();
+
+  ReadAndInterpretStatusByte();
+
+  // Waits for the child process to exit if it haven't already. This
+  // returns immediately if the child has already exited, regardless of
+  // whether previous calls to WaitForMultipleObjects synchronized on this
+  // handle or not.
+  GTEST_DEATH_TEST_CHECK_(WAIT_OBJECT_0 ==
+                          ::WaitForSingleObject(child_handle_.Get(), INFINITE));
+  DWORD status_code;
+  GTEST_DEATH_TEST_CHECK_(
+      ::GetExitCodeProcess(child_handle_.Get(), &status_code) != FALSE);
+  child_handle_.Reset();
+  set_status(static_cast<int>(status_code));
+  return status();
+}
+
+// The AssumeRole process for a Windows death test.  It creates a child
+// process with the same executable as the current process to run the
+// death test.  The child process is given the --gtest_filter and
+// --gtest_internal_run_death_test flags such that it knows to run the
+// current death test only.
+DeathTest::TestRole WindowsDeathTest::AssumeRole() {
+  const UnitTestImpl* const impl = GetUnitTestImpl();
+  const InternalRunDeathTestFlag* const flag =
+      impl->internal_run_death_test_flag();
+  const TestInfo* const info = impl->current_test_info();
+  const int death_test_index = info->result()->death_test_count();
+
+  if (flag != nullptr) {
+    // ParseInternalRunDeathTestFlag() has performed all the necessary
+    // processing.
+    set_write_fd(flag->write_fd());
+    return EXECUTE_TEST;
+  }
+
+  // WindowsDeathTest uses an anonymous pipe to communicate results of
+  // a death test.
+  SECURITY_ATTRIBUTES handles_are_inheritable = {sizeof(SECURITY_ATTRIBUTES),
+                                                 nullptr, TRUE};
+  HANDLE read_handle, write_handle;
+  GTEST_DEATH_TEST_CHECK_(::CreatePipe(&read_handle, &write_handle,
+                                       &handles_are_inheritable,
+                                       0)  // Default buffer size.
+                          != FALSE);
+  set_read_fd(
+      ::_open_osfhandle(reinterpret_cast<intptr_t>(read_handle), O_RDONLY));
+  write_handle_.Reset(write_handle);
+  event_handle_.Reset(::CreateEvent(
+      &handles_are_inheritable,
+      TRUE,       // The event will automatically reset to non-signaled state.
+      FALSE,      // The initial state is non-signalled.
+      nullptr));  // The even is unnamed.
+  GTEST_DEATH_TEST_CHECK_(event_handle_.Get() != nullptr);
+  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
+                                  "filter=" + info->test_suite_name() + "." +
+                                  info->name();
+  const std::string internal_flag =
+      std::string("--") + GTEST_FLAG_PREFIX_ +
+      "internal_run_death_test=" + file_ + "|" + StreamableToString(line_) +
+      "|" + StreamableToString(death_test_index) + "|" +
+      StreamableToString(static_cast<unsigned int>(::GetCurrentProcessId())) +
+      // size_t has the same width as pointers on both 32-bit and 64-bit
+      // Windows platforms.
+      // See http://msdn.microsoft.com/en-us/library/tcxf1dw6.aspx.
+      "|" + StreamableToString(reinterpret_cast<size_t>(write_handle)) + "|" +
+      StreamableToString(reinterpret_cast<size_t>(event_handle_.Get()));
+
+  char executable_path[_MAX_PATH + 1];  // NOLINT
+  GTEST_DEATH_TEST_CHECK_(_MAX_PATH + 1 != ::GetModuleFileNameA(nullptr,
+                                                                executable_path,
+                                                                _MAX_PATH));
+
+  std::string command_line = std::string(::GetCommandLineA()) + " " +
+                             filter_flag + " \"" + internal_flag + "\"";
+
+  DeathTest::set_last_death_test_message("");
+
+  CaptureStderr();
+  // Flush the log buffers since the log streams are shared with the child.
+  FlushInfoLog();
+
+  // The child process will share the standard handles with the parent.
+  STARTUPINFOA startup_info;
+  memset(&startup_info, 0, sizeof(STARTUPINFO));
+  startup_info.dwFlags = STARTF_USESTDHANDLES;
+  startup_info.hStdInput = ::GetStdHandle(STD_INPUT_HANDLE);
+  startup_info.hStdOutput = ::GetStdHandle(STD_OUTPUT_HANDLE);
+  startup_info.hStdError = ::GetStdHandle(STD_ERROR_HANDLE);
+
+  PROCESS_INFORMATION process_info;
+  GTEST_DEATH_TEST_CHECK_(
+      ::CreateProcessA(
+          executable_path, const_cast<char*>(command_line.c_str()),
+          nullptr,  // Returned process handle is not inheritable.
+          nullptr,  // Returned thread handle is not inheritable.
+          TRUE,  // Child inherits all inheritable handles (for write_handle_).
+          0x0,   // Default creation flags.
+          nullptr,  // Inherit the parent's environment.
+          UnitTest::GetInstance()->original_working_dir(), &startup_info,
+          &process_info) != FALSE);
+  child_handle_.Reset(process_info.hProcess);
+  ::CloseHandle(process_info.hThread);
+  set_spawned(true);
+  return OVERSEE_TEST;
+}
+
+#elif GTEST_OS_FUCHSIA
+
+class FuchsiaDeathTest : public DeathTestImpl {
+ public:
+  FuchsiaDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
+                   const char* file, int line)
+      : DeathTestImpl(a_statement, std::move(matcher)),
+        file_(file),
+        line_(line) {}
+
+  // All of these virtual functions are inherited from DeathTest.
+  int Wait() override;
+  TestRole AssumeRole() override;
+  std::string GetErrorLogs() override;
+
+ private:
+  // The name of the file in which the death test is located.
+  const char* const file_;
+  // The line number on which the death test is located.
+  const int line_;
+  // The stderr data captured by the child process.
+  std::string captured_stderr_;
+
+  zx::process child_process_;
+  zx::channel exception_channel_;
+  zx::socket stderr_socket_;
+};
+
+// Utility class for accumulating command-line arguments.
+class Arguments {
+ public:
+  Arguments() { args_.push_back(nullptr); }
+
+  ~Arguments() {
+    for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
+         ++i) {
+      free(*i);
+    }
+  }
+  void AddArgument(const char* argument) {
+    args_.insert(args_.end() - 1, posix::StrDup(argument));
+  }
+
+  template <typename Str>
+  void AddArguments(const ::std::vector<Str>& arguments) {
+    for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
+         i != arguments.end(); ++i) {
+      args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
+    }
+  }
+  char* const* Argv() { return &args_[0]; }
+
+  int size() { return static_cast<int>(args_.size()) - 1; }
+
+ private:
+  std::vector<char*> args_;
+};
+
+// Waits for the child in a death test to exit, returning its exit
+// status, or 0 if no child process exists.  As a side effect, sets the
+// outcome data member.
+int FuchsiaDeathTest::Wait() {
+  const int kProcessKey = 0;
+  const int kSocketKey = 1;
+  const int kExceptionKey = 2;
+
+  if (!spawned()) return 0;
+
+  // Create a port to wait for socket/task/exception events.
+  zx_status_t status_zx;
+  zx::port port;
+  status_zx = zx::port::create(0, &port);
+  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+  // Register to wait for the child process to terminate.
+  status_zx =
+      child_process_.wait_async(port, kProcessKey, ZX_PROCESS_TERMINATED, 0);
+  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+  // Register to wait for the socket to be readable or closed.
+  status_zx = stderr_socket_.wait_async(
+      port, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED, 0);
+  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+  // Register to wait for an exception.
+  status_zx = exception_channel_.wait_async(port, kExceptionKey,
+                                            ZX_CHANNEL_READABLE, 0);
+  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+  bool process_terminated = false;
+  bool socket_closed = false;
+  do {
+    zx_port_packet_t packet = {};
+    status_zx = port.wait(zx::time::infinite(), &packet);
+    GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+    if (packet.key == kExceptionKey) {
+      // Process encountered an exception. Kill it directly rather than
+      // letting other handlers process the event. We will get a kProcessKey
+      // event when the process actually terminates.
+      status_zx = child_process_.kill();
+      GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+    } else if (packet.key == kProcessKey) {
+      // Process terminated.
+      GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
+      GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_PROCESS_TERMINATED);
+      process_terminated = true;
+    } else if (packet.key == kSocketKey) {
+      GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
+      if (packet.signal.observed & ZX_SOCKET_READABLE) {
+        // Read data from the socket.
+        constexpr size_t kBufferSize = 1024;
+        do {
+          size_t old_length = captured_stderr_.length();
+          size_t bytes_read = 0;
+          captured_stderr_.resize(old_length + kBufferSize);
+          status_zx =
+              stderr_socket_.read(0, &captured_stderr_.front() + old_length,
+                                  kBufferSize, &bytes_read);
+          captured_stderr_.resize(old_length + bytes_read);
+        } while (status_zx == ZX_OK);
+        if (status_zx == ZX_ERR_PEER_CLOSED) {
+          socket_closed = true;
+        } else {
+          GTEST_DEATH_TEST_CHECK_(status_zx == ZX_ERR_SHOULD_WAIT);
+          status_zx = stderr_socket_.wait_async(
+              port, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED, 0);
+          GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+        }
+      } else {
+        GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_SOCKET_PEER_CLOSED);
+        socket_closed = true;
+      }
+    }
+  } while (!process_terminated && !socket_closed);
+
+  ReadAndInterpretStatusByte();
+
+  zx_info_process_t buffer;
+  status_zx = child_process_.get_info(ZX_INFO_PROCESS, &buffer, sizeof(buffer),
+                                      nullptr, nullptr);
+  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+  GTEST_DEATH_TEST_CHECK_(buffer.flags & ZX_INFO_PROCESS_FLAG_EXITED);
+  set_status(static_cast<int>(buffer.return_code));
+  return status();
+}
+
+// The AssumeRole process for a Fuchsia death test.  It creates a child
+// process with the same executable as the current process to run the
+// death test.  The child process is given the --gtest_filter and
+// --gtest_internal_run_death_test flags such that it knows to run the
+// current death test only.
+DeathTest::TestRole FuchsiaDeathTest::AssumeRole() {
+  const UnitTestImpl* const impl = GetUnitTestImpl();
+  const InternalRunDeathTestFlag* const flag =
+      impl->internal_run_death_test_flag();
+  const TestInfo* const info = impl->current_test_info();
+  const int death_test_index = info->result()->death_test_count();
+
+  if (flag != nullptr) {
+    // ParseInternalRunDeathTestFlag() has performed all the necessary
+    // processing.
+    set_write_fd(kFuchsiaReadPipeFd);
+    return EXECUTE_TEST;
+  }
+
+  // Flush the log buffers since the log streams are shared with the child.
+  FlushInfoLog();
+
+  // Build the child process command line.
+  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
+                                  "filter=" + info->test_suite_name() + "." +
+                                  info->name();
+  const std::string internal_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
+                                    kInternalRunDeathTestFlag + "=" + file_ +
+                                    "|" + StreamableToString(line_) + "|" +
+                                    StreamableToString(death_test_index);
+  Arguments args;
+  args.AddArguments(GetInjectableArgvs());
+  args.AddArgument(filter_flag.c_str());
+  args.AddArgument(internal_flag.c_str());
+
+  // Build the pipe for communication with the child.
+  zx_status_t status;
+  zx_handle_t child_pipe_handle;
+  int child_pipe_fd;
+  status = fdio_pipe_half(&child_pipe_fd, &child_pipe_handle);
+  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
+  set_read_fd(child_pipe_fd);
+
+  // Set the pipe handle for the child.
+  fdio_spawn_action_t spawn_actions[2] = {};
+  fdio_spawn_action_t* add_handle_action = &spawn_actions[0];
+  add_handle_action->action = FDIO_SPAWN_ACTION_ADD_HANDLE;
+  add_handle_action->h.id = PA_HND(PA_FD, kFuchsiaReadPipeFd);
+  add_handle_action->h.handle = child_pipe_handle;
+
+  // Create a socket pair will be used to receive the child process' stderr.
+  zx::socket stderr_producer_socket;
+  status = zx::socket::create(0, &stderr_producer_socket, &stderr_socket_);
+  GTEST_DEATH_TEST_CHECK_(status >= 0);
+  int stderr_producer_fd = -1;
+  status =
+      fdio_fd_create(stderr_producer_socket.release(), &stderr_producer_fd);
+  GTEST_DEATH_TEST_CHECK_(status >= 0);
+
+  // Make the stderr socket nonblocking.
+  GTEST_DEATH_TEST_CHECK_(fcntl(stderr_producer_fd, F_SETFL, 0) == 0);
+
+  fdio_spawn_action_t* add_stderr_action = &spawn_actions[1];
+  add_stderr_action->action = FDIO_SPAWN_ACTION_CLONE_FD;
+  add_stderr_action->fd.local_fd = stderr_producer_fd;
+  add_stderr_action->fd.target_fd = STDERR_FILENO;
+
+  // Create a child job.
+  zx_handle_t child_job = ZX_HANDLE_INVALID;
+  status = zx_job_create(zx_job_default(), 0, &child_job);
+  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
+  zx_policy_basic_t policy;
+  policy.condition = ZX_POL_NEW_ANY;
+  policy.policy = ZX_POL_ACTION_ALLOW;
+  status = zx_job_set_policy(child_job, ZX_JOB_POL_RELATIVE, ZX_JOB_POL_BASIC,
+                             &policy, 1);
+  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
+
+  // Create an exception channel attached to the |child_job|, to allow
+  // us to suppress the system default exception handler from firing.
+  status = zx_task_create_exception_channel(
+      child_job, 0, exception_channel_.reset_and_get_address());
+  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
+
+  // Spawn the child process.
+  status = fdio_spawn_etc(child_job, FDIO_SPAWN_CLONE_ALL, args.Argv()[0],
+                          args.Argv(), nullptr, 2, spawn_actions,
+                          child_process_.reset_and_get_address(), nullptr);
+  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
+
+  set_spawned(true);
+  return OVERSEE_TEST;
+}
+
+std::string FuchsiaDeathTest::GetErrorLogs() { return captured_stderr_; }
+
+#else  // We are neither on Windows, nor on Fuchsia.
+
+// ForkingDeathTest provides implementations for most of the abstract
+// methods of the DeathTest interface.  Only the AssumeRole method is
+// left undefined.
+class ForkingDeathTest : public DeathTestImpl {
+ public:
+  ForkingDeathTest(const char* statement, Matcher<const std::string&> matcher);
+
+  // All of these virtual functions are inherited from DeathTest.
+  int Wait() override;
+
+ protected:
+  void set_child_pid(pid_t child_pid) { child_pid_ = child_pid; }
+
+ private:
+  // PID of child process during death test; 0 in the child process itself.
+  pid_t child_pid_;
+};
+
+// Constructs a ForkingDeathTest.
+ForkingDeathTest::ForkingDeathTest(const char* a_statement,
+                                   Matcher<const std::string&> matcher)
+    : DeathTestImpl(a_statement, std::move(matcher)), child_pid_(-1) {}
+
+// Waits for the child in a death test to exit, returning its exit
+// status, or 0 if no child process exists.  As a side effect, sets the
+// outcome data member.
+int ForkingDeathTest::Wait() {
+  if (!spawned()) return 0;
+
+  ReadAndInterpretStatusByte();
+
+  int status_value;
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(waitpid(child_pid_, &status_value, 0));
+  set_status(status_value);
+  return status_value;
+}
+
+// A concrete death test class that forks, then immediately runs the test
+// in the child process.
+class NoExecDeathTest : public ForkingDeathTest {
+ public:
+  NoExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher)
+      : ForkingDeathTest(a_statement, std::move(matcher)) {}
+  TestRole AssumeRole() override;
+};
+
+// The AssumeRole process for a fork-and-run death test.  It implements a
+// straightforward fork, with a simple pipe to transmit the status byte.
+DeathTest::TestRole NoExecDeathTest::AssumeRole() {
+  const size_t thread_count = GetThreadCount();
+  if (thread_count != 1) {
+    GTEST_LOG_(WARNING) << DeathTestThreadWarning(thread_count);
+  }
+
+  int pipe_fd[2];
+  GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
+
+  DeathTest::set_last_death_test_message("");
+  CaptureStderr();
+  // When we fork the process below, the log file buffers are copied, but the
+  // file descriptors are shared.  We flush all log files here so that closing
+  // the file descriptors in the child process doesn't throw off the
+  // synchronization between descriptors and buffers in the parent process.
+  // This is as close to the fork as possible to avoid a race condition in case
+  // there are multiple threads running before the death test, and another
+  // thread writes to the log file.
+  FlushInfoLog();
+
+  const pid_t child_pid = fork();
+  GTEST_DEATH_TEST_CHECK_(child_pid != -1);
+  set_child_pid(child_pid);
+  if (child_pid == 0) {
+    GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[0]));
+    set_write_fd(pipe_fd[1]);
+    // Redirects all logging to stderr in the child process to prevent
+    // concurrent writes to the log files.  We capture stderr in the parent
+    // process and append the child process' output to a log.
+    LogToStderr();
+    // Event forwarding to the listeners of event listener API mush be shut
+    // down in death test subprocesses.
+    GetUnitTestImpl()->listeners()->SuppressEventForwarding();
+    g_in_fast_death_test_child = true;
+    return EXECUTE_TEST;
+  } else {
+    GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
+    set_read_fd(pipe_fd[0]);
+    set_spawned(true);
+    return OVERSEE_TEST;
+  }
+}
+
+// A concrete death test class that forks and re-executes the main
+// program from the beginning, with command-line flags set that cause
+// only this specific death test to be run.
+class ExecDeathTest : public ForkingDeathTest {
+ public:
+  ExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
+                const char* file, int line)
+      : ForkingDeathTest(a_statement, std::move(matcher)),
+        file_(file),
+        line_(line) {}
+  TestRole AssumeRole() override;
+
+ private:
+  static ::std::vector<std::string> GetArgvsForDeathTestChildProcess() {
+    ::std::vector<std::string> args = GetInjectableArgvs();
+#if defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
+    ::std::vector<std::string> extra_args =
+        GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_();
+    args.insert(args.end(), extra_args.begin(), extra_args.end());
+#endif  // defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
+    return args;
+  }
+  // The name of the file in which the death test is located.
+  const char* const file_;
+  // The line number on which the death test is located.
+  const int line_;
+};
+
+// Utility class for accumulating command-line arguments.
+class Arguments {
+ public:
+  Arguments() { args_.push_back(nullptr); }
+
+  ~Arguments() {
+    for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
+         ++i) {
+      free(*i);
+    }
+  }
+  void AddArgument(const char* argument) {
+    args_.insert(args_.end() - 1, posix::StrDup(argument));
+  }
+
+  template <typename Str>
+  void AddArguments(const ::std::vector<Str>& arguments) {
+    for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
+         i != arguments.end(); ++i) {
+      args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
+    }
+  }
+  char* const* Argv() { return &args_[0]; }
+
+ private:
+  std::vector<char*> args_;
+};
+
+// A struct that encompasses the arguments to the child process of a
+// threadsafe-style death test process.
+struct ExecDeathTestArgs {
+  char* const* argv;  // Command-line arguments for the child's call to exec
+  int close_fd;       // File descriptor to close; the read end of a pipe
+};
+
+#if GTEST_OS_QNX
+extern "C" char** environ;
+#else   // GTEST_OS_QNX
+// The main function for a threadsafe-style death test child process.
+// This function is called in a clone()-ed process and thus must avoid
+// any potentially unsafe operations like malloc or libc functions.
+static int ExecDeathTestChildMain(void* child_arg) {
+  ExecDeathTestArgs* const args = static_cast<ExecDeathTestArgs*>(child_arg);
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(args->close_fd));
+
+  // We need to execute the test program in the same environment where
+  // it was originally invoked.  Therefore we change to the original
+  // working directory first.
+  const char* const original_dir =
+      UnitTest::GetInstance()->original_working_dir();
+  // We can safely call chdir() as it's a direct system call.
+  if (chdir(original_dir) != 0) {
+    DeathTestAbort(std::string("chdir(\"") + original_dir +
+                   "\") failed: " + GetLastErrnoDescription());
+    return EXIT_FAILURE;
+  }
+
+  // We can safely call execv() as it's almost a direct system call. We
+  // cannot use execvp() as it's a libc function and thus potentially
+  // unsafe.  Since execv() doesn't search the PATH, the user must
+  // invoke the test program via a valid path that contains at least
+  // one path separator.
+  execv(args->argv[0], args->argv);
+  DeathTestAbort(std::string("execv(") + args->argv[0] + ", ...) in " +
+                 original_dir + " failed: " + GetLastErrnoDescription());
+  return EXIT_FAILURE;
+}
+#endif  // GTEST_OS_QNX
+
+#if GTEST_HAS_CLONE
+// Two utility routines that together determine the direction the stack
+// grows.
+// This could be accomplished more elegantly by a single recursive
+// function, but we want to guard against the unlikely possibility of
+// a smart compiler optimizing the recursion away.
+//
+// GTEST_NO_INLINE_ is required to prevent GCC 4.6 from inlining
+// StackLowerThanAddress into StackGrowsDown, which then doesn't give
+// correct answer.
+static void StackLowerThanAddress(const void* ptr,
+                                  bool* result) GTEST_NO_INLINE_;
+// Make sure sanitizers do not tamper with the stack here.
+// Ideally, we want to use `__builtin_frame_address` instead of a local variable
+// address with sanitizer disabled, but it does not work when the
+// compiler optimizes the stack frame out, which happens on PowerPC targets.
+// HWAddressSanitizer add a random tag to the MSB of the local variable address,
+// making comparison result unpredictable.
+GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+static void StackLowerThanAddress(const void* ptr, bool* result) {
+  int dummy = 0;
+  *result = std::less<const void*>()(&dummy, ptr);
+}
+
+// Make sure AddressSanitizer does not tamper with the stack here.
+GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+static bool StackGrowsDown() {
+  int dummy = 0;
+  bool result;
+  StackLowerThanAddress(&dummy, &result);
+  return result;
+}
+#endif  // GTEST_HAS_CLONE
+
+// Spawns a child process with the same executable as the current process in
+// a thread-safe manner and instructs it to run the death test.  The
+// implementation uses fork(2) + exec.  On systems where clone(2) is
+// available, it is used instead, being slightly more thread-safe.  On QNX,
+// fork supports only single-threaded environments, so this function uses
+// spawn(2) there instead.  The function dies with an error message if
+// anything goes wrong.
+static pid_t ExecDeathTestSpawnChild(char* const* argv, int close_fd) {
+  ExecDeathTestArgs args = {argv, close_fd};
+  pid_t child_pid = -1;
+
+#if GTEST_OS_QNX
+  // Obtains the current directory and sets it to be closed in the child
+  // process.
+  const int cwd_fd = open(".", O_RDONLY);
+  GTEST_DEATH_TEST_CHECK_(cwd_fd != -1);
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(cwd_fd, F_SETFD, FD_CLOEXEC));
+  // We need to execute the test program in the same environment where
+  // it was originally invoked.  Therefore we change to the original
+  // working directory first.
+  const char* const original_dir =
+      UnitTest::GetInstance()->original_working_dir();
+  // We can safely call chdir() as it's a direct system call.
+  if (chdir(original_dir) != 0) {
+    DeathTestAbort(std::string("chdir(\"") + original_dir +
+                   "\") failed: " + GetLastErrnoDescription());
+    return EXIT_FAILURE;
+  }
+
+  int fd_flags;
+  // Set close_fd to be closed after spawn.
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(fd_flags = fcntl(close_fd, F_GETFD));
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(
+      fcntl(close_fd, F_SETFD, fd_flags | FD_CLOEXEC));
+  struct inheritance inherit = {0};
+  // spawn is a system call.
+  child_pid = spawn(args.argv[0], 0, nullptr, &inherit, args.argv, environ);
+  // Restores the current working directory.
+  GTEST_DEATH_TEST_CHECK_(fchdir(cwd_fd) != -1);
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(cwd_fd));
+
+#else  // GTEST_OS_QNX
+#if GTEST_OS_LINUX
+  // When a SIGPROF signal is received while fork() or clone() are executing,
+  // the process may hang. To avoid this, we ignore SIGPROF here and re-enable
+  // it after the call to fork()/clone() is complete.
+  struct sigaction saved_sigprof_action;
+  struct sigaction ignore_sigprof_action;
+  memset(&ignore_sigprof_action, 0, sizeof(ignore_sigprof_action));
+  sigemptyset(&ignore_sigprof_action.sa_mask);
+  ignore_sigprof_action.sa_handler = SIG_IGN;
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(
+      sigaction(SIGPROF, &ignore_sigprof_action, &saved_sigprof_action));
+#endif  // GTEST_OS_LINUX
+
+#if GTEST_HAS_CLONE
+  const bool use_fork = GTEST_FLAG_GET(death_test_use_fork);
+
+  if (!use_fork) {
+    static const bool stack_grows_down = StackGrowsDown();
+    const auto stack_size = static_cast<size_t>(getpagesize() * 2);
+    // MMAP_ANONYMOUS is not defined on Mac, so we use MAP_ANON instead.
+    void* const stack = mmap(nullptr, stack_size, PROT_READ | PROT_WRITE,
+                             MAP_ANON | MAP_PRIVATE, -1, 0);
+    GTEST_DEATH_TEST_CHECK_(stack != MAP_FAILED);
+
+    // Maximum stack alignment in bytes:  For a downward-growing stack, this
+    // amount is subtracted from size of the stack space to get an address
+    // that is within the stack space and is aligned on all systems we care
+    // about.  As far as I know there is no ABI with stack alignment greater
+    // than 64.  We assume stack and stack_size already have alignment of
+    // kMaxStackAlignment.
+    const size_t kMaxStackAlignment = 64;
+    void* const stack_top =
+        static_cast<char*>(stack) +
+        (stack_grows_down ? stack_size - kMaxStackAlignment : 0);
+    GTEST_DEATH_TEST_CHECK_(
+        static_cast<size_t>(stack_size) > kMaxStackAlignment &&
+        reinterpret_cast<uintptr_t>(stack_top) % kMaxStackAlignment == 0);
+
+    child_pid = clone(&ExecDeathTestChildMain, stack_top, SIGCHLD, &args);
+
+    GTEST_DEATH_TEST_CHECK_(munmap(stack, stack_size) != -1);
+  }
+#else
+  const bool use_fork = true;
+#endif  // GTEST_HAS_CLONE
+
+  if (use_fork && (child_pid = fork()) == 0) {
+    ExecDeathTestChildMain(&args);
+    _exit(0);
+  }
+#endif  // GTEST_OS_QNX
+#if GTEST_OS_LINUX
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(
+      sigaction(SIGPROF, &saved_sigprof_action, nullptr));
+#endif  // GTEST_OS_LINUX
+
+  GTEST_DEATH_TEST_CHECK_(child_pid != -1);
+  return child_pid;
+}
+
+// The AssumeRole process for a fork-and-exec death test.  It re-executes the
+// main program from the beginning, setting the --gtest_filter
+// and --gtest_internal_run_death_test flags to cause only the current
+// death test to be re-run.
+DeathTest::TestRole ExecDeathTest::AssumeRole() {
+  const UnitTestImpl* const impl = GetUnitTestImpl();
+  const InternalRunDeathTestFlag* const flag =
+      impl->internal_run_death_test_flag();
+  const TestInfo* const info = impl->current_test_info();
+  const int death_test_index = info->result()->death_test_count();
+
+  if (flag != nullptr) {
+    set_write_fd(flag->write_fd());
+    return EXECUTE_TEST;
+  }
+
+  int pipe_fd[2];
+  GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
+  // Clear the close-on-exec flag on the write end of the pipe, lest
+  // it be closed when the child process does an exec:
+  GTEST_DEATH_TEST_CHECK_(fcntl(pipe_fd[1], F_SETFD, 0) != -1);
+
+  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
+                                  "filter=" + info->test_suite_name() + "." +
+                                  info->name();
+  const std::string internal_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
+                                    "internal_run_death_test=" + file_ + "|" +
+                                    StreamableToString(line_) + "|" +
+                                    StreamableToString(death_test_index) + "|" +
+                                    StreamableToString(pipe_fd[1]);
+  Arguments args;
+  args.AddArguments(GetArgvsForDeathTestChildProcess());
+  args.AddArgument(filter_flag.c_str());
+  args.AddArgument(internal_flag.c_str());
+
+  DeathTest::set_last_death_test_message("");
+
+  CaptureStderr();
+  // See the comment in NoExecDeathTest::AssumeRole for why the next line
+  // is necessary.
+  FlushInfoLog();
+
+  const pid_t child_pid = ExecDeathTestSpawnChild(args.Argv(), pipe_fd[0]);
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
+  set_child_pid(child_pid);
+  set_read_fd(pipe_fd[0]);
+  set_spawned(true);
+  return OVERSEE_TEST;
+}
+
+#endif  // !GTEST_OS_WINDOWS
+
+// Creates a concrete DeathTest-derived class that depends on the
+// --gtest_death_test_style flag, and sets the pointer pointed to
+// by the "test" argument to its address.  If the test should be
+// skipped, sets that pointer to NULL.  Returns true, unless the
+// flag is set to an invalid value.
+bool DefaultDeathTestFactory::Create(const char* statement,
+                                     Matcher<const std::string&> matcher,
+                                     const char* file, int line,
+                                     DeathTest** test) {
+  UnitTestImpl* const impl = GetUnitTestImpl();
+  const InternalRunDeathTestFlag* const flag =
+      impl->internal_run_death_test_flag();
+  const int death_test_index =
+      impl->current_test_info()->increment_death_test_count();
+
+  if (flag != nullptr) {
+    if (death_test_index > flag->index()) {
+      DeathTest::set_last_death_test_message(
+          "Death test count (" + StreamableToString(death_test_index) +
+          ") somehow exceeded expected maximum (" +
+          StreamableToString(flag->index()) + ")");
+      return false;
+    }
+
+    if (!(flag->file() == file && flag->line() == line &&
+          flag->index() == death_test_index)) {
+      *test = nullptr;
+      return true;
+    }
+  }
+
+#if GTEST_OS_WINDOWS
+
+  if (GTEST_FLAG_GET(death_test_style) == "threadsafe" ||
+      GTEST_FLAG_GET(death_test_style) == "fast") {
+    *test = new WindowsDeathTest(statement, std::move(matcher), file, line);
+  }
+
+#elif GTEST_OS_FUCHSIA
+
+  if (GTEST_FLAG_GET(death_test_style) == "threadsafe" ||
+      GTEST_FLAG_GET(death_test_style) == "fast") {
+    *test = new FuchsiaDeathTest(statement, std::move(matcher), file, line);
+  }
+
+#else
+
+  if (GTEST_FLAG_GET(death_test_style) == "threadsafe") {
+    *test = new ExecDeathTest(statement, std::move(matcher), file, line);
+  } else if (GTEST_FLAG_GET(death_test_style) == "fast") {
+    *test = new NoExecDeathTest(statement, std::move(matcher));
+  }
+
+#endif  // GTEST_OS_WINDOWS
+
+  else {  // NOLINT - this is more readable than unbalanced brackets inside #if.
+    DeathTest::set_last_death_test_message("Unknown death test style \"" +
+                                           GTEST_FLAG_GET(death_test_style) +
+                                           "\" encountered");
+    return false;
+  }
+
+  return true;
+}
+
+#if GTEST_OS_WINDOWS
+// Recreates the pipe and event handles from the provided parameters,
+// signals the event, and returns a file descriptor wrapped around the pipe
+// handle. This function is called in the child process only.
+static int GetStatusFileDescriptor(unsigned int parent_process_id,
+                                   size_t write_handle_as_size_t,
+                                   size_t event_handle_as_size_t) {
+  AutoHandle parent_process_handle(::OpenProcess(PROCESS_DUP_HANDLE,
+                                                 FALSE,  // Non-inheritable.
+                                                 parent_process_id));
+  if (parent_process_handle.Get() == INVALID_HANDLE_VALUE) {
+    DeathTestAbort("Unable to open parent process " +
+                   StreamableToString(parent_process_id));
+  }
+
+  GTEST_CHECK_(sizeof(HANDLE) <= sizeof(size_t));
+
+  const HANDLE write_handle = reinterpret_cast<HANDLE>(write_handle_as_size_t);
+  HANDLE dup_write_handle;
+
+  // The newly initialized handle is accessible only in the parent
+  // process. To obtain one accessible within the child, we need to use
+  // DuplicateHandle.
+  if (!::DuplicateHandle(parent_process_handle.Get(), write_handle,
+                         ::GetCurrentProcess(), &dup_write_handle,
+                         0x0,    // Requested privileges ignored since
+                                 // DUPLICATE_SAME_ACCESS is used.
+                         FALSE,  // Request non-inheritable handler.
+                         DUPLICATE_SAME_ACCESS)) {
+    DeathTestAbort("Unable to duplicate the pipe handle " +
+                   StreamableToString(write_handle_as_size_t) +
+                   " from the parent process " +
+                   StreamableToString(parent_process_id));
+  }
+
+  const HANDLE event_handle = reinterpret_cast<HANDLE>(event_handle_as_size_t);
+  HANDLE dup_event_handle;
+
+  if (!::DuplicateHandle(parent_process_handle.Get(), event_handle,
+                         ::GetCurrentProcess(), &dup_event_handle, 0x0, FALSE,
+                         DUPLICATE_SAME_ACCESS)) {
+    DeathTestAbort("Unable to duplicate the event handle " +
+                   StreamableToString(event_handle_as_size_t) +
+                   " from the parent process " +
+                   StreamableToString(parent_process_id));
+  }
+
+  const int write_fd =
+      ::_open_osfhandle(reinterpret_cast<intptr_t>(dup_write_handle), O_APPEND);
+  if (write_fd == -1) {
+    DeathTestAbort("Unable to convert pipe handle " +
+                   StreamableToString(write_handle_as_size_t) +
+                   " to a file descriptor");
+  }
+
+  // Signals the parent that the write end of the pipe has been acquired
+  // so the parent can release its own write end.
+  ::SetEvent(dup_event_handle);
+
+  return write_fd;
+}
+#endif  // GTEST_OS_WINDOWS
+
+// Returns a newly created InternalRunDeathTestFlag object with fields
+// initialized from the GTEST_FLAG(internal_run_death_test) flag if
+// the flag is specified; otherwise returns NULL.
+InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag() {
+  if (GTEST_FLAG_GET(internal_run_death_test) == "") return nullptr;
+
+  // GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we
+  // can use it here.
+  int line = -1;
+  int index = -1;
+  ::std::vector< ::std::string> fields;
+  SplitString(GTEST_FLAG_GET(internal_run_death_test), '|', &fields);
+  int write_fd = -1;
+
+#if GTEST_OS_WINDOWS
+
+  unsigned int parent_process_id = 0;
+  size_t write_handle_as_size_t = 0;
+  size_t event_handle_as_size_t = 0;
+
+  if (fields.size() != 6 || !ParseNaturalNumber(fields[1], &line) ||
+      !ParseNaturalNumber(fields[2], &index) ||
+      !ParseNaturalNumber(fields[3], &parent_process_id) ||
+      !ParseNaturalNumber(fields[4], &write_handle_as_size_t) ||
+      !ParseNaturalNumber(fields[5], &event_handle_as_size_t)) {
+    DeathTestAbort("Bad --gtest_internal_run_death_test flag: " +
+                   GTEST_FLAG_GET(internal_run_death_test));
+  }
+  write_fd = GetStatusFileDescriptor(parent_process_id, write_handle_as_size_t,
+                                     event_handle_as_size_t);
+
+#elif GTEST_OS_FUCHSIA
+
+  if (fields.size() != 3 || !ParseNaturalNumber(fields[1], &line) ||
+      !ParseNaturalNumber(fields[2], &index)) {
+    DeathTestAbort("Bad --gtest_internal_run_death_test flag: " +
+                   GTEST_FLAG_GET(internal_run_death_test));
+  }
+
+#else
+
+  if (fields.size() != 4 || !ParseNaturalNumber(fields[1], &line) ||
+      !ParseNaturalNumber(fields[2], &index) ||
+      !ParseNaturalNumber(fields[3], &write_fd)) {
+    DeathTestAbort("Bad --gtest_internal_run_death_test flag: " +
+                   GTEST_FLAG_GET(internal_run_death_test));
+  }
+
+#endif  // GTEST_OS_WINDOWS
+
+  return new InternalRunDeathTestFlag(fields[0], line, index, write_fd);
+}
+
+}  // namespace internal
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+}  // namespace testing
diff --git a/test/gtest/src/gtest-filepath.cc b/test/gtest/src/gtest-filepath.cc
new file mode 100644
index 0000000..f6ee90c
--- /dev/null
+++ b/test/gtest/src/gtest-filepath.cc
@@ -0,0 +1,367 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "gtest/internal/gtest-filepath.h"
+
+#include <stdlib.h>
+
+#include "gtest/gtest-message.h"
+#include "gtest/internal/gtest-port.h"
+
+#if GTEST_OS_WINDOWS_MOBILE
+#include <windows.h>
+#elif GTEST_OS_WINDOWS
+#include <direct.h>
+#include <io.h>
+#else
+#include <limits.h>
+
+#include <climits>  // Some Linux distributions define PATH_MAX here.
+#endif              // GTEST_OS_WINDOWS_MOBILE
+
+#include "gtest/internal/gtest-string.h"
+
+#if GTEST_OS_WINDOWS
+#define GTEST_PATH_MAX_ _MAX_PATH
+#elif defined(PATH_MAX)
+#define GTEST_PATH_MAX_ PATH_MAX
+#elif defined(_XOPEN_PATH_MAX)
+#define GTEST_PATH_MAX_ _XOPEN_PATH_MAX
+#else
+#define GTEST_PATH_MAX_ _POSIX_PATH_MAX
+#endif  // GTEST_OS_WINDOWS
+
+namespace testing {
+namespace internal {
+
+#if GTEST_OS_WINDOWS
+// On Windows, '\\' is the standard path separator, but many tools and the
+// Windows API also accept '/' as an alternate path separator. Unless otherwise
+// noted, a file path can contain either kind of path separators, or a mixture
+// of them.
+const char kPathSeparator = '\\';
+const char kAlternatePathSeparator = '/';
+const char kAlternatePathSeparatorString[] = "/";
+#if GTEST_OS_WINDOWS_MOBILE
+// Windows CE doesn't have a current directory. You should not use
+// the current directory in tests on Windows CE, but this at least
+// provides a reasonable fallback.
+const char kCurrentDirectoryString[] = "\\";
+// Windows CE doesn't define INVALID_FILE_ATTRIBUTES
+const DWORD kInvalidFileAttributes = 0xffffffff;
+#else
+const char kCurrentDirectoryString[] = ".\\";
+#endif  // GTEST_OS_WINDOWS_MOBILE
+#else
+const char kPathSeparator = '/';
+const char kCurrentDirectoryString[] = "./";
+#endif  // GTEST_OS_WINDOWS
+
+// Returns whether the given character is a valid path separator.
+static bool IsPathSeparator(char c) {
+#if GTEST_HAS_ALT_PATH_SEP_
+  return (c == kPathSeparator) || (c == kAlternatePathSeparator);
+#else
+  return c == kPathSeparator;
+#endif
+}
+
+// Returns the current working directory, or "" if unsuccessful.
+FilePath FilePath::GetCurrentDir() {
+#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_PHONE ||         \
+    GTEST_OS_WINDOWS_RT || GTEST_OS_ESP8266 || GTEST_OS_ESP32 || \
+    GTEST_OS_XTENSA
+  // These platforms do not have a current directory, so we just return
+  // something reasonable.
+  return FilePath(kCurrentDirectoryString);
+#elif GTEST_OS_WINDOWS
+  char cwd[GTEST_PATH_MAX_ + 1] = {'\0'};
+  return FilePath(_getcwd(cwd, sizeof(cwd)) == nullptr ? "" : cwd);
+#else
+  char cwd[GTEST_PATH_MAX_ + 1] = {'\0'};
+  char* result = getcwd(cwd, sizeof(cwd));
+#if GTEST_OS_NACL
+  // getcwd will likely fail in NaCl due to the sandbox, so return something
+  // reasonable. The user may have provided a shim implementation for getcwd,
+  // however, so fallback only when failure is detected.
+  return FilePath(result == nullptr ? kCurrentDirectoryString : cwd);
+#endif  // GTEST_OS_NACL
+  return FilePath(result == nullptr ? "" : cwd);
+#endif  // GTEST_OS_WINDOWS_MOBILE
+}
+
+// Returns a copy of the FilePath with the case-insensitive extension removed.
+// Example: FilePath("dir/file.exe").RemoveExtension("EXE") returns
+// FilePath("dir/file"). If a case-insensitive extension is not
+// found, returns a copy of the original FilePath.
+FilePath FilePath::RemoveExtension(const char* extension) const {
+  const std::string dot_extension = std::string(".") + extension;
+  if (String::EndsWithCaseInsensitive(pathname_, dot_extension)) {
+    return FilePath(
+        pathname_.substr(0, pathname_.length() - dot_extension.length()));
+  }
+  return *this;
+}
+
+// Returns a pointer to the last occurrence of a valid path separator in
+// the FilePath. On Windows, for example, both '/' and '\' are valid path
+// separators. Returns NULL if no path separator was found.
+const char* FilePath::FindLastPathSeparator() const {
+  const char* const last_sep = strrchr(c_str(), kPathSeparator);
+#if GTEST_HAS_ALT_PATH_SEP_
+  const char* const last_alt_sep = strrchr(c_str(), kAlternatePathSeparator);
+  // Comparing two pointers of which only one is NULL is undefined.
+  if (last_alt_sep != nullptr &&
+      (last_sep == nullptr || last_alt_sep > last_sep)) {
+    return last_alt_sep;
+  }
+#endif
+  return last_sep;
+}
+
+// Returns a copy of the FilePath with the directory part removed.
+// Example: FilePath("path/to/file").RemoveDirectoryName() returns
+// FilePath("file"). If there is no directory part ("just_a_file"), it returns
+// the FilePath unmodified. If there is no file part ("just_a_dir/") it
+// returns an empty FilePath ("").
+// On Windows platform, '\' is the path separator, otherwise it is '/'.
+FilePath FilePath::RemoveDirectoryName() const {
+  const char* const last_sep = FindLastPathSeparator();
+  return last_sep ? FilePath(last_sep + 1) : *this;
+}
+
+// RemoveFileName returns the directory path with the filename removed.
+// Example: FilePath("path/to/file").RemoveFileName() returns "path/to/".
+// If the FilePath is "a_file" or "/a_file", RemoveFileName returns
+// FilePath("./") or, on Windows, FilePath(".\\"). If the filepath does
+// not have a file, like "just/a/dir/", it returns the FilePath unmodified.
+// On Windows platform, '\' is the path separator, otherwise it is '/'.
+FilePath FilePath::RemoveFileName() const {
+  const char* const last_sep = FindLastPathSeparator();
+  std::string dir;
+  if (last_sep) {
+    dir = std::string(c_str(), static_cast<size_t>(last_sep + 1 - c_str()));
+  } else {
+    dir = kCurrentDirectoryString;
+  }
+  return FilePath(dir);
+}
+
+// Helper functions for naming files in a directory for xml output.
+
+// Given directory = "dir", base_name = "test", number = 0,
+// extension = "xml", returns "dir/test.xml". If number is greater
+// than zero (e.g., 12), returns "dir/test_12.xml".
+// On Windows platform, uses \ as the separator rather than /.
+FilePath FilePath::MakeFileName(const FilePath& directory,
+                                const FilePath& base_name, int number,
+                                const char* extension) {
+  std::string file;
+  if (number == 0) {
+    file = base_name.string() + "." + extension;
+  } else {
+    file =
+        base_name.string() + "_" + StreamableToString(number) + "." + extension;
+  }
+  return ConcatPaths(directory, FilePath(file));
+}
+
+// Given directory = "dir", relative_path = "test.xml", returns "dir/test.xml".
+// On Windows, uses \ as the separator rather than /.
+FilePath FilePath::ConcatPaths(const FilePath& directory,
+                               const FilePath& relative_path) {
+  if (directory.IsEmpty()) return relative_path;
+  const FilePath dir(directory.RemoveTrailingPathSeparator());
+  return FilePath(dir.string() + kPathSeparator + relative_path.string());
+}
+
+// Returns true if pathname describes something findable in the file-system,
+// either a file, directory, or whatever.
+bool FilePath::FileOrDirectoryExists() const {
+#if GTEST_OS_WINDOWS_MOBILE
+  LPCWSTR unicode = String::AnsiToUtf16(pathname_.c_str());
+  const DWORD attributes = GetFileAttributes(unicode);
+  delete[] unicode;
+  return attributes != kInvalidFileAttributes;
+#else
+  posix::StatStruct file_stat{};
+  return posix::Stat(pathname_.c_str(), &file_stat) == 0;
+#endif  // GTEST_OS_WINDOWS_MOBILE
+}
+
+// Returns true if pathname describes a directory in the file-system
+// that exists.
+bool FilePath::DirectoryExists() const {
+  bool result = false;
+#if GTEST_OS_WINDOWS
+  // Don't strip off trailing separator if path is a root directory on
+  // Windows (like "C:\\").
+  const FilePath& path(IsRootDirectory() ? *this
+                                         : RemoveTrailingPathSeparator());
+#else
+  const FilePath& path(*this);
+#endif
+
+#if GTEST_OS_WINDOWS_MOBILE
+  LPCWSTR unicode = String::AnsiToUtf16(path.c_str());
+  const DWORD attributes = GetFileAttributes(unicode);
+  delete[] unicode;
+  if ((attributes != kInvalidFileAttributes) &&
+      (attributes & FILE_ATTRIBUTE_DIRECTORY)) {
+    result = true;
+  }
+#else
+  posix::StatStruct file_stat{};
+  result =
+      posix::Stat(path.c_str(), &file_stat) == 0 && posix::IsDir(file_stat);
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+  return result;
+}
+
+// Returns true if pathname describes a root directory. (Windows has one
+// root directory per disk drive.)
+bool FilePath::IsRootDirectory() const {
+#if GTEST_OS_WINDOWS
+  return pathname_.length() == 3 && IsAbsolutePath();
+#else
+  return pathname_.length() == 1 && IsPathSeparator(pathname_.c_str()[0]);
+#endif
+}
+
+// Returns true if pathname describes an absolute path.
+bool FilePath::IsAbsolutePath() const {
+  const char* const name = pathname_.c_str();
+#if GTEST_OS_WINDOWS
+  return pathname_.length() >= 3 &&
+         ((name[0] >= 'a' && name[0] <= 'z') ||
+          (name[0] >= 'A' && name[0] <= 'Z')) &&
+         name[1] == ':' && IsPathSeparator(name[2]);
+#else
+  return IsPathSeparator(name[0]);
+#endif
+}
+
+// Returns a pathname for a file that does not currently exist. The pathname
+// will be directory/base_name.extension or
+// directory/base_name_<number>.extension if directory/base_name.extension
+// already exists. The number will be incremented until a pathname is found
+// that does not already exist.
+// Examples: 'dir/foo_test.xml' or 'dir/foo_test_1.xml'.
+// There could be a race condition if two or more processes are calling this
+// function at the same time -- they could both pick the same filename.
+FilePath FilePath::GenerateUniqueFileName(const FilePath& directory,
+                                          const FilePath& base_name,
+                                          const char* extension) {
+  FilePath full_pathname;
+  int number = 0;
+  do {
+    full_pathname.Set(MakeFileName(directory, base_name, number++, extension));
+  } while (full_pathname.FileOrDirectoryExists());
+  return full_pathname;
+}
+
+// Returns true if FilePath ends with a path separator, which indicates that
+// it is intended to represent a directory. Returns false otherwise.
+// This does NOT check that a directory (or file) actually exists.
+bool FilePath::IsDirectory() const {
+  return !pathname_.empty() &&
+         IsPathSeparator(pathname_.c_str()[pathname_.length() - 1]);
+}
+
+// Create directories so that path exists. Returns true if successful or if
+// the directories already exist; returns false if unable to create directories
+// for any reason.
+bool FilePath::CreateDirectoriesRecursively() const {
+  if (!this->IsDirectory()) {
+    return false;
+  }
+
+  if (pathname_.length() == 0 || this->DirectoryExists()) {
+    return true;
+  }
+
+  const FilePath parent(this->RemoveTrailingPathSeparator().RemoveFileName());
+  return parent.CreateDirectoriesRecursively() && this->CreateFolder();
+}
+
+// Create the directory so that path exists. Returns true if successful or
+// if the directory already exists; returns false if unable to create the
+// directory for any reason, including if the parent directory does not
+// exist. Not named "CreateDirectory" because that's a macro on Windows.
+bool FilePath::CreateFolder() const {
+#if GTEST_OS_WINDOWS_MOBILE
+  FilePath removed_sep(this->RemoveTrailingPathSeparator());
+  LPCWSTR unicode = String::AnsiToUtf16(removed_sep.c_str());
+  int result = CreateDirectory(unicode, nullptr) ? 0 : -1;
+  delete[] unicode;
+#elif GTEST_OS_WINDOWS
+  int result = _mkdir(pathname_.c_str());
+#elif GTEST_OS_ESP8266 || GTEST_OS_XTENSA
+  // do nothing
+  int result = 0;
+#else
+  int result = mkdir(pathname_.c_str(), 0777);
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+  if (result == -1) {
+    return this->DirectoryExists();  // An error is OK if the directory exists.
+  }
+  return true;  // No error.
+}
+
+// If input name has a trailing separator character, remove it and return the
+// name, otherwise return the name string unmodified.
+// On Windows platform, uses \ as the separator, other platforms use /.
+FilePath FilePath::RemoveTrailingPathSeparator() const {
+  return IsDirectory() ? FilePath(pathname_.substr(0, pathname_.length() - 1))
+                       : *this;
+}
+
+// Removes any redundant separators that might be in the pathname.
+// For example, "bar///foo" becomes "bar/foo". Does not eliminate other
+// redundancies that might be in a pathname involving "." or "..".
+void FilePath::Normalize() {
+  auto out = pathname_.begin();
+
+  for (const char character : pathname_) {
+    if (!IsPathSeparator(character)) {
+      *(out++) = character;
+    } else if (out == pathname_.begin() || *std::prev(out) != kPathSeparator) {
+      *(out++) = kPathSeparator;
+    } else {
+      continue;
+    }
+  }
+
+  pathname_.erase(out, pathname_.end());
+}
+
+}  // namespace internal
+}  // namespace testing
diff --git a/test/gtest/src/gtest-internal-inl.h b/test/gtest/src/gtest-internal-inl.h
new file mode 100644
index 0000000..0b9e929
--- /dev/null
+++ b/test/gtest/src/gtest-internal-inl.h
@@ -0,0 +1,1212 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Utility functions and classes used by the Google C++ testing framework.//
+// This file contains purely Google Test's internal implementation.  Please
+// DO NOT #INCLUDE IT IN A USER PROGRAM.
+
+#ifndef GOOGLETEST_SRC_GTEST_INTERNAL_INL_H_
+#define GOOGLETEST_SRC_GTEST_INTERNAL_INL_H_
+
+#ifndef _WIN32_WCE
+#include <errno.h>
+#endif  // !_WIN32_WCE
+#include <stddef.h>
+#include <stdlib.h>  // For strtoll/_strtoul64/malloc/free.
+#include <string.h>  // For memmove.
+
+#include <algorithm>
+#include <cstdint>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "gtest/internal/gtest-port.h"
+
+#if GTEST_CAN_STREAM_RESULTS_
+#include <arpa/inet.h>  // NOLINT
+#include <netdb.h>      // NOLINT
+#endif
+
+#if GTEST_OS_WINDOWS
+#include <windows.h>  // NOLINT
+#endif                // GTEST_OS_WINDOWS
+
+#include "gtest/gtest-spi.h"
+#include "gtest/gtest.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+// Declares the flags.
+//
+// We don't want the users to modify this flag in the code, but want
+// Google Test's own unit tests to be able to access it. Therefore we
+// declare it here as opposed to in gtest.h.
+GTEST_DECLARE_bool_(death_test_use_fork);
+
+namespace testing {
+namespace internal {
+
+// The value of GetTestTypeId() as seen from within the Google Test
+// library.  This is solely for testing GetTestTypeId().
+GTEST_API_ extern const TypeId kTestTypeIdInGoogleTest;
+
+// A valid random seed must be in [1, kMaxRandomSeed].
+const int kMaxRandomSeed = 99999;
+
+// g_help_flag is true if and only if the --help flag or an equivalent form
+// is specified on the command line.
+GTEST_API_ extern bool g_help_flag;
+
+// Returns the current time in milliseconds.
+GTEST_API_ TimeInMillis GetTimeInMillis();
+
+// Returns true if and only if Google Test should use colors in the output.
+GTEST_API_ bool ShouldUseColor(bool stdout_is_tty);
+
+// Formats the given time in milliseconds as seconds.
+GTEST_API_ std::string FormatTimeInMillisAsSeconds(TimeInMillis ms);
+
+// Converts the given time in milliseconds to a date string in the ISO 8601
+// format, without the timezone information.  N.B.: due to the use the
+// non-reentrant localtime() function, this function is not thread safe.  Do
+// not use it in any code that can be called from multiple threads.
+GTEST_API_ std::string FormatEpochTimeInMillisAsIso8601(TimeInMillis ms);
+
+// Parses a string for an Int32 flag, in the form of "--flag=value".
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+GTEST_API_ bool ParseFlag(const char* str, const char* flag, int32_t* value);
+
+// Returns a random seed in range [1, kMaxRandomSeed] based on the
+// given --gtest_random_seed flag value.
+inline int GetRandomSeedFromFlag(int32_t random_seed_flag) {
+  const unsigned int raw_seed =
+      (random_seed_flag == 0) ? static_cast<unsigned int>(GetTimeInMillis())
+                              : static_cast<unsigned int>(random_seed_flag);
+
+  // Normalizes the actual seed to range [1, kMaxRandomSeed] such that
+  // it's easy to type.
+  const int normalized_seed =
+      static_cast<int>((raw_seed - 1U) %
+                       static_cast<unsigned int>(kMaxRandomSeed)) +
+      1;
+  return normalized_seed;
+}
+
+// Returns the first valid random seed after 'seed'.  The behavior is
+// undefined if 'seed' is invalid.  The seed after kMaxRandomSeed is
+// considered to be 1.
+inline int GetNextRandomSeed(int seed) {
+  GTEST_CHECK_(1 <= seed && seed <= kMaxRandomSeed)
+      << "Invalid random seed " << seed << " - must be in [1, "
+      << kMaxRandomSeed << "].";
+  const int next_seed = seed + 1;
+  return (next_seed > kMaxRandomSeed) ? 1 : next_seed;
+}
+
+// This class saves the values of all Google Test flags in its c'tor, and
+// restores them in its d'tor.
+class GTestFlagSaver {
+ public:
+  // The c'tor.
+  GTestFlagSaver() {
+    also_run_disabled_tests_ = GTEST_FLAG_GET(also_run_disabled_tests);
+    break_on_failure_ = GTEST_FLAG_GET(break_on_failure);
+    catch_exceptions_ = GTEST_FLAG_GET(catch_exceptions);
+    color_ = GTEST_FLAG_GET(color);
+    death_test_style_ = GTEST_FLAG_GET(death_test_style);
+    death_test_use_fork_ = GTEST_FLAG_GET(death_test_use_fork);
+    fail_fast_ = GTEST_FLAG_GET(fail_fast);
+    filter_ = GTEST_FLAG_GET(filter);
+    internal_run_death_test_ = GTEST_FLAG_GET(internal_run_death_test);
+    list_tests_ = GTEST_FLAG_GET(list_tests);
+    output_ = GTEST_FLAG_GET(output);
+    brief_ = GTEST_FLAG_GET(brief);
+    print_time_ = GTEST_FLAG_GET(print_time);
+    print_utf8_ = GTEST_FLAG_GET(print_utf8);
+    random_seed_ = GTEST_FLAG_GET(random_seed);
+    repeat_ = GTEST_FLAG_GET(repeat);
+    recreate_environments_when_repeating_ =
+        GTEST_FLAG_GET(recreate_environments_when_repeating);
+    shuffle_ = GTEST_FLAG_GET(shuffle);
+    stack_trace_depth_ = GTEST_FLAG_GET(stack_trace_depth);
+    stream_result_to_ = GTEST_FLAG_GET(stream_result_to);
+    throw_on_failure_ = GTEST_FLAG_GET(throw_on_failure);
+  }
+
+  // The d'tor is not virtual.  DO NOT INHERIT FROM THIS CLASS.
+  ~GTestFlagSaver() {
+    GTEST_FLAG_SET(also_run_disabled_tests, also_run_disabled_tests_);
+    GTEST_FLAG_SET(break_on_failure, break_on_failure_);
+    GTEST_FLAG_SET(catch_exceptions, catch_exceptions_);
+    GTEST_FLAG_SET(color, color_);
+    GTEST_FLAG_SET(death_test_style, death_test_style_);
+    GTEST_FLAG_SET(death_test_use_fork, death_test_use_fork_);
+    GTEST_FLAG_SET(filter, filter_);
+    GTEST_FLAG_SET(fail_fast, fail_fast_);
+    GTEST_FLAG_SET(internal_run_death_test, internal_run_death_test_);
+    GTEST_FLAG_SET(list_tests, list_tests_);
+    GTEST_FLAG_SET(output, output_);
+    GTEST_FLAG_SET(brief, brief_);
+    GTEST_FLAG_SET(print_time, print_time_);
+    GTEST_FLAG_SET(print_utf8, print_utf8_);
+    GTEST_FLAG_SET(random_seed, random_seed_);
+    GTEST_FLAG_SET(repeat, repeat_);
+    GTEST_FLAG_SET(recreate_environments_when_repeating,
+                   recreate_environments_when_repeating_);
+    GTEST_FLAG_SET(shuffle, shuffle_);
+    GTEST_FLAG_SET(stack_trace_depth, stack_trace_depth_);
+    GTEST_FLAG_SET(stream_result_to, stream_result_to_);
+    GTEST_FLAG_SET(throw_on_failure, throw_on_failure_);
+  }
+
+ private:
+  // Fields for saving the original values of flags.
+  bool also_run_disabled_tests_;
+  bool break_on_failure_;
+  bool catch_exceptions_;
+  std::string color_;
+  std::string death_test_style_;
+  bool death_test_use_fork_;
+  bool fail_fast_;
+  std::string filter_;
+  std::string internal_run_death_test_;
+  bool list_tests_;
+  std::string output_;
+  bool brief_;
+  bool print_time_;
+  bool print_utf8_;
+  int32_t random_seed_;
+  int32_t repeat_;
+  bool recreate_environments_when_repeating_;
+  bool shuffle_;
+  int32_t stack_trace_depth_;
+  std::string stream_result_to_;
+  bool throw_on_failure_;
+} GTEST_ATTRIBUTE_UNUSED_;
+
+// Converts a Unicode code point to a narrow string in UTF-8 encoding.
+// code_point parameter is of type UInt32 because wchar_t may not be
+// wide enough to contain a code point.
+// If the code_point is not a valid Unicode code point
+// (i.e. outside of Unicode range U+0 to U+10FFFF) it will be converted
+// to "(Invalid Unicode 0xXXXXXXXX)".
+GTEST_API_ std::string CodePointToUtf8(uint32_t code_point);
+
+// Converts a wide string to a narrow string in UTF-8 encoding.
+// The wide string is assumed to have the following encoding:
+//   UTF-16 if sizeof(wchar_t) == 2 (on Windows, Cygwin)
+//   UTF-32 if sizeof(wchar_t) == 4 (on Linux)
+// Parameter str points to a null-terminated wide string.
+// Parameter num_chars may additionally limit the number
+// of wchar_t characters processed. -1 is used when the entire string
+// should be processed.
+// If the string contains code points that are not valid Unicode code points
+// (i.e. outside of Unicode range U+0 to U+10FFFF) they will be output
+// as '(Invalid Unicode 0xXXXXXXXX)'. If the string is in UTF16 encoding
+// and contains invalid UTF-16 surrogate pairs, values in those pairs
+// will be encoded as individual Unicode characters from Basic Normal Plane.
+GTEST_API_ std::string WideStringToUtf8(const wchar_t* str, int num_chars);
+
+// Reads the GTEST_SHARD_STATUS_FILE environment variable, and creates the file
+// if the variable is present. If a file already exists at this location, this
+// function will write over it. If the variable is present, but the file cannot
+// be created, prints an error and exits.
+void WriteToShardStatusFileIfNeeded();
+
+// Checks whether sharding is enabled by examining the relevant
+// environment variable values. If the variables are present,
+// but inconsistent (e.g., shard_index >= total_shards), prints
+// an error and exits. If in_subprocess_for_death_test, sharding is
+// disabled because it must only be applied to the original test
+// process. Otherwise, we could filter out death tests we intended to execute.
+GTEST_API_ bool ShouldShard(const char* total_shards_str,
+                            const char* shard_index_str,
+                            bool in_subprocess_for_death_test);
+
+// Parses the environment variable var as a 32-bit integer. If it is unset,
+// returns default_val. If it is not a 32-bit integer, prints an error and
+// and aborts.
+GTEST_API_ int32_t Int32FromEnvOrDie(const char* env_var, int32_t default_val);
+
+// Given the total number of shards, the shard index, and the test id,
+// returns true if and only if the test should be run on this shard. The test id
+// is some arbitrary but unique non-negative integer assigned to each test
+// method. Assumes that 0 <= shard_index < total_shards.
+GTEST_API_ bool ShouldRunTestOnShard(int total_shards, int shard_index,
+                                     int test_id);
+
+// STL container utilities.
+
+// Returns the number of elements in the given container that satisfy
+// the given predicate.
+template <class Container, typename Predicate>
+inline int CountIf(const Container& c, Predicate predicate) {
+  // Implemented as an explicit loop since std::count_if() in libCstd on
+  // Solaris has a non-standard signature.
+  int count = 0;
+  for (auto it = c.begin(); it != c.end(); ++it) {
+    if (predicate(*it)) ++count;
+  }
+  return count;
+}
+
+// Applies a function/functor to each element in the container.
+template <class Container, typename Functor>
+void ForEach(const Container& c, Functor functor) {
+  std::for_each(c.begin(), c.end(), functor);
+}
+
+// Returns the i-th element of the vector, or default_value if i is not
+// in range [0, v.size()).
+template <typename E>
+inline E GetElementOr(const std::vector<E>& v, int i, E default_value) {
+  return (i < 0 || i >= static_cast<int>(v.size())) ? default_value
+                                                    : v[static_cast<size_t>(i)];
+}
+
+// Performs an in-place shuffle of a range of the vector's elements.
+// 'begin' and 'end' are element indices as an STL-style range;
+// i.e. [begin, end) are shuffled, where 'end' == size() means to
+// shuffle to the end of the vector.
+template <typename E>
+void ShuffleRange(internal::Random* random, int begin, int end,
+                  std::vector<E>* v) {
+  const int size = static_cast<int>(v->size());
+  GTEST_CHECK_(0 <= begin && begin <= size)
+      << "Invalid shuffle range start " << begin << ": must be in range [0, "
+      << size << "].";
+  GTEST_CHECK_(begin <= end && end <= size)
+      << "Invalid shuffle range finish " << end << ": must be in range ["
+      << begin << ", " << size << "].";
+
+  // Fisher-Yates shuffle, from
+  // http://en.wikipedia.org/wiki/Fisher-Yates_shuffle
+  for (int range_width = end - begin; range_width >= 2; range_width--) {
+    const int last_in_range = begin + range_width - 1;
+    const int selected =
+        begin +
+        static_cast<int>(random->Generate(static_cast<uint32_t>(range_width)));
+    std::swap((*v)[static_cast<size_t>(selected)],
+              (*v)[static_cast<size_t>(last_in_range)]);
+  }
+}
+
+// Performs an in-place shuffle of the vector's elements.
+template <typename E>
+inline void Shuffle(internal::Random* random, std::vector<E>* v) {
+  ShuffleRange(random, 0, static_cast<int>(v->size()), v);
+}
+
+// A function for deleting an object.  Handy for being used as a
+// functor.
+template <typename T>
+static void Delete(T* x) {
+  delete x;
+}
+
+// A predicate that checks the key of a TestProperty against a known key.
+//
+// TestPropertyKeyIs is copyable.
+class TestPropertyKeyIs {
+ public:
+  // Constructor.
+  //
+  // TestPropertyKeyIs has NO default constructor.
+  explicit TestPropertyKeyIs(const std::string& key) : key_(key) {}
+
+  // Returns true if and only if the test name of test property matches on key_.
+  bool operator()(const TestProperty& test_property) const {
+    return test_property.key() == key_;
+  }
+
+ private:
+  std::string key_;
+};
+
+// Class UnitTestOptions.
+//
+// This class contains functions for processing options the user
+// specifies when running the tests.  It has only static members.
+//
+// In most cases, the user can specify an option using either an
+// environment variable or a command line flag.  E.g. you can set the
+// test filter using either GTEST_FILTER or --gtest_filter.  If both
+// the variable and the flag are present, the latter overrides the
+// former.
+class GTEST_API_ UnitTestOptions {
+ public:
+  // Functions for processing the gtest_output flag.
+
+  // Returns the output format, or "" for normal printed output.
+  static std::string GetOutputFormat();
+
+  // Returns the absolute path of the requested output file, or the
+  // default (test_detail.xml in the original working directory) if
+  // none was explicitly specified.
+  static std::string GetAbsolutePathToOutputFile();
+
+  // Functions for processing the gtest_filter flag.
+
+  // Returns true if and only if the user-specified filter matches the test
+  // suite name and the test name.
+  static bool FilterMatchesTest(const std::string& test_suite_name,
+                                const std::string& test_name);
+
+#if GTEST_OS_WINDOWS
+  // Function for supporting the gtest_catch_exception flag.
+
+  // Returns EXCEPTION_EXECUTE_HANDLER if Google Test should handle the
+  // given SEH exception, or EXCEPTION_CONTINUE_SEARCH otherwise.
+  // This function is useful as an __except condition.
+  static int GTestShouldProcessSEH(DWORD exception_code);
+#endif  // GTEST_OS_WINDOWS
+
+  // Returns true if "name" matches the ':' separated list of glob-style
+  // filters in "filter".
+  static bool MatchesFilter(const std::string& name, const char* filter);
+};
+
+// Returns the current application's name, removing directory path if that
+// is present.  Used by UnitTestOptions::GetOutputFile.
+GTEST_API_ FilePath GetCurrentExecutableName();
+
+// The role interface for getting the OS stack trace as a string.
+class OsStackTraceGetterInterface {
+ public:
+  OsStackTraceGetterInterface() {}
+  virtual ~OsStackTraceGetterInterface() {}
+
+  // Returns the current OS stack trace as an std::string.  Parameters:
+  //
+  //   max_depth  - the maximum number of stack frames to be included
+  //                in the trace.
+  //   skip_count - the number of top frames to be skipped; doesn't count
+  //                against max_depth.
+  virtual std::string CurrentStackTrace(int max_depth, int skip_count) = 0;
+
+  // UponLeavingGTest() should be called immediately before Google Test calls
+  // user code. It saves some information about the current stack that
+  // CurrentStackTrace() will use to find and hide Google Test stack frames.
+  virtual void UponLeavingGTest() = 0;
+
+  // This string is inserted in place of stack frames that are part of
+  // Google Test's implementation.
+  static const char* const kElidedFramesMarker;
+
+ private:
+  OsStackTraceGetterInterface(const OsStackTraceGetterInterface&) = delete;
+  OsStackTraceGetterInterface& operator=(const OsStackTraceGetterInterface&) =
+      delete;
+};
+
+// A working implementation of the OsStackTraceGetterInterface interface.
+class OsStackTraceGetter : public OsStackTraceGetterInterface {
+ public:
+  OsStackTraceGetter() {}
+
+  std::string CurrentStackTrace(int max_depth, int skip_count) override;
+  void UponLeavingGTest() override;
+
+ private:
+#if GTEST_HAS_ABSL
+  Mutex mutex_;  // Protects all internal state.
+
+  // We save the stack frame below the frame that calls user code.
+  // We do this because the address of the frame immediately below
+  // the user code changes between the call to UponLeavingGTest()
+  // and any calls to the stack trace code from within the user code.
+  void* caller_frame_ = nullptr;
+#endif  // GTEST_HAS_ABSL
+
+  OsStackTraceGetter(const OsStackTraceGetter&) = delete;
+  OsStackTraceGetter& operator=(const OsStackTraceGetter&) = delete;
+};
+
+// Information about a Google Test trace point.
+struct TraceInfo {
+  const char* file;
+  int line;
+  std::string message;
+};
+
+// This is the default global test part result reporter used in UnitTestImpl.
+// This class should only be used by UnitTestImpl.
+class DefaultGlobalTestPartResultReporter
+    : public TestPartResultReporterInterface {
+ public:
+  explicit DefaultGlobalTestPartResultReporter(UnitTestImpl* unit_test);
+  // Implements the TestPartResultReporterInterface. Reports the test part
+  // result in the current test.
+  void ReportTestPartResult(const TestPartResult& result) override;
+
+ private:
+  UnitTestImpl* const unit_test_;
+
+  DefaultGlobalTestPartResultReporter(
+      const DefaultGlobalTestPartResultReporter&) = delete;
+  DefaultGlobalTestPartResultReporter& operator=(
+      const DefaultGlobalTestPartResultReporter&) = delete;
+};
+
+// This is the default per thread test part result reporter used in
+// UnitTestImpl. This class should only be used by UnitTestImpl.
+class DefaultPerThreadTestPartResultReporter
+    : public TestPartResultReporterInterface {
+ public:
+  explicit DefaultPerThreadTestPartResultReporter(UnitTestImpl* unit_test);
+  // Implements the TestPartResultReporterInterface. The implementation just
+  // delegates to the current global test part result reporter of *unit_test_.
+  void ReportTestPartResult(const TestPartResult& result) override;
+
+ private:
+  UnitTestImpl* const unit_test_;
+
+  DefaultPerThreadTestPartResultReporter(
+      const DefaultPerThreadTestPartResultReporter&) = delete;
+  DefaultPerThreadTestPartResultReporter& operator=(
+      const DefaultPerThreadTestPartResultReporter&) = delete;
+};
+
+// The private implementation of the UnitTest class.  We don't protect
+// the methods under a mutex, as this class is not accessible by a
+// user and the UnitTest class that delegates work to this class does
+// proper locking.
+class GTEST_API_ UnitTestImpl {
+ public:
+  explicit UnitTestImpl(UnitTest* parent);
+  virtual ~UnitTestImpl();
+
+  // There are two different ways to register your own TestPartResultReporter.
+  // You can register your own repoter to listen either only for test results
+  // from the current thread or for results from all threads.
+  // By default, each per-thread test result repoter just passes a new
+  // TestPartResult to the global test result reporter, which registers the
+  // test part result for the currently running test.
+
+  // Returns the global test part result reporter.
+  TestPartResultReporterInterface* GetGlobalTestPartResultReporter();
+
+  // Sets the global test part result reporter.
+  void SetGlobalTestPartResultReporter(
+      TestPartResultReporterInterface* reporter);
+
+  // Returns the test part result reporter for the current thread.
+  TestPartResultReporterInterface* GetTestPartResultReporterForCurrentThread();
+
+  // Sets the test part result reporter for the current thread.
+  void SetTestPartResultReporterForCurrentThread(
+      TestPartResultReporterInterface* reporter);
+
+  // Gets the number of successful test suites.
+  int successful_test_suite_count() const;
+
+  // Gets the number of failed test suites.
+  int failed_test_suite_count() const;
+
+  // Gets the number of all test suites.
+  int total_test_suite_count() const;
+
+  // Gets the number of all test suites that contain at least one test
+  // that should run.
+  int test_suite_to_run_count() const;
+
+  // Gets the number of successful tests.
+  int successful_test_count() const;
+
+  // Gets the number of skipped tests.
+  int skipped_test_count() const;
+
+  // Gets the number of failed tests.
+  int failed_test_count() const;
+
+  // Gets the number of disabled tests that will be reported in the XML report.
+  int reportable_disabled_test_count() const;
+
+  // Gets the number of disabled tests.
+  int disabled_test_count() const;
+
+  // Gets the number of tests to be printed in the XML report.
+  int reportable_test_count() const;
+
+  // Gets the number of all tests.
+  int total_test_count() const;
+
+  // Gets the number of tests that should run.
+  int test_to_run_count() const;
+
+  // Gets the time of the test program start, in ms from the start of the
+  // UNIX epoch.
+  TimeInMillis start_timestamp() const { return start_timestamp_; }
+
+  // Gets the elapsed time, in milliseconds.
+  TimeInMillis elapsed_time() const { return elapsed_time_; }
+
+  // Returns true if and only if the unit test passed (i.e. all test suites
+  // passed).
+  bool Passed() const { return !Failed(); }
+
+  // Returns true if and only if the unit test failed (i.e. some test suite
+  // failed or something outside of all tests failed).
+  bool Failed() const {
+    return failed_test_suite_count() > 0 || ad_hoc_test_result()->Failed();
+  }
+
+  // Gets the i-th test suite among all the test suites. i can range from 0 to
+  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
+  const TestSuite* GetTestSuite(int i) const {
+    const int index = GetElementOr(test_suite_indices_, i, -1);
+    return index < 0 ? nullptr : test_suites_[static_cast<size_t>(i)];
+  }
+
+  //  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  const TestCase* GetTestCase(int i) const { return GetTestSuite(i); }
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Gets the i-th test suite among all the test suites. i can range from 0 to
+  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
+  TestSuite* GetMutableSuiteCase(int i) {
+    const int index = GetElementOr(test_suite_indices_, i, -1);
+    return index < 0 ? nullptr : test_suites_[static_cast<size_t>(index)];
+  }
+
+  // Provides access to the event listener list.
+  TestEventListeners* listeners() { return &listeners_; }
+
+  // Returns the TestResult for the test that's currently running, or
+  // the TestResult for the ad hoc test if no test is running.
+  TestResult* current_test_result();
+
+  // Returns the TestResult for the ad hoc test.
+  const TestResult* ad_hoc_test_result() const { return &ad_hoc_test_result_; }
+
+  // Sets the OS stack trace getter.
+  //
+  // Does nothing if the input and the current OS stack trace getter
+  // are the same; otherwise, deletes the old getter and makes the
+  // input the current getter.
+  void set_os_stack_trace_getter(OsStackTraceGetterInterface* getter);
+
+  // Returns the current OS stack trace getter if it is not NULL;
+  // otherwise, creates an OsStackTraceGetter, makes it the current
+  // getter, and returns it.
+  OsStackTraceGetterInterface* os_stack_trace_getter();
+
+  // Returns the current OS stack trace as an std::string.
+  //
+  // The maximum number of stack frames to be included is specified by
+  // the gtest_stack_trace_depth flag.  The skip_count parameter
+  // specifies the number of top frames to be skipped, which doesn't
+  // count against the number of frames to be included.
+  //
+  // For example, if Foo() calls Bar(), which in turn calls
+  // CurrentOsStackTraceExceptTop(1), Foo() will be included in the
+  // trace but Bar() and CurrentOsStackTraceExceptTop() won't.
+  std::string CurrentOsStackTraceExceptTop(int skip_count)
+      GTEST_NO_INLINE_ GTEST_NO_TAIL_CALL_;
+
+  // Finds and returns a TestSuite with the given name.  If one doesn't
+  // exist, creates one and returns it.
+  //
+  // Arguments:
+  //
+  //   test_suite_name: name of the test suite
+  //   type_param:      the name of the test's type parameter, or NULL if
+  //                    this is not a typed or a type-parameterized test.
+  //   set_up_tc:       pointer to the function that sets up the test suite
+  //   tear_down_tc:    pointer to the function that tears down the test suite
+  TestSuite* GetTestSuite(const char* test_suite_name, const char* type_param,
+                          internal::SetUpTestSuiteFunc set_up_tc,
+                          internal::TearDownTestSuiteFunc tear_down_tc);
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  TestCase* GetTestCase(const char* test_case_name, const char* type_param,
+                        internal::SetUpTestSuiteFunc set_up_tc,
+                        internal::TearDownTestSuiteFunc tear_down_tc) {
+    return GetTestSuite(test_case_name, type_param, set_up_tc, tear_down_tc);
+  }
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Adds a TestInfo to the unit test.
+  //
+  // Arguments:
+  //
+  //   set_up_tc:    pointer to the function that sets up the test suite
+  //   tear_down_tc: pointer to the function that tears down the test suite
+  //   test_info:    the TestInfo object
+  void AddTestInfo(internal::SetUpTestSuiteFunc set_up_tc,
+                   internal::TearDownTestSuiteFunc tear_down_tc,
+                   TestInfo* test_info) {
+#if GTEST_HAS_DEATH_TEST
+    // In order to support thread-safe death tests, we need to
+    // remember the original working directory when the test program
+    // was first invoked.  We cannot do this in RUN_ALL_TESTS(), as
+    // the user may have changed the current directory before calling
+    // RUN_ALL_TESTS().  Therefore we capture the current directory in
+    // AddTestInfo(), which is called to register a TEST or TEST_F
+    // before main() is reached.
+    if (original_working_dir_.IsEmpty()) {
+      original_working_dir_.Set(FilePath::GetCurrentDir());
+      GTEST_CHECK_(!original_working_dir_.IsEmpty())
+          << "Failed to get the current working directory.";
+    }
+#endif  // GTEST_HAS_DEATH_TEST
+
+    GetTestSuite(test_info->test_suite_name(), test_info->type_param(),
+                 set_up_tc, tear_down_tc)
+        ->AddTestInfo(test_info);
+  }
+
+  // Returns ParameterizedTestSuiteRegistry object used to keep track of
+  // value-parameterized tests and instantiate and register them.
+  internal::ParameterizedTestSuiteRegistry& parameterized_test_registry() {
+    return parameterized_test_registry_;
+  }
+
+  std::set<std::string>* ignored_parameterized_test_suites() {
+    return &ignored_parameterized_test_suites_;
+  }
+
+  // Returns TypeParameterizedTestSuiteRegistry object used to keep track of
+  // type-parameterized tests and instantiations of them.
+  internal::TypeParameterizedTestSuiteRegistry&
+  type_parameterized_test_registry() {
+    return type_parameterized_test_registry_;
+  }
+
+  // Sets the TestSuite object for the test that's currently running.
+  void set_current_test_suite(TestSuite* a_current_test_suite) {
+    current_test_suite_ = a_current_test_suite;
+  }
+
+  // Sets the TestInfo object for the test that's currently running.  If
+  // current_test_info is NULL, the assertion results will be stored in
+  // ad_hoc_test_result_.
+  void set_current_test_info(TestInfo* a_current_test_info) {
+    current_test_info_ = a_current_test_info;
+  }
+
+  // Registers all parameterized tests defined using TEST_P and
+  // INSTANTIATE_TEST_SUITE_P, creating regular tests for each test/parameter
+  // combination. This method can be called more then once; it has guards
+  // protecting from registering the tests more then once.  If
+  // value-parameterized tests are disabled, RegisterParameterizedTests is
+  // present but does nothing.
+  void RegisterParameterizedTests();
+
+  // Runs all tests in this UnitTest object, prints the result, and
+  // returns true if all tests are successful.  If any exception is
+  // thrown during a test, this test is considered to be failed, but
+  // the rest of the tests will still be run.
+  bool RunAllTests();
+
+  // Clears the results of all tests, except the ad hoc tests.
+  void ClearNonAdHocTestResult() {
+    ForEach(test_suites_, TestSuite::ClearTestSuiteResult);
+  }
+
+  // Clears the results of ad-hoc test assertions.
+  void ClearAdHocTestResult() { ad_hoc_test_result_.Clear(); }
+
+  // Adds a TestProperty to the current TestResult object when invoked in a
+  // context of a test or a test suite, or to the global property set. If the
+  // result already contains a property with the same key, the value will be
+  // updated.
+  void RecordProperty(const TestProperty& test_property);
+
+  enum ReactionToSharding { HONOR_SHARDING_PROTOCOL, IGNORE_SHARDING_PROTOCOL };
+
+  // Matches the full name of each test against the user-specified
+  // filter to decide whether the test should run, then records the
+  // result in each TestSuite and TestInfo object.
+  // If shard_tests == HONOR_SHARDING_PROTOCOL, further filters tests
+  // based on sharding variables in the environment.
+  // Returns the number of tests that should run.
+  int FilterTests(ReactionToSharding shard_tests);
+
+  // Prints the names of the tests matching the user-specified filter flag.
+  void ListTestsMatchingFilter();
+
+  const TestSuite* current_test_suite() const { return current_test_suite_; }
+  TestInfo* current_test_info() { return current_test_info_; }
+  const TestInfo* current_test_info() const { return current_test_info_; }
+
+  // Returns the vector of environments that need to be set-up/torn-down
+  // before/after the tests are run.
+  std::vector<Environment*>& environments() { return environments_; }
+
+  // Getters for the per-thread Google Test trace stack.
+  std::vector<TraceInfo>& gtest_trace_stack() {
+    return *(gtest_trace_stack_.pointer());
+  }
+  const std::vector<TraceInfo>& gtest_trace_stack() const {
+    return gtest_trace_stack_.get();
+  }
+
+#if GTEST_HAS_DEATH_TEST
+  void InitDeathTestSubprocessControlInfo() {
+    internal_run_death_test_flag_.reset(ParseInternalRunDeathTestFlag());
+  }
+  // Returns a pointer to the parsed --gtest_internal_run_death_test
+  // flag, or NULL if that flag was not specified.
+  // This information is useful only in a death test child process.
+  // Must not be called before a call to InitGoogleTest.
+  const InternalRunDeathTestFlag* internal_run_death_test_flag() const {
+    return internal_run_death_test_flag_.get();
+  }
+
+  // Returns a pointer to the current death test factory.
+  internal::DeathTestFactory* death_test_factory() {
+    return death_test_factory_.get();
+  }
+
+  void SuppressTestEventsIfInSubprocess();
+
+  friend class ReplaceDeathTestFactory;
+#endif  // GTEST_HAS_DEATH_TEST
+
+  // Initializes the event listener performing XML output as specified by
+  // UnitTestOptions. Must not be called before InitGoogleTest.
+  void ConfigureXmlOutput();
+
+#if GTEST_CAN_STREAM_RESULTS_
+  // Initializes the event listener for streaming test results to a socket.
+  // Must not be called before InitGoogleTest.
+  void ConfigureStreamingOutput();
+#endif
+
+  // Performs initialization dependent upon flag values obtained in
+  // ParseGoogleTestFlagsOnly.  Is called from InitGoogleTest after the call to
+  // ParseGoogleTestFlagsOnly.  In case a user neglects to call InitGoogleTest
+  // this function is also called from RunAllTests.  Since this function can be
+  // called more than once, it has to be idempotent.
+  void PostFlagParsingInit();
+
+  // Gets the random seed used at the start of the current test iteration.
+  int random_seed() const { return random_seed_; }
+
+  // Gets the random number generator.
+  internal::Random* random() { return &random_; }
+
+  // Shuffles all test suites, and the tests within each test suite,
+  // making sure that death tests are still run first.
+  void ShuffleTests();
+
+  // Restores the test suites and tests to their order before the first shuffle.
+  void UnshuffleTests();
+
+  // Returns the value of GTEST_FLAG(catch_exceptions) at the moment
+  // UnitTest::Run() starts.
+  bool catch_exceptions() const { return catch_exceptions_; }
+
+ private:
+  friend class ::testing::UnitTest;
+
+  // Used by UnitTest::Run() to capture the state of
+  // GTEST_FLAG(catch_exceptions) at the moment it starts.
+  void set_catch_exceptions(bool value) { catch_exceptions_ = value; }
+
+  // The UnitTest object that owns this implementation object.
+  UnitTest* const parent_;
+
+  // The working directory when the first TEST() or TEST_F() was
+  // executed.
+  internal::FilePath original_working_dir_;
+
+  // The default test part result reporters.
+  DefaultGlobalTestPartResultReporter default_global_test_part_result_reporter_;
+  DefaultPerThreadTestPartResultReporter
+      default_per_thread_test_part_result_reporter_;
+
+  // Points to (but doesn't own) the global test part result reporter.
+  TestPartResultReporterInterface* global_test_part_result_repoter_;
+
+  // Protects read and write access to global_test_part_result_reporter_.
+  internal::Mutex global_test_part_result_reporter_mutex_;
+
+  // Points to (but doesn't own) the per-thread test part result reporter.
+  internal::ThreadLocal<TestPartResultReporterInterface*>
+      per_thread_test_part_result_reporter_;
+
+  // The vector of environments that need to be set-up/torn-down
+  // before/after the tests are run.
+  std::vector<Environment*> environments_;
+
+  // The vector of TestSuites in their original order.  It owns the
+  // elements in the vector.
+  std::vector<TestSuite*> test_suites_;
+
+  // Provides a level of indirection for the test suite list to allow
+  // easy shuffling and restoring the test suite order.  The i-th
+  // element of this vector is the index of the i-th test suite in the
+  // shuffled order.
+  std::vector<int> test_suite_indices_;
+
+  // ParameterizedTestRegistry object used to register value-parameterized
+  // tests.
+  internal::ParameterizedTestSuiteRegistry parameterized_test_registry_;
+  internal::TypeParameterizedTestSuiteRegistry
+      type_parameterized_test_registry_;
+
+  // The set holding the name of parameterized
+  // test suites that may go uninstantiated.
+  std::set<std::string> ignored_parameterized_test_suites_;
+
+  // Indicates whether RegisterParameterizedTests() has been called already.
+  bool parameterized_tests_registered_;
+
+  // Index of the last death test suite registered.  Initially -1.
+  int last_death_test_suite_;
+
+  // This points to the TestSuite for the currently running test.  It
+  // changes as Google Test goes through one test suite after another.
+  // When no test is running, this is set to NULL and Google Test
+  // stores assertion results in ad_hoc_test_result_.  Initially NULL.
+  TestSuite* current_test_suite_;
+
+  // This points to the TestInfo for the currently running test.  It
+  // changes as Google Test goes through one test after another.  When
+  // no test is running, this is set to NULL and Google Test stores
+  // assertion results in ad_hoc_test_result_.  Initially NULL.
+  TestInfo* current_test_info_;
+
+  // Normally, a user only writes assertions inside a TEST or TEST_F,
+  // or inside a function called by a TEST or TEST_F.  Since Google
+  // Test keeps track of which test is current running, it can
+  // associate such an assertion with the test it belongs to.
+  //
+  // If an assertion is encountered when no TEST or TEST_F is running,
+  // Google Test attributes the assertion result to an imaginary "ad hoc"
+  // test, and records the result in ad_hoc_test_result_.
+  TestResult ad_hoc_test_result_;
+
+  // The list of event listeners that can be used to track events inside
+  // Google Test.
+  TestEventListeners listeners_;
+
+  // The OS stack trace getter.  Will be deleted when the UnitTest
+  // object is destructed.  By default, an OsStackTraceGetter is used,
+  // but the user can set this field to use a custom getter if that is
+  // desired.
+  OsStackTraceGetterInterface* os_stack_trace_getter_;
+
+  // True if and only if PostFlagParsingInit() has been called.
+  bool post_flag_parse_init_performed_;
+
+  // The random number seed used at the beginning of the test run.
+  int random_seed_;
+
+  // Our random number generator.
+  internal::Random random_;
+
+  // The time of the test program start, in ms from the start of the
+  // UNIX epoch.
+  TimeInMillis start_timestamp_;
+
+  // How long the test took to run, in milliseconds.
+  TimeInMillis elapsed_time_;
+
+#if GTEST_HAS_DEATH_TEST
+  // The decomposed components of the gtest_internal_run_death_test flag,
+  // parsed when RUN_ALL_TESTS is called.
+  std::unique_ptr<InternalRunDeathTestFlag> internal_run_death_test_flag_;
+  std::unique_ptr<internal::DeathTestFactory> death_test_factory_;
+#endif  // GTEST_HAS_DEATH_TEST
+
+  // A per-thread stack of traces created by the SCOPED_TRACE() macro.
+  internal::ThreadLocal<std::vector<TraceInfo> > gtest_trace_stack_;
+
+  // The value of GTEST_FLAG(catch_exceptions) at the moment RunAllTests()
+  // starts.
+  bool catch_exceptions_;
+
+  UnitTestImpl(const UnitTestImpl&) = delete;
+  UnitTestImpl& operator=(const UnitTestImpl&) = delete;
+};  // class UnitTestImpl
+
+// Convenience function for accessing the global UnitTest
+// implementation object.
+inline UnitTestImpl* GetUnitTestImpl() {
+  return UnitTest::GetInstance()->impl();
+}
+
+#if GTEST_USES_SIMPLE_RE
+
+// Internal helper functions for implementing the simple regular
+// expression matcher.
+GTEST_API_ bool IsInSet(char ch, const char* str);
+GTEST_API_ bool IsAsciiDigit(char ch);
+GTEST_API_ bool IsAsciiPunct(char ch);
+GTEST_API_ bool IsRepeat(char ch);
+GTEST_API_ bool IsAsciiWhiteSpace(char ch);
+GTEST_API_ bool IsAsciiWordChar(char ch);
+GTEST_API_ bool IsValidEscape(char ch);
+GTEST_API_ bool AtomMatchesChar(bool escaped, char pattern, char ch);
+GTEST_API_ bool ValidateRegex(const char* regex);
+GTEST_API_ bool MatchRegexAtHead(const char* regex, const char* str);
+GTEST_API_ bool MatchRepetitionAndRegexAtHead(bool escaped, char ch,
+                                              char repeat, const char* regex,
+                                              const char* str);
+GTEST_API_ bool MatchRegexAnywhere(const char* regex, const char* str);
+
+#endif  // GTEST_USES_SIMPLE_RE
+
+// Parses the command line for Google Test flags, without initializing
+// other parts of Google Test.
+GTEST_API_ void ParseGoogleTestFlagsOnly(int* argc, char** argv);
+GTEST_API_ void ParseGoogleTestFlagsOnly(int* argc, wchar_t** argv);
+
+#if GTEST_HAS_DEATH_TEST
+
+// Returns the message describing the last system error, regardless of the
+// platform.
+GTEST_API_ std::string GetLastErrnoDescription();
+
+// Attempts to parse a string into a positive integer pointed to by the
+// number parameter.  Returns true if that is possible.
+// GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we can use
+// it here.
+template <typename Integer>
+bool ParseNaturalNumber(const ::std::string& str, Integer* number) {
+  // Fail fast if the given string does not begin with a digit;
+  // this bypasses strtoXXX's "optional leading whitespace and plus
+  // or minus sign" semantics, which are undesirable here.
+  if (str.empty() || !IsDigit(str[0])) {
+    return false;
+  }
+  errno = 0;
+
+  char* end;
+  // BiggestConvertible is the largest integer type that system-provided
+  // string-to-number conversion routines can return.
+  using BiggestConvertible = unsigned long long;  // NOLINT
+
+  const BiggestConvertible parsed = strtoull(str.c_str(), &end, 10);  // NOLINT
+  const bool parse_success = *end == '\0' && errno == 0;
+
+  GTEST_CHECK_(sizeof(Integer) <= sizeof(parsed));
+
+  const Integer result = static_cast<Integer>(parsed);
+  if (parse_success && static_cast<BiggestConvertible>(result) == parsed) {
+    *number = result;
+    return true;
+  }
+  return false;
+}
+#endif  // GTEST_HAS_DEATH_TEST
+
+// TestResult contains some private methods that should be hidden from
+// Google Test user but are required for testing. This class allow our tests
+// to access them.
+//
+// This class is supplied only for the purpose of testing Google Test's own
+// constructs. Do not use it in user tests, either directly or indirectly.
+class TestResultAccessor {
+ public:
+  static void RecordProperty(TestResult* test_result,
+                             const std::string& xml_element,
+                             const TestProperty& property) {
+    test_result->RecordProperty(xml_element, property);
+  }
+
+  static void ClearTestPartResults(TestResult* test_result) {
+    test_result->ClearTestPartResults();
+  }
+
+  static const std::vector<testing::TestPartResult>& test_part_results(
+      const TestResult& test_result) {
+    return test_result.test_part_results();
+  }
+};
+
+#if GTEST_CAN_STREAM_RESULTS_
+
+// Streams test results to the given port on the given host machine.
+class StreamingListener : public EmptyTestEventListener {
+ public:
+  // Abstract base class for writing strings to a socket.
+  class AbstractSocketWriter {
+   public:
+    virtual ~AbstractSocketWriter() {}
+
+    // Sends a string to the socket.
+    virtual void Send(const std::string& message) = 0;
+
+    // Closes the socket.
+    virtual void CloseConnection() {}
+
+    // Sends a string and a newline to the socket.
+    void SendLn(const std::string& message) { Send(message + "\n"); }
+  };
+
+  // Concrete class for actually writing strings to a socket.
+  class SocketWriter : public AbstractSocketWriter {
+   public:
+    SocketWriter(const std::string& host, const std::string& port)
+        : sockfd_(-1), host_name_(host), port_num_(port) {
+      MakeConnection();
+    }
+
+    ~SocketWriter() override {
+      if (sockfd_ != -1) CloseConnection();
+    }
+
+    // Sends a string to the socket.
+    void Send(const std::string& message) override {
+      GTEST_CHECK_(sockfd_ != -1)
+          << "Send() can be called only when there is a connection.";
+
+      const auto len = static_cast<size_t>(message.length());
+      if (write(sockfd_, message.c_str(), len) != static_cast<ssize_t>(len)) {
+        GTEST_LOG_(WARNING) << "stream_result_to: failed to stream to "
+                            << host_name_ << ":" << port_num_;
+      }
+    }
+
+   private:
+    // Creates a client socket and connects to the server.
+    void MakeConnection();
+
+    // Closes the socket.
+    void CloseConnection() override {
+      GTEST_CHECK_(sockfd_ != -1)
+          << "CloseConnection() can be called only when there is a connection.";
+
+      close(sockfd_);
+      sockfd_ = -1;
+    }
+
+    int sockfd_;  // socket file descriptor
+    const std::string host_name_;
+    const std::string port_num_;
+
+    SocketWriter(const SocketWriter&) = delete;
+    SocketWriter& operator=(const SocketWriter&) = delete;
+  };  // class SocketWriter
+
+  // Escapes '=', '&', '%', and '\n' characters in str as "%xx".
+  static std::string UrlEncode(const char* str);
+
+  StreamingListener(const std::string& host, const std::string& port)
+      : socket_writer_(new SocketWriter(host, port)) {
+    Start();
+  }
+
+  explicit StreamingListener(AbstractSocketWriter* socket_writer)
+      : socket_writer_(socket_writer) {
+    Start();
+  }
+
+  void OnTestProgramStart(const UnitTest& /* unit_test */) override {
+    SendLn("event=TestProgramStart");
+  }
+
+  void OnTestProgramEnd(const UnitTest& unit_test) override {
+    // Note that Google Test current only report elapsed time for each
+    // test iteration, not for the entire test program.
+    SendLn("event=TestProgramEnd&passed=" + FormatBool(unit_test.Passed()));
+
+    // Notify the streaming server to stop.
+    socket_writer_->CloseConnection();
+  }
+
+  void OnTestIterationStart(const UnitTest& /* unit_test */,
+                            int iteration) override {
+    SendLn("event=TestIterationStart&iteration=" +
+           StreamableToString(iteration));
+  }
+
+  void OnTestIterationEnd(const UnitTest& unit_test,
+                          int /* iteration */) override {
+    SendLn("event=TestIterationEnd&passed=" + FormatBool(unit_test.Passed()) +
+           "&elapsed_time=" + StreamableToString(unit_test.elapsed_time()) +
+           "ms");
+  }
+
+  // Note that "event=TestCaseStart" is a wire format and has to remain
+  // "case" for compatibility
+  void OnTestSuiteStart(const TestSuite& test_suite) override {
+    SendLn(std::string("event=TestCaseStart&name=") + test_suite.name());
+  }
+
+  // Note that "event=TestCaseEnd" is a wire format and has to remain
+  // "case" for compatibility
+  void OnTestSuiteEnd(const TestSuite& test_suite) override {
+    SendLn("event=TestCaseEnd&passed=" + FormatBool(test_suite.Passed()) +
+           "&elapsed_time=" + StreamableToString(test_suite.elapsed_time()) +
+           "ms");
+  }
+
+  void OnTestStart(const TestInfo& test_info) override {
+    SendLn(std::string("event=TestStart&name=") + test_info.name());
+  }
+
+  void OnTestEnd(const TestInfo& test_info) override {
+    SendLn("event=TestEnd&passed=" +
+           FormatBool((test_info.result())->Passed()) + "&elapsed_time=" +
+           StreamableToString((test_info.result())->elapsed_time()) + "ms");
+  }
+
+  void OnTestPartResult(const TestPartResult& test_part_result) override {
+    const char* file_name = test_part_result.file_name();
+    if (file_name == nullptr) file_name = "";
+    SendLn("event=TestPartResult&file=" + UrlEncode(file_name) +
+           "&line=" + StreamableToString(test_part_result.line_number()) +
+           "&message=" + UrlEncode(test_part_result.message()));
+  }
+
+ private:
+  // Sends the given message and a newline to the socket.
+  void SendLn(const std::string& message) { socket_writer_->SendLn(message); }
+
+  // Called at the start of streaming to notify the receiver what
+  // protocol we are using.
+  void Start() { SendLn("gtest_streaming_protocol_version=1.0"); }
+
+  std::string FormatBool(bool value) { return value ? "1" : "0"; }
+
+  const std::unique_ptr<AbstractSocketWriter> socket_writer_;
+
+  StreamingListener(const StreamingListener&) = delete;
+  StreamingListener& operator=(const StreamingListener&) = delete;
+};  // class StreamingListener
+
+#endif  // GTEST_CAN_STREAM_RESULTS_
+
+}  // namespace internal
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+#endif  // GOOGLETEST_SRC_GTEST_INTERNAL_INL_H_
diff --git a/test/gtest/src/gtest-matchers.cc b/test/gtest/src/gtest-matchers.cc
new file mode 100644
index 0000000..7e3bcc0
--- /dev/null
+++ b/test/gtest/src/gtest-matchers.cc
@@ -0,0 +1,98 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This file implements just enough of the matcher interface to allow
+// EXPECT_DEATH and friends to accept a matcher argument.
+
+#include "gtest/gtest-matchers.h"
+
+#include <string>
+
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-port.h"
+
+namespace testing {
+
+// Constructs a matcher that matches a const std::string& whose value is
+// equal to s.
+Matcher<const std::string&>::Matcher(const std::string& s) { *this = Eq(s); }
+
+// Constructs a matcher that matches a const std::string& whose value is
+// equal to s.
+Matcher<const std::string&>::Matcher(const char* s) {
+  *this = Eq(std::string(s));
+}
+
+// Constructs a matcher that matches a std::string whose value is equal to
+// s.
+Matcher<std::string>::Matcher(const std::string& s) { *this = Eq(s); }
+
+// Constructs a matcher that matches a std::string whose value is equal to
+// s.
+Matcher<std::string>::Matcher(const char* s) { *this = Eq(std::string(s)); }
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+// Constructs a matcher that matches a const StringView& whose value is
+// equal to s.
+Matcher<const internal::StringView&>::Matcher(const std::string& s) {
+  *this = Eq(s);
+}
+
+// Constructs a matcher that matches a const StringView& whose value is
+// equal to s.
+Matcher<const internal::StringView&>::Matcher(const char* s) {
+  *this = Eq(std::string(s));
+}
+
+// Constructs a matcher that matches a const StringView& whose value is
+// equal to s.
+Matcher<const internal::StringView&>::Matcher(internal::StringView s) {
+  *this = Eq(std::string(s));
+}
+
+// Constructs a matcher that matches a StringView whose value is equal to
+// s.
+Matcher<internal::StringView>::Matcher(const std::string& s) { *this = Eq(s); }
+
+// Constructs a matcher that matches a StringView whose value is equal to
+// s.
+Matcher<internal::StringView>::Matcher(const char* s) {
+  *this = Eq(std::string(s));
+}
+
+// Constructs a matcher that matches a StringView whose value is equal to
+// s.
+Matcher<internal::StringView>::Matcher(internal::StringView s) {
+  *this = Eq(std::string(s));
+}
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+
+}  // namespace testing
diff --git a/test/gtest/src/gtest-port.cc b/test/gtest/src/gtest-port.cc
new file mode 100644
index 0000000..d797fe4
--- /dev/null
+++ b/test/gtest/src/gtest-port.cc
@@ -0,0 +1,1394 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "gtest/internal/gtest-port.h"
+
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <cstdint>
+#include <fstream>
+#include <memory>
+
+#if GTEST_OS_WINDOWS
+#include <io.h>
+#include <sys/stat.h>
+#include <windows.h>
+
+#include <map>  // Used in ThreadLocal.
+#ifdef _MSC_VER
+#include <crtdbg.h>
+#endif  // _MSC_VER
+#else
+#include <unistd.h>
+#endif  // GTEST_OS_WINDOWS
+
+#if GTEST_OS_MAC
+#include <mach/mach_init.h>
+#include <mach/task.h>
+#include <mach/vm_map.h>
+#endif  // GTEST_OS_MAC
+
+#if GTEST_OS_DRAGONFLY || GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD || \
+    GTEST_OS_NETBSD || GTEST_OS_OPENBSD
+#include <sys/sysctl.h>
+#if GTEST_OS_DRAGONFLY || GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD
+#include <sys/user.h>
+#endif
+#endif
+
+#if GTEST_OS_QNX
+#include <devctl.h>
+#include <fcntl.h>
+#include <sys/procfs.h>
+#endif  // GTEST_OS_QNX
+
+#if GTEST_OS_AIX
+#include <procinfo.h>
+#include <sys/types.h>
+#endif  // GTEST_OS_AIX
+
+#if GTEST_OS_FUCHSIA
+#include <zircon/process.h>
+#include <zircon/syscalls.h>
+#endif  // GTEST_OS_FUCHSIA
+
+#include "gtest/gtest-message.h"
+#include "gtest/gtest-spi.h"
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-string.h"
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+namespace internal {
+
+#if GTEST_OS_LINUX || GTEST_OS_GNU_HURD
+
+namespace {
+template <typename T>
+T ReadProcFileField(const std::string& filename, int field) {
+  std::string dummy;
+  std::ifstream file(filename.c_str());
+  while (field-- > 0) {
+    file >> dummy;
+  }
+  T output = 0;
+  file >> output;
+  return output;
+}
+}  // namespace
+
+// Returns the number of active threads, or 0 when there is an error.
+size_t GetThreadCount() {
+  const std::string filename =
+      (Message() << "/proc/" << getpid() << "/stat").GetString();
+  return ReadProcFileField<size_t>(filename, 19);
+}
+
+#elif GTEST_OS_MAC
+
+size_t GetThreadCount() {
+  const task_t task = mach_task_self();
+  mach_msg_type_number_t thread_count;
+  thread_act_array_t thread_list;
+  const kern_return_t status = task_threads(task, &thread_list, &thread_count);
+  if (status == KERN_SUCCESS) {
+    // task_threads allocates resources in thread_list and we need to free them
+    // to avoid leaks.
+    vm_deallocate(task, reinterpret_cast<vm_address_t>(thread_list),
+                  sizeof(thread_t) * thread_count);
+    return static_cast<size_t>(thread_count);
+  } else {
+    return 0;
+  }
+}
+
+#elif GTEST_OS_DRAGONFLY || GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD || \
+    GTEST_OS_NETBSD
+
+#if GTEST_OS_NETBSD
+#undef KERN_PROC
+#define KERN_PROC KERN_PROC2
+#define kinfo_proc kinfo_proc2
+#endif
+
+#if GTEST_OS_DRAGONFLY
+#define KP_NLWP(kp) (kp.kp_nthreads)
+#elif GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD
+#define KP_NLWP(kp) (kp.ki_numthreads)
+#elif GTEST_OS_NETBSD
+#define KP_NLWP(kp) (kp.p_nlwps)
+#endif
+
+// Returns the number of threads running in the process, or 0 to indicate that
+// we cannot detect it.
+size_t GetThreadCount() {
+  int mib[] = {
+    CTL_KERN,
+    KERN_PROC,
+    KERN_PROC_PID,
+    getpid(),
+#if GTEST_OS_NETBSD
+    sizeof(struct kinfo_proc),
+    1,
+#endif
+  };
+  u_int miblen = sizeof(mib) / sizeof(mib[0]);
+  struct kinfo_proc info;
+  size_t size = sizeof(info);
+  if (sysctl(mib, miblen, &info, &size, NULL, 0)) {
+    return 0;
+  }
+  return static_cast<size_t>(KP_NLWP(info));
+}
+#elif GTEST_OS_OPENBSD
+
+// Returns the number of threads running in the process, or 0 to indicate that
+// we cannot detect it.
+size_t GetThreadCount() {
+  int mib[] = {
+      CTL_KERN,
+      KERN_PROC,
+      KERN_PROC_PID | KERN_PROC_SHOW_THREADS,
+      getpid(),
+      sizeof(struct kinfo_proc),
+      0,
+  };
+  u_int miblen = sizeof(mib) / sizeof(mib[0]);
+
+  // get number of structs
+  size_t size;
+  if (sysctl(mib, miblen, NULL, &size, NULL, 0)) {
+    return 0;
+  }
+
+  mib[5] = static_cast<int>(size / static_cast<size_t>(mib[4]));
+
+  // populate array of structs
+  struct kinfo_proc info[mib[5]];
+  if (sysctl(mib, miblen, &info, &size, NULL, 0)) {
+    return 0;
+  }
+
+  // exclude empty members
+  size_t nthreads = 0;
+  for (size_t i = 0; i < size / static_cast<size_t>(mib[4]); i++) {
+    if (info[i].p_tid != -1) nthreads++;
+  }
+  return nthreads;
+}
+
+#elif GTEST_OS_QNX
+
+// Returns the number of threads running in the process, or 0 to indicate that
+// we cannot detect it.
+size_t GetThreadCount() {
+  const int fd = open("/proc/self/as", O_RDONLY);
+  if (fd < 0) {
+    return 0;
+  }
+  procfs_info process_info;
+  const int status =
+      devctl(fd, DCMD_PROC_INFO, &process_info, sizeof(process_info), nullptr);
+  close(fd);
+  if (status == EOK) {
+    return static_cast<size_t>(process_info.num_threads);
+  } else {
+    return 0;
+  }
+}
+
+#elif GTEST_OS_AIX
+
+size_t GetThreadCount() {
+  struct procentry64 entry;
+  pid_t pid = getpid();
+  int status = getprocs64(&entry, sizeof(entry), nullptr, 0, &pid, 1);
+  if (status == 1) {
+    return entry.pi_thcount;
+  } else {
+    return 0;
+  }
+}
+
+#elif GTEST_OS_FUCHSIA
+
+size_t GetThreadCount() {
+  int dummy_buffer;
+  size_t avail;
+  zx_status_t status =
+      zx_object_get_info(zx_process_self(), ZX_INFO_PROCESS_THREADS,
+                         &dummy_buffer, 0, nullptr, &avail);
+  if (status == ZX_OK) {
+    return avail;
+  } else {
+    return 0;
+  }
+}
+
+#else
+
+size_t GetThreadCount() {
+  // There's no portable way to detect the number of threads, so we just
+  // return 0 to indicate that we cannot detect it.
+  return 0;
+}
+
+#endif  // GTEST_OS_LINUX
+
+#if GTEST_IS_THREADSAFE && GTEST_OS_WINDOWS
+
+AutoHandle::AutoHandle() : handle_(INVALID_HANDLE_VALUE) {}
+
+AutoHandle::AutoHandle(Handle handle) : handle_(handle) {}
+
+AutoHandle::~AutoHandle() { Reset(); }
+
+AutoHandle::Handle AutoHandle::Get() const { return handle_; }
+
+void AutoHandle::Reset() { Reset(INVALID_HANDLE_VALUE); }
+
+void AutoHandle::Reset(HANDLE handle) {
+  // Resetting with the same handle we already own is invalid.
+  if (handle_ != handle) {
+    if (IsCloseable()) {
+      ::CloseHandle(handle_);
+    }
+    handle_ = handle;
+  } else {
+    GTEST_CHECK_(!IsCloseable())
+        << "Resetting a valid handle to itself is likely a programmer error "
+           "and thus not allowed.";
+  }
+}
+
+bool AutoHandle::IsCloseable() const {
+  // Different Windows APIs may use either of these values to represent an
+  // invalid handle.
+  return handle_ != nullptr && handle_ != INVALID_HANDLE_VALUE;
+}
+
+Mutex::Mutex()
+    : owner_thread_id_(0),
+      type_(kDynamic),
+      critical_section_init_phase_(0),
+      critical_section_(new CRITICAL_SECTION) {
+  ::InitializeCriticalSection(critical_section_);
+}
+
+Mutex::~Mutex() {
+  // Static mutexes are leaked intentionally. It is not thread-safe to try
+  // to clean them up.
+  if (type_ == kDynamic) {
+    ::DeleteCriticalSection(critical_section_);
+    delete critical_section_;
+    critical_section_ = nullptr;
+  }
+}
+
+void Mutex::Lock() {
+  ThreadSafeLazyInit();
+  ::EnterCriticalSection(critical_section_);
+  owner_thread_id_ = ::GetCurrentThreadId();
+}
+
+void Mutex::Unlock() {
+  ThreadSafeLazyInit();
+  // We don't protect writing to owner_thread_id_ here, as it's the
+  // caller's responsibility to ensure that the current thread holds the
+  // mutex when this is called.
+  owner_thread_id_ = 0;
+  ::LeaveCriticalSection(critical_section_);
+}
+
+// Does nothing if the current thread holds the mutex. Otherwise, crashes
+// with high probability.
+void Mutex::AssertHeld() {
+  ThreadSafeLazyInit();
+  GTEST_CHECK_(owner_thread_id_ == ::GetCurrentThreadId())
+      << "The current thread is not holding the mutex @" << this;
+}
+
+namespace {
+
+#ifdef _MSC_VER
+// Use the RAII idiom to flag mem allocs that are intentionally never
+// deallocated. The motivation is to silence the false positive mem leaks
+// that are reported by the debug version of MS's CRT which can only detect
+// if an alloc is missing a matching deallocation.
+// Example:
+//    MemoryIsNotDeallocated memory_is_not_deallocated;
+//    critical_section_ = new CRITICAL_SECTION;
+//
+class MemoryIsNotDeallocated {
+ public:
+  MemoryIsNotDeallocated() : old_crtdbg_flag_(0) {
+    old_crtdbg_flag_ = _CrtSetDbgFlag(_CRTDBG_REPORT_FLAG);
+    // Set heap allocation block type to _IGNORE_BLOCK so that MS debug CRT
+    // doesn't report mem leak if there's no matching deallocation.
+    (void)_CrtSetDbgFlag(old_crtdbg_flag_ & ~_CRTDBG_ALLOC_MEM_DF);
+  }
+
+  ~MemoryIsNotDeallocated() {
+    // Restore the original _CRTDBG_ALLOC_MEM_DF flag
+    (void)_CrtSetDbgFlag(old_crtdbg_flag_);
+  }
+
+ private:
+  int old_crtdbg_flag_;
+
+  MemoryIsNotDeallocated(const MemoryIsNotDeallocated&) = delete;
+  MemoryIsNotDeallocated& operator=(const MemoryIsNotDeallocated&) = delete;
+};
+#endif  // _MSC_VER
+
+}  // namespace
+
+// Initializes owner_thread_id_ and critical_section_ in static mutexes.
+void Mutex::ThreadSafeLazyInit() {
+  // Dynamic mutexes are initialized in the constructor.
+  if (type_ == kStatic) {
+    switch (
+        ::InterlockedCompareExchange(&critical_section_init_phase_, 1L, 0L)) {
+      case 0:
+        // If critical_section_init_phase_ was 0 before the exchange, we
+        // are the first to test it and need to perform the initialization.
+        owner_thread_id_ = 0;
+        {
+          // Use RAII to flag that following mem alloc is never deallocated.
+#ifdef _MSC_VER
+          MemoryIsNotDeallocated memory_is_not_deallocated;
+#endif  // _MSC_VER
+          critical_section_ = new CRITICAL_SECTION;
+        }
+        ::InitializeCriticalSection(critical_section_);
+        // Updates the critical_section_init_phase_ to 2 to signal
+        // initialization complete.
+        GTEST_CHECK_(::InterlockedCompareExchange(&critical_section_init_phase_,
+                                                  2L, 1L) == 1L);
+        break;
+      case 1:
+        // Somebody else is already initializing the mutex; spin until they
+        // are done.
+        while (::InterlockedCompareExchange(&critical_section_init_phase_, 2L,
+                                            2L) != 2L) {
+          // Possibly yields the rest of the thread's time slice to other
+          // threads.
+          ::Sleep(0);
+        }
+        break;
+
+      case 2:
+        break;  // The mutex is already initialized and ready for use.
+
+      default:
+        GTEST_CHECK_(false)
+            << "Unexpected value of critical_section_init_phase_ "
+            << "while initializing a static mutex.";
+    }
+  }
+}
+
+namespace {
+
+class ThreadWithParamSupport : public ThreadWithParamBase {
+ public:
+  static HANDLE CreateThread(Runnable* runnable,
+                             Notification* thread_can_start) {
+    ThreadMainParam* param = new ThreadMainParam(runnable, thread_can_start);
+    DWORD thread_id;
+    HANDLE thread_handle = ::CreateThread(
+        nullptr,  // Default security.
+        0,        // Default stack size.
+        &ThreadWithParamSupport::ThreadMain,
+        param,        // Parameter to ThreadMainStatic
+        0x0,          // Default creation flags.
+        &thread_id);  // Need a valid pointer for the call to work under Win98.
+    GTEST_CHECK_(thread_handle != nullptr)
+        << "CreateThread failed with error " << ::GetLastError() << ".";
+    if (thread_handle == nullptr) {
+      delete param;
+    }
+    return thread_handle;
+  }
+
+ private:
+  struct ThreadMainParam {
+    ThreadMainParam(Runnable* runnable, Notification* thread_can_start)
+        : runnable_(runnable), thread_can_start_(thread_can_start) {}
+    std::unique_ptr<Runnable> runnable_;
+    // Does not own.
+    Notification* thread_can_start_;
+  };
+
+  static DWORD WINAPI ThreadMain(void* ptr) {
+    // Transfers ownership.
+    std::unique_ptr<ThreadMainParam> param(static_cast<ThreadMainParam*>(ptr));
+    if (param->thread_can_start_ != nullptr)
+      param->thread_can_start_->WaitForNotification();
+    param->runnable_->Run();
+    return 0;
+  }
+
+  // Prohibit instantiation.
+  ThreadWithParamSupport();
+
+  ThreadWithParamSupport(const ThreadWithParamSupport&) = delete;
+  ThreadWithParamSupport& operator=(const ThreadWithParamSupport&) = delete;
+};
+
+}  // namespace
+
+ThreadWithParamBase::ThreadWithParamBase(Runnable* runnable,
+                                         Notification* thread_can_start)
+    : thread_(
+          ThreadWithParamSupport::CreateThread(runnable, thread_can_start)) {}
+
+ThreadWithParamBase::~ThreadWithParamBase() { Join(); }
+
+void ThreadWithParamBase::Join() {
+  GTEST_CHECK_(::WaitForSingleObject(thread_.Get(), INFINITE) == WAIT_OBJECT_0)
+      << "Failed to join the thread with error " << ::GetLastError() << ".";
+}
+
+// Maps a thread to a set of ThreadIdToThreadLocals that have values
+// instantiated on that thread and notifies them when the thread exits.  A
+// ThreadLocal instance is expected to persist until all threads it has
+// values on have terminated.
+class ThreadLocalRegistryImpl {
+ public:
+  // Registers thread_local_instance as having value on the current thread.
+  // Returns a value that can be used to identify the thread from other threads.
+  static ThreadLocalValueHolderBase* GetValueOnCurrentThread(
+      const ThreadLocalBase* thread_local_instance) {
+#ifdef _MSC_VER
+    MemoryIsNotDeallocated memory_is_not_deallocated;
+#endif  // _MSC_VER
+    DWORD current_thread = ::GetCurrentThreadId();
+    MutexLock lock(&mutex_);
+    ThreadIdToThreadLocals* const thread_to_thread_locals =
+        GetThreadLocalsMapLocked();
+    ThreadIdToThreadLocals::iterator thread_local_pos =
+        thread_to_thread_locals->find(current_thread);
+    if (thread_local_pos == thread_to_thread_locals->end()) {
+      thread_local_pos =
+          thread_to_thread_locals
+              ->insert(std::make_pair(current_thread, ThreadLocalValues()))
+              .first;
+      StartWatcherThreadFor(current_thread);
+    }
+    ThreadLocalValues& thread_local_values = thread_local_pos->second;
+    ThreadLocalValues::iterator value_pos =
+        thread_local_values.find(thread_local_instance);
+    if (value_pos == thread_local_values.end()) {
+      value_pos =
+          thread_local_values
+              .insert(std::make_pair(
+                  thread_local_instance,
+                  std::shared_ptr<ThreadLocalValueHolderBase>(
+                      thread_local_instance->NewValueForCurrentThread())))
+              .first;
+    }
+    return value_pos->second.get();
+  }
+
+  static void OnThreadLocalDestroyed(
+      const ThreadLocalBase* thread_local_instance) {
+    std::vector<std::shared_ptr<ThreadLocalValueHolderBase> > value_holders;
+    // Clean up the ThreadLocalValues data structure while holding the lock, but
+    // defer the destruction of the ThreadLocalValueHolderBases.
+    {
+      MutexLock lock(&mutex_);
+      ThreadIdToThreadLocals* const thread_to_thread_locals =
+          GetThreadLocalsMapLocked();
+      for (ThreadIdToThreadLocals::iterator it =
+               thread_to_thread_locals->begin();
+           it != thread_to_thread_locals->end(); ++it) {
+        ThreadLocalValues& thread_local_values = it->second;
+        ThreadLocalValues::iterator value_pos =
+            thread_local_values.find(thread_local_instance);
+        if (value_pos != thread_local_values.end()) {
+          value_holders.push_back(value_pos->second);
+          thread_local_values.erase(value_pos);
+          // This 'if' can only be successful at most once, so theoretically we
+          // could break out of the loop here, but we don't bother doing so.
+        }
+      }
+    }
+    // Outside the lock, let the destructor for 'value_holders' deallocate the
+    // ThreadLocalValueHolderBases.
+  }
+
+  static void OnThreadExit(DWORD thread_id) {
+    GTEST_CHECK_(thread_id != 0) << ::GetLastError();
+    std::vector<std::shared_ptr<ThreadLocalValueHolderBase> > value_holders;
+    // Clean up the ThreadIdToThreadLocals data structure while holding the
+    // lock, but defer the destruction of the ThreadLocalValueHolderBases.
+    {
+      MutexLock lock(&mutex_);
+      ThreadIdToThreadLocals* const thread_to_thread_locals =
+          GetThreadLocalsMapLocked();
+      ThreadIdToThreadLocals::iterator thread_local_pos =
+          thread_to_thread_locals->find(thread_id);
+      if (thread_local_pos != thread_to_thread_locals->end()) {
+        ThreadLocalValues& thread_local_values = thread_local_pos->second;
+        for (ThreadLocalValues::iterator value_pos =
+                 thread_local_values.begin();
+             value_pos != thread_local_values.end(); ++value_pos) {
+          value_holders.push_back(value_pos->second);
+        }
+        thread_to_thread_locals->erase(thread_local_pos);
+      }
+    }
+    // Outside the lock, let the destructor for 'value_holders' deallocate the
+    // ThreadLocalValueHolderBases.
+  }
+
+ private:
+  // In a particular thread, maps a ThreadLocal object to its value.
+  typedef std::map<const ThreadLocalBase*,
+                   std::shared_ptr<ThreadLocalValueHolderBase> >
+      ThreadLocalValues;
+  // Stores all ThreadIdToThreadLocals having values in a thread, indexed by
+  // thread's ID.
+  typedef std::map<DWORD, ThreadLocalValues> ThreadIdToThreadLocals;
+
+  // Holds the thread id and thread handle that we pass from
+  // StartWatcherThreadFor to WatcherThreadFunc.
+  typedef std::pair<DWORD, HANDLE> ThreadIdAndHandle;
+
+  static void StartWatcherThreadFor(DWORD thread_id) {
+    // The returned handle will be kept in thread_map and closed by
+    // watcher_thread in WatcherThreadFunc.
+    HANDLE thread =
+        ::OpenThread(SYNCHRONIZE | THREAD_QUERY_INFORMATION, FALSE, thread_id);
+    GTEST_CHECK_(thread != nullptr);
+    // We need to pass a valid thread ID pointer into CreateThread for it
+    // to work correctly under Win98.
+    DWORD watcher_thread_id;
+    HANDLE watcher_thread = ::CreateThread(
+        nullptr,  // Default security.
+        0,        // Default stack size
+        &ThreadLocalRegistryImpl::WatcherThreadFunc,
+        reinterpret_cast<LPVOID>(new ThreadIdAndHandle(thread_id, thread)),
+        CREATE_SUSPENDED, &watcher_thread_id);
+    GTEST_CHECK_(watcher_thread != nullptr)
+        << "CreateThread failed with error " << ::GetLastError() << ".";
+    // Give the watcher thread the same priority as ours to avoid being
+    // blocked by it.
+    ::SetThreadPriority(watcher_thread,
+                        ::GetThreadPriority(::GetCurrentThread()));
+    ::ResumeThread(watcher_thread);
+    ::CloseHandle(watcher_thread);
+  }
+
+  // Monitors exit from a given thread and notifies those
+  // ThreadIdToThreadLocals about thread termination.
+  static DWORD WINAPI WatcherThreadFunc(LPVOID param) {
+    const ThreadIdAndHandle* tah =
+        reinterpret_cast<const ThreadIdAndHandle*>(param);
+    GTEST_CHECK_(::WaitForSingleObject(tah->second, INFINITE) == WAIT_OBJECT_0);
+    OnThreadExit(tah->first);
+    ::CloseHandle(tah->second);
+    delete tah;
+    return 0;
+  }
+
+  // Returns map of thread local instances.
+  static ThreadIdToThreadLocals* GetThreadLocalsMapLocked() {
+    mutex_.AssertHeld();
+#ifdef _MSC_VER
+    MemoryIsNotDeallocated memory_is_not_deallocated;
+#endif  // _MSC_VER
+    static ThreadIdToThreadLocals* map = new ThreadIdToThreadLocals();
+    return map;
+  }
+
+  // Protects access to GetThreadLocalsMapLocked() and its return value.
+  static Mutex mutex_;
+  // Protects access to GetThreadMapLocked() and its return value.
+  static Mutex thread_map_mutex_;
+};
+
+Mutex ThreadLocalRegistryImpl::mutex_(Mutex::kStaticMutex);  // NOLINT
+Mutex ThreadLocalRegistryImpl::thread_map_mutex_(
+    Mutex::kStaticMutex);  // NOLINT
+
+ThreadLocalValueHolderBase* ThreadLocalRegistry::GetValueOnCurrentThread(
+    const ThreadLocalBase* thread_local_instance) {
+  return ThreadLocalRegistryImpl::GetValueOnCurrentThread(
+      thread_local_instance);
+}
+
+void ThreadLocalRegistry::OnThreadLocalDestroyed(
+    const ThreadLocalBase* thread_local_instance) {
+  ThreadLocalRegistryImpl::OnThreadLocalDestroyed(thread_local_instance);
+}
+
+#endif  // GTEST_IS_THREADSAFE && GTEST_OS_WINDOWS
+
+#if GTEST_USES_POSIX_RE
+
+// Implements RE.  Currently only needed for death tests.
+
+RE::~RE() {
+  if (is_valid_) {
+    // regfree'ing an invalid regex might crash because the content
+    // of the regex is undefined. Since the regex's are essentially
+    // the same, one cannot be valid (or invalid) without the other
+    // being so too.
+    regfree(&partial_regex_);
+    regfree(&full_regex_);
+  }
+  free(const_cast<char*>(pattern_));
+}
+
+// Returns true if and only if regular expression re matches the entire str.
+bool RE::FullMatch(const char* str, const RE& re) {
+  if (!re.is_valid_) return false;
+
+  regmatch_t match;
+  return regexec(&re.full_regex_, str, 1, &match, 0) == 0;
+}
+
+// Returns true if and only if regular expression re matches a substring of
+// str (including str itself).
+bool RE::PartialMatch(const char* str, const RE& re) {
+  if (!re.is_valid_) return false;
+
+  regmatch_t match;
+  return regexec(&re.partial_regex_, str, 1, &match, 0) == 0;
+}
+
+// Initializes an RE from its string representation.
+void RE::Init(const char* regex) {
+  pattern_ = posix::StrDup(regex);
+
+  // Reserves enough bytes to hold the regular expression used for a
+  // full match.
+  const size_t full_regex_len = strlen(regex) + 10;
+  char* const full_pattern = new char[full_regex_len];
+
+  snprintf(full_pattern, full_regex_len, "^(%s)$", regex);
+  is_valid_ = regcomp(&full_regex_, full_pattern, REG_EXTENDED) == 0;
+  // We want to call regcomp(&partial_regex_, ...) even if the
+  // previous expression returns false.  Otherwise partial_regex_ may
+  // not be properly initialized can may cause trouble when it's
+  // freed.
+  //
+  // Some implementation of POSIX regex (e.g. on at least some
+  // versions of Cygwin) doesn't accept the empty string as a valid
+  // regex.  We change it to an equivalent form "()" to be safe.
+  if (is_valid_) {
+    const char* const partial_regex = (*regex == '\0') ? "()" : regex;
+    is_valid_ = regcomp(&partial_regex_, partial_regex, REG_EXTENDED) == 0;
+  }
+  EXPECT_TRUE(is_valid_)
+      << "Regular expression \"" << regex
+      << "\" is not a valid POSIX Extended regular expression.";
+
+  delete[] full_pattern;
+}
+
+#elif GTEST_USES_SIMPLE_RE
+
+// Returns true if and only if ch appears anywhere in str (excluding the
+// terminating '\0' character).
+bool IsInSet(char ch, const char* str) {
+  return ch != '\0' && strchr(str, ch) != nullptr;
+}
+
+// Returns true if and only if ch belongs to the given classification.
+// Unlike similar functions in <ctype.h>, these aren't affected by the
+// current locale.
+bool IsAsciiDigit(char ch) { return '0' <= ch && ch <= '9'; }
+bool IsAsciiPunct(char ch) {
+  return IsInSet(ch, "^-!\"#$%&'()*+,./:;<=>?@[\\]_`{|}~");
+}
+bool IsRepeat(char ch) { return IsInSet(ch, "?*+"); }
+bool IsAsciiWhiteSpace(char ch) { return IsInSet(ch, " \f\n\r\t\v"); }
+bool IsAsciiWordChar(char ch) {
+  return ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') ||
+         ('0' <= ch && ch <= '9') || ch == '_';
+}
+
+// Returns true if and only if "\\c" is a supported escape sequence.
+bool IsValidEscape(char c) {
+  return (IsAsciiPunct(c) || IsInSet(c, "dDfnrsStvwW"));
+}
+
+// Returns true if and only if the given atom (specified by escaped and
+// pattern) matches ch.  The result is undefined if the atom is invalid.
+bool AtomMatchesChar(bool escaped, char pattern_char, char ch) {
+  if (escaped) {  // "\\p" where p is pattern_char.
+    switch (pattern_char) {
+      case 'd':
+        return IsAsciiDigit(ch);
+      case 'D':
+        return !IsAsciiDigit(ch);
+      case 'f':
+        return ch == '\f';
+      case 'n':
+        return ch == '\n';
+      case 'r':
+        return ch == '\r';
+      case 's':
+        return IsAsciiWhiteSpace(ch);
+      case 'S':
+        return !IsAsciiWhiteSpace(ch);
+      case 't':
+        return ch == '\t';
+      case 'v':
+        return ch == '\v';
+      case 'w':
+        return IsAsciiWordChar(ch);
+      case 'W':
+        return !IsAsciiWordChar(ch);
+    }
+    return IsAsciiPunct(pattern_char) && pattern_char == ch;
+  }
+
+  return (pattern_char == '.' && ch != '\n') || pattern_char == ch;
+}
+
+// Helper function used by ValidateRegex() to format error messages.
+static std::string FormatRegexSyntaxError(const char* regex, int index) {
+  return (Message() << "Syntax error at index " << index
+                    << " in simple regular expression \"" << regex << "\": ")
+      .GetString();
+}
+
+// Generates non-fatal failures and returns false if regex is invalid;
+// otherwise returns true.
+bool ValidateRegex(const char* regex) {
+  if (regex == nullptr) {
+    ADD_FAILURE() << "NULL is not a valid simple regular expression.";
+    return false;
+  }
+
+  bool is_valid = true;
+
+  // True if and only if ?, *, or + can follow the previous atom.
+  bool prev_repeatable = false;
+  for (int i = 0; regex[i]; i++) {
+    if (regex[i] == '\\') {  // An escape sequence
+      i++;
+      if (regex[i] == '\0') {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i - 1)
+                      << "'\\' cannot appear at the end.";
+        return false;
+      }
+
+      if (!IsValidEscape(regex[i])) {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i - 1)
+                      << "invalid escape sequence \"\\" << regex[i] << "\".";
+        is_valid = false;
+      }
+      prev_repeatable = true;
+    } else {  // Not an escape sequence.
+      const char ch = regex[i];
+
+      if (ch == '^' && i > 0) {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
+                      << "'^' can only appear at the beginning.";
+        is_valid = false;
+      } else if (ch == '$' && regex[i + 1] != '\0') {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
+                      << "'$' can only appear at the end.";
+        is_valid = false;
+      } else if (IsInSet(ch, "()[]{}|")) {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i) << "'" << ch
+                      << "' is unsupported.";
+        is_valid = false;
+      } else if (IsRepeat(ch) && !prev_repeatable) {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i) << "'" << ch
+                      << "' can only follow a repeatable token.";
+        is_valid = false;
+      }
+
+      prev_repeatable = !IsInSet(ch, "^$?*+");
+    }
+  }
+
+  return is_valid;
+}
+
+// Matches a repeated regex atom followed by a valid simple regular
+// expression.  The regex atom is defined as c if escaped is false,
+// or \c otherwise.  repeat is the repetition meta character (?, *,
+// or +).  The behavior is undefined if str contains too many
+// characters to be indexable by size_t, in which case the test will
+// probably time out anyway.  We are fine with this limitation as
+// std::string has it too.
+bool MatchRepetitionAndRegexAtHead(bool escaped, char c, char repeat,
+                                   const char* regex, const char* str) {
+  const size_t min_count = (repeat == '+') ? 1 : 0;
+  const size_t max_count = (repeat == '?') ? 1 : static_cast<size_t>(-1) - 1;
+  // We cannot call numeric_limits::max() as it conflicts with the
+  // max() macro on Windows.
+
+  for (size_t i = 0; i <= max_count; ++i) {
+    // We know that the atom matches each of the first i characters in str.
+    if (i >= min_count && MatchRegexAtHead(regex, str + i)) {
+      // We have enough matches at the head, and the tail matches too.
+      // Since we only care about *whether* the pattern matches str
+      // (as opposed to *how* it matches), there is no need to find a
+      // greedy match.
+      return true;
+    }
+    if (str[i] == '\0' || !AtomMatchesChar(escaped, c, str[i])) return false;
+  }
+  return false;
+}
+
+// Returns true if and only if regex matches a prefix of str. regex must
+// be a valid simple regular expression and not start with "^", or the
+// result is undefined.
+bool MatchRegexAtHead(const char* regex, const char* str) {
+  if (*regex == '\0')  // An empty regex matches a prefix of anything.
+    return true;
+
+  // "$" only matches the end of a string.  Note that regex being
+  // valid guarantees that there's nothing after "$" in it.
+  if (*regex == '$') return *str == '\0';
+
+  // Is the first thing in regex an escape sequence?
+  const bool escaped = *regex == '\\';
+  if (escaped) ++regex;
+  if (IsRepeat(regex[1])) {
+    // MatchRepetitionAndRegexAtHead() calls MatchRegexAtHead(), so
+    // here's an indirect recursion.  It terminates as the regex gets
+    // shorter in each recursion.
+    return MatchRepetitionAndRegexAtHead(escaped, regex[0], regex[1], regex + 2,
+                                         str);
+  } else {
+    // regex isn't empty, isn't "$", and doesn't start with a
+    // repetition.  We match the first atom of regex with the first
+    // character of str and recurse.
+    return (*str != '\0') && AtomMatchesChar(escaped, *regex, *str) &&
+           MatchRegexAtHead(regex + 1, str + 1);
+  }
+}
+
+// Returns true if and only if regex matches any substring of str.  regex must
+// be a valid simple regular expression, or the result is undefined.
+//
+// The algorithm is recursive, but the recursion depth doesn't exceed
+// the regex length, so we won't need to worry about running out of
+// stack space normally.  In rare cases the time complexity can be
+// exponential with respect to the regex length + the string length,
+// but usually it's must faster (often close to linear).
+bool MatchRegexAnywhere(const char* regex, const char* str) {
+  if (regex == nullptr || str == nullptr) return false;
+
+  if (*regex == '^') return MatchRegexAtHead(regex + 1, str);
+
+  // A successful match can be anywhere in str.
+  do {
+    if (MatchRegexAtHead(regex, str)) return true;
+  } while (*str++ != '\0');
+  return false;
+}
+
+// Implements the RE class.
+
+RE::~RE() {
+  free(const_cast<char*>(pattern_));
+  free(const_cast<char*>(full_pattern_));
+}
+
+// Returns true if and only if regular expression re matches the entire str.
+bool RE::FullMatch(const char* str, const RE& re) {
+  return re.is_valid_ && MatchRegexAnywhere(re.full_pattern_, str);
+}
+
+// Returns true if and only if regular expression re matches a substring of
+// str (including str itself).
+bool RE::PartialMatch(const char* str, const RE& re) {
+  return re.is_valid_ && MatchRegexAnywhere(re.pattern_, str);
+}
+
+// Initializes an RE from its string representation.
+void RE::Init(const char* regex) {
+  pattern_ = full_pattern_ = nullptr;
+  if (regex != nullptr) {
+    pattern_ = posix::StrDup(regex);
+  }
+
+  is_valid_ = ValidateRegex(regex);
+  if (!is_valid_) {
+    // No need to calculate the full pattern when the regex is invalid.
+    return;
+  }
+
+  const size_t len = strlen(regex);
+  // Reserves enough bytes to hold the regular expression used for a
+  // full match: we need space to prepend a '^', append a '$', and
+  // terminate the string with '\0'.
+  char* buffer = static_cast<char*>(malloc(len + 3));
+  full_pattern_ = buffer;
+
+  if (*regex != '^')
+    *buffer++ = '^';  // Makes sure full_pattern_ starts with '^'.
+
+  // We don't use snprintf or strncpy, as they trigger a warning when
+  // compiled with VC++ 8.0.
+  memcpy(buffer, regex, len);
+  buffer += len;
+
+  if (len == 0 || regex[len - 1] != '$')
+    *buffer++ = '$';  // Makes sure full_pattern_ ends with '$'.
+
+  *buffer = '\0';
+}
+
+#endif  // GTEST_USES_POSIX_RE
+
+const char kUnknownFile[] = "unknown file";
+
+// Formats a source file path and a line number as they would appear
+// in an error message from the compiler used to compile this code.
+GTEST_API_ ::std::string FormatFileLocation(const char* file, int line) {
+  const std::string file_name(file == nullptr ? kUnknownFile : file);
+
+  if (line < 0) {
+    return file_name + ":";
+  }
+#ifdef _MSC_VER
+  return file_name + "(" + StreamableToString(line) + "):";
+#else
+  return file_name + ":" + StreamableToString(line) + ":";
+#endif  // _MSC_VER
+}
+
+// Formats a file location for compiler-independent XML output.
+// Although this function is not platform dependent, we put it next to
+// FormatFileLocation in order to contrast the two functions.
+// Note that FormatCompilerIndependentFileLocation() does NOT append colon
+// to the file location it produces, unlike FormatFileLocation().
+GTEST_API_ ::std::string FormatCompilerIndependentFileLocation(const char* file,
+                                                               int line) {
+  const std::string file_name(file == nullptr ? kUnknownFile : file);
+
+  if (line < 0)
+    return file_name;
+  else
+    return file_name + ":" + StreamableToString(line);
+}
+
+GTestLog::GTestLog(GTestLogSeverity severity, const char* file, int line)
+    : severity_(severity) {
+  const char* const marker = severity == GTEST_INFO      ? "[  INFO ]"
+                             : severity == GTEST_WARNING ? "[WARNING]"
+                             : severity == GTEST_ERROR   ? "[ ERROR ]"
+                                                         : "[ FATAL ]";
+  GetStream() << ::std::endl
+              << marker << " " << FormatFileLocation(file, line).c_str()
+              << ": ";
+}
+
+// Flushes the buffers and, if severity is GTEST_FATAL, aborts the program.
+GTestLog::~GTestLog() {
+  GetStream() << ::std::endl;
+  if (severity_ == GTEST_FATAL) {
+    fflush(stderr);
+    posix::Abort();
+  }
+}
+
+// Disable Microsoft deprecation warnings for POSIX functions called from
+// this class (creat, dup, dup2, and close)
+GTEST_DISABLE_MSC_DEPRECATED_PUSH_()
+
+#if GTEST_HAS_STREAM_REDIRECTION
+
+// Object that captures an output stream (stdout/stderr).
+class CapturedStream {
+ public:
+  // The ctor redirects the stream to a temporary file.
+  explicit CapturedStream(int fd) : fd_(fd), uncaptured_fd_(dup(fd)) {
+#if GTEST_OS_WINDOWS
+    char temp_dir_path[MAX_PATH + 1] = {'\0'};   // NOLINT
+    char temp_file_path[MAX_PATH + 1] = {'\0'};  // NOLINT
+
+    ::GetTempPathA(sizeof(temp_dir_path), temp_dir_path);
+    const UINT success = ::GetTempFileNameA(temp_dir_path, "gtest_redir",
+                                            0,  // Generate unique file name.
+                                            temp_file_path);
+    GTEST_CHECK_(success != 0)
+        << "Unable to create a temporary file in " << temp_dir_path;
+    const int captured_fd = creat(temp_file_path, _S_IREAD | _S_IWRITE);
+    GTEST_CHECK_(captured_fd != -1)
+        << "Unable to open temporary file " << temp_file_path;
+    filename_ = temp_file_path;
+#else
+    // There's no guarantee that a test has write access to the current
+    // directory, so we create the temporary file in a temporary directory.
+    std::string name_template;
+
+#if GTEST_OS_LINUX_ANDROID
+    // Note: Android applications are expected to call the framework's
+    // Context.getExternalStorageDirectory() method through JNI to get
+    // the location of the world-writable SD Card directory. However,
+    // this requires a Context handle, which cannot be retrieved
+    // globally from native code. Doing so also precludes running the
+    // code as part of a regular standalone executable, which doesn't
+    // run in a Dalvik process (e.g. when running it through 'adb shell').
+    //
+    // The location /data/local/tmp is directly accessible from native code.
+    // '/sdcard' and other variants cannot be relied on, as they are not
+    // guaranteed to be mounted, or may have a delay in mounting.
+    name_template = "/data/local/tmp/";
+#elif GTEST_OS_IOS
+    char user_temp_dir[PATH_MAX + 1];
+
+    // Documented alternative to NSTemporaryDirectory() (for obtaining creating
+    // a temporary directory) at
+    // https://developer.apple.com/library/archive/documentation/Security/Conceptual/SecureCodingGuide/Articles/RaceConditions.html#//apple_ref/doc/uid/TP40002585-SW10
+    //
+    // _CS_DARWIN_USER_TEMP_DIR (as well as _CS_DARWIN_USER_CACHE_DIR) is not
+    // documented in the confstr() man page at
+    // https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/confstr.3.html#//apple_ref/doc/man/3/confstr
+    // but are still available, according to the WebKit patches at
+    // https://trac.webkit.org/changeset/262004/webkit
+    // https://trac.webkit.org/changeset/263705/webkit
+    //
+    // The confstr() implementation falls back to getenv("TMPDIR"). See
+    // https://opensource.apple.com/source/Libc/Libc-1439.100.3/gen/confstr.c.auto.html
+    ::confstr(_CS_DARWIN_USER_TEMP_DIR, user_temp_dir, sizeof(user_temp_dir));
+
+    name_template = user_temp_dir;
+    if (name_template.back() != GTEST_PATH_SEP_[0])
+      name_template.push_back(GTEST_PATH_SEP_[0]);
+#else
+    name_template = "/tmp/";
+#endif
+    name_template.append("gtest_captured_stream.XXXXXX");
+
+    // mkstemp() modifies the string bytes in place, and does not go beyond the
+    // string's length. This results in well-defined behavior in C++17.
+    //
+    // The const_cast is needed below C++17. The constraints on std::string
+    // implementations in C++11 and above make assumption behind the const_cast
+    // fairly safe.
+    const int captured_fd = ::mkstemp(const_cast<char*>(name_template.data()));
+    if (captured_fd == -1) {
+      GTEST_LOG_(WARNING)
+          << "Failed to create tmp file " << name_template
+          << " for test; does the test have access to the /tmp directory?";
+    }
+    filename_ = std::move(name_template);
+#endif  // GTEST_OS_WINDOWS
+    fflush(nullptr);
+    dup2(captured_fd, fd_);
+    close(captured_fd);
+  }
+
+  ~CapturedStream() { remove(filename_.c_str()); }
+
+  std::string GetCapturedString() {
+    if (uncaptured_fd_ != -1) {
+      // Restores the original stream.
+      fflush(nullptr);
+      dup2(uncaptured_fd_, fd_);
+      close(uncaptured_fd_);
+      uncaptured_fd_ = -1;
+    }
+
+    FILE* const file = posix::FOpen(filename_.c_str(), "r");
+    if (file == nullptr) {
+      GTEST_LOG_(FATAL) << "Failed to open tmp file " << filename_
+                        << " for capturing stream.";
+    }
+    const std::string content = ReadEntireFile(file);
+    posix::FClose(file);
+    return content;
+  }
+
+ private:
+  const int fd_;  // A stream to capture.
+  int uncaptured_fd_;
+  // Name of the temporary file holding the stderr output.
+  ::std::string filename_;
+
+  CapturedStream(const CapturedStream&) = delete;
+  CapturedStream& operator=(const CapturedStream&) = delete;
+};
+
+GTEST_DISABLE_MSC_DEPRECATED_POP_()
+
+static CapturedStream* g_captured_stderr = nullptr;
+static CapturedStream* g_captured_stdout = nullptr;
+
+// Starts capturing an output stream (stdout/stderr).
+static void CaptureStream(int fd, const char* stream_name,
+                          CapturedStream** stream) {
+  if (*stream != nullptr) {
+    GTEST_LOG_(FATAL) << "Only one " << stream_name
+                      << " capturer can exist at a time.";
+  }
+  *stream = new CapturedStream(fd);
+}
+
+// Stops capturing the output stream and returns the captured string.
+static std::string GetCapturedStream(CapturedStream** captured_stream) {
+  const std::string content = (*captured_stream)->GetCapturedString();
+
+  delete *captured_stream;
+  *captured_stream = nullptr;
+
+  return content;
+}
+
+#if defined(_MSC_VER) || defined(__BORLANDC__)
+// MSVC and C++Builder do not provide a definition of STDERR_FILENO.
+const int kStdOutFileno = 1;
+const int kStdErrFileno = 2;
+#else
+const int kStdOutFileno = STDOUT_FILENO;
+const int kStdErrFileno = STDERR_FILENO;
+#endif  // defined(_MSC_VER) || defined(__BORLANDC__)
+
+// Starts capturing stdout.
+void CaptureStdout() {
+  CaptureStream(kStdOutFileno, "stdout", &g_captured_stdout);
+}
+
+// Starts capturing stderr.
+void CaptureStderr() {
+  CaptureStream(kStdErrFileno, "stderr", &g_captured_stderr);
+}
+
+// Stops capturing stdout and returns the captured string.
+std::string GetCapturedStdout() {
+  return GetCapturedStream(&g_captured_stdout);
+}
+
+// Stops capturing stderr and returns the captured string.
+std::string GetCapturedStderr() {
+  return GetCapturedStream(&g_captured_stderr);
+}
+
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+
+size_t GetFileSize(FILE* file) {
+  fseek(file, 0, SEEK_END);
+  return static_cast<size_t>(ftell(file));
+}
+
+std::string ReadEntireFile(FILE* file) {
+  const size_t file_size = GetFileSize(file);
+  char* const buffer = new char[file_size];
+
+  size_t bytes_last_read = 0;  // # of bytes read in the last fread()
+  size_t bytes_read = 0;       // # of bytes read so far
+
+  fseek(file, 0, SEEK_SET);
+
+  // Keeps reading the file until we cannot read further or the
+  // pre-determined file size is reached.
+  do {
+    bytes_last_read =
+        fread(buffer + bytes_read, 1, file_size - bytes_read, file);
+    bytes_read += bytes_last_read;
+  } while (bytes_last_read > 0 && bytes_read < file_size);
+
+  const std::string content(buffer, bytes_read);
+  delete[] buffer;
+
+  return content;
+}
+
+#if GTEST_HAS_DEATH_TEST
+static const std::vector<std::string>* g_injected_test_argvs =
+    nullptr;  // Owned.
+
+std::vector<std::string> GetInjectableArgvs() {
+  if (g_injected_test_argvs != nullptr) {
+    return *g_injected_test_argvs;
+  }
+  return GetArgvs();
+}
+
+void SetInjectableArgvs(const std::vector<std::string>* new_argvs) {
+  if (g_injected_test_argvs != new_argvs) delete g_injected_test_argvs;
+  g_injected_test_argvs = new_argvs;
+}
+
+void SetInjectableArgvs(const std::vector<std::string>& new_argvs) {
+  SetInjectableArgvs(
+      new std::vector<std::string>(new_argvs.begin(), new_argvs.end()));
+}
+
+void ClearInjectableArgvs() {
+  delete g_injected_test_argvs;
+  g_injected_test_argvs = nullptr;
+}
+#endif  // GTEST_HAS_DEATH_TEST
+
+#if GTEST_OS_WINDOWS_MOBILE
+namespace posix {
+void Abort() {
+  DebugBreak();
+  TerminateProcess(GetCurrentProcess(), 1);
+}
+}  // namespace posix
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+// Returns the name of the environment variable corresponding to the
+// given flag.  For example, FlagToEnvVar("foo") will return
+// "GTEST_FOO" in the open-source version.
+static std::string FlagToEnvVar(const char* flag) {
+  const std::string full_flag =
+      (Message() << GTEST_FLAG_PREFIX_ << flag).GetString();
+
+  Message env_var;
+  for (size_t i = 0; i != full_flag.length(); i++) {
+    env_var << ToUpper(full_flag.c_str()[i]);
+  }
+
+  return env_var.GetString();
+}
+
+// Parses 'str' for a 32-bit signed integer.  If successful, writes
+// the result to *value and returns true; otherwise leaves *value
+// unchanged and returns false.
+bool ParseInt32(const Message& src_text, const char* str, int32_t* value) {
+  // Parses the environment variable as a decimal integer.
+  char* end = nullptr;
+  const long long_value = strtol(str, &end, 10);  // NOLINT
+
+  // Has strtol() consumed all characters in the string?
+  if (*end != '\0') {
+    // No - an invalid character was encountered.
+    Message msg;
+    msg << "WARNING: " << src_text
+        << " is expected to be a 32-bit integer, but actually"
+        << " has value \"" << str << "\".\n";
+    printf("%s", msg.GetString().c_str());
+    fflush(stdout);
+    return false;
+  }
+
+  // Is the parsed value in the range of an int32_t?
+  const auto result = static_cast<int32_t>(long_value);
+  if (long_value == LONG_MAX || long_value == LONG_MIN ||
+      // The parsed value overflows as a long.  (strtol() returns
+      // LONG_MAX or LONG_MIN when the input overflows.)
+      result != long_value
+      // The parsed value overflows as an int32_t.
+  ) {
+    Message msg;
+    msg << "WARNING: " << src_text
+        << " is expected to be a 32-bit integer, but actually"
+        << " has value " << str << ", which overflows.\n";
+    printf("%s", msg.GetString().c_str());
+    fflush(stdout);
+    return false;
+  }
+
+  *value = result;
+  return true;
+}
+
+// Reads and returns the Boolean environment variable corresponding to
+// the given flag; if it's not set, returns default_value.
+//
+// The value is considered true if and only if it's not "0".
+bool BoolFromGTestEnv(const char* flag, bool default_value) {
+#if defined(GTEST_GET_BOOL_FROM_ENV_)
+  return GTEST_GET_BOOL_FROM_ENV_(flag, default_value);
+#else
+  const std::string env_var = FlagToEnvVar(flag);
+  const char* const string_value = posix::GetEnv(env_var.c_str());
+  return string_value == nullptr ? default_value
+                                 : strcmp(string_value, "0") != 0;
+#endif  // defined(GTEST_GET_BOOL_FROM_ENV_)
+}
+
+// Reads and returns a 32-bit integer stored in the environment
+// variable corresponding to the given flag; if it isn't set or
+// doesn't represent a valid 32-bit integer, returns default_value.
+int32_t Int32FromGTestEnv(const char* flag, int32_t default_value) {
+#if defined(GTEST_GET_INT32_FROM_ENV_)
+  return GTEST_GET_INT32_FROM_ENV_(flag, default_value);
+#else
+  const std::string env_var = FlagToEnvVar(flag);
+  const char* const string_value = posix::GetEnv(env_var.c_str());
+  if (string_value == nullptr) {
+    // The environment variable is not set.
+    return default_value;
+  }
+
+  int32_t result = default_value;
+  if (!ParseInt32(Message() << "Environment variable " << env_var, string_value,
+                  &result)) {
+    printf("The default value %s is used.\n",
+           (Message() << default_value).GetString().c_str());
+    fflush(stdout);
+    return default_value;
+  }
+
+  return result;
+#endif  // defined(GTEST_GET_INT32_FROM_ENV_)
+}
+
+// As a special case for the 'output' flag, if GTEST_OUTPUT is not
+// set, we look for XML_OUTPUT_FILE, which is set by the Bazel build
+// system.  The value of XML_OUTPUT_FILE is a filename without the
+// "xml:" prefix of GTEST_OUTPUT.
+// Note that this is meant to be called at the call site so it does
+// not check that the flag is 'output'
+// In essence this checks an env variable called XML_OUTPUT_FILE
+// and if it is set we prepend "xml:" to its value, if it not set we return ""
+std::string OutputFlagAlsoCheckEnvVar() {
+  std::string default_value_for_output_flag = "";
+  const char* xml_output_file_env = posix::GetEnv("XML_OUTPUT_FILE");
+  if (nullptr != xml_output_file_env) {
+    default_value_for_output_flag = std::string("xml:") + xml_output_file_env;
+  }
+  return default_value_for_output_flag;
+}
+
+// Reads and returns the string environment variable corresponding to
+// the given flag; if it's not set, returns default_value.
+const char* StringFromGTestEnv(const char* flag, const char* default_value) {
+#if defined(GTEST_GET_STRING_FROM_ENV_)
+  return GTEST_GET_STRING_FROM_ENV_(flag, default_value);
+#else
+  const std::string env_var = FlagToEnvVar(flag);
+  const char* const value = posix::GetEnv(env_var.c_str());
+  return value == nullptr ? default_value : value;
+#endif  // defined(GTEST_GET_STRING_FROM_ENV_)
+}
+
+}  // namespace internal
+}  // namespace testing
diff --git a/test/gtest/src/gtest-printers.cc b/test/gtest/src/gtest-printers.cc
new file mode 100644
index 0000000..f3976d2
--- /dev/null
+++ b/test/gtest/src/gtest-printers.cc
@@ -0,0 +1,553 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Test - The Google C++ Testing and Mocking Framework
+//
+// This file implements a universal value printer that can print a
+// value of any type T:
+//
+//   void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr);
+//
+// It uses the << operator when possible, and prints the bytes in the
+// object otherwise.  A user can override its behavior for a class
+// type Foo by defining either operator<<(::std::ostream&, const Foo&)
+// or void PrintTo(const Foo&, ::std::ostream*) in the namespace that
+// defines Foo.
+
+#include "gtest/gtest-printers.h"
+
+#include <stdio.h>
+
+#include <cctype>
+#include <cstdint>
+#include <cwchar>
+#include <ostream>  // NOLINT
+#include <string>
+#include <type_traits>
+
+#include "gtest/internal/gtest-port.h"
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+
+namespace {
+
+using ::std::ostream;
+
+// Prints a segment of bytes in the given object.
+GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
+GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
+void PrintByteSegmentInObjectTo(const unsigned char* obj_bytes, size_t start,
+                                size_t count, ostream* os) {
+  char text[5] = "";
+  for (size_t i = 0; i != count; i++) {
+    const size_t j = start + i;
+    if (i != 0) {
+      // Organizes the bytes into groups of 2 for easy parsing by
+      // human.
+      if ((j % 2) == 0)
+        *os << ' ';
+      else
+        *os << '-';
+    }
+    GTEST_SNPRINTF_(text, sizeof(text), "%02X", obj_bytes[j]);
+    *os << text;
+  }
+}
+
+// Prints the bytes in the given value to the given ostream.
+void PrintBytesInObjectToImpl(const unsigned char* obj_bytes, size_t count,
+                              ostream* os) {
+  // Tells the user how big the object is.
+  *os << count << "-byte object <";
+
+  const size_t kThreshold = 132;
+  const size_t kChunkSize = 64;
+  // If the object size is bigger than kThreshold, we'll have to omit
+  // some details by printing only the first and the last kChunkSize
+  // bytes.
+  if (count < kThreshold) {
+    PrintByteSegmentInObjectTo(obj_bytes, 0, count, os);
+  } else {
+    PrintByteSegmentInObjectTo(obj_bytes, 0, kChunkSize, os);
+    *os << " ... ";
+    // Rounds up to 2-byte boundary.
+    const size_t resume_pos = (count - kChunkSize + 1) / 2 * 2;
+    PrintByteSegmentInObjectTo(obj_bytes, resume_pos, count - resume_pos, os);
+  }
+  *os << ">";
+}
+
+// Helpers for widening a character to char32_t. Since the standard does not
+// specify if char / wchar_t is signed or unsigned, it is important to first
+// convert it to the unsigned type of the same width before widening it to
+// char32_t.
+template <typename CharType>
+char32_t ToChar32(CharType in) {
+  return static_cast<char32_t>(
+      static_cast<typename std::make_unsigned<CharType>::type>(in));
+}
+
+}  // namespace
+
+namespace internal {
+
+// Delegates to PrintBytesInObjectToImpl() to print the bytes in the
+// given object.  The delegation simplifies the implementation, which
+// uses the << operator and thus is easier done outside of the
+// ::testing::internal namespace, which contains a << operator that
+// sometimes conflicts with the one in STL.
+void PrintBytesInObjectTo(const unsigned char* obj_bytes, size_t count,
+                          ostream* os) {
+  PrintBytesInObjectToImpl(obj_bytes, count, os);
+}
+
+// Depending on the value of a char (or wchar_t), we print it in one
+// of three formats:
+//   - as is if it's a printable ASCII (e.g. 'a', '2', ' '),
+//   - as a hexadecimal escape sequence (e.g. '\x7F'), or
+//   - as a special escape sequence (e.g. '\r', '\n').
+enum CharFormat { kAsIs, kHexEscape, kSpecialEscape };
+
+// Returns true if c is a printable ASCII character.  We test the
+// value of c directly instead of calling isprint(), which is buggy on
+// Windows Mobile.
+inline bool IsPrintableAscii(char32_t c) { return 0x20 <= c && c <= 0x7E; }
+
+// Prints c (of type char, char8_t, char16_t, char32_t, or wchar_t) as a
+// character literal without the quotes, escaping it when necessary; returns how
+// c was formatted.
+template <typename Char>
+static CharFormat PrintAsCharLiteralTo(Char c, ostream* os) {
+  const char32_t u_c = ToChar32(c);
+  switch (u_c) {
+    case L'\0':
+      *os << "\\0";
+      break;
+    case L'\'':
+      *os << "\\'";
+      break;
+    case L'\\':
+      *os << "\\\\";
+      break;
+    case L'\a':
+      *os << "\\a";
+      break;
+    case L'\b':
+      *os << "\\b";
+      break;
+    case L'\f':
+      *os << "\\f";
+      break;
+    case L'\n':
+      *os << "\\n";
+      break;
+    case L'\r':
+      *os << "\\r";
+      break;
+    case L'\t':
+      *os << "\\t";
+      break;
+    case L'\v':
+      *os << "\\v";
+      break;
+    default:
+      if (IsPrintableAscii(u_c)) {
+        *os << static_cast<char>(c);
+        return kAsIs;
+      } else {
+        ostream::fmtflags flags = os->flags();
+        *os << "\\x" << std::hex << std::uppercase << static_cast<int>(u_c);
+        os->flags(flags);
+        return kHexEscape;
+      }
+  }
+  return kSpecialEscape;
+}
+
+// Prints a char32_t c as if it's part of a string literal, escaping it when
+// necessary; returns how c was formatted.
+static CharFormat PrintAsStringLiteralTo(char32_t c, ostream* os) {
+  switch (c) {
+    case L'\'':
+      *os << "'";
+      return kAsIs;
+    case L'"':
+      *os << "\\\"";
+      return kSpecialEscape;
+    default:
+      return PrintAsCharLiteralTo(c, os);
+  }
+}
+
+static const char* GetCharWidthPrefix(char) { return ""; }
+
+static const char* GetCharWidthPrefix(signed char) { return ""; }
+
+static const char* GetCharWidthPrefix(unsigned char) { return ""; }
+
+#ifdef __cpp_char8_t
+static const char* GetCharWidthPrefix(char8_t) { return "u8"; }
+#endif
+
+static const char* GetCharWidthPrefix(char16_t) { return "u"; }
+
+static const char* GetCharWidthPrefix(char32_t) { return "U"; }
+
+static const char* GetCharWidthPrefix(wchar_t) { return "L"; }
+
+// Prints a char c as if it's part of a string literal, escaping it when
+// necessary; returns how c was formatted.
+static CharFormat PrintAsStringLiteralTo(char c, ostream* os) {
+  return PrintAsStringLiteralTo(ToChar32(c), os);
+}
+
+#ifdef __cpp_char8_t
+static CharFormat PrintAsStringLiteralTo(char8_t c, ostream* os) {
+  return PrintAsStringLiteralTo(ToChar32(c), os);
+}
+#endif
+
+static CharFormat PrintAsStringLiteralTo(char16_t c, ostream* os) {
+  return PrintAsStringLiteralTo(ToChar32(c), os);
+}
+
+static CharFormat PrintAsStringLiteralTo(wchar_t c, ostream* os) {
+  return PrintAsStringLiteralTo(ToChar32(c), os);
+}
+
+// Prints a character c (of type char, char8_t, char16_t, char32_t, or wchar_t)
+// and its code. '\0' is printed as "'\\0'", other unprintable characters are
+// also properly escaped using the standard C++ escape sequence.
+template <typename Char>
+void PrintCharAndCodeTo(Char c, ostream* os) {
+  // First, print c as a literal in the most readable form we can find.
+  *os << GetCharWidthPrefix(c) << "'";
+  const CharFormat format = PrintAsCharLiteralTo(c, os);
+  *os << "'";
+
+  // To aid user debugging, we also print c's code in decimal, unless
+  // it's 0 (in which case c was printed as '\\0', making the code
+  // obvious).
+  if (c == 0) return;
+  *os << " (" << static_cast<int>(c);
+
+  // For more convenience, we print c's code again in hexadecimal,
+  // unless c was already printed in the form '\x##' or the code is in
+  // [1, 9].
+  if (format == kHexEscape || (1 <= c && c <= 9)) {
+    // Do nothing.
+  } else {
+    *os << ", 0x" << String::FormatHexInt(static_cast<int>(c));
+  }
+  *os << ")";
+}
+
+void PrintTo(unsigned char c, ::std::ostream* os) { PrintCharAndCodeTo(c, os); }
+void PrintTo(signed char c, ::std::ostream* os) { PrintCharAndCodeTo(c, os); }
+
+// Prints a wchar_t as a symbol if it is printable or as its internal
+// code otherwise and also as its code.  L'\0' is printed as "L'\\0'".
+void PrintTo(wchar_t wc, ostream* os) { PrintCharAndCodeTo(wc, os); }
+
+// TODO(dcheng): Consider making this delegate to PrintCharAndCodeTo() as well.
+void PrintTo(char32_t c, ::std::ostream* os) {
+  *os << std::hex << "U+" << std::uppercase << std::setfill('0') << std::setw(4)
+      << static_cast<uint32_t>(c);
+}
+
+// gcc/clang __{u,}int128_t
+#if defined(__SIZEOF_INT128__)
+void PrintTo(__uint128_t v, ::std::ostream* os) {
+  if (v == 0) {
+    *os << "0";
+    return;
+  }
+
+  // Buffer large enough for ceil(log10(2^128))==39 and the null terminator
+  char buf[40];
+  char* p = buf + sizeof(buf);
+
+  // Some configurations have a __uint128_t, but no support for built in
+  // division. Do manual long division instead.
+
+  uint64_t high = static_cast<uint64_t>(v >> 64);
+  uint64_t low = static_cast<uint64_t>(v);
+
+  *--p = 0;
+  while (high != 0 || low != 0) {
+    uint64_t high_mod = high % 10;
+    high = high / 10;
+    // This is the long division algorithm specialized for a divisor of 10 and
+    // only two elements.
+    // Notable values:
+    //   2^64 / 10 == 1844674407370955161
+    //   2^64 % 10 == 6
+    const uint64_t carry = 6 * high_mod + low % 10;
+    low = low / 10 + high_mod * 1844674407370955161 + carry / 10;
+
+    char digit = static_cast<char>(carry % 10);
+    *--p = '0' + digit;
+  }
+  *os << p;
+}
+void PrintTo(__int128_t v, ::std::ostream* os) {
+  __uint128_t uv = static_cast<__uint128_t>(v);
+  if (v < 0) {
+    *os << "-";
+    uv = -uv;
+  }
+  PrintTo(uv, os);
+}
+#endif  // __SIZEOF_INT128__
+
+// Prints the given array of characters to the ostream.  CharType must be either
+// char, char8_t, char16_t, char32_t, or wchar_t.
+// The array starts at begin, the length is len, it may include '\0' characters
+// and may not be NUL-terminated.
+template <typename CharType>
+GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_ GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+    GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+        GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_ static CharFormat
+        PrintCharsAsStringTo(const CharType* begin, size_t len, ostream* os) {
+  const char* const quote_prefix = GetCharWidthPrefix(*begin);
+  *os << quote_prefix << "\"";
+  bool is_previous_hex = false;
+  CharFormat print_format = kAsIs;
+  for (size_t index = 0; index < len; ++index) {
+    const CharType cur = begin[index];
+    if (is_previous_hex && IsXDigit(cur)) {
+      // Previous character is of '\x..' form and this character can be
+      // interpreted as another hexadecimal digit in its number. Break string to
+      // disambiguate.
+      *os << "\" " << quote_prefix << "\"";
+    }
+    is_previous_hex = PrintAsStringLiteralTo(cur, os) == kHexEscape;
+    // Remember if any characters required hex escaping.
+    if (is_previous_hex) {
+      print_format = kHexEscape;
+    }
+  }
+  *os << "\"";
+  return print_format;
+}
+
+// Prints a (const) char/wchar_t array of 'len' elements, starting at address
+// 'begin'.  CharType must be either char or wchar_t.
+template <typename CharType>
+GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_ GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+    GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+        GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_ static void
+        UniversalPrintCharArray(const CharType* begin, size_t len,
+                                ostream* os) {
+  // The code
+  //   const char kFoo[] = "foo";
+  // generates an array of 4, not 3, elements, with the last one being '\0'.
+  //
+  // Therefore when printing a char array, we don't print the last element if
+  // it's '\0', such that the output matches the string literal as it's
+  // written in the source code.
+  if (len > 0 && begin[len - 1] == '\0') {
+    PrintCharsAsStringTo(begin, len - 1, os);
+    return;
+  }
+
+  // If, however, the last element in the array is not '\0', e.g.
+  //    const char kFoo[] = { 'f', 'o', 'o' };
+  // we must print the entire array.  We also print a message to indicate
+  // that the array is not NUL-terminated.
+  PrintCharsAsStringTo(begin, len, os);
+  *os << " (no terminating NUL)";
+}
+
+// Prints a (const) char array of 'len' elements, starting at address 'begin'.
+void UniversalPrintArray(const char* begin, size_t len, ostream* os) {
+  UniversalPrintCharArray(begin, len, os);
+}
+
+#ifdef __cpp_char8_t
+// Prints a (const) char8_t array of 'len' elements, starting at address
+// 'begin'.
+void UniversalPrintArray(const char8_t* begin, size_t len, ostream* os) {
+  UniversalPrintCharArray(begin, len, os);
+}
+#endif
+
+// Prints a (const) char16_t array of 'len' elements, starting at address
+// 'begin'.
+void UniversalPrintArray(const char16_t* begin, size_t len, ostream* os) {
+  UniversalPrintCharArray(begin, len, os);
+}
+
+// Prints a (const) char32_t array of 'len' elements, starting at address
+// 'begin'.
+void UniversalPrintArray(const char32_t* begin, size_t len, ostream* os) {
+  UniversalPrintCharArray(begin, len, os);
+}
+
+// Prints a (const) wchar_t array of 'len' elements, starting at address
+// 'begin'.
+void UniversalPrintArray(const wchar_t* begin, size_t len, ostream* os) {
+  UniversalPrintCharArray(begin, len, os);
+}
+
+namespace {
+
+// Prints a null-terminated C-style string to the ostream.
+template <typename Char>
+void PrintCStringTo(const Char* s, ostream* os) {
+  if (s == nullptr) {
+    *os << "NULL";
+  } else {
+    *os << ImplicitCast_<const void*>(s) << " pointing to ";
+    PrintCharsAsStringTo(s, std::char_traits<Char>::length(s), os);
+  }
+}
+
+}  // anonymous namespace
+
+void PrintTo(const char* s, ostream* os) { PrintCStringTo(s, os); }
+
+#ifdef __cpp_char8_t
+void PrintTo(const char8_t* s, ostream* os) { PrintCStringTo(s, os); }
+#endif
+
+void PrintTo(const char16_t* s, ostream* os) { PrintCStringTo(s, os); }
+
+void PrintTo(const char32_t* s, ostream* os) { PrintCStringTo(s, os); }
+
+// MSVC compiler can be configured to define whar_t as a typedef
+// of unsigned short. Defining an overload for const wchar_t* in that case
+// would cause pointers to unsigned shorts be printed as wide strings,
+// possibly accessing more memory than intended and causing invalid
+// memory accesses. MSVC defines _NATIVE_WCHAR_T_DEFINED symbol when
+// wchar_t is implemented as a native type.
+#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
+// Prints the given wide C string to the ostream.
+void PrintTo(const wchar_t* s, ostream* os) { PrintCStringTo(s, os); }
+#endif  // wchar_t is native
+
+namespace {
+
+bool ContainsUnprintableControlCodes(const char* str, size_t length) {
+  const unsigned char* s = reinterpret_cast<const unsigned char*>(str);
+
+  for (size_t i = 0; i < length; i++) {
+    unsigned char ch = *s++;
+    if (std::iscntrl(ch)) {
+      switch (ch) {
+        case '\t':
+        case '\n':
+        case '\r':
+          break;
+        default:
+          return true;
+      }
+    }
+  }
+  return false;
+}
+
+bool IsUTF8TrailByte(unsigned char t) { return 0x80 <= t && t <= 0xbf; }
+
+bool IsValidUTF8(const char* str, size_t length) {
+  const unsigned char* s = reinterpret_cast<const unsigned char*>(str);
+
+  for (size_t i = 0; i < length;) {
+    unsigned char lead = s[i++];
+
+    if (lead <= 0x7f) {
+      continue;  // single-byte character (ASCII) 0..7F
+    }
+    if (lead < 0xc2) {
+      return false;  // trail byte or non-shortest form
+    } else if (lead <= 0xdf && (i + 1) <= length && IsUTF8TrailByte(s[i])) {
+      ++i;  // 2-byte character
+    } else if (0xe0 <= lead && lead <= 0xef && (i + 2) <= length &&
+               IsUTF8TrailByte(s[i]) && IsUTF8TrailByte(s[i + 1]) &&
+               // check for non-shortest form and surrogate
+               (lead != 0xe0 || s[i] >= 0xa0) &&
+               (lead != 0xed || s[i] < 0xa0)) {
+      i += 2;  // 3-byte character
+    } else if (0xf0 <= lead && lead <= 0xf4 && (i + 3) <= length &&
+               IsUTF8TrailByte(s[i]) && IsUTF8TrailByte(s[i + 1]) &&
+               IsUTF8TrailByte(s[i + 2]) &&
+               // check for non-shortest form
+               (lead != 0xf0 || s[i] >= 0x90) &&
+               (lead != 0xf4 || s[i] < 0x90)) {
+      i += 3;  // 4-byte character
+    } else {
+      return false;
+    }
+  }
+  return true;
+}
+
+void ConditionalPrintAsText(const char* str, size_t length, ostream* os) {
+  if (!ContainsUnprintableControlCodes(str, length) &&
+      IsValidUTF8(str, length)) {
+    *os << "\n    As Text: \"" << str << "\"";
+  }
+}
+
+}  // anonymous namespace
+
+void PrintStringTo(const ::std::string& s, ostream* os) {
+  if (PrintCharsAsStringTo(s.data(), s.size(), os) == kHexEscape) {
+    if (GTEST_FLAG_GET(print_utf8)) {
+      ConditionalPrintAsText(s.data(), s.size(), os);
+    }
+  }
+}
+
+#ifdef __cpp_char8_t
+void PrintU8StringTo(const ::std::u8string& s, ostream* os) {
+  PrintCharsAsStringTo(s.data(), s.size(), os);
+}
+#endif
+
+void PrintU16StringTo(const ::std::u16string& s, ostream* os) {
+  PrintCharsAsStringTo(s.data(), s.size(), os);
+}
+
+void PrintU32StringTo(const ::std::u32string& s, ostream* os) {
+  PrintCharsAsStringTo(s.data(), s.size(), os);
+}
+
+#if GTEST_HAS_STD_WSTRING
+void PrintWideStringTo(const ::std::wstring& s, ostream* os) {
+  PrintCharsAsStringTo(s.data(), s.size(), os);
+}
+#endif  // GTEST_HAS_STD_WSTRING
+
+}  // namespace internal
+
+}  // namespace testing
diff --git a/test/gtest/src/gtest-test-part.cc b/test/gtest/src/gtest-test-part.cc
new file mode 100644
index 0000000..eb7c8d1
--- /dev/null
+++ b/test/gtest/src/gtest-test-part.cc
@@ -0,0 +1,105 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+
+#include "gtest/gtest-test-part.h"
+
+#include "gtest/internal/gtest-port.h"
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+
+using internal::GetUnitTestImpl;
+
+// Gets the summary of the failure message by omitting the stack trace
+// in it.
+std::string TestPartResult::ExtractSummary(const char* message) {
+  const char* const stack_trace = strstr(message, internal::kStackTraceMarker);
+  return stack_trace == nullptr ? message : std::string(message, stack_trace);
+}
+
+// Prints a TestPartResult object.
+std::ostream& operator<<(std::ostream& os, const TestPartResult& result) {
+  return os << internal::FormatFileLocation(result.file_name(),
+                                            result.line_number())
+            << " "
+            << (result.type() == TestPartResult::kSuccess ? "Success"
+                : result.type() == TestPartResult::kSkip  ? "Skipped"
+                : result.type() == TestPartResult::kFatalFailure
+                    ? "Fatal failure"
+                    : "Non-fatal failure")
+            << ":\n"
+            << result.message() << std::endl;
+}
+
+// Appends a TestPartResult to the array.
+void TestPartResultArray::Append(const TestPartResult& result) {
+  array_.push_back(result);
+}
+
+// Returns the TestPartResult at the given index (0-based).
+const TestPartResult& TestPartResultArray::GetTestPartResult(int index) const {
+  if (index < 0 || index >= size()) {
+    printf("\nInvalid index (%d) into TestPartResultArray.\n", index);
+    internal::posix::Abort();
+  }
+
+  return array_[static_cast<size_t>(index)];
+}
+
+// Returns the number of TestPartResult objects in the array.
+int TestPartResultArray::size() const {
+  return static_cast<int>(array_.size());
+}
+
+namespace internal {
+
+HasNewFatalFailureHelper::HasNewFatalFailureHelper()
+    : has_new_fatal_failure_(false),
+      original_reporter_(
+          GetUnitTestImpl()->GetTestPartResultReporterForCurrentThread()) {
+  GetUnitTestImpl()->SetTestPartResultReporterForCurrentThread(this);
+}
+
+HasNewFatalFailureHelper::~HasNewFatalFailureHelper() {
+  GetUnitTestImpl()->SetTestPartResultReporterForCurrentThread(
+      original_reporter_);
+}
+
+void HasNewFatalFailureHelper::ReportTestPartResult(
+    const TestPartResult& result) {
+  if (result.fatally_failed()) has_new_fatal_failure_ = true;
+  original_reporter_->ReportTestPartResult(result);
+}
+
+}  // namespace internal
+
+}  // namespace testing
diff --git a/test/gtest/src/gtest-typed-test.cc b/test/gtest/src/gtest-typed-test.cc
new file mode 100644
index 0000000..a2828b8
--- /dev/null
+++ b/test/gtest/src/gtest-typed-test.cc
@@ -0,0 +1,104 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "gtest/gtest-typed-test.h"
+
+#include "gtest/gtest.h"
+
+namespace testing {
+namespace internal {
+
+// Skips to the first non-space char in str. Returns an empty string if str
+// contains only whitespace characters.
+static const char* SkipSpaces(const char* str) {
+  while (IsSpace(*str)) str++;
+  return str;
+}
+
+static std::vector<std::string> SplitIntoTestNames(const char* src) {
+  std::vector<std::string> name_vec;
+  src = SkipSpaces(src);
+  for (; src != nullptr; src = SkipComma(src)) {
+    name_vec.push_back(StripTrailingSpaces(GetPrefixUntilComma(src)));
+  }
+  return name_vec;
+}
+
+// Verifies that registered_tests match the test names in
+// registered_tests_; returns registered_tests if successful, or
+// aborts the program otherwise.
+const char* TypedTestSuitePState::VerifyRegisteredTestNames(
+    const char* test_suite_name, const char* file, int line,
+    const char* registered_tests) {
+  RegisterTypeParameterizedTestSuite(test_suite_name, CodeLocation(file, line));
+
+  typedef RegisteredTestsMap::const_iterator RegisteredTestIter;
+  registered_ = true;
+
+  std::vector<std::string> name_vec = SplitIntoTestNames(registered_tests);
+
+  Message errors;
+
+  std::set<std::string> tests;
+  for (std::vector<std::string>::const_iterator name_it = name_vec.begin();
+       name_it != name_vec.end(); ++name_it) {
+    const std::string& name = *name_it;
+    if (tests.count(name) != 0) {
+      errors << "Test " << name << " is listed more than once.\n";
+      continue;
+    }
+
+    if (registered_tests_.count(name) != 0) {
+      tests.insert(name);
+    } else {
+      errors << "No test named " << name
+             << " can be found in this test suite.\n";
+    }
+  }
+
+  for (RegisteredTestIter it = registered_tests_.begin();
+       it != registered_tests_.end(); ++it) {
+    if (tests.count(it->first) == 0) {
+      errors << "You forgot to list test " << it->first << ".\n";
+    }
+  }
+
+  const std::string& errors_str = errors.GetString();
+  if (errors_str != "") {
+    fprintf(stderr, "%s %s", FormatFileLocation(file, line).c_str(),
+            errors_str.c_str());
+    fflush(stderr);
+    posix::Abort();
+  }
+
+  return registered_tests;
+}
+
+}  // namespace internal
+}  // namespace testing
diff --git a/test/gtest/src/gtest.cc b/test/gtest/src/gtest.cc
new file mode 100644
index 0000000..6f31dd2
--- /dev/null
+++ b/test/gtest/src/gtest.cc
@@ -0,0 +1,6795 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+
+#include "gtest/gtest.h"
+
+#include <ctype.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <wchar.h>
+#include <wctype.h>
+
+#include <algorithm>
+#include <chrono>  // NOLINT
+#include <cmath>
+#include <cstdint>
+#include <initializer_list>
+#include <iomanip>
+#include <iterator>
+#include <limits>
+#include <list>
+#include <map>
+#include <ostream>  // NOLINT
+#include <sstream>
+#include <unordered_set>
+#include <vector>
+
+#include "gtest/gtest-assertion-result.h"
+#include "gtest/gtest-spi.h"
+#include "gtest/internal/custom/gtest.h"
+
+#if GTEST_OS_LINUX
+
+#include <fcntl.h>   // NOLINT
+#include <limits.h>  // NOLINT
+#include <sched.h>   // NOLINT
+// Declares vsnprintf().  This header is not available on Windows.
+#include <strings.h>   // NOLINT
+#include <sys/mman.h>  // NOLINT
+#include <sys/time.h>  // NOLINT
+#include <unistd.h>    // NOLINT
+
+#include <string>
+
+#elif GTEST_OS_ZOS
+#include <sys/time.h>  // NOLINT
+
+// On z/OS we additionally need strings.h for strcasecmp.
+#include <strings.h>   // NOLINT
+
+#elif GTEST_OS_WINDOWS_MOBILE  // We are on Windows CE.
+
+#include <windows.h>  // NOLINT
+#undef min
+
+#elif GTEST_OS_WINDOWS  // We are on Windows proper.
+
+#include <windows.h>  // NOLINT
+#undef min
+
+#ifdef _MSC_VER
+#include <crtdbg.h>  // NOLINT
+#endif
+
+#include <io.h>         // NOLINT
+#include <sys/stat.h>   // NOLINT
+#include <sys/timeb.h>  // NOLINT
+#include <sys/types.h>  // NOLINT
+
+#if GTEST_OS_WINDOWS_MINGW
+#include <sys/time.h>  // NOLINT
+#endif                 // GTEST_OS_WINDOWS_MINGW
+
+#else
+
+// cpplint thinks that the header is already included, so we want to
+// silence it.
+#include <sys/time.h>  // NOLINT
+#include <unistd.h>    // NOLINT
+
+#endif  // GTEST_OS_LINUX
+
+#if GTEST_HAS_EXCEPTIONS
+#include <stdexcept>
+#endif
+
+#if GTEST_CAN_STREAM_RESULTS_
+#include <arpa/inet.h>   // NOLINT
+#include <netdb.h>       // NOLINT
+#include <sys/socket.h>  // NOLINT
+#include <sys/types.h>   // NOLINT
+#endif
+
+#include "src/gtest-internal-inl.h"
+
+#if GTEST_OS_WINDOWS
+#define vsnprintf _vsnprintf
+#endif  // GTEST_OS_WINDOWS
+
+#if GTEST_OS_MAC
+#ifndef GTEST_OS_IOS
+#include <crt_externs.h>
+#endif
+#endif
+
+#if GTEST_HAS_ABSL
+#include "absl/debugging/failure_signal_handler.h"
+#include "absl/debugging/stacktrace.h"
+#include "absl/debugging/symbolize.h"
+#include "absl/flags/parse.h"
+#include "absl/flags/usage.h"
+#include "absl/strings/str_cat.h"
+#include "absl/strings/str_replace.h"
+#endif  // GTEST_HAS_ABSL
+
+namespace testing {
+
+using internal::CountIf;
+using internal::ForEach;
+using internal::GetElementOr;
+using internal::Shuffle;
+
+// Constants.
+
+// A test whose test suite name or test name matches this filter is
+// disabled and not run.
+static const char kDisableTestFilter[] = "DISABLED_*:*/DISABLED_*";
+
+// A test suite whose name matches this filter is considered a death
+// test suite and will be run before test suites whose name doesn't
+// match this filter.
+static const char kDeathTestSuiteFilter[] = "*DeathTest:*DeathTest/*";
+
+// A test filter that matches everything.
+static const char kUniversalFilter[] = "*";
+
+// The default output format.
+static const char kDefaultOutputFormat[] = "xml";
+// The default output file.
+static const char kDefaultOutputFile[] = "test_detail";
+
+// The environment variable name for the test shard index.
+static const char kTestShardIndex[] = "GTEST_SHARD_INDEX";
+// The environment variable name for the total number of test shards.
+static const char kTestTotalShards[] = "GTEST_TOTAL_SHARDS";
+// The environment variable name for the test shard status file.
+static const char kTestShardStatusFile[] = "GTEST_SHARD_STATUS_FILE";
+
+namespace internal {
+
+// The text used in failure messages to indicate the start of the
+// stack trace.
+const char kStackTraceMarker[] = "\nStack trace:\n";
+
+// g_help_flag is true if and only if the --help flag or an equivalent form
+// is specified on the command line.
+bool g_help_flag = false;
+
+// Utility function to Open File for Writing
+static FILE* OpenFileForWriting(const std::string& output_file) {
+  FILE* fileout = nullptr;
+  FilePath output_file_path(output_file);
+  FilePath output_dir(output_file_path.RemoveFileName());
+
+  if (output_dir.CreateDirectoriesRecursively()) {
+    fileout = posix::FOpen(output_file.c_str(), "w");
+  }
+  if (fileout == nullptr) {
+    GTEST_LOG_(FATAL) << "Unable to open file \"" << output_file << "\"";
+  }
+  return fileout;
+}
+
+}  // namespace internal
+
+// Bazel passes in the argument to '--test_filter' via the TESTBRIDGE_TEST_ONLY
+// environment variable.
+static const char* GetDefaultFilter() {
+  const char* const testbridge_test_only =
+      internal::posix::GetEnv("TESTBRIDGE_TEST_ONLY");
+  if (testbridge_test_only != nullptr) {
+    return testbridge_test_only;
+  }
+  return kUniversalFilter;
+}
+
+// Bazel passes in the argument to '--test_runner_fail_fast' via the
+// TESTBRIDGE_TEST_RUNNER_FAIL_FAST environment variable.
+static bool GetDefaultFailFast() {
+  const char* const testbridge_test_runner_fail_fast =
+      internal::posix::GetEnv("TESTBRIDGE_TEST_RUNNER_FAIL_FAST");
+  if (testbridge_test_runner_fail_fast != nullptr) {
+    return strcmp(testbridge_test_runner_fail_fast, "1") == 0;
+  }
+  return false;
+}
+
+}  // namespace testing
+
+GTEST_DEFINE_bool_(
+    fail_fast,
+    testing::internal::BoolFromGTestEnv("fail_fast",
+                                        testing::GetDefaultFailFast()),
+    "True if and only if a test failure should stop further test execution.");
+
+GTEST_DEFINE_bool_(
+    also_run_disabled_tests,
+    testing::internal::BoolFromGTestEnv("also_run_disabled_tests", false),
+    "Run disabled tests too, in addition to the tests normally being run.");
+
+GTEST_DEFINE_bool_(
+    break_on_failure,
+    testing::internal::BoolFromGTestEnv("break_on_failure", false),
+    "True if and only if a failed assertion should be a debugger "
+    "break-point.");
+
+GTEST_DEFINE_bool_(catch_exceptions,
+                   testing::internal::BoolFromGTestEnv("catch_exceptions",
+                                                       true),
+                   "True if and only if " GTEST_NAME_
+                   " should catch exceptions and treat them as test failures.");
+
+GTEST_DEFINE_string_(
+    color, testing::internal::StringFromGTestEnv("color", "auto"),
+    "Whether to use colors in the output.  Valid values: yes, no, "
+    "and auto.  'auto' means to use colors if the output is "
+    "being sent to a terminal and the TERM environment variable "
+    "is set to a terminal type that supports colors.");
+
+GTEST_DEFINE_string_(
+    filter,
+    testing::internal::StringFromGTestEnv("filter",
+                                          testing::GetDefaultFilter()),
+    "A colon-separated list of glob (not regex) patterns "
+    "for filtering the tests to run, optionally followed by a "
+    "'-' and a : separated list of negative patterns (tests to "
+    "exclude).  A test is run if it matches one of the positive "
+    "patterns and does not match any of the negative patterns.");
+
+GTEST_DEFINE_bool_(
+    install_failure_signal_handler,
+    testing::internal::BoolFromGTestEnv("install_failure_signal_handler",
+                                        false),
+    "If true and supported on the current platform, " GTEST_NAME_
+    " should "
+    "install a signal handler that dumps debugging information when fatal "
+    "signals are raised.");
+
+GTEST_DEFINE_bool_(list_tests, false, "List all tests without running them.");
+
+// The net priority order after flag processing is thus:
+//   --gtest_output command line flag
+//   GTEST_OUTPUT environment variable
+//   XML_OUTPUT_FILE environment variable
+//   ''
+GTEST_DEFINE_string_(
+    output,
+    testing::internal::StringFromGTestEnv(
+        "output", testing::internal::OutputFlagAlsoCheckEnvVar().c_str()),
+    "A format (defaults to \"xml\" but can be specified to be \"json\"), "
+    "optionally followed by a colon and an output file name or directory. "
+    "A directory is indicated by a trailing pathname separator. "
+    "Examples: \"xml:filename.xml\", \"xml::directoryname/\". "
+    "If a directory is specified, output files will be created "
+    "within that directory, with file-names based on the test "
+    "executable's name and, if necessary, made unique by adding "
+    "digits.");
+
+GTEST_DEFINE_bool_(
+    brief, testing::internal::BoolFromGTestEnv("brief", false),
+    "True if only test failures should be displayed in text output.");
+
+GTEST_DEFINE_bool_(print_time,
+                   testing::internal::BoolFromGTestEnv("print_time", true),
+                   "True if and only if " GTEST_NAME_
+                   " should display elapsed time in text output.");
+
+GTEST_DEFINE_bool_(print_utf8,
+                   testing::internal::BoolFromGTestEnv("print_utf8", true),
+                   "True if and only if " GTEST_NAME_
+                   " prints UTF8 characters as text.");
+
+GTEST_DEFINE_int32_(
+    random_seed, testing::internal::Int32FromGTestEnv("random_seed", 0),
+    "Random number seed to use when shuffling test orders.  Must be in range "
+    "[1, 99999], or 0 to use a seed based on the current time.");
+
+GTEST_DEFINE_int32_(
+    repeat, testing::internal::Int32FromGTestEnv("repeat", 1),
+    "How many times to repeat each test.  Specify a negative number "
+    "for repeating forever.  Useful for shaking out flaky tests.");
+
+GTEST_DEFINE_bool_(
+    recreate_environments_when_repeating,
+    testing::internal::BoolFromGTestEnv("recreate_environments_when_repeating",
+                                        false),
+    "Controls whether global test environments are recreated for each repeat "
+    "of the tests. If set to false the global test environments are only set "
+    "up once, for the first iteration, and only torn down once, for the last. "
+    "Useful for shaking out flaky tests with stable, expensive test "
+    "environments. If --gtest_repeat is set to a negative number, meaning "
+    "there is no last run, the environments will always be recreated to avoid "
+    "leaks.");
+
+GTEST_DEFINE_bool_(show_internal_stack_frames, false,
+                   "True if and only if " GTEST_NAME_
+                   " should include internal stack frames when "
+                   "printing test failure stack traces.");
+
+GTEST_DEFINE_bool_(shuffle,
+                   testing::internal::BoolFromGTestEnv("shuffle", false),
+                   "True if and only if " GTEST_NAME_
+                   " should randomize tests' order on every run.");
+
+GTEST_DEFINE_int32_(
+    stack_trace_depth,
+    testing::internal::Int32FromGTestEnv("stack_trace_depth",
+                                         testing::kMaxStackTraceDepth),
+    "The maximum number of stack frames to print when an "
+    "assertion fails.  The valid range is 0 through 100, inclusive.");
+
+GTEST_DEFINE_string_(
+    stream_result_to,
+    testing::internal::StringFromGTestEnv("stream_result_to", ""),
+    "This flag specifies the host name and the port number on which to stream "
+    "test results. Example: \"localhost:555\". The flag is effective only on "
+    "Linux.");
+
+GTEST_DEFINE_bool_(
+    throw_on_failure,
+    testing::internal::BoolFromGTestEnv("throw_on_failure", false),
+    "When this flag is specified, a failed assertion will throw an exception "
+    "if exceptions are enabled or exit the program with a non-zero code "
+    "otherwise. For use with an external test framework.");
+
+#if GTEST_USE_OWN_FLAGFILE_FLAG_
+GTEST_DEFINE_string_(
+    flagfile, testing::internal::StringFromGTestEnv("flagfile", ""),
+    "This flag specifies the flagfile to read command-line flags from.");
+#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
+
+namespace testing {
+namespace internal {
+
+// Generates a random number from [0, range), using a Linear
+// Congruential Generator (LCG).  Crashes if 'range' is 0 or greater
+// than kMaxRange.
+uint32_t Random::Generate(uint32_t range) {
+  // These constants are the same as are used in glibc's rand(3).
+  // Use wider types than necessary to prevent unsigned overflow diagnostics.
+  state_ = static_cast<uint32_t>(1103515245ULL * state_ + 12345U) % kMaxRange;
+
+  GTEST_CHECK_(range > 0) << "Cannot generate a number in the range [0, 0).";
+  GTEST_CHECK_(range <= kMaxRange)
+      << "Generation of a number in [0, " << range << ") was requested, "
+      << "but this can only generate numbers in [0, " << kMaxRange << ").";
+
+  // Converting via modulus introduces a bit of downward bias, but
+  // it's simple, and a linear congruential generator isn't too good
+  // to begin with.
+  return state_ % range;
+}
+
+// GTestIsInitialized() returns true if and only if the user has initialized
+// Google Test.  Useful for catching the user mistake of not initializing
+// Google Test before calling RUN_ALL_TESTS().
+static bool GTestIsInitialized() { return GetArgvs().size() > 0; }
+
+// Iterates over a vector of TestSuites, keeping a running sum of the
+// results of calling a given int-returning method on each.
+// Returns the sum.
+static int SumOverTestSuiteList(const std::vector<TestSuite*>& case_list,
+                                int (TestSuite::*method)() const) {
+  int sum = 0;
+  for (size_t i = 0; i < case_list.size(); i++) {
+    sum += (case_list[i]->*method)();
+  }
+  return sum;
+}
+
+// Returns true if and only if the test suite passed.
+static bool TestSuitePassed(const TestSuite* test_suite) {
+  return test_suite->should_run() && test_suite->Passed();
+}
+
+// Returns true if and only if the test suite failed.
+static bool TestSuiteFailed(const TestSuite* test_suite) {
+  return test_suite->should_run() && test_suite->Failed();
+}
+
+// Returns true if and only if test_suite contains at least one test that
+// should run.
+static bool ShouldRunTestSuite(const TestSuite* test_suite) {
+  return test_suite->should_run();
+}
+
+// AssertHelper constructor.
+AssertHelper::AssertHelper(TestPartResult::Type type, const char* file,
+                           int line, const char* message)
+    : data_(new AssertHelperData(type, file, line, message)) {}
+
+AssertHelper::~AssertHelper() { delete data_; }
+
+// Message assignment, for assertion streaming support.
+void AssertHelper::operator=(const Message& message) const {
+  UnitTest::GetInstance()->AddTestPartResult(
+      data_->type, data_->file, data_->line,
+      AppendUserMessage(data_->message, message),
+      UnitTest::GetInstance()->impl()->CurrentOsStackTraceExceptTop(1)
+      // Skips the stack frame for this function itself.
+  );  // NOLINT
+}
+
+namespace {
+
+// When TEST_P is found without a matching INSTANTIATE_TEST_SUITE_P
+// to creates test cases for it, a synthetic test case is
+// inserted to report ether an error or a log message.
+//
+// This configuration bit will likely be removed at some point.
+constexpr bool kErrorOnUninstantiatedParameterizedTest = true;
+constexpr bool kErrorOnUninstantiatedTypeParameterizedTest = true;
+
+// A test that fails at a given file/line location with a given message.
+class FailureTest : public Test {
+ public:
+  explicit FailureTest(const CodeLocation& loc, std::string error_message,
+                       bool as_error)
+      : loc_(loc),
+        error_message_(std::move(error_message)),
+        as_error_(as_error) {}
+
+  void TestBody() override {
+    if (as_error_) {
+      AssertHelper(TestPartResult::kNonFatalFailure, loc_.file.c_str(),
+                   loc_.line, "") = Message() << error_message_;
+    } else {
+      std::cout << error_message_ << std::endl;
+    }
+  }
+
+ private:
+  const CodeLocation loc_;
+  const std::string error_message_;
+  const bool as_error_;
+};
+
+}  // namespace
+
+std::set<std::string>* GetIgnoredParameterizedTestSuites() {
+  return UnitTest::GetInstance()->impl()->ignored_parameterized_test_suites();
+}
+
+// Add a given test_suit to the list of them allow to go un-instantiated.
+MarkAsIgnored::MarkAsIgnored(const char* test_suite) {
+  GetIgnoredParameterizedTestSuites()->insert(test_suite);
+}
+
+// If this parameterized test suite has no instantiations (and that
+// has not been marked as okay), emit a test case reporting that.
+void InsertSyntheticTestCase(const std::string& name, CodeLocation location,
+                             bool has_test_p) {
+  const auto& ignored = *GetIgnoredParameterizedTestSuites();
+  if (ignored.find(name) != ignored.end()) return;
+
+  const char kMissingInstantiation[] =  //
+      " is defined via TEST_P, but never instantiated. None of the test cases "
+      "will run. Either no INSTANTIATE_TEST_SUITE_P is provided or the only "
+      "ones provided expand to nothing."
+      "\n\n"
+      "Ideally, TEST_P definitions should only ever be included as part of "
+      "binaries that intend to use them. (As opposed to, for example, being "
+      "placed in a library that may be linked in to get other utilities.)";
+
+  const char kMissingTestCase[] =  //
+      " is instantiated via INSTANTIATE_TEST_SUITE_P, but no tests are "
+      "defined via TEST_P . No test cases will run."
+      "\n\n"
+      "Ideally, INSTANTIATE_TEST_SUITE_P should only ever be invoked from "
+      "code that always depend on code that provides TEST_P. Failing to do "
+      "so is often an indication of dead code, e.g. the last TEST_P was "
+      "removed but the rest got left behind.";
+
+  std::string message =
+      "Parameterized test suite " + name +
+      (has_test_p ? kMissingInstantiation : kMissingTestCase) +
+      "\n\n"
+      "To suppress this error for this test suite, insert the following line "
+      "(in a non-header) in the namespace it is defined in:"
+      "\n\n"
+      "GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(" +
+      name + ");";
+
+  std::string full_name = "UninstantiatedParameterizedTestSuite<" + name + ">";
+  RegisterTest(  //
+      "GoogleTestVerification", full_name.c_str(),
+      nullptr,  // No type parameter.
+      nullptr,  // No value parameter.
+      location.file.c_str(), location.line, [message, location] {
+        return new FailureTest(location, message,
+                               kErrorOnUninstantiatedParameterizedTest);
+      });
+}
+
+void RegisterTypeParameterizedTestSuite(const char* test_suite_name,
+                                        CodeLocation code_location) {
+  GetUnitTestImpl()->type_parameterized_test_registry().RegisterTestSuite(
+      test_suite_name, code_location);
+}
+
+void RegisterTypeParameterizedTestSuiteInstantiation(const char* case_name) {
+  GetUnitTestImpl()->type_parameterized_test_registry().RegisterInstantiation(
+      case_name);
+}
+
+void TypeParameterizedTestSuiteRegistry::RegisterTestSuite(
+    const char* test_suite_name, CodeLocation code_location) {
+  suites_.emplace(std::string(test_suite_name),
+                  TypeParameterizedTestSuiteInfo(code_location));
+}
+
+void TypeParameterizedTestSuiteRegistry::RegisterInstantiation(
+    const char* test_suite_name) {
+  auto it = suites_.find(std::string(test_suite_name));
+  if (it != suites_.end()) {
+    it->second.instantiated = true;
+  } else {
+    GTEST_LOG_(ERROR) << "Unknown type parameterized test suit '"
+                      << test_suite_name << "'";
+  }
+}
+
+void TypeParameterizedTestSuiteRegistry::CheckForInstantiations() {
+  const auto& ignored = *GetIgnoredParameterizedTestSuites();
+  for (const auto& testcase : suites_) {
+    if (testcase.second.instantiated) continue;
+    if (ignored.find(testcase.first) != ignored.end()) continue;
+
+    std::string message =
+        "Type parameterized test suite " + testcase.first +
+        " is defined via REGISTER_TYPED_TEST_SUITE_P, but never instantiated "
+        "via INSTANTIATE_TYPED_TEST_SUITE_P. None of the test cases will run."
+        "\n\n"
+        "Ideally, TYPED_TEST_P definitions should only ever be included as "
+        "part of binaries that intend to use them. (As opposed to, for "
+        "example, being placed in a library that may be linked in to get other "
+        "utilities.)"
+        "\n\n"
+        "To suppress this error for this test suite, insert the following line "
+        "(in a non-header) in the namespace it is defined in:"
+        "\n\n"
+        "GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(" +
+        testcase.first + ");";
+
+    std::string full_name =
+        "UninstantiatedTypeParameterizedTestSuite<" + testcase.first + ">";
+    RegisterTest(  //
+        "GoogleTestVerification", full_name.c_str(),
+        nullptr,  // No type parameter.
+        nullptr,  // No value parameter.
+        testcase.second.code_location.file.c_str(),
+        testcase.second.code_location.line, [message, testcase] {
+          return new FailureTest(testcase.second.code_location, message,
+                                 kErrorOnUninstantiatedTypeParameterizedTest);
+        });
+  }
+}
+
+// A copy of all command line arguments.  Set by InitGoogleTest().
+static ::std::vector<std::string> g_argvs;
+
+::std::vector<std::string> GetArgvs() {
+#if defined(GTEST_CUSTOM_GET_ARGVS_)
+  // GTEST_CUSTOM_GET_ARGVS_() may return a container of std::string or
+  // ::string. This code converts it to the appropriate type.
+  const auto& custom = GTEST_CUSTOM_GET_ARGVS_();
+  return ::std::vector<std::string>(custom.begin(), custom.end());
+#else   // defined(GTEST_CUSTOM_GET_ARGVS_)
+  return g_argvs;
+#endif  // defined(GTEST_CUSTOM_GET_ARGVS_)
+}
+
+// Returns the current application's name, removing directory path if that
+// is present.
+FilePath GetCurrentExecutableName() {
+  FilePath result;
+
+#if GTEST_OS_WINDOWS || GTEST_OS_OS2
+  result.Set(FilePath(GetArgvs()[0]).RemoveExtension("exe"));
+#else
+  result.Set(FilePath(GetArgvs()[0]));
+#endif  // GTEST_OS_WINDOWS
+
+  return result.RemoveDirectoryName();
+}
+
+// Functions for processing the gtest_output flag.
+
+// Returns the output format, or "" for normal printed output.
+std::string UnitTestOptions::GetOutputFormat() {
+  std::string s = GTEST_FLAG_GET(output);
+  const char* const gtest_output_flag = s.c_str();
+  const char* const colon = strchr(gtest_output_flag, ':');
+  return (colon == nullptr)
+             ? std::string(gtest_output_flag)
+             : std::string(gtest_output_flag,
+                           static_cast<size_t>(colon - gtest_output_flag));
+}
+
+// Returns the name of the requested output file, or the default if none
+// was explicitly specified.
+std::string UnitTestOptions::GetAbsolutePathToOutputFile() {
+  std::string s = GTEST_FLAG_GET(output);
+  const char* const gtest_output_flag = s.c_str();
+
+  std::string format = GetOutputFormat();
+  if (format.empty()) format = std::string(kDefaultOutputFormat);
+
+  const char* const colon = strchr(gtest_output_flag, ':');
+  if (colon == nullptr)
+    return internal::FilePath::MakeFileName(
+               internal::FilePath(
+                   UnitTest::GetInstance()->original_working_dir()),
+               internal::FilePath(kDefaultOutputFile), 0, format.c_str())
+        .string();
+
+  internal::FilePath output_name(colon + 1);
+  if (!output_name.IsAbsolutePath())
+    output_name = internal::FilePath::ConcatPaths(
+        internal::FilePath(UnitTest::GetInstance()->original_working_dir()),
+        internal::FilePath(colon + 1));
+
+  if (!output_name.IsDirectory()) return output_name.string();
+
+  internal::FilePath result(internal::FilePath::GenerateUniqueFileName(
+      output_name, internal::GetCurrentExecutableName(),
+      GetOutputFormat().c_str()));
+  return result.string();
+}
+
+// Returns true if and only if the wildcard pattern matches the string. Each
+// pattern consists of regular characters, single-character wildcards (?), and
+// multi-character wildcards (*).
+//
+// This function implements a linear-time string globbing algorithm based on
+// https://research.swtch.com/glob.
+static bool PatternMatchesString(const std::string& name_str,
+                                 const char* pattern, const char* pattern_end) {
+  const char* name = name_str.c_str();
+  const char* const name_begin = name;
+  const char* const name_end = name + name_str.size();
+
+  const char* pattern_next = pattern;
+  const char* name_next = name;
+
+  while (pattern < pattern_end || name < name_end) {
+    if (pattern < pattern_end) {
+      switch (*pattern) {
+        default:  // Match an ordinary character.
+          if (name < name_end && *name == *pattern) {
+            ++pattern;
+            ++name;
+            continue;
+          }
+          break;
+        case '?':  // Match any single character.
+          if (name < name_end) {
+            ++pattern;
+            ++name;
+            continue;
+          }
+          break;
+        case '*':
+          // Match zero or more characters. Start by skipping over the wildcard
+          // and matching zero characters from name. If that fails, restart and
+          // match one more character than the last attempt.
+          pattern_next = pattern;
+          name_next = name + 1;
+          ++pattern;
+          continue;
+      }
+    }
+    // Failed to match a character. Restart if possible.
+    if (name_begin < name_next && name_next <= name_end) {
+      pattern = pattern_next;
+      name = name_next;
+      continue;
+    }
+    return false;
+  }
+  return true;
+}
+
+namespace {
+
+bool IsGlobPattern(const std::string& pattern) {
+  return std::any_of(pattern.begin(), pattern.end(),
+                     [](const char c) { return c == '?' || c == '*'; });
+}
+
+class UnitTestFilter {
+ public:
+  UnitTestFilter() = default;
+
+  // Constructs a filter from a string of patterns separated by `:`.
+  explicit UnitTestFilter(const std::string& filter) {
+    // By design "" filter matches "" string.
+    std::vector<std::string> all_patterns;
+    SplitString(filter, ':', &all_patterns);
+    const auto exact_match_patterns_begin = std::partition(
+        all_patterns.begin(), all_patterns.end(), &IsGlobPattern);
+
+    glob_patterns_.reserve(static_cast<size_t>(
+        std::distance(all_patterns.begin(), exact_match_patterns_begin)));
+    std::move(all_patterns.begin(), exact_match_patterns_begin,
+              std::inserter(glob_patterns_, glob_patterns_.begin()));
+    std::move(
+        exact_match_patterns_begin, all_patterns.end(),
+        std::inserter(exact_match_patterns_, exact_match_patterns_.begin()));
+  }
+
+  // Returns true if and only if name matches at least one of the patterns in
+  // the filter.
+  bool MatchesName(const std::string& name) const {
+    return exact_match_patterns_.count(name) > 0 ||
+           std::any_of(glob_patterns_.begin(), glob_patterns_.end(),
+                       [&name](const std::string& pattern) {
+                         return PatternMatchesString(
+                             name, pattern.c_str(),
+                             pattern.c_str() + pattern.size());
+                       });
+  }
+
+ private:
+  std::vector<std::string> glob_patterns_;
+  std::unordered_set<std::string> exact_match_patterns_;
+};
+
+class PositiveAndNegativeUnitTestFilter {
+ public:
+  // Constructs a positive and a negative filter from a string. The string
+  // contains a positive filter optionally followed by a '-' character and a
+  // negative filter. In case only a negative filter is provided the positive
+  // filter will be assumed "*".
+  // A filter is a list of patterns separated by ':'.
+  explicit PositiveAndNegativeUnitTestFilter(const std::string& filter) {
+    std::vector<std::string> positive_and_negative_filters;
+
+    // NOTE: `SplitString` always returns a non-empty container.
+    SplitString(filter, '-', &positive_and_negative_filters);
+    const auto& positive_filter = positive_and_negative_filters.front();
+
+    if (positive_and_negative_filters.size() > 1) {
+      positive_filter_ = UnitTestFilter(
+          positive_filter.empty() ? kUniversalFilter : positive_filter);
+
+      // TODO(b/214626361): Fail on multiple '-' characters
+      // For the moment to preserve old behavior we concatenate the rest of the
+      // string parts with `-` as separator to generate the negative filter.
+      auto negative_filter_string = positive_and_negative_filters[1];
+      for (std::size_t i = 2; i < positive_and_negative_filters.size(); i++)
+        negative_filter_string =
+            negative_filter_string + '-' + positive_and_negative_filters[i];
+      negative_filter_ = UnitTestFilter(negative_filter_string);
+    } else {
+      // In case we don't have a negative filter and positive filter is ""
+      // we do not use kUniversalFilter by design as opposed to when we have a
+      // negative filter.
+      positive_filter_ = UnitTestFilter(positive_filter);
+    }
+  }
+
+  // Returns true if and only if test name (this is generated by appending test
+  // suit name and test name via a '.' character) matches the positive filter
+  // and does not match the negative filter.
+  bool MatchesTest(const std::string& test_suite_name,
+                   const std::string& test_name) const {
+    return MatchesName(test_suite_name + "." + test_name);
+  }
+
+  // Returns true if and only if name matches the positive filter and does not
+  // match the negative filter.
+  bool MatchesName(const std::string& name) const {
+    return positive_filter_.MatchesName(name) &&
+           !negative_filter_.MatchesName(name);
+  }
+
+ private:
+  UnitTestFilter positive_filter_;
+  UnitTestFilter negative_filter_;
+};
+}  // namespace
+
+bool UnitTestOptions::MatchesFilter(const std::string& name_str,
+                                    const char* filter) {
+  return UnitTestFilter(filter).MatchesName(name_str);
+}
+
+// Returns true if and only if the user-specified filter matches the test
+// suite name and the test name.
+bool UnitTestOptions::FilterMatchesTest(const std::string& test_suite_name,
+                                        const std::string& test_name) {
+  // Split --gtest_filter at '-', if there is one, to separate into
+  // positive filter and negative filter portions
+  return PositiveAndNegativeUnitTestFilter(GTEST_FLAG_GET(filter))
+      .MatchesTest(test_suite_name, test_name);
+}
+
+#if GTEST_HAS_SEH
+// Returns EXCEPTION_EXECUTE_HANDLER if Google Test should handle the
+// given SEH exception, or EXCEPTION_CONTINUE_SEARCH otherwise.
+// This function is useful as an __except condition.
+int UnitTestOptions::GTestShouldProcessSEH(DWORD exception_code) {
+  // Google Test should handle a SEH exception if:
+  //   1. the user wants it to, AND
+  //   2. this is not a breakpoint exception, AND
+  //   3. this is not a C++ exception (VC++ implements them via SEH,
+  //      apparently).
+  //
+  // SEH exception code for C++ exceptions.
+  // (see http://support.microsoft.com/kb/185294 for more information).
+  const DWORD kCxxExceptionCode = 0xe06d7363;
+
+  bool should_handle = true;
+
+  if (!GTEST_FLAG_GET(catch_exceptions))
+    should_handle = false;
+  else if (exception_code == EXCEPTION_BREAKPOINT)
+    should_handle = false;
+  else if (exception_code == kCxxExceptionCode)
+    should_handle = false;
+
+  return should_handle ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH;
+}
+#endif  // GTEST_HAS_SEH
+
+}  // namespace internal
+
+// The c'tor sets this object as the test part result reporter used by
+// Google Test.  The 'result' parameter specifies where to report the
+// results. Intercepts only failures from the current thread.
+ScopedFakeTestPartResultReporter::ScopedFakeTestPartResultReporter(
+    TestPartResultArray* result)
+    : intercept_mode_(INTERCEPT_ONLY_CURRENT_THREAD), result_(result) {
+  Init();
+}
+
+// The c'tor sets this object as the test part result reporter used by
+// Google Test.  The 'result' parameter specifies where to report the
+// results.
+ScopedFakeTestPartResultReporter::ScopedFakeTestPartResultReporter(
+    InterceptMode intercept_mode, TestPartResultArray* result)
+    : intercept_mode_(intercept_mode), result_(result) {
+  Init();
+}
+
+void ScopedFakeTestPartResultReporter::Init() {
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  if (intercept_mode_ == INTERCEPT_ALL_THREADS) {
+    old_reporter_ = impl->GetGlobalTestPartResultReporter();
+    impl->SetGlobalTestPartResultReporter(this);
+  } else {
+    old_reporter_ = impl->GetTestPartResultReporterForCurrentThread();
+    impl->SetTestPartResultReporterForCurrentThread(this);
+  }
+}
+
+// The d'tor restores the test part result reporter used by Google Test
+// before.
+ScopedFakeTestPartResultReporter::~ScopedFakeTestPartResultReporter() {
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  if (intercept_mode_ == INTERCEPT_ALL_THREADS) {
+    impl->SetGlobalTestPartResultReporter(old_reporter_);
+  } else {
+    impl->SetTestPartResultReporterForCurrentThread(old_reporter_);
+  }
+}
+
+// Increments the test part result count and remembers the result.
+// This method is from the TestPartResultReporterInterface interface.
+void ScopedFakeTestPartResultReporter::ReportTestPartResult(
+    const TestPartResult& result) {
+  result_->Append(result);
+}
+
+namespace internal {
+
+// Returns the type ID of ::testing::Test.  We should always call this
+// instead of GetTypeId< ::testing::Test>() to get the type ID of
+// testing::Test.  This is to work around a suspected linker bug when
+// using Google Test as a framework on Mac OS X.  The bug causes
+// GetTypeId< ::testing::Test>() to return different values depending
+// on whether the call is from the Google Test framework itself or
+// from user test code.  GetTestTypeId() is guaranteed to always
+// return the same value, as it always calls GetTypeId<>() from the
+// gtest.cc, which is within the Google Test framework.
+TypeId GetTestTypeId() { return GetTypeId<Test>(); }
+
+// The value of GetTestTypeId() as seen from within the Google Test
+// library.  This is solely for testing GetTestTypeId().
+extern const TypeId kTestTypeIdInGoogleTest = GetTestTypeId();
+
+// This predicate-formatter checks that 'results' contains a test part
+// failure of the given type and that the failure message contains the
+// given substring.
+static AssertionResult HasOneFailure(const char* /* results_expr */,
+                                     const char* /* type_expr */,
+                                     const char* /* substr_expr */,
+                                     const TestPartResultArray& results,
+                                     TestPartResult::Type type,
+                                     const std::string& substr) {
+  const std::string expected(type == TestPartResult::kFatalFailure
+                                 ? "1 fatal failure"
+                                 : "1 non-fatal failure");
+  Message msg;
+  if (results.size() != 1) {
+    msg << "Expected: " << expected << "\n"
+        << "  Actual: " << results.size() << " failures";
+    for (int i = 0; i < results.size(); i++) {
+      msg << "\n" << results.GetTestPartResult(i);
+    }
+    return AssertionFailure() << msg;
+  }
+
+  const TestPartResult& r = results.GetTestPartResult(0);
+  if (r.type() != type) {
+    return AssertionFailure() << "Expected: " << expected << "\n"
+                              << "  Actual:\n"
+                              << r;
+  }
+
+  if (strstr(r.message(), substr.c_str()) == nullptr) {
+    return AssertionFailure()
+           << "Expected: " << expected << " containing \"" << substr << "\"\n"
+           << "  Actual:\n"
+           << r;
+  }
+
+  return AssertionSuccess();
+}
+
+// The constructor of SingleFailureChecker remembers where to look up
+// test part results, what type of failure we expect, and what
+// substring the failure message should contain.
+SingleFailureChecker::SingleFailureChecker(const TestPartResultArray* results,
+                                           TestPartResult::Type type,
+                                           const std::string& substr)
+    : results_(results), type_(type), substr_(substr) {}
+
+// The destructor of SingleFailureChecker verifies that the given
+// TestPartResultArray contains exactly one failure that has the given
+// type and contains the given substring.  If that's not the case, a
+// non-fatal failure will be generated.
+SingleFailureChecker::~SingleFailureChecker() {
+  EXPECT_PRED_FORMAT3(HasOneFailure, *results_, type_, substr_);
+}
+
+DefaultGlobalTestPartResultReporter::DefaultGlobalTestPartResultReporter(
+    UnitTestImpl* unit_test)
+    : unit_test_(unit_test) {}
+
+void DefaultGlobalTestPartResultReporter::ReportTestPartResult(
+    const TestPartResult& result) {
+  unit_test_->current_test_result()->AddTestPartResult(result);
+  unit_test_->listeners()->repeater()->OnTestPartResult(result);
+}
+
+DefaultPerThreadTestPartResultReporter::DefaultPerThreadTestPartResultReporter(
+    UnitTestImpl* unit_test)
+    : unit_test_(unit_test) {}
+
+void DefaultPerThreadTestPartResultReporter::ReportTestPartResult(
+    const TestPartResult& result) {
+  unit_test_->GetGlobalTestPartResultReporter()->ReportTestPartResult(result);
+}
+
+// Returns the global test part result reporter.
+TestPartResultReporterInterface*
+UnitTestImpl::GetGlobalTestPartResultReporter() {
+  internal::MutexLock lock(&global_test_part_result_reporter_mutex_);
+  return global_test_part_result_repoter_;
+}
+
+// Sets the global test part result reporter.
+void UnitTestImpl::SetGlobalTestPartResultReporter(
+    TestPartResultReporterInterface* reporter) {
+  internal::MutexLock lock(&global_test_part_result_reporter_mutex_);
+  global_test_part_result_repoter_ = reporter;
+}
+
+// Returns the test part result reporter for the current thread.
+TestPartResultReporterInterface*
+UnitTestImpl::GetTestPartResultReporterForCurrentThread() {
+  return per_thread_test_part_result_reporter_.get();
+}
+
+// Sets the test part result reporter for the current thread.
+void UnitTestImpl::SetTestPartResultReporterForCurrentThread(
+    TestPartResultReporterInterface* reporter) {
+  per_thread_test_part_result_reporter_.set(reporter);
+}
+
+// Gets the number of successful test suites.
+int UnitTestImpl::successful_test_suite_count() const {
+  return CountIf(test_suites_, TestSuitePassed);
+}
+
+// Gets the number of failed test suites.
+int UnitTestImpl::failed_test_suite_count() const {
+  return CountIf(test_suites_, TestSuiteFailed);
+}
+
+// Gets the number of all test suites.
+int UnitTestImpl::total_test_suite_count() const {
+  return static_cast<int>(test_suites_.size());
+}
+
+// Gets the number of all test suites that contain at least one test
+// that should run.
+int UnitTestImpl::test_suite_to_run_count() const {
+  return CountIf(test_suites_, ShouldRunTestSuite);
+}
+
+// Gets the number of successful tests.
+int UnitTestImpl::successful_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::successful_test_count);
+}
+
+// Gets the number of skipped tests.
+int UnitTestImpl::skipped_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::skipped_test_count);
+}
+
+// Gets the number of failed tests.
+int UnitTestImpl::failed_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::failed_test_count);
+}
+
+// Gets the number of disabled tests that will be reported in the XML report.
+int UnitTestImpl::reportable_disabled_test_count() const {
+  return SumOverTestSuiteList(test_suites_,
+                              &TestSuite::reportable_disabled_test_count);
+}
+
+// Gets the number of disabled tests.
+int UnitTestImpl::disabled_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::disabled_test_count);
+}
+
+// Gets the number of tests to be printed in the XML report.
+int UnitTestImpl::reportable_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::reportable_test_count);
+}
+
+// Gets the number of all tests.
+int UnitTestImpl::total_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::total_test_count);
+}
+
+// Gets the number of tests that should run.
+int UnitTestImpl::test_to_run_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::test_to_run_count);
+}
+
+// Returns the current OS stack trace as an std::string.
+//
+// The maximum number of stack frames to be included is specified by
+// the gtest_stack_trace_depth flag.  The skip_count parameter
+// specifies the number of top frames to be skipped, which doesn't
+// count against the number of frames to be included.
+//
+// For example, if Foo() calls Bar(), which in turn calls
+// CurrentOsStackTraceExceptTop(1), Foo() will be included in the
+// trace but Bar() and CurrentOsStackTraceExceptTop() won't.
+std::string UnitTestImpl::CurrentOsStackTraceExceptTop(int skip_count) {
+  return os_stack_trace_getter()->CurrentStackTrace(
+      static_cast<int>(GTEST_FLAG_GET(stack_trace_depth)), skip_count + 1
+      // Skips the user-specified number of frames plus this function
+      // itself.
+  );  // NOLINT
+}
+
+// A helper class for measuring elapsed times.
+class Timer {
+ public:
+  Timer() : start_(std::chrono::steady_clock::now()) {}
+
+  // Return time elapsed in milliseconds since the timer was created.
+  TimeInMillis Elapsed() {
+    return std::chrono::duration_cast<std::chrono::milliseconds>(
+               std::chrono::steady_clock::now() - start_)
+        .count();
+  }
+
+ private:
+  std::chrono::steady_clock::time_point start_;
+};
+
+// Returns a timestamp as milliseconds since the epoch. Note this time may jump
+// around subject to adjustments by the system, to measure elapsed time use
+// Timer instead.
+TimeInMillis GetTimeInMillis() {
+  return std::chrono::duration_cast<std::chrono::milliseconds>(
+             std::chrono::system_clock::now() -
+             std::chrono::system_clock::from_time_t(0))
+      .count();
+}
+
+// Utilities
+
+// class String.
+
+#if GTEST_OS_WINDOWS_MOBILE
+// Creates a UTF-16 wide string from the given ANSI string, allocating
+// memory using new. The caller is responsible for deleting the return
+// value using delete[]. Returns the wide string, or NULL if the
+// input is NULL.
+LPCWSTR String::AnsiToUtf16(const char* ansi) {
+  if (!ansi) return nullptr;
+  const int length = strlen(ansi);
+  const int unicode_length =
+      MultiByteToWideChar(CP_ACP, 0, ansi, length, nullptr, 0);
+  WCHAR* unicode = new WCHAR[unicode_length + 1];
+  MultiByteToWideChar(CP_ACP, 0, ansi, length, unicode, unicode_length);
+  unicode[unicode_length] = 0;
+  return unicode;
+}
+
+// Creates an ANSI string from the given wide string, allocating
+// memory using new. The caller is responsible for deleting the return
+// value using delete[]. Returns the ANSI string, or NULL if the
+// input is NULL.
+const char* String::Utf16ToAnsi(LPCWSTR utf16_str) {
+  if (!utf16_str) return nullptr;
+  const int ansi_length = WideCharToMultiByte(CP_ACP, 0, utf16_str, -1, nullptr,
+                                              0, nullptr, nullptr);
+  char* ansi = new char[ansi_length + 1];
+  WideCharToMultiByte(CP_ACP, 0, utf16_str, -1, ansi, ansi_length, nullptr,
+                      nullptr);
+  ansi[ansi_length] = 0;
+  return ansi;
+}
+
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+// Compares two C strings.  Returns true if and only if they have the same
+// content.
+//
+// Unlike strcmp(), this function can handle NULL argument(s).  A NULL
+// C string is considered different to any non-NULL C string,
+// including the empty string.
+bool String::CStringEquals(const char* lhs, const char* rhs) {
+  if (lhs == nullptr) return rhs == nullptr;
+
+  if (rhs == nullptr) return false;
+
+  return strcmp(lhs, rhs) == 0;
+}
+
+#if GTEST_HAS_STD_WSTRING
+
+// Converts an array of wide chars to a narrow string using the UTF-8
+// encoding, and streams the result to the given Message object.
+static void StreamWideCharsToMessage(const wchar_t* wstr, size_t length,
+                                     Message* msg) {
+  for (size_t i = 0; i != length;) {  // NOLINT
+    if (wstr[i] != L'\0') {
+      *msg << WideStringToUtf8(wstr + i, static_cast<int>(length - i));
+      while (i != length && wstr[i] != L'\0') i++;
+    } else {
+      *msg << '\0';
+      i++;
+    }
+  }
+}
+
+#endif  // GTEST_HAS_STD_WSTRING
+
+void SplitString(const ::std::string& str, char delimiter,
+                 ::std::vector< ::std::string>* dest) {
+  ::std::vector< ::std::string> parsed;
+  ::std::string::size_type pos = 0;
+  while (::testing::internal::AlwaysTrue()) {
+    const ::std::string::size_type colon = str.find(delimiter, pos);
+    if (colon == ::std::string::npos) {
+      parsed.push_back(str.substr(pos));
+      break;
+    } else {
+      parsed.push_back(str.substr(pos, colon - pos));
+      pos = colon + 1;
+    }
+  }
+  dest->swap(parsed);
+}
+
+}  // namespace internal
+
+// Constructs an empty Message.
+// We allocate the stringstream separately because otherwise each use of
+// ASSERT/EXPECT in a procedure adds over 200 bytes to the procedure's
+// stack frame leading to huge stack frames in some cases; gcc does not reuse
+// the stack space.
+Message::Message() : ss_(new ::std::stringstream) {
+  // By default, we want there to be enough precision when printing
+  // a double to a Message.
+  *ss_ << std::setprecision(std::numeric_limits<double>::digits10 + 2);
+}
+
+// These two overloads allow streaming a wide C string to a Message
+// using the UTF-8 encoding.
+Message& Message::operator<<(const wchar_t* wide_c_str) {
+  return *this << internal::String::ShowWideCString(wide_c_str);
+}
+Message& Message::operator<<(wchar_t* wide_c_str) {
+  return *this << internal::String::ShowWideCString(wide_c_str);
+}
+
+#if GTEST_HAS_STD_WSTRING
+// Converts the given wide string to a narrow string using the UTF-8
+// encoding, and streams the result to this Message object.
+Message& Message::operator<<(const ::std::wstring& wstr) {
+  internal::StreamWideCharsToMessage(wstr.c_str(), wstr.length(), this);
+  return *this;
+}
+#endif  // GTEST_HAS_STD_WSTRING
+
+// Gets the text streamed to this object so far as an std::string.
+// Each '\0' character in the buffer is replaced with "\\0".
+std::string Message::GetString() const {
+  return internal::StringStreamToString(ss_.get());
+}
+
+namespace internal {
+
+namespace edit_distance {
+std::vector<EditType> CalculateOptimalEdits(const std::vector<size_t>& left,
+                                            const std::vector<size_t>& right) {
+  std::vector<std::vector<double> > costs(
+      left.size() + 1, std::vector<double>(right.size() + 1));
+  std::vector<std::vector<EditType> > best_move(
+      left.size() + 1, std::vector<EditType>(right.size() + 1));
+
+  // Populate for empty right.
+  for (size_t l_i = 0; l_i < costs.size(); ++l_i) {
+    costs[l_i][0] = static_cast<double>(l_i);
+    best_move[l_i][0] = kRemove;
+  }
+  // Populate for empty left.
+  for (size_t r_i = 1; r_i < costs[0].size(); ++r_i) {
+    costs[0][r_i] = static_cast<double>(r_i);
+    best_move[0][r_i] = kAdd;
+  }
+
+  for (size_t l_i = 0; l_i < left.size(); ++l_i) {
+    for (size_t r_i = 0; r_i < right.size(); ++r_i) {
+      if (left[l_i] == right[r_i]) {
+        // Found a match. Consume it.
+        costs[l_i + 1][r_i + 1] = costs[l_i][r_i];
+        best_move[l_i + 1][r_i + 1] = kMatch;
+        continue;
+      }
+
+      const double add = costs[l_i + 1][r_i];
+      const double remove = costs[l_i][r_i + 1];
+      const double replace = costs[l_i][r_i];
+      if (add < remove && add < replace) {
+        costs[l_i + 1][r_i + 1] = add + 1;
+        best_move[l_i + 1][r_i + 1] = kAdd;
+      } else if (remove < add && remove < replace) {
+        costs[l_i + 1][r_i + 1] = remove + 1;
+        best_move[l_i + 1][r_i + 1] = kRemove;
+      } else {
+        // We make replace a little more expensive than add/remove to lower
+        // their priority.
+        costs[l_i + 1][r_i + 1] = replace + 1.00001;
+        best_move[l_i + 1][r_i + 1] = kReplace;
+      }
+    }
+  }
+
+  // Reconstruct the best path. We do it in reverse order.
+  std::vector<EditType> best_path;
+  for (size_t l_i = left.size(), r_i = right.size(); l_i > 0 || r_i > 0;) {
+    EditType move = best_move[l_i][r_i];
+    best_path.push_back(move);
+    l_i -= move != kAdd;
+    r_i -= move != kRemove;
+  }
+  std::reverse(best_path.begin(), best_path.end());
+  return best_path;
+}
+
+namespace {
+
+// Helper class to convert string into ids with deduplication.
+class InternalStrings {
+ public:
+  size_t GetId(const std::string& str) {
+    IdMap::iterator it = ids_.find(str);
+    if (it != ids_.end()) return it->second;
+    size_t id = ids_.size();
+    return ids_[str] = id;
+  }
+
+ private:
+  typedef std::map<std::string, size_t> IdMap;
+  IdMap ids_;
+};
+
+}  // namespace
+
+std::vector<EditType> CalculateOptimalEdits(
+    const std::vector<std::string>& left,
+    const std::vector<std::string>& right) {
+  std::vector<size_t> left_ids, right_ids;
+  {
+    InternalStrings intern_table;
+    for (size_t i = 0; i < left.size(); ++i) {
+      left_ids.push_back(intern_table.GetId(left[i]));
+    }
+    for (size_t i = 0; i < right.size(); ++i) {
+      right_ids.push_back(intern_table.GetId(right[i]));
+    }
+  }
+  return CalculateOptimalEdits(left_ids, right_ids);
+}
+
+namespace {
+
+// Helper class that holds the state for one hunk and prints it out to the
+// stream.
+// It reorders adds/removes when possible to group all removes before all
+// adds. It also adds the hunk header before printint into the stream.
+class Hunk {
+ public:
+  Hunk(size_t left_start, size_t right_start)
+      : left_start_(left_start),
+        right_start_(right_start),
+        adds_(),
+        removes_(),
+        common_() {}
+
+  void PushLine(char edit, const char* line) {
+    switch (edit) {
+      case ' ':
+        ++common_;
+        FlushEdits();
+        hunk_.push_back(std::make_pair(' ', line));
+        break;
+      case '-':
+        ++removes_;
+        hunk_removes_.push_back(std::make_pair('-', line));
+        break;
+      case '+':
+        ++adds_;
+        hunk_adds_.push_back(std::make_pair('+', line));
+        break;
+    }
+  }
+
+  void PrintTo(std::ostream* os) {
+    PrintHeader(os);
+    FlushEdits();
+    for (std::list<std::pair<char, const char*> >::const_iterator it =
+             hunk_.begin();
+         it != hunk_.end(); ++it) {
+      *os << it->first << it->second << "\n";
+    }
+  }
+
+  bool has_edits() const { return adds_ || removes_; }
+
+ private:
+  void FlushEdits() {
+    hunk_.splice(hunk_.end(), hunk_removes_);
+    hunk_.splice(hunk_.end(), hunk_adds_);
+  }
+
+  // Print a unified diff header for one hunk.
+  // The format is
+  //   "@@ -<left_start>,<left_length> +<right_start>,<right_length> @@"
+  // where the left/right parts are omitted if unnecessary.
+  void PrintHeader(std::ostream* ss) const {
+    *ss << "@@ ";
+    if (removes_) {
+      *ss << "-" << left_start_ << "," << (removes_ + common_);
+    }
+    if (removes_ && adds_) {
+      *ss << " ";
+    }
+    if (adds_) {
+      *ss << "+" << right_start_ << "," << (adds_ + common_);
+    }
+    *ss << " @@\n";
+  }
+
+  size_t left_start_, right_start_;
+  size_t adds_, removes_, common_;
+  std::list<std::pair<char, const char*> > hunk_, hunk_adds_, hunk_removes_;
+};
+
+}  // namespace
+
+// Create a list of diff hunks in Unified diff format.
+// Each hunk has a header generated by PrintHeader above plus a body with
+// lines prefixed with ' ' for no change, '-' for deletion and '+' for
+// addition.
+// 'context' represents the desired unchanged prefix/suffix around the diff.
+// If two hunks are close enough that their contexts overlap, then they are
+// joined into one hunk.
+std::string CreateUnifiedDiff(const std::vector<std::string>& left,
+                              const std::vector<std::string>& right,
+                              size_t context) {
+  const std::vector<EditType> edits = CalculateOptimalEdits(left, right);
+
+  size_t l_i = 0, r_i = 0, edit_i = 0;
+  std::stringstream ss;
+  while (edit_i < edits.size()) {
+    // Find first edit.
+    while (edit_i < edits.size() && edits[edit_i] == kMatch) {
+      ++l_i;
+      ++r_i;
+      ++edit_i;
+    }
+
+    // Find the first line to include in the hunk.
+    const size_t prefix_context = std::min(l_i, context);
+    Hunk hunk(l_i - prefix_context + 1, r_i - prefix_context + 1);
+    for (size_t i = prefix_context; i > 0; --i) {
+      hunk.PushLine(' ', left[l_i - i].c_str());
+    }
+
+    // Iterate the edits until we found enough suffix for the hunk or the input
+    // is over.
+    size_t n_suffix = 0;
+    for (; edit_i < edits.size(); ++edit_i) {
+      if (n_suffix >= context) {
+        // Continue only if the next hunk is very close.
+        auto it = edits.begin() + static_cast<int>(edit_i);
+        while (it != edits.end() && *it == kMatch) ++it;
+        if (it == edits.end() ||
+            static_cast<size_t>(it - edits.begin()) - edit_i >= context) {
+          // There is no next edit or it is too far away.
+          break;
+        }
+      }
+
+      EditType edit = edits[edit_i];
+      // Reset count when a non match is found.
+      n_suffix = edit == kMatch ? n_suffix + 1 : 0;
+
+      if (edit == kMatch || edit == kRemove || edit == kReplace) {
+        hunk.PushLine(edit == kMatch ? ' ' : '-', left[l_i].c_str());
+      }
+      if (edit == kAdd || edit == kReplace) {
+        hunk.PushLine('+', right[r_i].c_str());
+      }
+
+      // Advance indices, depending on edit type.
+      l_i += edit != kAdd;
+      r_i += edit != kRemove;
+    }
+
+    if (!hunk.has_edits()) {
+      // We are done. We don't want this hunk.
+      break;
+    }
+
+    hunk.PrintTo(&ss);
+  }
+  return ss.str();
+}
+
+}  // namespace edit_distance
+
+namespace {
+
+// The string representation of the values received in EqFailure() are already
+// escaped. Split them on escaped '\n' boundaries. Leave all other escaped
+// characters the same.
+std::vector<std::string> SplitEscapedString(const std::string& str) {
+  std::vector<std::string> lines;
+  size_t start = 0, end = str.size();
+  if (end > 2 && str[0] == '"' && str[end - 1] == '"') {
+    ++start;
+    --end;
+  }
+  bool escaped = false;
+  for (size_t i = start; i + 1 < end; ++i) {
+    if (escaped) {
+      escaped = false;
+      if (str[i] == 'n') {
+        lines.push_back(str.substr(start, i - start - 1));
+        start = i + 1;
+      }
+    } else {
+      escaped = str[i] == '\\';
+    }
+  }
+  lines.push_back(str.substr(start, end - start));
+  return lines;
+}
+
+}  // namespace
+
+// Constructs and returns the message for an equality assertion
+// (e.g. ASSERT_EQ, EXPECT_STREQ, etc) failure.
+//
+// The first four parameters are the expressions used in the assertion
+// and their values, as strings.  For example, for ASSERT_EQ(foo, bar)
+// where foo is 5 and bar is 6, we have:
+//
+//   lhs_expression: "foo"
+//   rhs_expression: "bar"
+//   lhs_value:      "5"
+//   rhs_value:      "6"
+//
+// The ignoring_case parameter is true if and only if the assertion is a
+// *_STRCASEEQ*.  When it's true, the string "Ignoring case" will
+// be inserted into the message.
+AssertionResult EqFailure(const char* lhs_expression,
+                          const char* rhs_expression,
+                          const std::string& lhs_value,
+                          const std::string& rhs_value, bool ignoring_case) {
+  Message msg;
+  msg << "Expected equality of these values:";
+  msg << "\n  " << lhs_expression;
+  if (lhs_value != lhs_expression) {
+    msg << "\n    Which is: " << lhs_value;
+  }
+  msg << "\n  " << rhs_expression;
+  if (rhs_value != rhs_expression) {
+    msg << "\n    Which is: " << rhs_value;
+  }
+
+  if (ignoring_case) {
+    msg << "\nIgnoring case";
+  }
+
+  if (!lhs_value.empty() && !rhs_value.empty()) {
+    const std::vector<std::string> lhs_lines = SplitEscapedString(lhs_value);
+    const std::vector<std::string> rhs_lines = SplitEscapedString(rhs_value);
+    if (lhs_lines.size() > 1 || rhs_lines.size() > 1) {
+      msg << "\nWith diff:\n"
+          << edit_distance::CreateUnifiedDiff(lhs_lines, rhs_lines);
+    }
+  }
+
+  return AssertionFailure() << msg;
+}
+
+// Constructs a failure message for Boolean assertions such as EXPECT_TRUE.
+std::string GetBoolAssertionFailureMessage(
+    const AssertionResult& assertion_result, const char* expression_text,
+    const char* actual_predicate_value, const char* expected_predicate_value) {
+  const char* actual_message = assertion_result.message();
+  Message msg;
+  msg << "Value of: " << expression_text
+      << "\n  Actual: " << actual_predicate_value;
+  if (actual_message[0] != '\0') msg << " (" << actual_message << ")";
+  msg << "\nExpected: " << expected_predicate_value;
+  return msg.GetString();
+}
+
+// Helper function for implementing ASSERT_NEAR.
+AssertionResult DoubleNearPredFormat(const char* expr1, const char* expr2,
+                                     const char* abs_error_expr, double val1,
+                                     double val2, double abs_error) {
+  const double diff = fabs(val1 - val2);
+  if (diff <= abs_error) return AssertionSuccess();
+
+  // Find the value which is closest to zero.
+  const double min_abs = std::min(fabs(val1), fabs(val2));
+  // Find the distance to the next double from that value.
+  const double epsilon =
+      nextafter(min_abs, std::numeric_limits<double>::infinity()) - min_abs;
+  // Detect the case where abs_error is so small that EXPECT_NEAR is
+  // effectively the same as EXPECT_EQUAL, and give an informative error
+  // message so that the situation can be more easily understood without
+  // requiring exotic floating-point knowledge.
+  // Don't do an epsilon check if abs_error is zero because that implies
+  // that an equality check was actually intended.
+  if (!(std::isnan)(val1) && !(std::isnan)(val2) && abs_error > 0 &&
+      abs_error < epsilon) {
+    return AssertionFailure()
+           << "The difference between " << expr1 << " and " << expr2 << " is "
+           << diff << ", where\n"
+           << expr1 << " evaluates to " << val1 << ",\n"
+           << expr2 << " evaluates to " << val2 << ".\nThe abs_error parameter "
+           << abs_error_expr << " evaluates to " << abs_error
+           << " which is smaller than the minimum distance between doubles for "
+              "numbers of this magnitude which is "
+           << epsilon
+           << ", thus making this EXPECT_NEAR check equivalent to "
+              "EXPECT_EQUAL. Consider using EXPECT_DOUBLE_EQ instead.";
+  }
+  return AssertionFailure()
+         << "The difference between " << expr1 << " and " << expr2 << " is "
+         << diff << ", which exceeds " << abs_error_expr << ", where\n"
+         << expr1 << " evaluates to " << val1 << ",\n"
+         << expr2 << " evaluates to " << val2 << ", and\n"
+         << abs_error_expr << " evaluates to " << abs_error << ".";
+}
+
+// Helper template for implementing FloatLE() and DoubleLE().
+template <typename RawType>
+AssertionResult FloatingPointLE(const char* expr1, const char* expr2,
+                                RawType val1, RawType val2) {
+  // Returns success if val1 is less than val2,
+  if (val1 < val2) {
+    return AssertionSuccess();
+  }
+
+  // or if val1 is almost equal to val2.
+  const FloatingPoint<RawType> lhs(val1), rhs(val2);
+  if (lhs.AlmostEquals(rhs)) {
+    return AssertionSuccess();
+  }
+
+  // Note that the above two checks will both fail if either val1 or
+  // val2 is NaN, as the IEEE floating-point standard requires that
+  // any predicate involving a NaN must return false.
+
+  ::std::stringstream val1_ss;
+  val1_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
+          << val1;
+
+  ::std::stringstream val2_ss;
+  val2_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
+          << val2;
+
+  return AssertionFailure()
+         << "Expected: (" << expr1 << ") <= (" << expr2 << ")\n"
+         << "  Actual: " << StringStreamToString(&val1_ss) << " vs "
+         << StringStreamToString(&val2_ss);
+}
+
+}  // namespace internal
+
+// Asserts that val1 is less than, or almost equal to, val2.  Fails
+// otherwise.  In particular, it fails if either val1 or val2 is NaN.
+AssertionResult FloatLE(const char* expr1, const char* expr2, float val1,
+                        float val2) {
+  return internal::FloatingPointLE<float>(expr1, expr2, val1, val2);
+}
+
+// Asserts that val1 is less than, or almost equal to, val2.  Fails
+// otherwise.  In particular, it fails if either val1 or val2 is NaN.
+AssertionResult DoubleLE(const char* expr1, const char* expr2, double val1,
+                         double val2) {
+  return internal::FloatingPointLE<double>(expr1, expr2, val1, val2);
+}
+
+namespace internal {
+
+// The helper function for {ASSERT|EXPECT}_STREQ.
+AssertionResult CmpHelperSTREQ(const char* lhs_expression,
+                               const char* rhs_expression, const char* lhs,
+                               const char* rhs) {
+  if (String::CStringEquals(lhs, rhs)) {
+    return AssertionSuccess();
+  }
+
+  return EqFailure(lhs_expression, rhs_expression, PrintToString(lhs),
+                   PrintToString(rhs), false);
+}
+
+// The helper function for {ASSERT|EXPECT}_STRCASEEQ.
+AssertionResult CmpHelperSTRCASEEQ(const char* lhs_expression,
+                                   const char* rhs_expression, const char* lhs,
+                                   const char* rhs) {
+  if (String::CaseInsensitiveCStringEquals(lhs, rhs)) {
+    return AssertionSuccess();
+  }
+
+  return EqFailure(lhs_expression, rhs_expression, PrintToString(lhs),
+                   PrintToString(rhs), true);
+}
+
+// The helper function for {ASSERT|EXPECT}_STRNE.
+AssertionResult CmpHelperSTRNE(const char* s1_expression,
+                               const char* s2_expression, const char* s1,
+                               const char* s2) {
+  if (!String::CStringEquals(s1, s2)) {
+    return AssertionSuccess();
+  } else {
+    return AssertionFailure()
+           << "Expected: (" << s1_expression << ") != (" << s2_expression
+           << "), actual: \"" << s1 << "\" vs \"" << s2 << "\"";
+  }
+}
+
+// The helper function for {ASSERT|EXPECT}_STRCASENE.
+AssertionResult CmpHelperSTRCASENE(const char* s1_expression,
+                                   const char* s2_expression, const char* s1,
+                                   const char* s2) {
+  if (!String::CaseInsensitiveCStringEquals(s1, s2)) {
+    return AssertionSuccess();
+  } else {
+    return AssertionFailure()
+           << "Expected: (" << s1_expression << ") != (" << s2_expression
+           << ") (ignoring case), actual: \"" << s1 << "\" vs \"" << s2 << "\"";
+  }
+}
+
+}  // namespace internal
+
+namespace {
+
+// Helper functions for implementing IsSubString() and IsNotSubstring().
+
+// This group of overloaded functions return true if and only if needle
+// is a substring of haystack.  NULL is considered a substring of
+// itself only.
+
+bool IsSubstringPred(const char* needle, const char* haystack) {
+  if (needle == nullptr || haystack == nullptr) return needle == haystack;
+
+  return strstr(haystack, needle) != nullptr;
+}
+
+bool IsSubstringPred(const wchar_t* needle, const wchar_t* haystack) {
+  if (needle == nullptr || haystack == nullptr) return needle == haystack;
+
+  return wcsstr(haystack, needle) != nullptr;
+}
+
+// StringType here can be either ::std::string or ::std::wstring.
+template <typename StringType>
+bool IsSubstringPred(const StringType& needle, const StringType& haystack) {
+  return haystack.find(needle) != StringType::npos;
+}
+
+// This function implements either IsSubstring() or IsNotSubstring(),
+// depending on the value of the expected_to_be_substring parameter.
+// StringType here can be const char*, const wchar_t*, ::std::string,
+// or ::std::wstring.
+template <typename StringType>
+AssertionResult IsSubstringImpl(bool expected_to_be_substring,
+                                const char* needle_expr,
+                                const char* haystack_expr,
+                                const StringType& needle,
+                                const StringType& haystack) {
+  if (IsSubstringPred(needle, haystack) == expected_to_be_substring)
+    return AssertionSuccess();
+
+  const bool is_wide_string = sizeof(needle[0]) > 1;
+  const char* const begin_string_quote = is_wide_string ? "L\"" : "\"";
+  return AssertionFailure()
+         << "Value of: " << needle_expr << "\n"
+         << "  Actual: " << begin_string_quote << needle << "\"\n"
+         << "Expected: " << (expected_to_be_substring ? "" : "not ")
+         << "a substring of " << haystack_expr << "\n"
+         << "Which is: " << begin_string_quote << haystack << "\"";
+}
+
+}  // namespace
+
+// IsSubstring() and IsNotSubstring() check whether needle is a
+// substring of haystack (NULL is considered a substring of itself
+// only), and return an appropriate error message when they fail.
+
+AssertionResult IsSubstring(const char* needle_expr, const char* haystack_expr,
+                            const char* needle, const char* haystack) {
+  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsSubstring(const char* needle_expr, const char* haystack_expr,
+                            const wchar_t* needle, const wchar_t* haystack) {
+  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsNotSubstring(const char* needle_expr,
+                               const char* haystack_expr, const char* needle,
+                               const char* haystack) {
+  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsNotSubstring(const char* needle_expr,
+                               const char* haystack_expr, const wchar_t* needle,
+                               const wchar_t* haystack) {
+  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsSubstring(const char* needle_expr, const char* haystack_expr,
+                            const ::std::string& needle,
+                            const ::std::string& haystack) {
+  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsNotSubstring(const char* needle_expr,
+                               const char* haystack_expr,
+                               const ::std::string& needle,
+                               const ::std::string& haystack) {
+  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
+}
+
+#if GTEST_HAS_STD_WSTRING
+AssertionResult IsSubstring(const char* needle_expr, const char* haystack_expr,
+                            const ::std::wstring& needle,
+                            const ::std::wstring& haystack) {
+  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsNotSubstring(const char* needle_expr,
+                               const char* haystack_expr,
+                               const ::std::wstring& needle,
+                               const ::std::wstring& haystack) {
+  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
+}
+#endif  // GTEST_HAS_STD_WSTRING
+
+namespace internal {
+
+#if GTEST_OS_WINDOWS
+
+namespace {
+
+// Helper function for IsHRESULT{SuccessFailure} predicates
+AssertionResult HRESULTFailureHelper(const char* expr, const char* expected,
+                                     long hr) {  // NOLINT
+#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_TV_TITLE
+
+  // Windows CE doesn't support FormatMessage.
+  const char error_text[] = "";
+
+#else
+
+  // Looks up the human-readable system message for the HRESULT code
+  // and since we're not passing any params to FormatMessage, we don't
+  // want inserts expanded.
+  const DWORD kFlags =
+      FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
+  const DWORD kBufSize = 4096;
+  // Gets the system's human readable message string for this HRESULT.
+  char error_text[kBufSize] = {'\0'};
+  DWORD message_length = ::FormatMessageA(kFlags,
+                                          0,  // no source, we're asking system
+                                          static_cast<DWORD>(hr),  // the error
+                                          0,  // no line width restrictions
+                                          error_text,  // output buffer
+                                          kBufSize,    // buf size
+                                          nullptr);  // no arguments for inserts
+  // Trims tailing white space (FormatMessage leaves a trailing CR-LF)
+  for (; message_length && IsSpace(error_text[message_length - 1]);
+       --message_length) {
+    error_text[message_length - 1] = '\0';
+  }
+
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+  const std::string error_hex("0x" + String::FormatHexInt(hr));
+  return ::testing::AssertionFailure()
+         << "Expected: " << expr << " " << expected << ".\n"
+         << "  Actual: " << error_hex << " " << error_text << "\n";
+}
+
+}  // namespace
+
+AssertionResult IsHRESULTSuccess(const char* expr, long hr) {  // NOLINT
+  if (SUCCEEDED(hr)) {
+    return AssertionSuccess();
+  }
+  return HRESULTFailureHelper(expr, "succeeds", hr);
+}
+
+AssertionResult IsHRESULTFailure(const char* expr, long hr) {  // NOLINT
+  if (FAILED(hr)) {
+    return AssertionSuccess();
+  }
+  return HRESULTFailureHelper(expr, "fails", hr);
+}
+
+#endif  // GTEST_OS_WINDOWS
+
+// Utility functions for encoding Unicode text (wide strings) in
+// UTF-8.
+
+// A Unicode code-point can have up to 21 bits, and is encoded in UTF-8
+// like this:
+//
+// Code-point length   Encoding
+//   0 -  7 bits       0xxxxxxx
+//   8 - 11 bits       110xxxxx 10xxxxxx
+//  12 - 16 bits       1110xxxx 10xxxxxx 10xxxxxx
+//  17 - 21 bits       11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+
+// The maximum code-point a one-byte UTF-8 sequence can represent.
+constexpr uint32_t kMaxCodePoint1 = (static_cast<uint32_t>(1) << 7) - 1;
+
+// The maximum code-point a two-byte UTF-8 sequence can represent.
+constexpr uint32_t kMaxCodePoint2 = (static_cast<uint32_t>(1) << (5 + 6)) - 1;
+
+// The maximum code-point a three-byte UTF-8 sequence can represent.
+constexpr uint32_t kMaxCodePoint3 =
+    (static_cast<uint32_t>(1) << (4 + 2 * 6)) - 1;
+
+// The maximum code-point a four-byte UTF-8 sequence can represent.
+constexpr uint32_t kMaxCodePoint4 =
+    (static_cast<uint32_t>(1) << (3 + 3 * 6)) - 1;
+
+// Chops off the n lowest bits from a bit pattern.  Returns the n
+// lowest bits.  As a side effect, the original bit pattern will be
+// shifted to the right by n bits.
+inline uint32_t ChopLowBits(uint32_t* bits, int n) {
+  const uint32_t low_bits = *bits & ((static_cast<uint32_t>(1) << n) - 1);
+  *bits >>= n;
+  return low_bits;
+}
+
+// Converts a Unicode code point to a narrow string in UTF-8 encoding.
+// code_point parameter is of type uint32_t because wchar_t may not be
+// wide enough to contain a code point.
+// If the code_point is not a valid Unicode code point
+// (i.e. outside of Unicode range U+0 to U+10FFFF) it will be converted
+// to "(Invalid Unicode 0xXXXXXXXX)".
+std::string CodePointToUtf8(uint32_t code_point) {
+  if (code_point > kMaxCodePoint4) {
+    return "(Invalid Unicode 0x" + String::FormatHexUInt32(code_point) + ")";
+  }
+
+  char str[5];  // Big enough for the largest valid code point.
+  if (code_point <= kMaxCodePoint1) {
+    str[1] = '\0';
+    str[0] = static_cast<char>(code_point);  // 0xxxxxxx
+  } else if (code_point <= kMaxCodePoint2) {
+    str[2] = '\0';
+    str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[0] = static_cast<char>(0xC0 | code_point);                   // 110xxxxx
+  } else if (code_point <= kMaxCodePoint3) {
+    str[3] = '\0';
+    str[2] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[0] = static_cast<char>(0xE0 | code_point);                   // 1110xxxx
+  } else {  // code_point <= kMaxCodePoint4
+    str[4] = '\0';
+    str[3] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[2] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[0] = static_cast<char>(0xF0 | code_point);                   // 11110xxx
+  }
+  return str;
+}
+
+// The following two functions only make sense if the system
+// uses UTF-16 for wide string encoding. All supported systems
+// with 16 bit wchar_t (Windows, Cygwin) do use UTF-16.
+
+// Determines if the arguments constitute UTF-16 surrogate pair
+// and thus should be combined into a single Unicode code point
+// using CreateCodePointFromUtf16SurrogatePair.
+inline bool IsUtf16SurrogatePair(wchar_t first, wchar_t second) {
+  return sizeof(wchar_t) == 2 && (first & 0xFC00) == 0xD800 &&
+         (second & 0xFC00) == 0xDC00;
+}
+
+// Creates a Unicode code point from UTF16 surrogate pair.
+inline uint32_t CreateCodePointFromUtf16SurrogatePair(wchar_t first,
+                                                      wchar_t second) {
+  const auto first_u = static_cast<uint32_t>(first);
+  const auto second_u = static_cast<uint32_t>(second);
+  const uint32_t mask = (1 << 10) - 1;
+  return (sizeof(wchar_t) == 2)
+             ? (((first_u & mask) << 10) | (second_u & mask)) + 0x10000
+             :
+             // This function should not be called when the condition is
+             // false, but we provide a sensible default in case it is.
+             first_u;
+}
+
+// Converts a wide string to a narrow string in UTF-8 encoding.
+// The wide string is assumed to have the following encoding:
+//   UTF-16 if sizeof(wchar_t) == 2 (on Windows, Cygwin)
+//   UTF-32 if sizeof(wchar_t) == 4 (on Linux)
+// Parameter str points to a null-terminated wide string.
+// Parameter num_chars may additionally limit the number
+// of wchar_t characters processed. -1 is used when the entire string
+// should be processed.
+// If the string contains code points that are not valid Unicode code points
+// (i.e. outside of Unicode range U+0 to U+10FFFF) they will be output
+// as '(Invalid Unicode 0xXXXXXXXX)'. If the string is in UTF16 encoding
+// and contains invalid UTF-16 surrogate pairs, values in those pairs
+// will be encoded as individual Unicode characters from Basic Normal Plane.
+std::string WideStringToUtf8(const wchar_t* str, int num_chars) {
+  if (num_chars == -1) num_chars = static_cast<int>(wcslen(str));
+
+  ::std::stringstream stream;
+  for (int i = 0; i < num_chars; ++i) {
+    uint32_t unicode_code_point;
+
+    if (str[i] == L'\0') {
+      break;
+    } else if (i + 1 < num_chars && IsUtf16SurrogatePair(str[i], str[i + 1])) {
+      unicode_code_point =
+          CreateCodePointFromUtf16SurrogatePair(str[i], str[i + 1]);
+      i++;
+    } else {
+      unicode_code_point = static_cast<uint32_t>(str[i]);
+    }
+
+    stream << CodePointToUtf8(unicode_code_point);
+  }
+  return StringStreamToString(&stream);
+}
+
+// Converts a wide C string to an std::string using the UTF-8 encoding.
+// NULL will be converted to "(null)".
+std::string String::ShowWideCString(const wchar_t* wide_c_str) {
+  if (wide_c_str == nullptr) return "(null)";
+
+  return internal::WideStringToUtf8(wide_c_str, -1);
+}
+
+// Compares two wide C strings.  Returns true if and only if they have the
+// same content.
+//
+// Unlike wcscmp(), this function can handle NULL argument(s).  A NULL
+// C string is considered different to any non-NULL C string,
+// including the empty string.
+bool String::WideCStringEquals(const wchar_t* lhs, const wchar_t* rhs) {
+  if (lhs == nullptr) return rhs == nullptr;
+
+  if (rhs == nullptr) return false;
+
+  return wcscmp(lhs, rhs) == 0;
+}
+
+// Helper function for *_STREQ on wide strings.
+AssertionResult CmpHelperSTREQ(const char* lhs_expression,
+                               const char* rhs_expression, const wchar_t* lhs,
+                               const wchar_t* rhs) {
+  if (String::WideCStringEquals(lhs, rhs)) {
+    return AssertionSuccess();
+  }
+
+  return EqFailure(lhs_expression, rhs_expression, PrintToString(lhs),
+                   PrintToString(rhs), false);
+}
+
+// Helper function for *_STRNE on wide strings.
+AssertionResult CmpHelperSTRNE(const char* s1_expression,
+                               const char* s2_expression, const wchar_t* s1,
+                               const wchar_t* s2) {
+  if (!String::WideCStringEquals(s1, s2)) {
+    return AssertionSuccess();
+  }
+
+  return AssertionFailure()
+         << "Expected: (" << s1_expression << ") != (" << s2_expression
+         << "), actual: " << PrintToString(s1) << " vs " << PrintToString(s2);
+}
+
+// Compares two C strings, ignoring case.  Returns true if and only if they have
+// the same content.
+//
+// Unlike strcasecmp(), this function can handle NULL argument(s).  A
+// NULL C string is considered different to any non-NULL C string,
+// including the empty string.
+bool String::CaseInsensitiveCStringEquals(const char* lhs, const char* rhs) {
+  if (lhs == nullptr) return rhs == nullptr;
+  if (rhs == nullptr) return false;
+  return posix::StrCaseCmp(lhs, rhs) == 0;
+}
+
+// Compares two wide C strings, ignoring case.  Returns true if and only if they
+// have the same content.
+//
+// Unlike wcscasecmp(), this function can handle NULL argument(s).
+// A NULL C string is considered different to any non-NULL wide C string,
+// including the empty string.
+// NB: The implementations on different platforms slightly differ.
+// On windows, this method uses _wcsicmp which compares according to LC_CTYPE
+// environment variable. On GNU platform this method uses wcscasecmp
+// which compares according to LC_CTYPE category of the current locale.
+// On MacOS X, it uses towlower, which also uses LC_CTYPE category of the
+// current locale.
+bool String::CaseInsensitiveWideCStringEquals(const wchar_t* lhs,
+                                              const wchar_t* rhs) {
+  if (lhs == nullptr) return rhs == nullptr;
+
+  if (rhs == nullptr) return false;
+
+#if GTEST_OS_WINDOWS
+  return _wcsicmp(lhs, rhs) == 0;
+#elif GTEST_OS_LINUX && !GTEST_OS_LINUX_ANDROID
+  return wcscasecmp(lhs, rhs) == 0;
+#else
+  // Android, Mac OS X and Cygwin don't define wcscasecmp.
+  // Other unknown OSes may not define it either.
+  wint_t left, right;
+  do {
+    left = towlower(static_cast<wint_t>(*lhs++));
+    right = towlower(static_cast<wint_t>(*rhs++));
+  } while (left && left == right);
+  return left == right;
+#endif  // OS selector
+}
+
+// Returns true if and only if str ends with the given suffix, ignoring case.
+// Any string is considered to end with an empty suffix.
+bool String::EndsWithCaseInsensitive(const std::string& str,
+                                     const std::string& suffix) {
+  const size_t str_len = str.length();
+  const size_t suffix_len = suffix.length();
+  return (str_len >= suffix_len) &&
+         CaseInsensitiveCStringEquals(str.c_str() + str_len - suffix_len,
+                                      suffix.c_str());
+}
+
+// Formats an int value as "%02d".
+std::string String::FormatIntWidth2(int value) {
+  return FormatIntWidthN(value, 2);
+}
+
+// Formats an int value to given width with leading zeros.
+std::string String::FormatIntWidthN(int value, int width) {
+  std::stringstream ss;
+  ss << std::setfill('0') << std::setw(width) << value;
+  return ss.str();
+}
+
+// Formats an int value as "%X".
+std::string String::FormatHexUInt32(uint32_t value) {
+  std::stringstream ss;
+  ss << std::hex << std::uppercase << value;
+  return ss.str();
+}
+
+// Formats an int value as "%X".
+std::string String::FormatHexInt(int value) {
+  return FormatHexUInt32(static_cast<uint32_t>(value));
+}
+
+// Formats a byte as "%02X".
+std::string String::FormatByte(unsigned char value) {
+  std::stringstream ss;
+  ss << std::setfill('0') << std::setw(2) << std::hex << std::uppercase
+     << static_cast<unsigned int>(value);
+  return ss.str();
+}
+
+// Converts the buffer in a stringstream to an std::string, converting NUL
+// bytes to "\\0" along the way.
+std::string StringStreamToString(::std::stringstream* ss) {
+  const ::std::string& str = ss->str();
+  const char* const start = str.c_str();
+  const char* const end = start + str.length();
+
+  std::string result;
+  result.reserve(static_cast<size_t>(2 * (end - start)));
+  for (const char* ch = start; ch != end; ++ch) {
+    if (*ch == '\0') {
+      result += "\\0";  // Replaces NUL with "\\0";
+    } else {
+      result += *ch;
+    }
+  }
+
+  return result;
+}
+
+// Appends the user-supplied message to the Google-Test-generated message.
+std::string AppendUserMessage(const std::string& gtest_msg,
+                              const Message& user_msg) {
+  // Appends the user message if it's non-empty.
+  const std::string user_msg_string = user_msg.GetString();
+  if (user_msg_string.empty()) {
+    return gtest_msg;
+  }
+  if (gtest_msg.empty()) {
+    return user_msg_string;
+  }
+  return gtest_msg + "\n" + user_msg_string;
+}
+
+}  // namespace internal
+
+// class TestResult
+
+// Creates an empty TestResult.
+TestResult::TestResult()
+    : death_test_count_(0), start_timestamp_(0), elapsed_time_(0) {}
+
+// D'tor.
+TestResult::~TestResult() {}
+
+// Returns the i-th test part result among all the results. i can
+// range from 0 to total_part_count() - 1. If i is not in that range,
+// aborts the program.
+const TestPartResult& TestResult::GetTestPartResult(int i) const {
+  if (i < 0 || i >= total_part_count()) internal::posix::Abort();
+  return test_part_results_.at(static_cast<size_t>(i));
+}
+
+// Returns the i-th test property. i can range from 0 to
+// test_property_count() - 1. If i is not in that range, aborts the
+// program.
+const TestProperty& TestResult::GetTestProperty(int i) const {
+  if (i < 0 || i >= test_property_count()) internal::posix::Abort();
+  return test_properties_.at(static_cast<size_t>(i));
+}
+
+// Clears the test part results.
+void TestResult::ClearTestPartResults() { test_part_results_.clear(); }
+
+// Adds a test part result to the list.
+void TestResult::AddTestPartResult(const TestPartResult& test_part_result) {
+  test_part_results_.push_back(test_part_result);
+}
+
+// Adds a test property to the list. If a property with the same key as the
+// supplied property is already represented, the value of this test_property
+// replaces the old value for that key.
+void TestResult::RecordProperty(const std::string& xml_element,
+                                const TestProperty& test_property) {
+  if (!ValidateTestProperty(xml_element, test_property)) {
+    return;
+  }
+  internal::MutexLock lock(&test_properties_mutex_);
+  const std::vector<TestProperty>::iterator property_with_matching_key =
+      std::find_if(test_properties_.begin(), test_properties_.end(),
+                   internal::TestPropertyKeyIs(test_property.key()));
+  if (property_with_matching_key == test_properties_.end()) {
+    test_properties_.push_back(test_property);
+    return;
+  }
+  property_with_matching_key->SetValue(test_property.value());
+}
+
+// The list of reserved attributes used in the <testsuites> element of XML
+// output.
+static const char* const kReservedTestSuitesAttributes[] = {
+    "disabled",    "errors", "failures", "name",
+    "random_seed", "tests",  "time",     "timestamp"};
+
+// The list of reserved attributes used in the <testsuite> element of XML
+// output.
+static const char* const kReservedTestSuiteAttributes[] = {
+    "disabled", "errors", "failures",  "name",
+    "tests",    "time",   "timestamp", "skipped"};
+
+// The list of reserved attributes used in the <testcase> element of XML output.
+static const char* const kReservedTestCaseAttributes[] = {
+    "classname",  "name",        "status", "time",
+    "type_param", "value_param", "file",   "line"};
+
+// Use a slightly different set for allowed output to ensure existing tests can
+// still RecordProperty("result") or "RecordProperty(timestamp")
+static const char* const kReservedOutputTestCaseAttributes[] = {
+    "classname",   "name", "status", "time",   "type_param",
+    "value_param", "file", "line",   "result", "timestamp"};
+
+template <size_t kSize>
+std::vector<std::string> ArrayAsVector(const char* const (&array)[kSize]) {
+  return std::vector<std::string>(array, array + kSize);
+}
+
+static std::vector<std::string> GetReservedAttributesForElement(
+    const std::string& xml_element) {
+  if (xml_element == "testsuites") {
+    return ArrayAsVector(kReservedTestSuitesAttributes);
+  } else if (xml_element == "testsuite") {
+    return ArrayAsVector(kReservedTestSuiteAttributes);
+  } else if (xml_element == "testcase") {
+    return ArrayAsVector(kReservedTestCaseAttributes);
+  } else {
+    GTEST_CHECK_(false) << "Unrecognized xml_element provided: " << xml_element;
+  }
+  // This code is unreachable but some compilers may not realizes that.
+  return std::vector<std::string>();
+}
+
+// TODO(jdesprez): Merge the two getReserved attributes once skip is improved
+static std::vector<std::string> GetReservedOutputAttributesForElement(
+    const std::string& xml_element) {
+  if (xml_element == "testsuites") {
+    return ArrayAsVector(kReservedTestSuitesAttributes);
+  } else if (xml_element == "testsuite") {
+    return ArrayAsVector(kReservedTestSuiteAttributes);
+  } else if (xml_element == "testcase") {
+    return ArrayAsVector(kReservedOutputTestCaseAttributes);
+  } else {
+    GTEST_CHECK_(false) << "Unrecognized xml_element provided: " << xml_element;
+  }
+  // This code is unreachable but some compilers may not realizes that.
+  return std::vector<std::string>();
+}
+
+static std::string FormatWordList(const std::vector<std::string>& words) {
+  Message word_list;
+  for (size_t i = 0; i < words.size(); ++i) {
+    if (i > 0 && words.size() > 2) {
+      word_list << ", ";
+    }
+    if (i == words.size() - 1) {
+      word_list << "and ";
+    }
+    word_list << "'" << words[i] << "'";
+  }
+  return word_list.GetString();
+}
+
+static bool ValidateTestPropertyName(
+    const std::string& property_name,
+    const std::vector<std::string>& reserved_names) {
+  if (std::find(reserved_names.begin(), reserved_names.end(), property_name) !=
+      reserved_names.end()) {
+    ADD_FAILURE() << "Reserved key used in RecordProperty(): " << property_name
+                  << " (" << FormatWordList(reserved_names)
+                  << " are reserved by " << GTEST_NAME_ << ")";
+    return false;
+  }
+  return true;
+}
+
+// Adds a failure if the key is a reserved attribute of the element named
+// xml_element.  Returns true if the property is valid.
+bool TestResult::ValidateTestProperty(const std::string& xml_element,
+                                      const TestProperty& test_property) {
+  return ValidateTestPropertyName(test_property.key(),
+                                  GetReservedAttributesForElement(xml_element));
+}
+
+// Clears the object.
+void TestResult::Clear() {
+  test_part_results_.clear();
+  test_properties_.clear();
+  death_test_count_ = 0;
+  elapsed_time_ = 0;
+}
+
+// Returns true off the test part was skipped.
+static bool TestPartSkipped(const TestPartResult& result) {
+  return result.skipped();
+}
+
+// Returns true if and only if the test was skipped.
+bool TestResult::Skipped() const {
+  return !Failed() && CountIf(test_part_results_, TestPartSkipped) > 0;
+}
+
+// Returns true if and only if the test failed.
+bool TestResult::Failed() const {
+  for (int i = 0; i < total_part_count(); ++i) {
+    if (GetTestPartResult(i).failed()) return true;
+  }
+  return false;
+}
+
+// Returns true if and only if the test part fatally failed.
+static bool TestPartFatallyFailed(const TestPartResult& result) {
+  return result.fatally_failed();
+}
+
+// Returns true if and only if the test fatally failed.
+bool TestResult::HasFatalFailure() const {
+  return CountIf(test_part_results_, TestPartFatallyFailed) > 0;
+}
+
+// Returns true if and only if the test part non-fatally failed.
+static bool TestPartNonfatallyFailed(const TestPartResult& result) {
+  return result.nonfatally_failed();
+}
+
+// Returns true if and only if the test has a non-fatal failure.
+bool TestResult::HasNonfatalFailure() const {
+  return CountIf(test_part_results_, TestPartNonfatallyFailed) > 0;
+}
+
+// Gets the number of all test parts.  This is the sum of the number
+// of successful test parts and the number of failed test parts.
+int TestResult::total_part_count() const {
+  return static_cast<int>(test_part_results_.size());
+}
+
+// Returns the number of the test properties.
+int TestResult::test_property_count() const {
+  return static_cast<int>(test_properties_.size());
+}
+
+// class Test
+
+// Creates a Test object.
+
+// The c'tor saves the states of all flags.
+Test::Test() : gtest_flag_saver_(new GTEST_FLAG_SAVER_) {}
+
+// The d'tor restores the states of all flags.  The actual work is
+// done by the d'tor of the gtest_flag_saver_ field, and thus not
+// visible here.
+Test::~Test() {}
+
+// Sets up the test fixture.
+//
+// A sub-class may override this.
+void Test::SetUp() {}
+
+// Tears down the test fixture.
+//
+// A sub-class may override this.
+void Test::TearDown() {}
+
+// Allows user supplied key value pairs to be recorded for later output.
+void Test::RecordProperty(const std::string& key, const std::string& value) {
+  UnitTest::GetInstance()->RecordProperty(key, value);
+}
+
+// Allows user supplied key value pairs to be recorded for later output.
+void Test::RecordProperty(const std::string& key, int value) {
+  Message value_message;
+  value_message << value;
+  RecordProperty(key, value_message.GetString().c_str());
+}
+
+namespace internal {
+
+void ReportFailureInUnknownLocation(TestPartResult::Type result_type,
+                                    const std::string& message) {
+  // This function is a friend of UnitTest and as such has access to
+  // AddTestPartResult.
+  UnitTest::GetInstance()->AddTestPartResult(
+      result_type,
+      nullptr,  // No info about the source file where the exception occurred.
+      -1,       // We have no info on which line caused the exception.
+      message,
+      "");  // No stack trace, either.
+}
+
+}  // namespace internal
+
+// Google Test requires all tests in the same test suite to use the same test
+// fixture class.  This function checks if the current test has the
+// same fixture class as the first test in the current test suite.  If
+// yes, it returns true; otherwise it generates a Google Test failure and
+// returns false.
+bool Test::HasSameFixtureClass() {
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  const TestSuite* const test_suite = impl->current_test_suite();
+
+  // Info about the first test in the current test suite.
+  const TestInfo* const first_test_info = test_suite->test_info_list()[0];
+  const internal::TypeId first_fixture_id = first_test_info->fixture_class_id_;
+  const char* const first_test_name = first_test_info->name();
+
+  // Info about the current test.
+  const TestInfo* const this_test_info = impl->current_test_info();
+  const internal::TypeId this_fixture_id = this_test_info->fixture_class_id_;
+  const char* const this_test_name = this_test_info->name();
+
+  if (this_fixture_id != first_fixture_id) {
+    // Is the first test defined using TEST?
+    const bool first_is_TEST = first_fixture_id == internal::GetTestTypeId();
+    // Is this test defined using TEST?
+    const bool this_is_TEST = this_fixture_id == internal::GetTestTypeId();
+
+    if (first_is_TEST || this_is_TEST) {
+      // Both TEST and TEST_F appear in same test suite, which is incorrect.
+      // Tell the user how to fix this.
+
+      // Gets the name of the TEST and the name of the TEST_F.  Note
+      // that first_is_TEST and this_is_TEST cannot both be true, as
+      // the fixture IDs are different for the two tests.
+      const char* const TEST_name =
+          first_is_TEST ? first_test_name : this_test_name;
+      const char* const TEST_F_name =
+          first_is_TEST ? this_test_name : first_test_name;
+
+      ADD_FAILURE()
+          << "All tests in the same test suite must use the same test fixture\n"
+          << "class, so mixing TEST_F and TEST in the same test suite is\n"
+          << "illegal.  In test suite " << this_test_info->test_suite_name()
+          << ",\n"
+          << "test " << TEST_F_name << " is defined using TEST_F but\n"
+          << "test " << TEST_name << " is defined using TEST.  You probably\n"
+          << "want to change the TEST to TEST_F or move it to another test\n"
+          << "case.";
+    } else {
+      // Two fixture classes with the same name appear in two different
+      // namespaces, which is not allowed. Tell the user how to fix this.
+      ADD_FAILURE()
+          << "All tests in the same test suite must use the same test fixture\n"
+          << "class.  However, in test suite "
+          << this_test_info->test_suite_name() << ",\n"
+          << "you defined test " << first_test_name << " and test "
+          << this_test_name << "\n"
+          << "using two different test fixture classes.  This can happen if\n"
+          << "the two classes are from different namespaces or translation\n"
+          << "units and have the same name.  You should probably rename one\n"
+          << "of the classes to put the tests into different test suites.";
+    }
+    return false;
+  }
+
+  return true;
+}
+
+#if GTEST_HAS_SEH
+
+// Adds an "exception thrown" fatal failure to the current test.  This
+// function returns its result via an output parameter pointer because VC++
+// prohibits creation of objects with destructors on stack in functions
+// using __try (see error C2712).
+static std::string* FormatSehExceptionMessage(DWORD exception_code,
+                                              const char* location) {
+  Message message;
+  message << "SEH exception with code 0x" << std::setbase(16) << exception_code
+          << std::setbase(10) << " thrown in " << location << ".";
+
+  return new std::string(message.GetString());
+}
+
+#endif  // GTEST_HAS_SEH
+
+namespace internal {
+
+#if GTEST_HAS_EXCEPTIONS
+
+// Adds an "exception thrown" fatal failure to the current test.
+static std::string FormatCxxExceptionMessage(const char* description,
+                                             const char* location) {
+  Message message;
+  if (description != nullptr) {
+    message << "C++ exception with description \"" << description << "\"";
+  } else {
+    message << "Unknown C++ exception";
+  }
+  message << " thrown in " << location << ".";
+
+  return message.GetString();
+}
+
+static std::string PrintTestPartResultToString(
+    const TestPartResult& test_part_result);
+
+GoogleTestFailureException::GoogleTestFailureException(
+    const TestPartResult& failure)
+    : ::std::runtime_error(PrintTestPartResultToString(failure).c_str()) {}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// We put these helper functions in the internal namespace as IBM's xlC
+// compiler rejects the code if they were declared static.
+
+// Runs the given method and handles SEH exceptions it throws, when
+// SEH is supported; returns the 0-value for type Result in case of an
+// SEH exception.  (Microsoft compilers cannot handle SEH and C++
+// exceptions in the same function.  Therefore, we provide a separate
+// wrapper function for handling SEH exceptions.)
+template <class T, typename Result>
+Result HandleSehExceptionsInMethodIfSupported(T* object, Result (T::*method)(),
+                                              const char* location) {
+#if GTEST_HAS_SEH
+  __try {
+    return (object->*method)();
+  } __except (internal::UnitTestOptions::GTestShouldProcessSEH(  // NOLINT
+      GetExceptionCode())) {
+    // We create the exception message on the heap because VC++ prohibits
+    // creation of objects with destructors on stack in functions using __try
+    // (see error C2712).
+    std::string* exception_message =
+        FormatSehExceptionMessage(GetExceptionCode(), location);
+    internal::ReportFailureInUnknownLocation(TestPartResult::kFatalFailure,
+                                             *exception_message);
+    delete exception_message;
+    return static_cast<Result>(0);
+  }
+#else
+  (void)location;
+  return (object->*method)();
+#endif  // GTEST_HAS_SEH
+}
+
+// Runs the given method and catches and reports C++ and/or SEH-style
+// exceptions, if they are supported; returns the 0-value for type
+// Result in case of an SEH exception.
+template <class T, typename Result>
+Result HandleExceptionsInMethodIfSupported(T* object, Result (T::*method)(),
+                                           const char* location) {
+  // NOTE: The user code can affect the way in which Google Test handles
+  // exceptions by setting GTEST_FLAG(catch_exceptions), but only before
+  // RUN_ALL_TESTS() starts. It is technically possible to check the flag
+  // after the exception is caught and either report or re-throw the
+  // exception based on the flag's value:
+  //
+  // try {
+  //   // Perform the test method.
+  // } catch (...) {
+  //   if (GTEST_FLAG_GET(catch_exceptions))
+  //     // Report the exception as failure.
+  //   else
+  //     throw;  // Re-throws the original exception.
+  // }
+  //
+  // However, the purpose of this flag is to allow the program to drop into
+  // the debugger when the exception is thrown. On most platforms, once the
+  // control enters the catch block, the exception origin information is
+  // lost and the debugger will stop the program at the point of the
+  // re-throw in this function -- instead of at the point of the original
+  // throw statement in the code under test.  For this reason, we perform
+  // the check early, sacrificing the ability to affect Google Test's
+  // exception handling in the method where the exception is thrown.
+  if (internal::GetUnitTestImpl()->catch_exceptions()) {
+#if GTEST_HAS_EXCEPTIONS
+    try {
+      return HandleSehExceptionsInMethodIfSupported(object, method, location);
+    } catch (const AssertionException&) {  // NOLINT
+      // This failure was reported already.
+    } catch (const internal::GoogleTestFailureException&) {  // NOLINT
+      // This exception type can only be thrown by a failed Google
+      // Test assertion with the intention of letting another testing
+      // framework catch it.  Therefore we just re-throw it.
+      throw;
+    } catch (const std::exception& e) {  // NOLINT
+      internal::ReportFailureInUnknownLocation(
+          TestPartResult::kFatalFailure,
+          FormatCxxExceptionMessage(e.what(), location));
+    } catch (...) {  // NOLINT
+      internal::ReportFailureInUnknownLocation(
+          TestPartResult::kFatalFailure,
+          FormatCxxExceptionMessage(nullptr, location));
+    }
+    return static_cast<Result>(0);
+#else
+    return HandleSehExceptionsInMethodIfSupported(object, method, location);
+#endif  // GTEST_HAS_EXCEPTIONS
+  } else {
+    return (object->*method)();
+  }
+}
+
+}  // namespace internal
+
+// Runs the test and updates the test result.
+void Test::Run() {
+  if (!HasSameFixtureClass()) return;
+
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  impl->os_stack_trace_getter()->UponLeavingGTest();
+  internal::HandleExceptionsInMethodIfSupported(this, &Test::SetUp, "SetUp()");
+  // We will run the test only if SetUp() was successful and didn't call
+  // GTEST_SKIP().
+  if (!HasFatalFailure() && !IsSkipped()) {
+    impl->os_stack_trace_getter()->UponLeavingGTest();
+    internal::HandleExceptionsInMethodIfSupported(this, &Test::TestBody,
+                                                  "the test body");
+  }
+
+  // However, we want to clean up as much as possible.  Hence we will
+  // always call TearDown(), even if SetUp() or the test body has
+  // failed.
+  impl->os_stack_trace_getter()->UponLeavingGTest();
+  internal::HandleExceptionsInMethodIfSupported(this, &Test::TearDown,
+                                                "TearDown()");
+}
+
+// Returns true if and only if the current test has a fatal failure.
+bool Test::HasFatalFailure() {
+  return internal::GetUnitTestImpl()->current_test_result()->HasFatalFailure();
+}
+
+// Returns true if and only if the current test has a non-fatal failure.
+bool Test::HasNonfatalFailure() {
+  return internal::GetUnitTestImpl()
+      ->current_test_result()
+      ->HasNonfatalFailure();
+}
+
+// Returns true if and only if the current test was skipped.
+bool Test::IsSkipped() {
+  return internal::GetUnitTestImpl()->current_test_result()->Skipped();
+}
+
+// class TestInfo
+
+// Constructs a TestInfo object. It assumes ownership of the test factory
+// object.
+TestInfo::TestInfo(const std::string& a_test_suite_name,
+                   const std::string& a_name, const char* a_type_param,
+                   const char* a_value_param,
+                   internal::CodeLocation a_code_location,
+                   internal::TypeId fixture_class_id,
+                   internal::TestFactoryBase* factory)
+    : test_suite_name_(a_test_suite_name),
+      name_(a_name),
+      type_param_(a_type_param ? new std::string(a_type_param) : nullptr),
+      value_param_(a_value_param ? new std::string(a_value_param) : nullptr),
+      location_(a_code_location),
+      fixture_class_id_(fixture_class_id),
+      should_run_(false),
+      is_disabled_(false),
+      matches_filter_(false),
+      is_in_another_shard_(false),
+      factory_(factory),
+      result_() {}
+
+// Destructs a TestInfo object.
+TestInfo::~TestInfo() { delete factory_; }
+
+namespace internal {
+
+// Creates a new TestInfo object and registers it with Google Test;
+// returns the created object.
+//
+// Arguments:
+//
+//   test_suite_name:  name of the test suite
+//   name:             name of the test
+//   type_param:       the name of the test's type parameter, or NULL if
+//                     this is not a typed or a type-parameterized test.
+//   value_param:      text representation of the test's value parameter,
+//                     or NULL if this is not a value-parameterized test.
+//   code_location:    code location where the test is defined
+//   fixture_class_id: ID of the test fixture class
+//   set_up_tc:        pointer to the function that sets up the test suite
+//   tear_down_tc:     pointer to the function that tears down the test suite
+//   factory:          pointer to the factory that creates a test object.
+//                     The newly created TestInfo instance will assume
+//                     ownership of the factory object.
+TestInfo* MakeAndRegisterTestInfo(
+    const char* test_suite_name, const char* name, const char* type_param,
+    const char* value_param, CodeLocation code_location,
+    TypeId fixture_class_id, SetUpTestSuiteFunc set_up_tc,
+    TearDownTestSuiteFunc tear_down_tc, TestFactoryBase* factory) {
+  TestInfo* const test_info =
+      new TestInfo(test_suite_name, name, type_param, value_param,
+                   code_location, fixture_class_id, factory);
+  GetUnitTestImpl()->AddTestInfo(set_up_tc, tear_down_tc, test_info);
+  return test_info;
+}
+
+void ReportInvalidTestSuiteType(const char* test_suite_name,
+                                CodeLocation code_location) {
+  Message errors;
+  errors
+      << "Attempted redefinition of test suite " << test_suite_name << ".\n"
+      << "All tests in the same test suite must use the same test fixture\n"
+      << "class.  However, in test suite " << test_suite_name << ", you tried\n"
+      << "to define a test using a fixture class different from the one\n"
+      << "used earlier. This can happen if the two fixture classes are\n"
+      << "from different namespaces and have the same name. You should\n"
+      << "probably rename one of the classes to put the tests into different\n"
+      << "test suites.";
+
+  GTEST_LOG_(ERROR) << FormatFileLocation(code_location.file.c_str(),
+                                          code_location.line)
+                    << " " << errors.GetString();
+}
+}  // namespace internal
+
+namespace {
+
+// A predicate that checks the test name of a TestInfo against a known
+// value.
+//
+// This is used for implementation of the TestSuite class only.  We put
+// it in the anonymous namespace to prevent polluting the outer
+// namespace.
+//
+// TestNameIs is copyable.
+class TestNameIs {
+ public:
+  // Constructor.
+  //
+  // TestNameIs has NO default constructor.
+  explicit TestNameIs(const char* name) : name_(name) {}
+
+  // Returns true if and only if the test name of test_info matches name_.
+  bool operator()(const TestInfo* test_info) const {
+    return test_info && test_info->name() == name_;
+  }
+
+ private:
+  std::string name_;
+};
+
+}  // namespace
+
+namespace internal {
+
+// This method expands all parameterized tests registered with macros TEST_P
+// and INSTANTIATE_TEST_SUITE_P into regular tests and registers those.
+// This will be done just once during the program runtime.
+void UnitTestImpl::RegisterParameterizedTests() {
+  if (!parameterized_tests_registered_) {
+    parameterized_test_registry_.RegisterTests();
+    type_parameterized_test_registry_.CheckForInstantiations();
+    parameterized_tests_registered_ = true;
+  }
+}
+
+}  // namespace internal
+
+// Creates the test object, runs it, records its result, and then
+// deletes it.
+void TestInfo::Run() {
+  TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
+  if (!should_run_) {
+    if (is_disabled_ && matches_filter_) repeater->OnTestDisabled(*this);
+    return;
+  }
+
+  // Tells UnitTest where to store test result.
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  impl->set_current_test_info(this);
+
+  // Notifies the unit test event listeners that a test is about to start.
+  repeater->OnTestStart(*this);
+  result_.set_start_timestamp(internal::GetTimeInMillis());
+  internal::Timer timer;
+  impl->os_stack_trace_getter()->UponLeavingGTest();
+
+  // Creates the test object.
+  Test* const test = internal::HandleExceptionsInMethodIfSupported(
+      factory_, &internal::TestFactoryBase::CreateTest,
+      "the test fixture's constructor");
+
+  // Runs the test if the constructor didn't generate a fatal failure or invoke
+  // GTEST_SKIP().
+  // Note that the object will not be null
+  if (!Test::HasFatalFailure() && !Test::IsSkipped()) {
+    // This doesn't throw as all user code that can throw are wrapped into
+    // exception handling code.
+    test->Run();
+  }
+
+  if (test != nullptr) {
+    // Deletes the test object.
+    impl->os_stack_trace_getter()->UponLeavingGTest();
+    internal::HandleExceptionsInMethodIfSupported(
+        test, &Test::DeleteSelf_, "the test fixture's destructor");
+  }
+
+  result_.set_elapsed_time(timer.Elapsed());
+
+  // Notifies the unit test event listener that a test has just finished.
+  repeater->OnTestEnd(*this);
+
+  // Tells UnitTest to stop associating assertion results to this
+  // test.
+  impl->set_current_test_info(nullptr);
+}
+
+// Skip and records a skipped test result for this object.
+void TestInfo::Skip() {
+  if (!should_run_) return;
+
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  impl->set_current_test_info(this);
+
+  TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
+
+  // Notifies the unit test event listeners that a test is about to start.
+  repeater->OnTestStart(*this);
+
+  const TestPartResult test_part_result =
+      TestPartResult(TestPartResult::kSkip, this->file(), this->line(), "");
+  impl->GetTestPartResultReporterForCurrentThread()->ReportTestPartResult(
+      test_part_result);
+
+  // Notifies the unit test event listener that a test has just finished.
+  repeater->OnTestEnd(*this);
+  impl->set_current_test_info(nullptr);
+}
+
+// class TestSuite
+
+// Gets the number of successful tests in this test suite.
+int TestSuite::successful_test_count() const {
+  return CountIf(test_info_list_, TestPassed);
+}
+
+// Gets the number of successful tests in this test suite.
+int TestSuite::skipped_test_count() const {
+  return CountIf(test_info_list_, TestSkipped);
+}
+
+// Gets the number of failed tests in this test suite.
+int TestSuite::failed_test_count() const {
+  return CountIf(test_info_list_, TestFailed);
+}
+
+// Gets the number of disabled tests that will be reported in the XML report.
+int TestSuite::reportable_disabled_test_count() const {
+  return CountIf(test_info_list_, TestReportableDisabled);
+}
+
+// Gets the number of disabled tests in this test suite.
+int TestSuite::disabled_test_count() const {
+  return CountIf(test_info_list_, TestDisabled);
+}
+
+// Gets the number of tests to be printed in the XML report.
+int TestSuite::reportable_test_count() const {
+  return CountIf(test_info_list_, TestReportable);
+}
+
+// Get the number of tests in this test suite that should run.
+int TestSuite::test_to_run_count() const {
+  return CountIf(test_info_list_, ShouldRunTest);
+}
+
+// Gets the number of all tests.
+int TestSuite::total_test_count() const {
+  return static_cast<int>(test_info_list_.size());
+}
+
+// Creates a TestSuite with the given name.
+//
+// Arguments:
+//
+//   a_name:       name of the test suite
+//   a_type_param: the name of the test suite's type parameter, or NULL if
+//                 this is not a typed or a type-parameterized test suite.
+//   set_up_tc:    pointer to the function that sets up the test suite
+//   tear_down_tc: pointer to the function that tears down the test suite
+TestSuite::TestSuite(const char* a_name, const char* a_type_param,
+                     internal::SetUpTestSuiteFunc set_up_tc,
+                     internal::TearDownTestSuiteFunc tear_down_tc)
+    : name_(a_name),
+      type_param_(a_type_param ? new std::string(a_type_param) : nullptr),
+      set_up_tc_(set_up_tc),
+      tear_down_tc_(tear_down_tc),
+      should_run_(false),
+      start_timestamp_(0),
+      elapsed_time_(0) {}
+
+// Destructor of TestSuite.
+TestSuite::~TestSuite() {
+  // Deletes every Test in the collection.
+  ForEach(test_info_list_, internal::Delete<TestInfo>);
+}
+
+// Returns the i-th test among all the tests. i can range from 0 to
+// total_test_count() - 1. If i is not in that range, returns NULL.
+const TestInfo* TestSuite::GetTestInfo(int i) const {
+  const int index = GetElementOr(test_indices_, i, -1);
+  return index < 0 ? nullptr : test_info_list_[static_cast<size_t>(index)];
+}
+
+// Returns the i-th test among all the tests. i can range from 0 to
+// total_test_count() - 1. If i is not in that range, returns NULL.
+TestInfo* TestSuite::GetMutableTestInfo(int i) {
+  const int index = GetElementOr(test_indices_, i, -1);
+  return index < 0 ? nullptr : test_info_list_[static_cast<size_t>(index)];
+}
+
+// Adds a test to this test suite.  Will delete the test upon
+// destruction of the TestSuite object.
+void TestSuite::AddTestInfo(TestInfo* test_info) {
+  test_info_list_.push_back(test_info);
+  test_indices_.push_back(static_cast<int>(test_indices_.size()));
+}
+
+// Runs every test in this TestSuite.
+void TestSuite::Run() {
+  if (!should_run_) return;
+
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  impl->set_current_test_suite(this);
+
+  TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
+
+  // Call both legacy and the new API
+  repeater->OnTestSuiteStart(*this);
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  repeater->OnTestCaseStart(*this);
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  impl->os_stack_trace_getter()->UponLeavingGTest();
+  internal::HandleExceptionsInMethodIfSupported(
+      this, &TestSuite::RunSetUpTestSuite, "SetUpTestSuite()");
+
+  const bool skip_all = ad_hoc_test_result().Failed();
+
+  start_timestamp_ = internal::GetTimeInMillis();
+  internal::Timer timer;
+  for (int i = 0; i < total_test_count(); i++) {
+    if (skip_all) {
+      GetMutableTestInfo(i)->Skip();
+    } else {
+      GetMutableTestInfo(i)->Run();
+    }
+    if (GTEST_FLAG_GET(fail_fast) &&
+        GetMutableTestInfo(i)->result()->Failed()) {
+      for (int j = i + 1; j < total_test_count(); j++) {
+        GetMutableTestInfo(j)->Skip();
+      }
+      break;
+    }
+  }
+  elapsed_time_ = timer.Elapsed();
+
+  impl->os_stack_trace_getter()->UponLeavingGTest();
+  internal::HandleExceptionsInMethodIfSupported(
+      this, &TestSuite::RunTearDownTestSuite, "TearDownTestSuite()");
+
+  // Call both legacy and the new API
+  repeater->OnTestSuiteEnd(*this);
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  repeater->OnTestCaseEnd(*this);
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  impl->set_current_test_suite(nullptr);
+}
+
+// Skips all tests under this TestSuite.
+void TestSuite::Skip() {
+  if (!should_run_) return;
+
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  impl->set_current_test_suite(this);
+
+  TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
+
+  // Call both legacy and the new API
+  repeater->OnTestSuiteStart(*this);
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  repeater->OnTestCaseStart(*this);
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  for (int i = 0; i < total_test_count(); i++) {
+    GetMutableTestInfo(i)->Skip();
+  }
+
+  // Call both legacy and the new API
+  repeater->OnTestSuiteEnd(*this);
+  // Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  repeater->OnTestCaseEnd(*this);
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  impl->set_current_test_suite(nullptr);
+}
+
+// Clears the results of all tests in this test suite.
+void TestSuite::ClearResult() {
+  ad_hoc_test_result_.Clear();
+  ForEach(test_info_list_, TestInfo::ClearTestResult);
+}
+
+// Shuffles the tests in this test suite.
+void TestSuite::ShuffleTests(internal::Random* random) {
+  Shuffle(random, &test_indices_);
+}
+
+// Restores the test order to before the first shuffle.
+void TestSuite::UnshuffleTests() {
+  for (size_t i = 0; i < test_indices_.size(); i++) {
+    test_indices_[i] = static_cast<int>(i);
+  }
+}
+
+// Formats a countable noun.  Depending on its quantity, either the
+// singular form or the plural form is used. e.g.
+//
+// FormatCountableNoun(1, "formula", "formuli") returns "1 formula".
+// FormatCountableNoun(5, "book", "books") returns "5 books".
+static std::string FormatCountableNoun(int count, const char* singular_form,
+                                       const char* plural_form) {
+  return internal::StreamableToString(count) + " " +
+         (count == 1 ? singular_form : plural_form);
+}
+
+// Formats the count of tests.
+static std::string FormatTestCount(int test_count) {
+  return FormatCountableNoun(test_count, "test", "tests");
+}
+
+// Formats the count of test suites.
+static std::string FormatTestSuiteCount(int test_suite_count) {
+  return FormatCountableNoun(test_suite_count, "test suite", "test suites");
+}
+
+// Converts a TestPartResult::Type enum to human-friendly string
+// representation.  Both kNonFatalFailure and kFatalFailure are translated
+// to "Failure", as the user usually doesn't care about the difference
+// between the two when viewing the test result.
+static const char* TestPartResultTypeToString(TestPartResult::Type type) {
+  switch (type) {
+    case TestPartResult::kSkip:
+      return "Skipped\n";
+    case TestPartResult::kSuccess:
+      return "Success";
+
+    case TestPartResult::kNonFatalFailure:
+    case TestPartResult::kFatalFailure:
+#ifdef _MSC_VER
+      return "error: ";
+#else
+      return "Failure\n";
+#endif
+    default:
+      return "Unknown result type";
+  }
+}
+
+namespace internal {
+namespace {
+enum class GTestColor { kDefault, kRed, kGreen, kYellow };
+}  // namespace
+
+// Prints a TestPartResult to an std::string.
+static std::string PrintTestPartResultToString(
+    const TestPartResult& test_part_result) {
+  return (Message() << internal::FormatFileLocation(
+                           test_part_result.file_name(),
+                           test_part_result.line_number())
+                    << " "
+                    << TestPartResultTypeToString(test_part_result.type())
+                    << test_part_result.message())
+      .GetString();
+}
+
+// Prints a TestPartResult.
+static void PrintTestPartResult(const TestPartResult& test_part_result) {
+  const std::string& result = PrintTestPartResultToString(test_part_result);
+  printf("%s\n", result.c_str());
+  fflush(stdout);
+  // If the test program runs in Visual Studio or a debugger, the
+  // following statements add the test part result message to the Output
+  // window such that the user can double-click on it to jump to the
+  // corresponding source code location; otherwise they do nothing.
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
+  // We don't call OutputDebugString*() on Windows Mobile, as printing
+  // to stdout is done by OutputDebugString() there already - we don't
+  // want the same message printed twice.
+  ::OutputDebugStringA(result.c_str());
+  ::OutputDebugStringA("\n");
+#endif
+}
+
+// class PrettyUnitTestResultPrinter
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE && !GTEST_OS_WINDOWS_PHONE && \
+    !GTEST_OS_WINDOWS_RT && !GTEST_OS_WINDOWS_MINGW
+
+// Returns the character attribute for the given color.
+static WORD GetColorAttribute(GTestColor color) {
+  switch (color) {
+    case GTestColor::kRed:
+      return FOREGROUND_RED;
+    case GTestColor::kGreen:
+      return FOREGROUND_GREEN;
+    case GTestColor::kYellow:
+      return FOREGROUND_RED | FOREGROUND_GREEN;
+    default:
+      return 0;
+  }
+}
+
+static int GetBitOffset(WORD color_mask) {
+  if (color_mask == 0) return 0;
+
+  int bitOffset = 0;
+  while ((color_mask & 1) == 0) {
+    color_mask >>= 1;
+    ++bitOffset;
+  }
+  return bitOffset;
+}
+
+static WORD GetNewColor(GTestColor color, WORD old_color_attrs) {
+  // Let's reuse the BG
+  static const WORD background_mask = BACKGROUND_BLUE | BACKGROUND_GREEN |
+                                      BACKGROUND_RED | BACKGROUND_INTENSITY;
+  static const WORD foreground_mask = FOREGROUND_BLUE | FOREGROUND_GREEN |
+                                      FOREGROUND_RED | FOREGROUND_INTENSITY;
+  const WORD existing_bg = old_color_attrs & background_mask;
+
+  WORD new_color =
+      GetColorAttribute(color) | existing_bg | FOREGROUND_INTENSITY;
+  static const int bg_bitOffset = GetBitOffset(background_mask);
+  static const int fg_bitOffset = GetBitOffset(foreground_mask);
+
+  if (((new_color & background_mask) >> bg_bitOffset) ==
+      ((new_color & foreground_mask) >> fg_bitOffset)) {
+    new_color ^= FOREGROUND_INTENSITY;  // invert intensity
+  }
+  return new_color;
+}
+
+#else
+
+// Returns the ANSI color code for the given color. GTestColor::kDefault is
+// an invalid input.
+static const char* GetAnsiColorCode(GTestColor color) {
+  switch (color) {
+    case GTestColor::kRed:
+      return "1";
+    case GTestColor::kGreen:
+      return "2";
+    case GTestColor::kYellow:
+      return "3";
+    default:
+      return nullptr;
+  }
+}
+
+#endif  // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
+
+// Returns true if and only if Google Test should use colors in the output.
+bool ShouldUseColor(bool stdout_is_tty) {
+  std::string c = GTEST_FLAG_GET(color);
+  const char* const gtest_color = c.c_str();
+
+  if (String::CaseInsensitiveCStringEquals(gtest_color, "auto")) {
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
+    // On Windows the TERM variable is usually not set, but the
+    // console there does support colors.
+    return stdout_is_tty;
+#else
+    // On non-Windows platforms, we rely on the TERM variable.
+    const char* const term = posix::GetEnv("TERM");
+    const bool term_supports_color =
+        String::CStringEquals(term, "xterm") ||
+        String::CStringEquals(term, "xterm-color") ||
+        String::CStringEquals(term, "xterm-256color") ||
+        String::CStringEquals(term, "screen") ||
+        String::CStringEquals(term, "screen-256color") ||
+        String::CStringEquals(term, "tmux") ||
+        String::CStringEquals(term, "tmux-256color") ||
+        String::CStringEquals(term, "rxvt-unicode") ||
+        String::CStringEquals(term, "rxvt-unicode-256color") ||
+        String::CStringEquals(term, "linux") ||
+        String::CStringEquals(term, "cygwin");
+    return stdout_is_tty && term_supports_color;
+#endif  // GTEST_OS_WINDOWS
+  }
+
+  return String::CaseInsensitiveCStringEquals(gtest_color, "yes") ||
+         String::CaseInsensitiveCStringEquals(gtest_color, "true") ||
+         String::CaseInsensitiveCStringEquals(gtest_color, "t") ||
+         String::CStringEquals(gtest_color, "1");
+  // We take "yes", "true", "t", and "1" as meaning "yes".  If the
+  // value is neither one of these nor "auto", we treat it as "no" to
+  // be conservative.
+}
+
+// Helpers for printing colored strings to stdout. Note that on Windows, we
+// cannot simply emit special characters and have the terminal change colors.
+// This routine must actually emit the characters rather than return a string
+// that would be colored when printed, as can be done on Linux.
+
+GTEST_ATTRIBUTE_PRINTF_(2, 3)
+static void ColoredPrintf(GTestColor color, const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+
+  static const bool in_color_mode =
+      ShouldUseColor(posix::IsATTY(posix::FileNo(stdout)) != 0);
+  const bool use_color = in_color_mode && (color != GTestColor::kDefault);
+
+  if (!use_color) {
+    vprintf(fmt, args);
+    va_end(args);
+    return;
+  }
+
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE && !GTEST_OS_WINDOWS_PHONE && \
+    !GTEST_OS_WINDOWS_RT && !GTEST_OS_WINDOWS_MINGW
+  const HANDLE stdout_handle = GetStdHandle(STD_OUTPUT_HANDLE);
+
+  // Gets the current text color.
+  CONSOLE_SCREEN_BUFFER_INFO buffer_info;
+  GetConsoleScreenBufferInfo(stdout_handle, &buffer_info);
+  const WORD old_color_attrs = buffer_info.wAttributes;
+  const WORD new_color = GetNewColor(color, old_color_attrs);
+
+  // We need to flush the stream buffers into the console before each
+  // SetConsoleTextAttribute call lest it affect the text that is already
+  // printed but has not yet reached the console.
+  fflush(stdout);
+  SetConsoleTextAttribute(stdout_handle, new_color);
+
+  vprintf(fmt, args);
+
+  fflush(stdout);
+  // Restores the text color.
+  SetConsoleTextAttribute(stdout_handle, old_color_attrs);
+#else
+  printf("\033[0;3%sm", GetAnsiColorCode(color));
+  vprintf(fmt, args);
+  printf("\033[m");  // Resets the terminal to default.
+#endif  // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
+  va_end(args);
+}
+
+// Text printed in Google Test's text output and --gtest_list_tests
+// output to label the type parameter and value parameter for a test.
+static const char kTypeParamLabel[] = "TypeParam";
+static const char kValueParamLabel[] = "GetParam()";
+
+static void PrintFullTestCommentIfPresent(const TestInfo& test_info) {
+  const char* const type_param = test_info.type_param();
+  const char* const value_param = test_info.value_param();
+
+  if (type_param != nullptr || value_param != nullptr) {
+    printf(", where ");
+    if (type_param != nullptr) {
+      printf("%s = %s", kTypeParamLabel, type_param);
+      if (value_param != nullptr) printf(" and ");
+    }
+    if (value_param != nullptr) {
+      printf("%s = %s", kValueParamLabel, value_param);
+    }
+  }
+}
+
+// This class implements the TestEventListener interface.
+//
+// Class PrettyUnitTestResultPrinter is copyable.
+class PrettyUnitTestResultPrinter : public TestEventListener {
+ public:
+  PrettyUnitTestResultPrinter() {}
+  static void PrintTestName(const char* test_suite, const char* test) {
+    printf("%s.%s", test_suite, test);
+  }
+
+  // The following methods override what's in the TestEventListener class.
+  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {}
+  void OnTestIterationStart(const UnitTest& unit_test, int iteration) override;
+  void OnEnvironmentsSetUpStart(const UnitTest& unit_test) override;
+  void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {}
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseStart(const TestCase& test_case) override;
+#else
+  void OnTestSuiteStart(const TestSuite& test_suite) override;
+#endif  // OnTestCaseStart
+
+  void OnTestStart(const TestInfo& test_info) override;
+  void OnTestDisabled(const TestInfo& test_info) override;
+
+  void OnTestPartResult(const TestPartResult& result) override;
+  void OnTestEnd(const TestInfo& test_info) override;
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseEnd(const TestCase& test_case) override;
+#else
+  void OnTestSuiteEnd(const TestSuite& test_suite) override;
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  void OnEnvironmentsTearDownStart(const UnitTest& unit_test) override;
+  void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {}
+  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
+  void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {}
+
+ private:
+  static void PrintFailedTests(const UnitTest& unit_test);
+  static void PrintFailedTestSuites(const UnitTest& unit_test);
+  static void PrintSkippedTests(const UnitTest& unit_test);
+};
+
+// Fired before each iteration of tests starts.
+void PrettyUnitTestResultPrinter::OnTestIterationStart(
+    const UnitTest& unit_test, int iteration) {
+  if (GTEST_FLAG_GET(repeat) != 1)
+    printf("\nRepeating all tests (iteration %d) . . .\n\n", iteration + 1);
+
+  std::string f = GTEST_FLAG_GET(filter);
+  const char* const filter = f.c_str();
+
+  // Prints the filter if it's not *.  This reminds the user that some
+  // tests may be skipped.
+  if (!String::CStringEquals(filter, kUniversalFilter)) {
+    ColoredPrintf(GTestColor::kYellow, "Note: %s filter = %s\n", GTEST_NAME_,
+                  filter);
+  }
+
+  if (internal::ShouldShard(kTestTotalShards, kTestShardIndex, false)) {
+    const int32_t shard_index = Int32FromEnvOrDie(kTestShardIndex, -1);
+    ColoredPrintf(GTestColor::kYellow, "Note: This is test shard %d of %s.\n",
+                  static_cast<int>(shard_index) + 1,
+                  internal::posix::GetEnv(kTestTotalShards));
+  }
+
+  if (GTEST_FLAG_GET(shuffle)) {
+    ColoredPrintf(GTestColor::kYellow,
+                  "Note: Randomizing tests' orders with a seed of %d .\n",
+                  unit_test.random_seed());
+  }
+
+  ColoredPrintf(GTestColor::kGreen, "[==========] ");
+  printf("Running %s from %s.\n",
+         FormatTestCount(unit_test.test_to_run_count()).c_str(),
+         FormatTestSuiteCount(unit_test.test_suite_to_run_count()).c_str());
+  fflush(stdout);
+}
+
+void PrettyUnitTestResultPrinter::OnEnvironmentsSetUpStart(
+    const UnitTest& /*unit_test*/) {
+  ColoredPrintf(GTestColor::kGreen, "[----------] ");
+  printf("Global test environment set-up.\n");
+  fflush(stdout);
+}
+
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+void PrettyUnitTestResultPrinter::OnTestCaseStart(const TestCase& test_case) {
+  const std::string counts =
+      FormatCountableNoun(test_case.test_to_run_count(), "test", "tests");
+  ColoredPrintf(GTestColor::kGreen, "[----------] ");
+  printf("%s from %s", counts.c_str(), test_case.name());
+  if (test_case.type_param() == nullptr) {
+    printf("\n");
+  } else {
+    printf(", where %s = %s\n", kTypeParamLabel, test_case.type_param());
+  }
+  fflush(stdout);
+}
+#else
+void PrettyUnitTestResultPrinter::OnTestSuiteStart(
+    const TestSuite& test_suite) {
+  const std::string counts =
+      FormatCountableNoun(test_suite.test_to_run_count(), "test", "tests");
+  ColoredPrintf(GTestColor::kGreen, "[----------] ");
+  printf("%s from %s", counts.c_str(), test_suite.name());
+  if (test_suite.type_param() == nullptr) {
+    printf("\n");
+  } else {
+    printf(", where %s = %s\n", kTypeParamLabel, test_suite.type_param());
+  }
+  fflush(stdout);
+}
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+void PrettyUnitTestResultPrinter::OnTestStart(const TestInfo& test_info) {
+  ColoredPrintf(GTestColor::kGreen, "[ RUN      ] ");
+  PrintTestName(test_info.test_suite_name(), test_info.name());
+  printf("\n");
+  fflush(stdout);
+}
+
+void PrettyUnitTestResultPrinter::OnTestDisabled(const TestInfo& test_info) {
+  ColoredPrintf(GTestColor::kYellow, "[ DISABLED ] ");
+  PrintTestName(test_info.test_suite_name(), test_info.name());
+  printf("\n");
+  fflush(stdout);
+}
+
+// Called after an assertion failure.
+void PrettyUnitTestResultPrinter::OnTestPartResult(
+    const TestPartResult& result) {
+  switch (result.type()) {
+    // If the test part succeeded, we don't need to do anything.
+    case TestPartResult::kSuccess:
+      return;
+    default:
+      // Print failure message from the assertion
+      // (e.g. expected this and got that).
+      PrintTestPartResult(result);
+      fflush(stdout);
+  }
+}
+
+void PrettyUnitTestResultPrinter::OnTestEnd(const TestInfo& test_info) {
+  if (test_info.result()->Passed()) {
+    ColoredPrintf(GTestColor::kGreen, "[       OK ] ");
+  } else if (test_info.result()->Skipped()) {
+    ColoredPrintf(GTestColor::kGreen, "[  SKIPPED ] ");
+  } else {
+    ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
+  }
+  PrintTestName(test_info.test_suite_name(), test_info.name());
+  if (test_info.result()->Failed()) PrintFullTestCommentIfPresent(test_info);
+
+  if (GTEST_FLAG_GET(print_time)) {
+    printf(" (%s ms)\n",
+           internal::StreamableToString(test_info.result()->elapsed_time())
+               .c_str());
+  } else {
+    printf("\n");
+  }
+  fflush(stdout);
+}
+
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+void PrettyUnitTestResultPrinter::OnTestCaseEnd(const TestCase& test_case) {
+  if (!GTEST_FLAG_GET(print_time)) return;
+
+  const std::string counts =
+      FormatCountableNoun(test_case.test_to_run_count(), "test", "tests");
+  ColoredPrintf(GTestColor::kGreen, "[----------] ");
+  printf("%s from %s (%s ms total)\n\n", counts.c_str(), test_case.name(),
+         internal::StreamableToString(test_case.elapsed_time()).c_str());
+  fflush(stdout);
+}
+#else
+void PrettyUnitTestResultPrinter::OnTestSuiteEnd(const TestSuite& test_suite) {
+  if (!GTEST_FLAG_GET(print_time)) return;
+
+  const std::string counts =
+      FormatCountableNoun(test_suite.test_to_run_count(), "test", "tests");
+  ColoredPrintf(GTestColor::kGreen, "[----------] ");
+  printf("%s from %s (%s ms total)\n\n", counts.c_str(), test_suite.name(),
+         internal::StreamableToString(test_suite.elapsed_time()).c_str());
+  fflush(stdout);
+}
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+void PrettyUnitTestResultPrinter::OnEnvironmentsTearDownStart(
+    const UnitTest& /*unit_test*/) {
+  ColoredPrintf(GTestColor::kGreen, "[----------] ");
+  printf("Global test environment tear-down\n");
+  fflush(stdout);
+}
+
+// Internal helper for printing the list of failed tests.
+void PrettyUnitTestResultPrinter::PrintFailedTests(const UnitTest& unit_test) {
+  const int failed_test_count = unit_test.failed_test_count();
+  ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
+  printf("%s, listed below:\n", FormatTestCount(failed_test_count).c_str());
+
+  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
+    const TestSuite& test_suite = *unit_test.GetTestSuite(i);
+    if (!test_suite.should_run() || (test_suite.failed_test_count() == 0)) {
+      continue;
+    }
+    for (int j = 0; j < test_suite.total_test_count(); ++j) {
+      const TestInfo& test_info = *test_suite.GetTestInfo(j);
+      if (!test_info.should_run() || !test_info.result()->Failed()) {
+        continue;
+      }
+      ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
+      printf("%s.%s", test_suite.name(), test_info.name());
+      PrintFullTestCommentIfPresent(test_info);
+      printf("\n");
+    }
+  }
+  printf("\n%2d FAILED %s\n", failed_test_count,
+         failed_test_count == 1 ? "TEST" : "TESTS");
+}
+
+// Internal helper for printing the list of test suite failures not covered by
+// PrintFailedTests.
+void PrettyUnitTestResultPrinter::PrintFailedTestSuites(
+    const UnitTest& unit_test) {
+  int suite_failure_count = 0;
+  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
+    const TestSuite& test_suite = *unit_test.GetTestSuite(i);
+    if (!test_suite.should_run()) {
+      continue;
+    }
+    if (test_suite.ad_hoc_test_result().Failed()) {
+      ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
+      printf("%s: SetUpTestSuite or TearDownTestSuite\n", test_suite.name());
+      ++suite_failure_count;
+    }
+  }
+  if (suite_failure_count > 0) {
+    printf("\n%2d FAILED TEST %s\n", suite_failure_count,
+           suite_failure_count == 1 ? "SUITE" : "SUITES");
+  }
+}
+
+// Internal helper for printing the list of skipped tests.
+void PrettyUnitTestResultPrinter::PrintSkippedTests(const UnitTest& unit_test) {
+  const int skipped_test_count = unit_test.skipped_test_count();
+  if (skipped_test_count == 0) {
+    return;
+  }
+
+  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
+    const TestSuite& test_suite = *unit_test.GetTestSuite(i);
+    if (!test_suite.should_run() || (test_suite.skipped_test_count() == 0)) {
+      continue;
+    }
+    for (int j = 0; j < test_suite.total_test_count(); ++j) {
+      const TestInfo& test_info = *test_suite.GetTestInfo(j);
+      if (!test_info.should_run() || !test_info.result()->Skipped()) {
+        continue;
+      }
+      ColoredPrintf(GTestColor::kGreen, "[  SKIPPED ] ");
+      printf("%s.%s", test_suite.name(), test_info.name());
+      printf("\n");
+    }
+  }
+}
+
+void PrettyUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
+                                                     int /*iteration*/) {
+  ColoredPrintf(GTestColor::kGreen, "[==========] ");
+  printf("%s from %s ran.",
+         FormatTestCount(unit_test.test_to_run_count()).c_str(),
+         FormatTestSuiteCount(unit_test.test_suite_to_run_count()).c_str());
+  if (GTEST_FLAG_GET(print_time)) {
+    printf(" (%s ms total)",
+           internal::StreamableToString(unit_test.elapsed_time()).c_str());
+  }
+  printf("\n");
+  ColoredPrintf(GTestColor::kGreen, "[  PASSED  ] ");
+  printf("%s.\n", FormatTestCount(unit_test.successful_test_count()).c_str());
+
+  const int skipped_test_count = unit_test.skipped_test_count();
+  if (skipped_test_count > 0) {
+    ColoredPrintf(GTestColor::kGreen, "[  SKIPPED ] ");
+    printf("%s, listed below:\n", FormatTestCount(skipped_test_count).c_str());
+    PrintSkippedTests(unit_test);
+  }
+
+  if (!unit_test.Passed()) {
+    PrintFailedTests(unit_test);
+    PrintFailedTestSuites(unit_test);
+  }
+
+  int num_disabled = unit_test.reportable_disabled_test_count();
+  if (num_disabled && !GTEST_FLAG_GET(also_run_disabled_tests)) {
+    if (unit_test.Passed()) {
+      printf("\n");  // Add a spacer if no FAILURE banner is displayed.
+    }
+    ColoredPrintf(GTestColor::kYellow, "  YOU HAVE %d DISABLED %s\n\n",
+                  num_disabled, num_disabled == 1 ? "TEST" : "TESTS");
+  }
+  // Ensure that Google Test output is printed before, e.g., heapchecker output.
+  fflush(stdout);
+}
+
+// End PrettyUnitTestResultPrinter
+
+// This class implements the TestEventListener interface.
+//
+// Class BriefUnitTestResultPrinter is copyable.
+class BriefUnitTestResultPrinter : public TestEventListener {
+ public:
+  BriefUnitTestResultPrinter() {}
+  static void PrintTestName(const char* test_suite, const char* test) {
+    printf("%s.%s", test_suite, test);
+  }
+
+  // The following methods override what's in the TestEventListener class.
+  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {}
+  void OnTestIterationStart(const UnitTest& /*unit_test*/,
+                            int /*iteration*/) override {}
+  void OnEnvironmentsSetUpStart(const UnitTest& /*unit_test*/) override {}
+  void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {}
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseStart(const TestCase& /*test_case*/) override {}
+#else
+  void OnTestSuiteStart(const TestSuite& /*test_suite*/) override {}
+#endif  // OnTestCaseStart
+
+  void OnTestStart(const TestInfo& /*test_info*/) override {}
+  void OnTestDisabled(const TestInfo& /*test_info*/) override {}
+
+  void OnTestPartResult(const TestPartResult& result) override;
+  void OnTestEnd(const TestInfo& test_info) override;
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseEnd(const TestCase& /*test_case*/) override {}
+#else
+  void OnTestSuiteEnd(const TestSuite& /*test_suite*/) override {}
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  void OnEnvironmentsTearDownStart(const UnitTest& /*unit_test*/) override {}
+  void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {}
+  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
+  void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {}
+};
+
+// Called after an assertion failure.
+void BriefUnitTestResultPrinter::OnTestPartResult(
+    const TestPartResult& result) {
+  switch (result.type()) {
+    // If the test part succeeded, we don't need to do anything.
+    case TestPartResult::kSuccess:
+      return;
+    default:
+      // Print failure message from the assertion
+      // (e.g. expected this and got that).
+      PrintTestPartResult(result);
+      fflush(stdout);
+  }
+}
+
+void BriefUnitTestResultPrinter::OnTestEnd(const TestInfo& test_info) {
+  if (test_info.result()->Failed()) {
+    ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
+    PrintTestName(test_info.test_suite_name(), test_info.name());
+    PrintFullTestCommentIfPresent(test_info);
+
+    if (GTEST_FLAG_GET(print_time)) {
+      printf(" (%s ms)\n",
+             internal::StreamableToString(test_info.result()->elapsed_time())
+                 .c_str());
+    } else {
+      printf("\n");
+    }
+    fflush(stdout);
+  }
+}
+
+void BriefUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
+                                                    int /*iteration*/) {
+  ColoredPrintf(GTestColor::kGreen, "[==========] ");
+  printf("%s from %s ran.",
+         FormatTestCount(unit_test.test_to_run_count()).c_str(),
+         FormatTestSuiteCount(unit_test.test_suite_to_run_count()).c_str());
+  if (GTEST_FLAG_GET(print_time)) {
+    printf(" (%s ms total)",
+           internal::StreamableToString(unit_test.elapsed_time()).c_str());
+  }
+  printf("\n");
+  ColoredPrintf(GTestColor::kGreen, "[  PASSED  ] ");
+  printf("%s.\n", FormatTestCount(unit_test.successful_test_count()).c_str());
+
+  const int skipped_test_count = unit_test.skipped_test_count();
+  if (skipped_test_count > 0) {
+    ColoredPrintf(GTestColor::kGreen, "[  SKIPPED ] ");
+    printf("%s.\n", FormatTestCount(skipped_test_count).c_str());
+  }
+
+  int num_disabled = unit_test.reportable_disabled_test_count();
+  if (num_disabled && !GTEST_FLAG_GET(also_run_disabled_tests)) {
+    if (unit_test.Passed()) {
+      printf("\n");  // Add a spacer if no FAILURE banner is displayed.
+    }
+    ColoredPrintf(GTestColor::kYellow, "  YOU HAVE %d DISABLED %s\n\n",
+                  num_disabled, num_disabled == 1 ? "TEST" : "TESTS");
+  }
+  // Ensure that Google Test output is printed before, e.g., heapchecker output.
+  fflush(stdout);
+}
+
+// End BriefUnitTestResultPrinter
+
+// class TestEventRepeater
+//
+// This class forwards events to other event listeners.
+class TestEventRepeater : public TestEventListener {
+ public:
+  TestEventRepeater() : forwarding_enabled_(true) {}
+  ~TestEventRepeater() override;
+  void Append(TestEventListener* listener);
+  TestEventListener* Release(TestEventListener* listener);
+
+  // Controls whether events will be forwarded to listeners_. Set to false
+  // in death test child processes.
+  bool forwarding_enabled() const { return forwarding_enabled_; }
+  void set_forwarding_enabled(bool enable) { forwarding_enabled_ = enable; }
+
+  void OnTestProgramStart(const UnitTest& unit_test) override;
+  void OnTestIterationStart(const UnitTest& unit_test, int iteration) override;
+  void OnEnvironmentsSetUpStart(const UnitTest& unit_test) override;
+  void OnEnvironmentsSetUpEnd(const UnitTest& unit_test) override;
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseStart(const TestSuite& parameter) override;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestSuiteStart(const TestSuite& parameter) override;
+  void OnTestStart(const TestInfo& test_info) override;
+  void OnTestDisabled(const TestInfo& test_info) override;
+  void OnTestPartResult(const TestPartResult& result) override;
+  void OnTestEnd(const TestInfo& test_info) override;
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseEnd(const TestCase& parameter) override;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestSuiteEnd(const TestSuite& parameter) override;
+  void OnEnvironmentsTearDownStart(const UnitTest& unit_test) override;
+  void OnEnvironmentsTearDownEnd(const UnitTest& unit_test) override;
+  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
+  void OnTestProgramEnd(const UnitTest& unit_test) override;
+
+ private:
+  // Controls whether events will be forwarded to listeners_. Set to false
+  // in death test child processes.
+  bool forwarding_enabled_;
+  // The list of listeners that receive events.
+  std::vector<TestEventListener*> listeners_;
+
+  TestEventRepeater(const TestEventRepeater&) = delete;
+  TestEventRepeater& operator=(const TestEventRepeater&) = delete;
+};
+
+TestEventRepeater::~TestEventRepeater() {
+  ForEach(listeners_, Delete<TestEventListener>);
+}
+
+void TestEventRepeater::Append(TestEventListener* listener) {
+  listeners_.push_back(listener);
+}
+
+TestEventListener* TestEventRepeater::Release(TestEventListener* listener) {
+  for (size_t i = 0; i < listeners_.size(); ++i) {
+    if (listeners_[i] == listener) {
+      listeners_.erase(listeners_.begin() + static_cast<int>(i));
+      return listener;
+    }
+  }
+
+  return nullptr;
+}
+
+// Since most methods are very similar, use macros to reduce boilerplate.
+// This defines a member that forwards the call to all listeners.
+#define GTEST_REPEATER_METHOD_(Name, Type)              \
+  void TestEventRepeater::Name(const Type& parameter) { \
+    if (forwarding_enabled_) {                          \
+      for (size_t i = 0; i < listeners_.size(); i++) {  \
+        listeners_[i]->Name(parameter);                 \
+      }                                                 \
+    }                                                   \
+  }
+// This defines a member that forwards the call to all listeners in reverse
+// order.
+#define GTEST_REVERSE_REPEATER_METHOD_(Name, Type)      \
+  void TestEventRepeater::Name(const Type& parameter) { \
+    if (forwarding_enabled_) {                          \
+      for (size_t i = listeners_.size(); i != 0; i--) { \
+        listeners_[i - 1]->Name(parameter);             \
+      }                                                 \
+    }                                                   \
+  }
+
+GTEST_REPEATER_METHOD_(OnTestProgramStart, UnitTest)
+GTEST_REPEATER_METHOD_(OnEnvironmentsSetUpStart, UnitTest)
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+GTEST_REPEATER_METHOD_(OnTestCaseStart, TestSuite)
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+GTEST_REPEATER_METHOD_(OnTestSuiteStart, TestSuite)
+GTEST_REPEATER_METHOD_(OnTestStart, TestInfo)
+GTEST_REPEATER_METHOD_(OnTestDisabled, TestInfo)
+GTEST_REPEATER_METHOD_(OnTestPartResult, TestPartResult)
+GTEST_REPEATER_METHOD_(OnEnvironmentsTearDownStart, UnitTest)
+GTEST_REVERSE_REPEATER_METHOD_(OnEnvironmentsSetUpEnd, UnitTest)
+GTEST_REVERSE_REPEATER_METHOD_(OnEnvironmentsTearDownEnd, UnitTest)
+GTEST_REVERSE_REPEATER_METHOD_(OnTestEnd, TestInfo)
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+GTEST_REVERSE_REPEATER_METHOD_(OnTestCaseEnd, TestSuite)
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+GTEST_REVERSE_REPEATER_METHOD_(OnTestSuiteEnd, TestSuite)
+GTEST_REVERSE_REPEATER_METHOD_(OnTestProgramEnd, UnitTest)
+
+#undef GTEST_REPEATER_METHOD_
+#undef GTEST_REVERSE_REPEATER_METHOD_
+
+void TestEventRepeater::OnTestIterationStart(const UnitTest& unit_test,
+                                             int iteration) {
+  if (forwarding_enabled_) {
+    for (size_t i = 0; i < listeners_.size(); i++) {
+      listeners_[i]->OnTestIterationStart(unit_test, iteration);
+    }
+  }
+}
+
+void TestEventRepeater::OnTestIterationEnd(const UnitTest& unit_test,
+                                           int iteration) {
+  if (forwarding_enabled_) {
+    for (size_t i = listeners_.size(); i > 0; i--) {
+      listeners_[i - 1]->OnTestIterationEnd(unit_test, iteration);
+    }
+  }
+}
+
+// End TestEventRepeater
+
+// This class generates an XML output file.
+class XmlUnitTestResultPrinter : public EmptyTestEventListener {
+ public:
+  explicit XmlUnitTestResultPrinter(const char* output_file);
+
+  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
+  void ListTestsMatchingFilter(const std::vector<TestSuite*>& test_suites);
+
+  // Prints an XML summary of all unit tests.
+  static void PrintXmlTestsList(std::ostream* stream,
+                                const std::vector<TestSuite*>& test_suites);
+
+ private:
+  // Is c a whitespace character that is normalized to a space character
+  // when it appears in an XML attribute value?
+  static bool IsNormalizableWhitespace(unsigned char c) {
+    return c == '\t' || c == '\n' || c == '\r';
+  }
+
+  // May c appear in a well-formed XML document?
+  // https://www.w3.org/TR/REC-xml/#charsets
+  static bool IsValidXmlCharacter(unsigned char c) {
+    return IsNormalizableWhitespace(c) || c >= 0x20;
+  }
+
+  // Returns an XML-escaped copy of the input string str.  If
+  // is_attribute is true, the text is meant to appear as an attribute
+  // value, and normalizable whitespace is preserved by replacing it
+  // with character references.
+  static std::string EscapeXml(const std::string& str, bool is_attribute);
+
+  // Returns the given string with all characters invalid in XML removed.
+  static std::string RemoveInvalidXmlCharacters(const std::string& str);
+
+  // Convenience wrapper around EscapeXml when str is an attribute value.
+  static std::string EscapeXmlAttribute(const std::string& str) {
+    return EscapeXml(str, true);
+  }
+
+  // Convenience wrapper around EscapeXml when str is not an attribute value.
+  static std::string EscapeXmlText(const char* str) {
+    return EscapeXml(str, false);
+  }
+
+  // Verifies that the given attribute belongs to the given element and
+  // streams the attribute as XML.
+  static void OutputXmlAttribute(std::ostream* stream,
+                                 const std::string& element_name,
+                                 const std::string& name,
+                                 const std::string& value);
+
+  // Streams an XML CDATA section, escaping invalid CDATA sequences as needed.
+  static void OutputXmlCDataSection(::std::ostream* stream, const char* data);
+
+  // Streams a test suite XML stanza containing the given test result.
+  //
+  // Requires: result.Failed()
+  static void OutputXmlTestSuiteForTestResult(::std::ostream* stream,
+                                              const TestResult& result);
+
+  // Streams an XML representation of a TestResult object.
+  static void OutputXmlTestResult(::std::ostream* stream,
+                                  const TestResult& result);
+
+  // Streams an XML representation of a TestInfo object.
+  static void OutputXmlTestInfo(::std::ostream* stream,
+                                const char* test_suite_name,
+                                const TestInfo& test_info);
+
+  // Prints an XML representation of a TestSuite object
+  static void PrintXmlTestSuite(::std::ostream* stream,
+                                const TestSuite& test_suite);
+
+  // Prints an XML summary of unit_test to output stream out.
+  static void PrintXmlUnitTest(::std::ostream* stream,
+                               const UnitTest& unit_test);
+
+  // Produces a string representing the test properties in a result as space
+  // delimited XML attributes based on the property key="value" pairs.
+  // When the std::string is not empty, it includes a space at the beginning,
+  // to delimit this attribute from prior attributes.
+  static std::string TestPropertiesAsXmlAttributes(const TestResult& result);
+
+  // Streams an XML representation of the test properties of a TestResult
+  // object.
+  static void OutputXmlTestProperties(std::ostream* stream,
+                                      const TestResult& result);
+
+  // The output file.
+  const std::string output_file_;
+
+  XmlUnitTestResultPrinter(const XmlUnitTestResultPrinter&) = delete;
+  XmlUnitTestResultPrinter& operator=(const XmlUnitTestResultPrinter&) = delete;
+};
+
+// Creates a new XmlUnitTestResultPrinter.
+XmlUnitTestResultPrinter::XmlUnitTestResultPrinter(const char* output_file)
+    : output_file_(output_file) {
+  if (output_file_.empty()) {
+    GTEST_LOG_(FATAL) << "XML output file may not be null";
+  }
+}
+
+// Called after the unit test ends.
+void XmlUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
+                                                  int /*iteration*/) {
+  FILE* xmlout = OpenFileForWriting(output_file_);
+  std::stringstream stream;
+  PrintXmlUnitTest(&stream, unit_test);
+  fprintf(xmlout, "%s", StringStreamToString(&stream).c_str());
+  fclose(xmlout);
+}
+
+void XmlUnitTestResultPrinter::ListTestsMatchingFilter(
+    const std::vector<TestSuite*>& test_suites) {
+  FILE* xmlout = OpenFileForWriting(output_file_);
+  std::stringstream stream;
+  PrintXmlTestsList(&stream, test_suites);
+  fprintf(xmlout, "%s", StringStreamToString(&stream).c_str());
+  fclose(xmlout);
+}
+
+// Returns an XML-escaped copy of the input string str.  If is_attribute
+// is true, the text is meant to appear as an attribute value, and
+// normalizable whitespace is preserved by replacing it with character
+// references.
+//
+// Invalid XML characters in str, if any, are stripped from the output.
+// It is expected that most, if not all, of the text processed by this
+// module will consist of ordinary English text.
+// If this module is ever modified to produce version 1.1 XML output,
+// most invalid characters can be retained using character references.
+std::string XmlUnitTestResultPrinter::EscapeXml(const std::string& str,
+                                                bool is_attribute) {
+  Message m;
+
+  for (size_t i = 0; i < str.size(); ++i) {
+    const char ch = str[i];
+    switch (ch) {
+      case '<':
+        m << "&lt;";
+        break;
+      case '>':
+        m << "&gt;";
+        break;
+      case '&':
+        m << "&amp;";
+        break;
+      case '\'':
+        if (is_attribute)
+          m << "&apos;";
+        else
+          m << '\'';
+        break;
+      case '"':
+        if (is_attribute)
+          m << "&quot;";
+        else
+          m << '"';
+        break;
+      default:
+        if (IsValidXmlCharacter(static_cast<unsigned char>(ch))) {
+          if (is_attribute &&
+              IsNormalizableWhitespace(static_cast<unsigned char>(ch)))
+            m << "&#x" << String::FormatByte(static_cast<unsigned char>(ch))
+              << ";";
+          else
+            m << ch;
+        }
+        break;
+    }
+  }
+
+  return m.GetString();
+}
+
+// Returns the given string with all characters invalid in XML removed.
+// Currently invalid characters are dropped from the string. An
+// alternative is to replace them with certain characters such as . or ?.
+std::string XmlUnitTestResultPrinter::RemoveInvalidXmlCharacters(
+    const std::string& str) {
+  std::string output;
+  output.reserve(str.size());
+  for (std::string::const_iterator it = str.begin(); it != str.end(); ++it)
+    if (IsValidXmlCharacter(static_cast<unsigned char>(*it)))
+      output.push_back(*it);
+
+  return output;
+}
+
+// The following routines generate an XML representation of a UnitTest
+// object.
+//
+// This is how Google Test concepts map to the DTD:
+//
+// <testsuites name="AllTests">        <-- corresponds to a UnitTest object
+//   <testsuite name="testcase-name">  <-- corresponds to a TestSuite object
+//     <testcase name="test-name">     <-- corresponds to a TestInfo object
+//       <failure message="...">...</failure>
+//       <failure message="...">...</failure>
+//       <failure message="...">...</failure>
+//                                     <-- individual assertion failures
+//     </testcase>
+//   </testsuite>
+// </testsuites>
+
+// Formats the given time in milliseconds as seconds.
+std::string FormatTimeInMillisAsSeconds(TimeInMillis ms) {
+  ::std::stringstream ss;
+  ss << (static_cast<double>(ms) * 1e-3);
+  return ss.str();
+}
+
+static bool PortableLocaltime(time_t seconds, struct tm* out) {
+#if defined(_MSC_VER)
+  return localtime_s(out, &seconds) == 0;
+#elif defined(__MINGW32__) || defined(__MINGW64__)
+  // MINGW <time.h> provides neither localtime_r nor localtime_s, but uses
+  // Windows' localtime(), which has a thread-local tm buffer.
+  struct tm* tm_ptr = localtime(&seconds);  // NOLINT
+  if (tm_ptr == nullptr) return false;
+  *out = *tm_ptr;
+  return true;
+#elif defined(__STDC_LIB_EXT1__)
+  // Uses localtime_s when available as localtime_r is only available from
+  // C23 standard.
+  return localtime_s(&seconds, out) != nullptr;
+#else
+  return localtime_r(&seconds, out) != nullptr;
+#endif
+}
+
+// Converts the given epoch time in milliseconds to a date string in the ISO
+// 8601 format, without the timezone information.
+std::string FormatEpochTimeInMillisAsIso8601(TimeInMillis ms) {
+  struct tm time_struct;
+  if (!PortableLocaltime(static_cast<time_t>(ms / 1000), &time_struct))
+    return "";
+  // YYYY-MM-DDThh:mm:ss.sss
+  return StreamableToString(time_struct.tm_year + 1900) + "-" +
+         String::FormatIntWidth2(time_struct.tm_mon + 1) + "-" +
+         String::FormatIntWidth2(time_struct.tm_mday) + "T" +
+         String::FormatIntWidth2(time_struct.tm_hour) + ":" +
+         String::FormatIntWidth2(time_struct.tm_min) + ":" +
+         String::FormatIntWidth2(time_struct.tm_sec) + "." +
+         String::FormatIntWidthN(static_cast<int>(ms % 1000), 3);
+}
+
+// Streams an XML CDATA section, escaping invalid CDATA sequences as needed.
+void XmlUnitTestResultPrinter::OutputXmlCDataSection(::std::ostream* stream,
+                                                     const char* data) {
+  const char* segment = data;
+  *stream << "<![CDATA[";
+  for (;;) {
+    const char* const next_segment = strstr(segment, "]]>");
+    if (next_segment != nullptr) {
+      stream->write(segment,
+                    static_cast<std::streamsize>(next_segment - segment));
+      *stream << "]]>]]&gt;<![CDATA[";
+      segment = next_segment + strlen("]]>");
+    } else {
+      *stream << segment;
+      break;
+    }
+  }
+  *stream << "]]>";
+}
+
+void XmlUnitTestResultPrinter::OutputXmlAttribute(
+    std::ostream* stream, const std::string& element_name,
+    const std::string& name, const std::string& value) {
+  const std::vector<std::string>& allowed_names =
+      GetReservedOutputAttributesForElement(element_name);
+
+  GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
+               allowed_names.end())
+      << "Attribute " << name << " is not allowed for element <" << element_name
+      << ">.";
+
+  *stream << " " << name << "=\"" << EscapeXmlAttribute(value) << "\"";
+}
+
+// Streams a test suite XML stanza containing the given test result.
+void XmlUnitTestResultPrinter::OutputXmlTestSuiteForTestResult(
+    ::std::ostream* stream, const TestResult& result) {
+  // Output the boilerplate for a minimal test suite with one test.
+  *stream << "  <testsuite";
+  OutputXmlAttribute(stream, "testsuite", "name", "NonTestSuiteFailure");
+  OutputXmlAttribute(stream, "testsuite", "tests", "1");
+  OutputXmlAttribute(stream, "testsuite", "failures", "1");
+  OutputXmlAttribute(stream, "testsuite", "disabled", "0");
+  OutputXmlAttribute(stream, "testsuite", "skipped", "0");
+  OutputXmlAttribute(stream, "testsuite", "errors", "0");
+  OutputXmlAttribute(stream, "testsuite", "time",
+                     FormatTimeInMillisAsSeconds(result.elapsed_time()));
+  OutputXmlAttribute(
+      stream, "testsuite", "timestamp",
+      FormatEpochTimeInMillisAsIso8601(result.start_timestamp()));
+  *stream << ">";
+
+  // Output the boilerplate for a minimal test case with a single test.
+  *stream << "    <testcase";
+  OutputXmlAttribute(stream, "testcase", "name", "");
+  OutputXmlAttribute(stream, "testcase", "status", "run");
+  OutputXmlAttribute(stream, "testcase", "result", "completed");
+  OutputXmlAttribute(stream, "testcase", "classname", "");
+  OutputXmlAttribute(stream, "testcase", "time",
+                     FormatTimeInMillisAsSeconds(result.elapsed_time()));
+  OutputXmlAttribute(
+      stream, "testcase", "timestamp",
+      FormatEpochTimeInMillisAsIso8601(result.start_timestamp()));
+
+  // Output the actual test result.
+  OutputXmlTestResult(stream, result);
+
+  // Complete the test suite.
+  *stream << "  </testsuite>\n";
+}
+
+// Prints an XML representation of a TestInfo object.
+void XmlUnitTestResultPrinter::OutputXmlTestInfo(::std::ostream* stream,
+                                                 const char* test_suite_name,
+                                                 const TestInfo& test_info) {
+  const TestResult& result = *test_info.result();
+  const std::string kTestsuite = "testcase";
+
+  if (test_info.is_in_another_shard()) {
+    return;
+  }
+
+  *stream << "    <testcase";
+  OutputXmlAttribute(stream, kTestsuite, "name", test_info.name());
+
+  if (test_info.value_param() != nullptr) {
+    OutputXmlAttribute(stream, kTestsuite, "value_param",
+                       test_info.value_param());
+  }
+  if (test_info.type_param() != nullptr) {
+    OutputXmlAttribute(stream, kTestsuite, "type_param",
+                       test_info.type_param());
+  }
+
+  OutputXmlAttribute(stream, kTestsuite, "file", test_info.file());
+  OutputXmlAttribute(stream, kTestsuite, "line",
+                     StreamableToString(test_info.line()));
+  if (GTEST_FLAG_GET(list_tests)) {
+    *stream << " />\n";
+    return;
+  }
+
+  OutputXmlAttribute(stream, kTestsuite, "status",
+                     test_info.should_run() ? "run" : "notrun");
+  OutputXmlAttribute(stream, kTestsuite, "result",
+                     test_info.should_run()
+                         ? (result.Skipped() ? "skipped" : "completed")
+                         : "suppressed");
+  OutputXmlAttribute(stream, kTestsuite, "time",
+                     FormatTimeInMillisAsSeconds(result.elapsed_time()));
+  OutputXmlAttribute(
+      stream, kTestsuite, "timestamp",
+      FormatEpochTimeInMillisAsIso8601(result.start_timestamp()));
+  OutputXmlAttribute(stream, kTestsuite, "classname", test_suite_name);
+
+  OutputXmlTestResult(stream, result);
+}
+
+void XmlUnitTestResultPrinter::OutputXmlTestResult(::std::ostream* stream,
+                                                   const TestResult& result) {
+  int failures = 0;
+  int skips = 0;
+  for (int i = 0; i < result.total_part_count(); ++i) {
+    const TestPartResult& part = result.GetTestPartResult(i);
+    if (part.failed()) {
+      if (++failures == 1 && skips == 0) {
+        *stream << ">\n";
+      }
+      const std::string location =
+          internal::FormatCompilerIndependentFileLocation(part.file_name(),
+                                                          part.line_number());
+      const std::string summary = location + "\n" + part.summary();
+      *stream << "      <failure message=\"" << EscapeXmlAttribute(summary)
+              << "\" type=\"\">";
+      const std::string detail = location + "\n" + part.message();
+      OutputXmlCDataSection(stream, RemoveInvalidXmlCharacters(detail).c_str());
+      *stream << "</failure>\n";
+    } else if (part.skipped()) {
+      if (++skips == 1 && failures == 0) {
+        *stream << ">\n";
+      }
+      const std::string location =
+          internal::FormatCompilerIndependentFileLocation(part.file_name(),
+                                                          part.line_number());
+      const std::string summary = location + "\n" + part.summary();
+      *stream << "      <skipped message=\""
+              << EscapeXmlAttribute(summary.c_str()) << "\">";
+      const std::string detail = location + "\n" + part.message();
+      OutputXmlCDataSection(stream, RemoveInvalidXmlCharacters(detail).c_str());
+      *stream << "</skipped>\n";
+    }
+  }
+
+  if (failures == 0 && skips == 0 && result.test_property_count() == 0) {
+    *stream << " />\n";
+  } else {
+    if (failures == 0 && skips == 0) {
+      *stream << ">\n";
+    }
+    OutputXmlTestProperties(stream, result);
+    *stream << "    </testcase>\n";
+  }
+}
+
+// Prints an XML representation of a TestSuite object
+void XmlUnitTestResultPrinter::PrintXmlTestSuite(std::ostream* stream,
+                                                 const TestSuite& test_suite) {
+  const std::string kTestsuite = "testsuite";
+  *stream << "  <" << kTestsuite;
+  OutputXmlAttribute(stream, kTestsuite, "name", test_suite.name());
+  OutputXmlAttribute(stream, kTestsuite, "tests",
+                     StreamableToString(test_suite.reportable_test_count()));
+  if (!GTEST_FLAG_GET(list_tests)) {
+    OutputXmlAttribute(stream, kTestsuite, "failures",
+                       StreamableToString(test_suite.failed_test_count()));
+    OutputXmlAttribute(
+        stream, kTestsuite, "disabled",
+        StreamableToString(test_suite.reportable_disabled_test_count()));
+    OutputXmlAttribute(stream, kTestsuite, "skipped",
+                       StreamableToString(test_suite.skipped_test_count()));
+
+    OutputXmlAttribute(stream, kTestsuite, "errors", "0");
+
+    OutputXmlAttribute(stream, kTestsuite, "time",
+                       FormatTimeInMillisAsSeconds(test_suite.elapsed_time()));
+    OutputXmlAttribute(
+        stream, kTestsuite, "timestamp",
+        FormatEpochTimeInMillisAsIso8601(test_suite.start_timestamp()));
+    *stream << TestPropertiesAsXmlAttributes(test_suite.ad_hoc_test_result());
+  }
+  *stream << ">\n";
+  for (int i = 0; i < test_suite.total_test_count(); ++i) {
+    if (test_suite.GetTestInfo(i)->is_reportable())
+      OutputXmlTestInfo(stream, test_suite.name(), *test_suite.GetTestInfo(i));
+  }
+  *stream << "  </" << kTestsuite << ">\n";
+}
+
+// Prints an XML summary of unit_test to output stream out.
+void XmlUnitTestResultPrinter::PrintXmlUnitTest(std::ostream* stream,
+                                                const UnitTest& unit_test) {
+  const std::string kTestsuites = "testsuites";
+
+  *stream << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
+  *stream << "<" << kTestsuites;
+
+  OutputXmlAttribute(stream, kTestsuites, "tests",
+                     StreamableToString(unit_test.reportable_test_count()));
+  OutputXmlAttribute(stream, kTestsuites, "failures",
+                     StreamableToString(unit_test.failed_test_count()));
+  OutputXmlAttribute(
+      stream, kTestsuites, "disabled",
+      StreamableToString(unit_test.reportable_disabled_test_count()));
+  OutputXmlAttribute(stream, kTestsuites, "errors", "0");
+  OutputXmlAttribute(stream, kTestsuites, "time",
+                     FormatTimeInMillisAsSeconds(unit_test.elapsed_time()));
+  OutputXmlAttribute(
+      stream, kTestsuites, "timestamp",
+      FormatEpochTimeInMillisAsIso8601(unit_test.start_timestamp()));
+
+  if (GTEST_FLAG_GET(shuffle)) {
+    OutputXmlAttribute(stream, kTestsuites, "random_seed",
+                       StreamableToString(unit_test.random_seed()));
+  }
+  *stream << TestPropertiesAsXmlAttributes(unit_test.ad_hoc_test_result());
+
+  OutputXmlAttribute(stream, kTestsuites, "name", "AllTests");
+  *stream << ">\n";
+
+  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
+    if (unit_test.GetTestSuite(i)->reportable_test_count() > 0)
+      PrintXmlTestSuite(stream, *unit_test.GetTestSuite(i));
+  }
+
+  // If there was a test failure outside of one of the test suites (like in a
+  // test environment) include that in the output.
+  if (unit_test.ad_hoc_test_result().Failed()) {
+    OutputXmlTestSuiteForTestResult(stream, unit_test.ad_hoc_test_result());
+  }
+
+  *stream << "</" << kTestsuites << ">\n";
+}
+
+void XmlUnitTestResultPrinter::PrintXmlTestsList(
+    std::ostream* stream, const std::vector<TestSuite*>& test_suites) {
+  const std::string kTestsuites = "testsuites";
+
+  *stream << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
+  *stream << "<" << kTestsuites;
+
+  int total_tests = 0;
+  for (auto test_suite : test_suites) {
+    total_tests += test_suite->total_test_count();
+  }
+  OutputXmlAttribute(stream, kTestsuites, "tests",
+                     StreamableToString(total_tests));
+  OutputXmlAttribute(stream, kTestsuites, "name", "AllTests");
+  *stream << ">\n";
+
+  for (auto test_suite : test_suites) {
+    PrintXmlTestSuite(stream, *test_suite);
+  }
+  *stream << "</" << kTestsuites << ">\n";
+}
+
+// Produces a string representing the test properties in a result as space
+// delimited XML attributes based on the property key="value" pairs.
+std::string XmlUnitTestResultPrinter::TestPropertiesAsXmlAttributes(
+    const TestResult& result) {
+  Message attributes;
+  for (int i = 0; i < result.test_property_count(); ++i) {
+    const TestProperty& property = result.GetTestProperty(i);
+    attributes << " " << property.key() << "="
+               << "\"" << EscapeXmlAttribute(property.value()) << "\"";
+  }
+  return attributes.GetString();
+}
+
+void XmlUnitTestResultPrinter::OutputXmlTestProperties(
+    std::ostream* stream, const TestResult& result) {
+  const std::string kProperties = "properties";
+  const std::string kProperty = "property";
+
+  if (result.test_property_count() <= 0) {
+    return;
+  }
+
+  *stream << "      <" << kProperties << ">\n";
+  for (int i = 0; i < result.test_property_count(); ++i) {
+    const TestProperty& property = result.GetTestProperty(i);
+    *stream << "        <" << kProperty;
+    *stream << " name=\"" << EscapeXmlAttribute(property.key()) << "\"";
+    *stream << " value=\"" << EscapeXmlAttribute(property.value()) << "\"";
+    *stream << "/>\n";
+  }
+  *stream << "      </" << kProperties << ">\n";
+}
+
+// End XmlUnitTestResultPrinter
+
+// This class generates an JSON output file.
+class JsonUnitTestResultPrinter : public EmptyTestEventListener {
+ public:
+  explicit JsonUnitTestResultPrinter(const char* output_file);
+
+  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
+
+  // Prints an JSON summary of all unit tests.
+  static void PrintJsonTestList(::std::ostream* stream,
+                                const std::vector<TestSuite*>& test_suites);
+
+ private:
+  // Returns an JSON-escaped copy of the input string str.
+  static std::string EscapeJson(const std::string& str);
+
+  //// Verifies that the given attribute belongs to the given element and
+  //// streams the attribute as JSON.
+  static void OutputJsonKey(std::ostream* stream,
+                            const std::string& element_name,
+                            const std::string& name, const std::string& value,
+                            const std::string& indent, bool comma = true);
+  static void OutputJsonKey(std::ostream* stream,
+                            const std::string& element_name,
+                            const std::string& name, int value,
+                            const std::string& indent, bool comma = true);
+
+  // Streams a test suite JSON stanza containing the given test result.
+  //
+  // Requires: result.Failed()
+  static void OutputJsonTestSuiteForTestResult(::std::ostream* stream,
+                                               const TestResult& result);
+
+  // Streams a JSON representation of a TestResult object.
+  static void OutputJsonTestResult(::std::ostream* stream,
+                                   const TestResult& result);
+
+  // Streams a JSON representation of a TestInfo object.
+  static void OutputJsonTestInfo(::std::ostream* stream,
+                                 const char* test_suite_name,
+                                 const TestInfo& test_info);
+
+  // Prints a JSON representation of a TestSuite object
+  static void PrintJsonTestSuite(::std::ostream* stream,
+                                 const TestSuite& test_suite);
+
+  // Prints a JSON summary of unit_test to output stream out.
+  static void PrintJsonUnitTest(::std::ostream* stream,
+                                const UnitTest& unit_test);
+
+  // Produces a string representing the test properties in a result as
+  // a JSON dictionary.
+  static std::string TestPropertiesAsJson(const TestResult& result,
+                                          const std::string& indent);
+
+  // The output file.
+  const std::string output_file_;
+
+  JsonUnitTestResultPrinter(const JsonUnitTestResultPrinter&) = delete;
+  JsonUnitTestResultPrinter& operator=(const JsonUnitTestResultPrinter&) =
+      delete;
+};
+
+// Creates a new JsonUnitTestResultPrinter.
+JsonUnitTestResultPrinter::JsonUnitTestResultPrinter(const char* output_file)
+    : output_file_(output_file) {
+  if (output_file_.empty()) {
+    GTEST_LOG_(FATAL) << "JSON output file may not be null";
+  }
+}
+
+void JsonUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
+                                                   int /*iteration*/) {
+  FILE* jsonout = OpenFileForWriting(output_file_);
+  std::stringstream stream;
+  PrintJsonUnitTest(&stream, unit_test);
+  fprintf(jsonout, "%s", StringStreamToString(&stream).c_str());
+  fclose(jsonout);
+}
+
+// Returns an JSON-escaped copy of the input string str.
+std::string JsonUnitTestResultPrinter::EscapeJson(const std::string& str) {
+  Message m;
+
+  for (size_t i = 0; i < str.size(); ++i) {
+    const char ch = str[i];
+    switch (ch) {
+      case '\\':
+      case '"':
+      case '/':
+        m << '\\' << ch;
+        break;
+      case '\b':
+        m << "\\b";
+        break;
+      case '\t':
+        m << "\\t";
+        break;
+      case '\n':
+        m << "\\n";
+        break;
+      case '\f':
+        m << "\\f";
+        break;
+      case '\r':
+        m << "\\r";
+        break;
+      default:
+        if (ch < ' ') {
+          m << "\\u00" << String::FormatByte(static_cast<unsigned char>(ch));
+        } else {
+          m << ch;
+        }
+        break;
+    }
+  }
+
+  return m.GetString();
+}
+
+// The following routines generate an JSON representation of a UnitTest
+// object.
+
+// Formats the given time in milliseconds as seconds.
+static std::string FormatTimeInMillisAsDuration(TimeInMillis ms) {
+  ::std::stringstream ss;
+  ss << (static_cast<double>(ms) * 1e-3) << "s";
+  return ss.str();
+}
+
+// Converts the given epoch time in milliseconds to a date string in the
+// RFC3339 format, without the timezone information.
+static std::string FormatEpochTimeInMillisAsRFC3339(TimeInMillis ms) {
+  struct tm time_struct;
+  if (!PortableLocaltime(static_cast<time_t>(ms / 1000), &time_struct))
+    return "";
+  // YYYY-MM-DDThh:mm:ss
+  return StreamableToString(time_struct.tm_year + 1900) + "-" +
+         String::FormatIntWidth2(time_struct.tm_mon + 1) + "-" +
+         String::FormatIntWidth2(time_struct.tm_mday) + "T" +
+         String::FormatIntWidth2(time_struct.tm_hour) + ":" +
+         String::FormatIntWidth2(time_struct.tm_min) + ":" +
+         String::FormatIntWidth2(time_struct.tm_sec) + "Z";
+}
+
+static inline std::string Indent(size_t width) {
+  return std::string(width, ' ');
+}
+
+void JsonUnitTestResultPrinter::OutputJsonKey(std::ostream* stream,
+                                              const std::string& element_name,
+                                              const std::string& name,
+                                              const std::string& value,
+                                              const std::string& indent,
+                                              bool comma) {
+  const std::vector<std::string>& allowed_names =
+      GetReservedOutputAttributesForElement(element_name);
+
+  GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
+               allowed_names.end())
+      << "Key \"" << name << "\" is not allowed for value \"" << element_name
+      << "\".";
+
+  *stream << indent << "\"" << name << "\": \"" << EscapeJson(value) << "\"";
+  if (comma) *stream << ",\n";
+}
+
+void JsonUnitTestResultPrinter::OutputJsonKey(
+    std::ostream* stream, const std::string& element_name,
+    const std::string& name, int value, const std::string& indent, bool comma) {
+  const std::vector<std::string>& allowed_names =
+      GetReservedOutputAttributesForElement(element_name);
+
+  GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
+               allowed_names.end())
+      << "Key \"" << name << "\" is not allowed for value \"" << element_name
+      << "\".";
+
+  *stream << indent << "\"" << name << "\": " << StreamableToString(value);
+  if (comma) *stream << ",\n";
+}
+
+// Streams a test suite JSON stanza containing the given test result.
+void JsonUnitTestResultPrinter::OutputJsonTestSuiteForTestResult(
+    ::std::ostream* stream, const TestResult& result) {
+  // Output the boilerplate for a new test suite.
+  *stream << Indent(4) << "{\n";
+  OutputJsonKey(stream, "testsuite", "name", "NonTestSuiteFailure", Indent(6));
+  OutputJsonKey(stream, "testsuite", "tests", 1, Indent(6));
+  if (!GTEST_FLAG_GET(list_tests)) {
+    OutputJsonKey(stream, "testsuite", "failures", 1, Indent(6));
+    OutputJsonKey(stream, "testsuite", "disabled", 0, Indent(6));
+    OutputJsonKey(stream, "testsuite", "skipped", 0, Indent(6));
+    OutputJsonKey(stream, "testsuite", "errors", 0, Indent(6));
+    OutputJsonKey(stream, "testsuite", "time",
+                  FormatTimeInMillisAsDuration(result.elapsed_time()),
+                  Indent(6));
+    OutputJsonKey(stream, "testsuite", "timestamp",
+                  FormatEpochTimeInMillisAsRFC3339(result.start_timestamp()),
+                  Indent(6));
+  }
+  *stream << Indent(6) << "\"testsuite\": [\n";
+
+  // Output the boilerplate for a new test case.
+  *stream << Indent(8) << "{\n";
+  OutputJsonKey(stream, "testcase", "name", "", Indent(10));
+  OutputJsonKey(stream, "testcase", "status", "RUN", Indent(10));
+  OutputJsonKey(stream, "testcase", "result", "COMPLETED", Indent(10));
+  OutputJsonKey(stream, "testcase", "timestamp",
+                FormatEpochTimeInMillisAsRFC3339(result.start_timestamp()),
+                Indent(10));
+  OutputJsonKey(stream, "testcase", "time",
+                FormatTimeInMillisAsDuration(result.elapsed_time()),
+                Indent(10));
+  OutputJsonKey(stream, "testcase", "classname", "", Indent(10), false);
+  *stream << TestPropertiesAsJson(result, Indent(10));
+
+  // Output the actual test result.
+  OutputJsonTestResult(stream, result);
+
+  // Finish the test suite.
+  *stream << "\n" << Indent(6) << "]\n" << Indent(4) << "}";
+}
+
+// Prints a JSON representation of a TestInfo object.
+void JsonUnitTestResultPrinter::OutputJsonTestInfo(::std::ostream* stream,
+                                                   const char* test_suite_name,
+                                                   const TestInfo& test_info) {
+  const TestResult& result = *test_info.result();
+  const std::string kTestsuite = "testcase";
+  const std::string kIndent = Indent(10);
+
+  *stream << Indent(8) << "{\n";
+  OutputJsonKey(stream, kTestsuite, "name", test_info.name(), kIndent);
+
+  if (test_info.value_param() != nullptr) {
+    OutputJsonKey(stream, kTestsuite, "value_param", test_info.value_param(),
+                  kIndent);
+  }
+  if (test_info.type_param() != nullptr) {
+    OutputJsonKey(stream, kTestsuite, "type_param", test_info.type_param(),
+                  kIndent);
+  }
+
+  OutputJsonKey(stream, kTestsuite, "file", test_info.file(), kIndent);
+  OutputJsonKey(stream, kTestsuite, "line", test_info.line(), kIndent, false);
+  if (GTEST_FLAG_GET(list_tests)) {
+    *stream << "\n" << Indent(8) << "}";
+    return;
+  } else {
+    *stream << ",\n";
+  }
+
+  OutputJsonKey(stream, kTestsuite, "status",
+                test_info.should_run() ? "RUN" : "NOTRUN", kIndent);
+  OutputJsonKey(stream, kTestsuite, "result",
+                test_info.should_run()
+                    ? (result.Skipped() ? "SKIPPED" : "COMPLETED")
+                    : "SUPPRESSED",
+                kIndent);
+  OutputJsonKey(stream, kTestsuite, "timestamp",
+                FormatEpochTimeInMillisAsRFC3339(result.start_timestamp()),
+                kIndent);
+  OutputJsonKey(stream, kTestsuite, "time",
+                FormatTimeInMillisAsDuration(result.elapsed_time()), kIndent);
+  OutputJsonKey(stream, kTestsuite, "classname", test_suite_name, kIndent,
+                false);
+  *stream << TestPropertiesAsJson(result, kIndent);
+
+  OutputJsonTestResult(stream, result);
+}
+
+void JsonUnitTestResultPrinter::OutputJsonTestResult(::std::ostream* stream,
+                                                     const TestResult& result) {
+  const std::string kIndent = Indent(10);
+
+  int failures = 0;
+  for (int i = 0; i < result.total_part_count(); ++i) {
+    const TestPartResult& part = result.GetTestPartResult(i);
+    if (part.failed()) {
+      *stream << ",\n";
+      if (++failures == 1) {
+        *stream << kIndent << "\""
+                << "failures"
+                << "\": [\n";
+      }
+      const std::string location =
+          internal::FormatCompilerIndependentFileLocation(part.file_name(),
+                                                          part.line_number());
+      const std::string message = EscapeJson(location + "\n" + part.message());
+      *stream << kIndent << "  {\n"
+              << kIndent << "    \"failure\": \"" << message << "\",\n"
+              << kIndent << "    \"type\": \"\"\n"
+              << kIndent << "  }";
+    }
+  }
+
+  if (failures > 0) *stream << "\n" << kIndent << "]";
+  *stream << "\n" << Indent(8) << "}";
+}
+
+// Prints an JSON representation of a TestSuite object
+void JsonUnitTestResultPrinter::PrintJsonTestSuite(
+    std::ostream* stream, const TestSuite& test_suite) {
+  const std::string kTestsuite = "testsuite";
+  const std::string kIndent = Indent(6);
+
+  *stream << Indent(4) << "{\n";
+  OutputJsonKey(stream, kTestsuite, "name", test_suite.name(), kIndent);
+  OutputJsonKey(stream, kTestsuite, "tests", test_suite.reportable_test_count(),
+                kIndent);
+  if (!GTEST_FLAG_GET(list_tests)) {
+    OutputJsonKey(stream, kTestsuite, "failures",
+                  test_suite.failed_test_count(), kIndent);
+    OutputJsonKey(stream, kTestsuite, "disabled",
+                  test_suite.reportable_disabled_test_count(), kIndent);
+    OutputJsonKey(stream, kTestsuite, "errors", 0, kIndent);
+    OutputJsonKey(
+        stream, kTestsuite, "timestamp",
+        FormatEpochTimeInMillisAsRFC3339(test_suite.start_timestamp()),
+        kIndent);
+    OutputJsonKey(stream, kTestsuite, "time",
+                  FormatTimeInMillisAsDuration(test_suite.elapsed_time()),
+                  kIndent, false);
+    *stream << TestPropertiesAsJson(test_suite.ad_hoc_test_result(), kIndent)
+            << ",\n";
+  }
+
+  *stream << kIndent << "\"" << kTestsuite << "\": [\n";
+
+  bool comma = false;
+  for (int i = 0; i < test_suite.total_test_count(); ++i) {
+    if (test_suite.GetTestInfo(i)->is_reportable()) {
+      if (comma) {
+        *stream << ",\n";
+      } else {
+        comma = true;
+      }
+      OutputJsonTestInfo(stream, test_suite.name(), *test_suite.GetTestInfo(i));
+    }
+  }
+  *stream << "\n" << kIndent << "]\n" << Indent(4) << "}";
+}
+
+// Prints a JSON summary of unit_test to output stream out.
+void JsonUnitTestResultPrinter::PrintJsonUnitTest(std::ostream* stream,
+                                                  const UnitTest& unit_test) {
+  const std::string kTestsuites = "testsuites";
+  const std::string kIndent = Indent(2);
+  *stream << "{\n";
+
+  OutputJsonKey(stream, kTestsuites, "tests", unit_test.reportable_test_count(),
+                kIndent);
+  OutputJsonKey(stream, kTestsuites, "failures", unit_test.failed_test_count(),
+                kIndent);
+  OutputJsonKey(stream, kTestsuites, "disabled",
+                unit_test.reportable_disabled_test_count(), kIndent);
+  OutputJsonKey(stream, kTestsuites, "errors", 0, kIndent);
+  if (GTEST_FLAG_GET(shuffle)) {
+    OutputJsonKey(stream, kTestsuites, "random_seed", unit_test.random_seed(),
+                  kIndent);
+  }
+  OutputJsonKey(stream, kTestsuites, "timestamp",
+                FormatEpochTimeInMillisAsRFC3339(unit_test.start_timestamp()),
+                kIndent);
+  OutputJsonKey(stream, kTestsuites, "time",
+                FormatTimeInMillisAsDuration(unit_test.elapsed_time()), kIndent,
+                false);
+
+  *stream << TestPropertiesAsJson(unit_test.ad_hoc_test_result(), kIndent)
+          << ",\n";
+
+  OutputJsonKey(stream, kTestsuites, "name", "AllTests", kIndent);
+  *stream << kIndent << "\"" << kTestsuites << "\": [\n";
+
+  bool comma = false;
+  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
+    if (unit_test.GetTestSuite(i)->reportable_test_count() > 0) {
+      if (comma) {
+        *stream << ",\n";
+      } else {
+        comma = true;
+      }
+      PrintJsonTestSuite(stream, *unit_test.GetTestSuite(i));
+    }
+  }
+
+  // If there was a test failure outside of one of the test suites (like in a
+  // test environment) include that in the output.
+  if (unit_test.ad_hoc_test_result().Failed()) {
+    OutputJsonTestSuiteForTestResult(stream, unit_test.ad_hoc_test_result());
+  }
+
+  *stream << "\n"
+          << kIndent << "]\n"
+          << "}\n";
+}
+
+void JsonUnitTestResultPrinter::PrintJsonTestList(
+    std::ostream* stream, const std::vector<TestSuite*>& test_suites) {
+  const std::string kTestsuites = "testsuites";
+  const std::string kIndent = Indent(2);
+  *stream << "{\n";
+  int total_tests = 0;
+  for (auto test_suite : test_suites) {
+    total_tests += test_suite->total_test_count();
+  }
+  OutputJsonKey(stream, kTestsuites, "tests", total_tests, kIndent);
+
+  OutputJsonKey(stream, kTestsuites, "name", "AllTests", kIndent);
+  *stream << kIndent << "\"" << kTestsuites << "\": [\n";
+
+  for (size_t i = 0; i < test_suites.size(); ++i) {
+    if (i != 0) {
+      *stream << ",\n";
+    }
+    PrintJsonTestSuite(stream, *test_suites[i]);
+  }
+
+  *stream << "\n"
+          << kIndent << "]\n"
+          << "}\n";
+}
+// Produces a string representing the test properties in a result as
+// a JSON dictionary.
+std::string JsonUnitTestResultPrinter::TestPropertiesAsJson(
+    const TestResult& result, const std::string& indent) {
+  Message attributes;
+  for (int i = 0; i < result.test_property_count(); ++i) {
+    const TestProperty& property = result.GetTestProperty(i);
+    attributes << ",\n"
+               << indent << "\"" << property.key() << "\": "
+               << "\"" << EscapeJson(property.value()) << "\"";
+  }
+  return attributes.GetString();
+}
+
+// End JsonUnitTestResultPrinter
+
+#if GTEST_CAN_STREAM_RESULTS_
+
+// Checks if str contains '=', '&', '%' or '\n' characters. If yes,
+// replaces them by "%xx" where xx is their hexadecimal value. For
+// example, replaces "=" with "%3D".  This algorithm is O(strlen(str))
+// in both time and space -- important as the input str may contain an
+// arbitrarily long test failure message and stack trace.
+std::string StreamingListener::UrlEncode(const char* str) {
+  std::string result;
+  result.reserve(strlen(str) + 1);
+  for (char ch = *str; ch != '\0'; ch = *++str) {
+    switch (ch) {
+      case '%':
+      case '=':
+      case '&':
+      case '\n':
+        result.append("%" + String::FormatByte(static_cast<unsigned char>(ch)));
+        break;
+      default:
+        result.push_back(ch);
+        break;
+    }
+  }
+  return result;
+}
+
+void StreamingListener::SocketWriter::MakeConnection() {
+  GTEST_CHECK_(sockfd_ == -1)
+      << "MakeConnection() can't be called when there is already a connection.";
+
+  addrinfo hints;
+  memset(&hints, 0, sizeof(hints));
+  hints.ai_family = AF_UNSPEC;  // To allow both IPv4 and IPv6 addresses.
+  hints.ai_socktype = SOCK_STREAM;
+  addrinfo* servinfo = nullptr;
+
+  // Use the getaddrinfo() to get a linked list of IP addresses for
+  // the given host name.
+  const int error_num =
+      getaddrinfo(host_name_.c_str(), port_num_.c_str(), &hints, &servinfo);
+  if (error_num != 0) {
+    GTEST_LOG_(WARNING) << "stream_result_to: getaddrinfo() failed: "
+                        << gai_strerror(error_num);
+  }
+
+  // Loop through all the results and connect to the first we can.
+  for (addrinfo* cur_addr = servinfo; sockfd_ == -1 && cur_addr != nullptr;
+       cur_addr = cur_addr->ai_next) {
+    sockfd_ = socket(cur_addr->ai_family, cur_addr->ai_socktype,
+                     cur_addr->ai_protocol);
+    if (sockfd_ != -1) {
+      // Connect the client socket to the server socket.
+      if (connect(sockfd_, cur_addr->ai_addr, cur_addr->ai_addrlen) == -1) {
+        close(sockfd_);
+        sockfd_ = -1;
+      }
+    }
+  }
+
+  freeaddrinfo(servinfo);  // all done with this structure
+
+  if (sockfd_ == -1) {
+    GTEST_LOG_(WARNING) << "stream_result_to: failed to connect to "
+                        << host_name_ << ":" << port_num_;
+  }
+}
+
+// End of class Streaming Listener
+#endif  // GTEST_CAN_STREAM_RESULTS__
+
+// class OsStackTraceGetter
+
+const char* const OsStackTraceGetterInterface::kElidedFramesMarker =
+    "... " GTEST_NAME_ " internal frames ...";
+
+std::string OsStackTraceGetter::CurrentStackTrace(int max_depth, int skip_count)
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+#if GTEST_HAS_ABSL
+  std::string result;
+
+  if (max_depth <= 0) {
+    return result;
+  }
+
+  max_depth = std::min(max_depth, kMaxStackTraceDepth);
+
+  std::vector<void*> raw_stack(max_depth);
+  // Skips the frames requested by the caller, plus this function.
+  const int raw_stack_size =
+      absl::GetStackTrace(&raw_stack[0], max_depth, skip_count + 1);
+
+  void* caller_frame = nullptr;
+  {
+    MutexLock lock(&mutex_);
+    caller_frame = caller_frame_;
+  }
+
+  for (int i = 0; i < raw_stack_size; ++i) {
+    if (raw_stack[i] == caller_frame &&
+        !GTEST_FLAG_GET(show_internal_stack_frames)) {
+      // Add a marker to the trace and stop adding frames.
+      absl::StrAppend(&result, kElidedFramesMarker, "\n");
+      break;
+    }
+
+    char tmp[1024];
+    const char* symbol = "(unknown)";
+    if (absl::Symbolize(raw_stack[i], tmp, sizeof(tmp))) {
+      symbol = tmp;
+    }
+
+    char line[1024];
+    snprintf(line, sizeof(line), "  %p: %s\n", raw_stack[i], symbol);
+    result += line;
+  }
+
+  return result;
+
+#else   // !GTEST_HAS_ABSL
+  static_cast<void>(max_depth);
+  static_cast<void>(skip_count);
+  return "";
+#endif  // GTEST_HAS_ABSL
+}
+
+void OsStackTraceGetter::UponLeavingGTest() GTEST_LOCK_EXCLUDED_(mutex_) {
+#if GTEST_HAS_ABSL
+  void* caller_frame = nullptr;
+  if (absl::GetStackTrace(&caller_frame, 1, 3) <= 0) {
+    caller_frame = nullptr;
+  }
+
+  MutexLock lock(&mutex_);
+  caller_frame_ = caller_frame;
+#endif  // GTEST_HAS_ABSL
+}
+
+// A helper class that creates the premature-exit file in its
+// constructor and deletes the file in its destructor.
+class ScopedPrematureExitFile {
+ public:
+  explicit ScopedPrematureExitFile(const char* premature_exit_filepath)
+      : premature_exit_filepath_(
+            premature_exit_filepath ? premature_exit_filepath : "") {
+    // If a path to the premature-exit file is specified...
+    if (!premature_exit_filepath_.empty()) {
+      // create the file with a single "0" character in it.  I/O
+      // errors are ignored as there's nothing better we can do and we
+      // don't want to fail the test because of this.
+      FILE* pfile = posix::FOpen(premature_exit_filepath_.c_str(), "w");
+      fwrite("0", 1, 1, pfile);
+      fclose(pfile);
+    }
+  }
+
+  ~ScopedPrematureExitFile() {
+#if !defined GTEST_OS_ESP8266
+    if (!premature_exit_filepath_.empty()) {
+      int retval = remove(premature_exit_filepath_.c_str());
+      if (retval) {
+        GTEST_LOG_(ERROR) << "Failed to remove premature exit filepath \""
+                          << premature_exit_filepath_ << "\" with error "
+                          << retval;
+      }
+    }
+#endif
+  }
+
+ private:
+  const std::string premature_exit_filepath_;
+
+  ScopedPrematureExitFile(const ScopedPrematureExitFile&) = delete;
+  ScopedPrematureExitFile& operator=(const ScopedPrematureExitFile&) = delete;
+};
+
+}  // namespace internal
+
+// class TestEventListeners
+
+TestEventListeners::TestEventListeners()
+    : repeater_(new internal::TestEventRepeater()),
+      default_result_printer_(nullptr),
+      default_xml_generator_(nullptr) {}
+
+TestEventListeners::~TestEventListeners() { delete repeater_; }
+
+// Returns the standard listener responsible for the default console
+// output.  Can be removed from the listeners list to shut down default
+// console output.  Note that removing this object from the listener list
+// with Release transfers its ownership to the user.
+void TestEventListeners::Append(TestEventListener* listener) {
+  repeater_->Append(listener);
+}
+
+// Removes the given event listener from the list and returns it.  It then
+// becomes the caller's responsibility to delete the listener. Returns
+// NULL if the listener is not found in the list.
+TestEventListener* TestEventListeners::Release(TestEventListener* listener) {
+  if (listener == default_result_printer_)
+    default_result_printer_ = nullptr;
+  else if (listener == default_xml_generator_)
+    default_xml_generator_ = nullptr;
+  return repeater_->Release(listener);
+}
+
+// Returns repeater that broadcasts the TestEventListener events to all
+// subscribers.
+TestEventListener* TestEventListeners::repeater() { return repeater_; }
+
+// Sets the default_result_printer attribute to the provided listener.
+// The listener is also added to the listener list and previous
+// default_result_printer is removed from it and deleted. The listener can
+// also be NULL in which case it will not be added to the list. Does
+// nothing if the previous and the current listener objects are the same.
+void TestEventListeners::SetDefaultResultPrinter(TestEventListener* listener) {
+  if (default_result_printer_ != listener) {
+    // It is an error to pass this method a listener that is already in the
+    // list.
+    delete Release(default_result_printer_);
+    default_result_printer_ = listener;
+    if (listener != nullptr) Append(listener);
+  }
+}
+
+// Sets the default_xml_generator attribute to the provided listener.  The
+// listener is also added to the listener list and previous
+// default_xml_generator is removed from it and deleted. The listener can
+// also be NULL in which case it will not be added to the list. Does
+// nothing if the previous and the current listener objects are the same.
+void TestEventListeners::SetDefaultXmlGenerator(TestEventListener* listener) {
+  if (default_xml_generator_ != listener) {
+    // It is an error to pass this method a listener that is already in the
+    // list.
+    delete Release(default_xml_generator_);
+    default_xml_generator_ = listener;
+    if (listener != nullptr) Append(listener);
+  }
+}
+
+// Controls whether events will be forwarded by the repeater to the
+// listeners in the list.
+bool TestEventListeners::EventForwardingEnabled() const {
+  return repeater_->forwarding_enabled();
+}
+
+void TestEventListeners::SuppressEventForwarding() {
+  repeater_->set_forwarding_enabled(false);
+}
+
+// class UnitTest
+
+// Gets the singleton UnitTest object.  The first time this method is
+// called, a UnitTest object is constructed and returned.  Consecutive
+// calls will return the same object.
+//
+// We don't protect this under mutex_ as a user is not supposed to
+// call this before main() starts, from which point on the return
+// value will never change.
+UnitTest* UnitTest::GetInstance() {
+  // CodeGear C++Builder insists on a public destructor for the
+  // default implementation.  Use this implementation to keep good OO
+  // design with private destructor.
+
+#if defined(__BORLANDC__)
+  static UnitTest* const instance = new UnitTest;
+  return instance;
+#else
+  static UnitTest instance;
+  return &instance;
+#endif  // defined(__BORLANDC__)
+}
+
+// Gets the number of successful test suites.
+int UnitTest::successful_test_suite_count() const {
+  return impl()->successful_test_suite_count();
+}
+
+// Gets the number of failed test suites.
+int UnitTest::failed_test_suite_count() const {
+  return impl()->failed_test_suite_count();
+}
+
+// Gets the number of all test suites.
+int UnitTest::total_test_suite_count() const {
+  return impl()->total_test_suite_count();
+}
+
+// Gets the number of all test suites that contain at least one test
+// that should run.
+int UnitTest::test_suite_to_run_count() const {
+  return impl()->test_suite_to_run_count();
+}
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+int UnitTest::successful_test_case_count() const {
+  return impl()->successful_test_suite_count();
+}
+int UnitTest::failed_test_case_count() const {
+  return impl()->failed_test_suite_count();
+}
+int UnitTest::total_test_case_count() const {
+  return impl()->total_test_suite_count();
+}
+int UnitTest::test_case_to_run_count() const {
+  return impl()->test_suite_to_run_count();
+}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+// Gets the number of successful tests.
+int UnitTest::successful_test_count() const {
+  return impl()->successful_test_count();
+}
+
+// Gets the number of skipped tests.
+int UnitTest::skipped_test_count() const {
+  return impl()->skipped_test_count();
+}
+
+// Gets the number of failed tests.
+int UnitTest::failed_test_count() const { return impl()->failed_test_count(); }
+
+// Gets the number of disabled tests that will be reported in the XML report.
+int UnitTest::reportable_disabled_test_count() const {
+  return impl()->reportable_disabled_test_count();
+}
+
+// Gets the number of disabled tests.
+int UnitTest::disabled_test_count() const {
+  return impl()->disabled_test_count();
+}
+
+// Gets the number of tests to be printed in the XML report.
+int UnitTest::reportable_test_count() const {
+  return impl()->reportable_test_count();
+}
+
+// Gets the number of all tests.
+int UnitTest::total_test_count() const { return impl()->total_test_count(); }
+
+// Gets the number of tests that should run.
+int UnitTest::test_to_run_count() const { return impl()->test_to_run_count(); }
+
+// Gets the time of the test program start, in ms from the start of the
+// UNIX epoch.
+internal::TimeInMillis UnitTest::start_timestamp() const {
+  return impl()->start_timestamp();
+}
+
+// Gets the elapsed time, in milliseconds.
+internal::TimeInMillis UnitTest::elapsed_time() const {
+  return impl()->elapsed_time();
+}
+
+// Returns true if and only if the unit test passed (i.e. all test suites
+// passed).
+bool UnitTest::Passed() const { return impl()->Passed(); }
+
+// Returns true if and only if the unit test failed (i.e. some test suite
+// failed or something outside of all tests failed).
+bool UnitTest::Failed() const { return impl()->Failed(); }
+
+// Gets the i-th test suite among all the test suites. i can range from 0 to
+// total_test_suite_count() - 1. If i is not in that range, returns NULL.
+const TestSuite* UnitTest::GetTestSuite(int i) const {
+  return impl()->GetTestSuite(i);
+}
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+const TestCase* UnitTest::GetTestCase(int i) const {
+  return impl()->GetTestCase(i);
+}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+// Returns the TestResult containing information on test failures and
+// properties logged outside of individual test suites.
+const TestResult& UnitTest::ad_hoc_test_result() const {
+  return *impl()->ad_hoc_test_result();
+}
+
+// Gets the i-th test suite among all the test suites. i can range from 0 to
+// total_test_suite_count() - 1. If i is not in that range, returns NULL.
+TestSuite* UnitTest::GetMutableTestSuite(int i) {
+  return impl()->GetMutableSuiteCase(i);
+}
+
+// Returns the list of event listeners that can be used to track events
+// inside Google Test.
+TestEventListeners& UnitTest::listeners() { return *impl()->listeners(); }
+
+// Registers and returns a global test environment.  When a test
+// program is run, all global test environments will be set-up in the
+// order they were registered.  After all tests in the program have
+// finished, all global test environments will be torn-down in the
+// *reverse* order they were registered.
+//
+// The UnitTest object takes ownership of the given environment.
+//
+// We don't protect this under mutex_, as we only support calling it
+// from the main thread.
+Environment* UnitTest::AddEnvironment(Environment* env) {
+  if (env == nullptr) {
+    return nullptr;
+  }
+
+  impl_->environments().push_back(env);
+  return env;
+}
+
+// Adds a TestPartResult to the current TestResult object.  All Google Test
+// assertion macros (e.g. ASSERT_TRUE, EXPECT_EQ, etc) eventually call
+// this to report their results.  The user code should use the
+// assertion macros instead of calling this directly.
+void UnitTest::AddTestPartResult(TestPartResult::Type result_type,
+                                 const char* file_name, int line_number,
+                                 const std::string& message,
+                                 const std::string& os_stack_trace)
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+  Message msg;
+  msg << message;
+
+  internal::MutexLock lock(&mutex_);
+  if (impl_->gtest_trace_stack().size() > 0) {
+    msg << "\n" << GTEST_NAME_ << " trace:";
+
+    for (size_t i = impl_->gtest_trace_stack().size(); i > 0; --i) {
+      const internal::TraceInfo& trace = impl_->gtest_trace_stack()[i - 1];
+      msg << "\n"
+          << internal::FormatFileLocation(trace.file, trace.line) << " "
+          << trace.message;
+    }
+  }
+
+  if (os_stack_trace.c_str() != nullptr && !os_stack_trace.empty()) {
+    msg << internal::kStackTraceMarker << os_stack_trace;
+  }
+
+  const TestPartResult result = TestPartResult(
+      result_type, file_name, line_number, msg.GetString().c_str());
+  impl_->GetTestPartResultReporterForCurrentThread()->ReportTestPartResult(
+      result);
+
+  if (result_type != TestPartResult::kSuccess &&
+      result_type != TestPartResult::kSkip) {
+    // gtest_break_on_failure takes precedence over
+    // gtest_throw_on_failure.  This allows a user to set the latter
+    // in the code (perhaps in order to use Google Test assertions
+    // with another testing framework) and specify the former on the
+    // command line for debugging.
+    if (GTEST_FLAG_GET(break_on_failure)) {
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
+      // Using DebugBreak on Windows allows gtest to still break into a debugger
+      // when a failure happens and both the --gtest_break_on_failure and
+      // the --gtest_catch_exceptions flags are specified.
+      DebugBreak();
+#elif (!defined(__native_client__)) &&            \
+    ((defined(__clang__) || defined(__GNUC__)) && \
+     (defined(__x86_64__) || defined(__i386__)))
+      // with clang/gcc we can achieve the same effect on x86 by invoking int3
+      asm("int3");
+#else
+      // Dereference nullptr through a volatile pointer to prevent the compiler
+      // from removing. We use this rather than abort() or __builtin_trap() for
+      // portability: some debuggers don't correctly trap abort().
+      *static_cast<volatile int*>(nullptr) = 1;
+#endif  // GTEST_OS_WINDOWS
+    } else if (GTEST_FLAG_GET(throw_on_failure)) {
+#if GTEST_HAS_EXCEPTIONS
+      throw internal::GoogleTestFailureException(result);
+#else
+      // We cannot call abort() as it generates a pop-up in debug mode
+      // that cannot be suppressed in VC 7.1 or below.
+      exit(1);
+#endif
+    }
+  }
+}
+
+// Adds a TestProperty to the current TestResult object when invoked from
+// inside a test, to current TestSuite's ad_hoc_test_result_ when invoked
+// from SetUpTestSuite or TearDownTestSuite, or to the global property set
+// when invoked elsewhere.  If the result already contains a property with
+// the same key, the value will be updated.
+void UnitTest::RecordProperty(const std::string& key,
+                              const std::string& value) {
+  impl_->RecordProperty(TestProperty(key, value));
+}
+
+// Runs all tests in this UnitTest object and prints the result.
+// Returns 0 if successful, or 1 otherwise.
+//
+// We don't protect this under mutex_, as we only support calling it
+// from the main thread.
+int UnitTest::Run() {
+  const bool in_death_test_child_process =
+      GTEST_FLAG_GET(internal_run_death_test).length() > 0;
+
+  // Google Test implements this protocol for catching that a test
+  // program exits before returning control to Google Test:
+  //
+  //   1. Upon start, Google Test creates a file whose absolute path
+  //      is specified by the environment variable
+  //      TEST_PREMATURE_EXIT_FILE.
+  //   2. When Google Test has finished its work, it deletes the file.
+  //
+  // This allows a test runner to set TEST_PREMATURE_EXIT_FILE before
+  // running a Google-Test-based test program and check the existence
+  // of the file at the end of the test execution to see if it has
+  // exited prematurely.
+
+  // If we are in the child process of a death test, don't
+  // create/delete the premature exit file, as doing so is unnecessary
+  // and will confuse the parent process.  Otherwise, create/delete
+  // the file upon entering/leaving this function.  If the program
+  // somehow exits before this function has a chance to return, the
+  // premature-exit file will be left undeleted, causing a test runner
+  // that understands the premature-exit-file protocol to report the
+  // test as having failed.
+  const internal::ScopedPrematureExitFile premature_exit_file(
+      in_death_test_child_process
+          ? nullptr
+          : internal::posix::GetEnv("TEST_PREMATURE_EXIT_FILE"));
+
+  // Captures the value of GTEST_FLAG(catch_exceptions).  This value will be
+  // used for the duration of the program.
+  impl()->set_catch_exceptions(GTEST_FLAG_GET(catch_exceptions));
+
+#if GTEST_OS_WINDOWS
+  // Either the user wants Google Test to catch exceptions thrown by the
+  // tests or this is executing in the context of death test child
+  // process. In either case the user does not want to see pop-up dialogs
+  // about crashes - they are expected.
+  if (impl()->catch_exceptions() || in_death_test_child_process) {
+#if !GTEST_OS_WINDOWS_MOBILE && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
+    // SetErrorMode doesn't exist on CE.
+    SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOALIGNMENTFAULTEXCEPT |
+                 SEM_NOGPFAULTERRORBOX | SEM_NOOPENFILEERRORBOX);
+#endif  // !GTEST_OS_WINDOWS_MOBILE
+
+#if (defined(_MSC_VER) || GTEST_OS_WINDOWS_MINGW) && !GTEST_OS_WINDOWS_MOBILE
+    // Death test children can be terminated with _abort().  On Windows,
+    // _abort() can show a dialog with a warning message.  This forces the
+    // abort message to go to stderr instead.
+    _set_error_mode(_OUT_TO_STDERR);
+#endif
+
+#if defined(_MSC_VER) && !GTEST_OS_WINDOWS_MOBILE
+    // In the debug version, Visual Studio pops up a separate dialog
+    // offering a choice to debug the aborted program. We need to suppress
+    // this dialog or it will pop up for every EXPECT/ASSERT_DEATH statement
+    // executed. Google Test will notify the user of any unexpected
+    // failure via stderr.
+    if (!GTEST_FLAG_GET(break_on_failure))
+      _set_abort_behavior(
+          0x0,                                    // Clear the following flags:
+          _WRITE_ABORT_MSG | _CALL_REPORTFAULT);  // pop-up window, core dump.
+
+    // In debug mode, the Windows CRT can crash with an assertion over invalid
+    // input (e.g. passing an invalid file descriptor).  The default handling
+    // for these assertions is to pop up a dialog and wait for user input.
+    // Instead ask the CRT to dump such assertions to stderr non-interactively.
+    if (!IsDebuggerPresent()) {
+      (void)_CrtSetReportMode(_CRT_ASSERT,
+                              _CRTDBG_MODE_FILE | _CRTDBG_MODE_DEBUG);
+      (void)_CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
+    }
+#endif
+  }
+#endif  // GTEST_OS_WINDOWS
+
+  return internal::HandleExceptionsInMethodIfSupported(
+             impl(), &internal::UnitTestImpl::RunAllTests,
+             "auxiliary test code (environments or event listeners)")
+             ? 0
+             : 1;
+}
+
+// Returns the working directory when the first TEST() or TEST_F() was
+// executed.
+const char* UnitTest::original_working_dir() const {
+  return impl_->original_working_dir_.c_str();
+}
+
+// Returns the TestSuite object for the test that's currently running,
+// or NULL if no test is running.
+const TestSuite* UnitTest::current_test_suite() const
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+  internal::MutexLock lock(&mutex_);
+  return impl_->current_test_suite();
+}
+
+// Legacy API is still available but deprecated
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+const TestCase* UnitTest::current_test_case() const
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+  internal::MutexLock lock(&mutex_);
+  return impl_->current_test_suite();
+}
+#endif
+
+// Returns the TestInfo object for the test that's currently running,
+// or NULL if no test is running.
+const TestInfo* UnitTest::current_test_info() const
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+  internal::MutexLock lock(&mutex_);
+  return impl_->current_test_info();
+}
+
+// Returns the random seed used at the start of the current test run.
+int UnitTest::random_seed() const { return impl_->random_seed(); }
+
+// Returns ParameterizedTestSuiteRegistry object used to keep track of
+// value-parameterized tests and instantiate and register them.
+internal::ParameterizedTestSuiteRegistry&
+UnitTest::parameterized_test_registry() GTEST_LOCK_EXCLUDED_(mutex_) {
+  return impl_->parameterized_test_registry();
+}
+
+// Creates an empty UnitTest.
+UnitTest::UnitTest() { impl_ = new internal::UnitTestImpl(this); }
+
+// Destructor of UnitTest.
+UnitTest::~UnitTest() { delete impl_; }
+
+// Pushes a trace defined by SCOPED_TRACE() on to the per-thread
+// Google Test trace stack.
+void UnitTest::PushGTestTrace(const internal::TraceInfo& trace)
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+  internal::MutexLock lock(&mutex_);
+  impl_->gtest_trace_stack().push_back(trace);
+}
+
+// Pops a trace from the per-thread Google Test trace stack.
+void UnitTest::PopGTestTrace() GTEST_LOCK_EXCLUDED_(mutex_) {
+  internal::MutexLock lock(&mutex_);
+  impl_->gtest_trace_stack().pop_back();
+}
+
+namespace internal {
+
+UnitTestImpl::UnitTestImpl(UnitTest* parent)
+    : parent_(parent),
+      GTEST_DISABLE_MSC_WARNINGS_PUSH_(4355 /* using this in initializer */)
+          default_global_test_part_result_reporter_(this),
+      default_per_thread_test_part_result_reporter_(this),
+      GTEST_DISABLE_MSC_WARNINGS_POP_() global_test_part_result_repoter_(
+          &default_global_test_part_result_reporter_),
+      per_thread_test_part_result_reporter_(
+          &default_per_thread_test_part_result_reporter_),
+      parameterized_test_registry_(),
+      parameterized_tests_registered_(false),
+      last_death_test_suite_(-1),
+      current_test_suite_(nullptr),
+      current_test_info_(nullptr),
+      ad_hoc_test_result_(),
+      os_stack_trace_getter_(nullptr),
+      post_flag_parse_init_performed_(false),
+      random_seed_(0),  // Will be overridden by the flag before first use.
+      random_(0),       // Will be reseeded before first use.
+      start_timestamp_(0),
+      elapsed_time_(0),
+#if GTEST_HAS_DEATH_TEST
+      death_test_factory_(new DefaultDeathTestFactory),
+#endif
+      // Will be overridden by the flag before first use.
+      catch_exceptions_(false) {
+  listeners()->SetDefaultResultPrinter(new PrettyUnitTestResultPrinter);
+}
+
+UnitTestImpl::~UnitTestImpl() {
+  // Deletes every TestSuite.
+  ForEach(test_suites_, internal::Delete<TestSuite>);
+
+  // Deletes every Environment.
+  ForEach(environments_, internal::Delete<Environment>);
+
+  delete os_stack_trace_getter_;
+}
+
+// Adds a TestProperty to the current TestResult object when invoked in a
+// context of a test, to current test suite's ad_hoc_test_result when invoke
+// from SetUpTestSuite/TearDownTestSuite, or to the global property set
+// otherwise.  If the result already contains a property with the same key,
+// the value will be updated.
+void UnitTestImpl::RecordProperty(const TestProperty& test_property) {
+  std::string xml_element;
+  TestResult* test_result;  // TestResult appropriate for property recording.
+
+  if (current_test_info_ != nullptr) {
+    xml_element = "testcase";
+    test_result = &(current_test_info_->result_);
+  } else if (current_test_suite_ != nullptr) {
+    xml_element = "testsuite";
+    test_result = &(current_test_suite_->ad_hoc_test_result_);
+  } else {
+    xml_element = "testsuites";
+    test_result = &ad_hoc_test_result_;
+  }
+  test_result->RecordProperty(xml_element, test_property);
+}
+
+#if GTEST_HAS_DEATH_TEST
+// Disables event forwarding if the control is currently in a death test
+// subprocess. Must not be called before InitGoogleTest.
+void UnitTestImpl::SuppressTestEventsIfInSubprocess() {
+  if (internal_run_death_test_flag_.get() != nullptr)
+    listeners()->SuppressEventForwarding();
+}
+#endif  // GTEST_HAS_DEATH_TEST
+
+// Initializes event listeners performing XML output as specified by
+// UnitTestOptions. Must not be called before InitGoogleTest.
+void UnitTestImpl::ConfigureXmlOutput() {
+  const std::string& output_format = UnitTestOptions::GetOutputFormat();
+  if (output_format == "xml") {
+    listeners()->SetDefaultXmlGenerator(new XmlUnitTestResultPrinter(
+        UnitTestOptions::GetAbsolutePathToOutputFile().c_str()));
+  } else if (output_format == "json") {
+    listeners()->SetDefaultXmlGenerator(new JsonUnitTestResultPrinter(
+        UnitTestOptions::GetAbsolutePathToOutputFile().c_str()));
+  } else if (output_format != "") {
+    GTEST_LOG_(WARNING) << "WARNING: unrecognized output format \""
+                        << output_format << "\" ignored.";
+  }
+}
+
+#if GTEST_CAN_STREAM_RESULTS_
+// Initializes event listeners for streaming test results in string form.
+// Must not be called before InitGoogleTest.
+void UnitTestImpl::ConfigureStreamingOutput() {
+  const std::string& target = GTEST_FLAG_GET(stream_result_to);
+  if (!target.empty()) {
+    const size_t pos = target.find(':');
+    if (pos != std::string::npos) {
+      listeners()->Append(
+          new StreamingListener(target.substr(0, pos), target.substr(pos + 1)));
+    } else {
+      GTEST_LOG_(WARNING) << "unrecognized streaming target \"" << target
+                          << "\" ignored.";
+    }
+  }
+}
+#endif  // GTEST_CAN_STREAM_RESULTS_
+
+// Performs initialization dependent upon flag values obtained in
+// ParseGoogleTestFlagsOnly.  Is called from InitGoogleTest after the call to
+// ParseGoogleTestFlagsOnly.  In case a user neglects to call InitGoogleTest
+// this function is also called from RunAllTests.  Since this function can be
+// called more than once, it has to be idempotent.
+void UnitTestImpl::PostFlagParsingInit() {
+  // Ensures that this function does not execute more than once.
+  if (!post_flag_parse_init_performed_) {
+    post_flag_parse_init_performed_ = true;
+
+#if defined(GTEST_CUSTOM_TEST_EVENT_LISTENER_)
+    // Register to send notifications about key process state changes.
+    listeners()->Append(new GTEST_CUSTOM_TEST_EVENT_LISTENER_());
+#endif  // defined(GTEST_CUSTOM_TEST_EVENT_LISTENER_)
+
+#if GTEST_HAS_DEATH_TEST
+    InitDeathTestSubprocessControlInfo();
+    SuppressTestEventsIfInSubprocess();
+#endif  // GTEST_HAS_DEATH_TEST
+
+    // Registers parameterized tests. This makes parameterized tests
+    // available to the UnitTest reflection API without running
+    // RUN_ALL_TESTS.
+    RegisterParameterizedTests();
+
+    // Configures listeners for XML output. This makes it possible for users
+    // to shut down the default XML output before invoking RUN_ALL_TESTS.
+    ConfigureXmlOutput();
+
+    if (GTEST_FLAG_GET(brief)) {
+      listeners()->SetDefaultResultPrinter(new BriefUnitTestResultPrinter);
+    }
+
+#if GTEST_CAN_STREAM_RESULTS_
+    // Configures listeners for streaming test results to the specified server.
+    ConfigureStreamingOutput();
+#endif  // GTEST_CAN_STREAM_RESULTS_
+
+#if GTEST_HAS_ABSL
+    if (GTEST_FLAG_GET(install_failure_signal_handler)) {
+      absl::FailureSignalHandlerOptions options;
+      absl::InstallFailureSignalHandler(options);
+    }
+#endif  // GTEST_HAS_ABSL
+  }
+}
+
+// A predicate that checks the name of a TestSuite against a known
+// value.
+//
+// This is used for implementation of the UnitTest class only.  We put
+// it in the anonymous namespace to prevent polluting the outer
+// namespace.
+//
+// TestSuiteNameIs is copyable.
+class TestSuiteNameIs {
+ public:
+  // Constructor.
+  explicit TestSuiteNameIs(const std::string& name) : name_(name) {}
+
+  // Returns true if and only if the name of test_suite matches name_.
+  bool operator()(const TestSuite* test_suite) const {
+    return test_suite != nullptr &&
+           strcmp(test_suite->name(), name_.c_str()) == 0;
+  }
+
+ private:
+  std::string name_;
+};
+
+// Finds and returns a TestSuite with the given name.  If one doesn't
+// exist, creates one and returns it.  It's the CALLER'S
+// RESPONSIBILITY to ensure that this function is only called WHEN THE
+// TESTS ARE NOT SHUFFLED.
+//
+// Arguments:
+//
+//   test_suite_name: name of the test suite
+//   type_param:      the name of the test suite's type parameter, or NULL if
+//                    this is not a typed or a type-parameterized test suite.
+//   set_up_tc:       pointer to the function that sets up the test suite
+//   tear_down_tc:    pointer to the function that tears down the test suite
+TestSuite* UnitTestImpl::GetTestSuite(
+    const char* test_suite_name, const char* type_param,
+    internal::SetUpTestSuiteFunc set_up_tc,
+    internal::TearDownTestSuiteFunc tear_down_tc) {
+  // Can we find a TestSuite with the given name?
+  const auto test_suite =
+      std::find_if(test_suites_.rbegin(), test_suites_.rend(),
+                   TestSuiteNameIs(test_suite_name));
+
+  if (test_suite != test_suites_.rend()) return *test_suite;
+
+  // No.  Let's create one.
+  auto* const new_test_suite =
+      new TestSuite(test_suite_name, type_param, set_up_tc, tear_down_tc);
+
+  const UnitTestFilter death_test_suite_filter(kDeathTestSuiteFilter);
+  // Is this a death test suite?
+  if (death_test_suite_filter.MatchesName(test_suite_name)) {
+    // Yes.  Inserts the test suite after the last death test suite
+    // defined so far.  This only works when the test suites haven't
+    // been shuffled.  Otherwise we may end up running a death test
+    // after a non-death test.
+    ++last_death_test_suite_;
+    test_suites_.insert(test_suites_.begin() + last_death_test_suite_,
+                        new_test_suite);
+  } else {
+    // No.  Appends to the end of the list.
+    test_suites_.push_back(new_test_suite);
+  }
+
+  test_suite_indices_.push_back(static_cast<int>(test_suite_indices_.size()));
+  return new_test_suite;
+}
+
+// Helpers for setting up / tearing down the given environment.  They
+// are for use in the ForEach() function.
+static void SetUpEnvironment(Environment* env) { env->SetUp(); }
+static void TearDownEnvironment(Environment* env) { env->TearDown(); }
+
+// Runs all tests in this UnitTest object, prints the result, and
+// returns true if all tests are successful.  If any exception is
+// thrown during a test, the test is considered to be failed, but the
+// rest of the tests will still be run.
+//
+// When parameterized tests are enabled, it expands and registers
+// parameterized tests first in RegisterParameterizedTests().
+// All other functions called from RunAllTests() may safely assume that
+// parameterized tests are ready to be counted and run.
+bool UnitTestImpl::RunAllTests() {
+  // True if and only if Google Test is initialized before RUN_ALL_TESTS() is
+  // called.
+  const bool gtest_is_initialized_before_run_all_tests = GTestIsInitialized();
+
+  // Do not run any test if the --help flag was specified.
+  if (g_help_flag) return true;
+
+  // Repeats the call to the post-flag parsing initialization in case the
+  // user didn't call InitGoogleTest.
+  PostFlagParsingInit();
+
+  // Even if sharding is not on, test runners may want to use the
+  // GTEST_SHARD_STATUS_FILE to query whether the test supports the sharding
+  // protocol.
+  internal::WriteToShardStatusFileIfNeeded();
+
+  // True if and only if we are in a subprocess for running a thread-safe-style
+  // death test.
+  bool in_subprocess_for_death_test = false;
+
+#if GTEST_HAS_DEATH_TEST
+  in_subprocess_for_death_test =
+      (internal_run_death_test_flag_.get() != nullptr);
+#if defined(GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_)
+  if (in_subprocess_for_death_test) {
+    GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_();
+  }
+#endif  // defined(GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_)
+#endif  // GTEST_HAS_DEATH_TEST
+
+  const bool should_shard = ShouldShard(kTestTotalShards, kTestShardIndex,
+                                        in_subprocess_for_death_test);
+
+  // Compares the full test names with the filter to decide which
+  // tests to run.
+  const bool has_tests_to_run =
+      FilterTests(should_shard ? HONOR_SHARDING_PROTOCOL
+                               : IGNORE_SHARDING_PROTOCOL) > 0;
+
+  // Lists the tests and exits if the --gtest_list_tests flag was specified.
+  if (GTEST_FLAG_GET(list_tests)) {
+    // This must be called *after* FilterTests() has been called.
+    ListTestsMatchingFilter();
+    return true;
+  }
+
+  random_seed_ = GetRandomSeedFromFlag(GTEST_FLAG_GET(random_seed));
+
+  // True if and only if at least one test has failed.
+  bool failed = false;
+
+  TestEventListener* repeater = listeners()->repeater();
+
+  start_timestamp_ = GetTimeInMillis();
+  repeater->OnTestProgramStart(*parent_);
+
+  // How many times to repeat the tests?  We don't want to repeat them
+  // when we are inside the subprocess of a death test.
+  const int repeat = in_subprocess_for_death_test ? 1 : GTEST_FLAG_GET(repeat);
+
+  // Repeats forever if the repeat count is negative.
+  const bool gtest_repeat_forever = repeat < 0;
+
+  // Should test environments be set up and torn down for each repeat, or only
+  // set up on the first and torn down on the last iteration? If there is no
+  // "last" iteration because the tests will repeat forever, always recreate the
+  // environments to avoid leaks in case one of the environments is using
+  // resources that are external to this process. Without this check there would
+  // be no way to clean up those external resources automatically.
+  const bool recreate_environments_when_repeating =
+      GTEST_FLAG_GET(recreate_environments_when_repeating) ||
+      gtest_repeat_forever;
+
+  for (int i = 0; gtest_repeat_forever || i != repeat; i++) {
+    // We want to preserve failures generated by ad-hoc test
+    // assertions executed before RUN_ALL_TESTS().
+    ClearNonAdHocTestResult();
+
+    Timer timer;
+
+    // Shuffles test suites and tests if requested.
+    if (has_tests_to_run && GTEST_FLAG_GET(shuffle)) {
+      random()->Reseed(static_cast<uint32_t>(random_seed_));
+      // This should be done before calling OnTestIterationStart(),
+      // such that a test event listener can see the actual test order
+      // in the event.
+      ShuffleTests();
+    }
+
+    // Tells the unit test event listeners that the tests are about to start.
+    repeater->OnTestIterationStart(*parent_, i);
+
+    // Runs each test suite if there is at least one test to run.
+    if (has_tests_to_run) {
+      // Sets up all environments beforehand. If test environments aren't
+      // recreated for each iteration, only do so on the first iteration.
+      if (i == 0 || recreate_environments_when_repeating) {
+        repeater->OnEnvironmentsSetUpStart(*parent_);
+        ForEach(environments_, SetUpEnvironment);
+        repeater->OnEnvironmentsSetUpEnd(*parent_);
+      }
+
+      // Runs the tests only if there was no fatal failure or skip triggered
+      // during global set-up.
+      if (Test::IsSkipped()) {
+        // Emit diagnostics when global set-up calls skip, as it will not be
+        // emitted by default.
+        TestResult& test_result =
+            *internal::GetUnitTestImpl()->current_test_result();
+        for (int j = 0; j < test_result.total_part_count(); ++j) {
+          const TestPartResult& test_part_result =
+              test_result.GetTestPartResult(j);
+          if (test_part_result.type() == TestPartResult::kSkip) {
+            const std::string& result = test_part_result.message();
+            printf("%s\n", result.c_str());
+          }
+        }
+        fflush(stdout);
+      } else if (!Test::HasFatalFailure()) {
+        for (int test_index = 0; test_index < total_test_suite_count();
+             test_index++) {
+          GetMutableSuiteCase(test_index)->Run();
+          if (GTEST_FLAG_GET(fail_fast) &&
+              GetMutableSuiteCase(test_index)->Failed()) {
+            for (int j = test_index + 1; j < total_test_suite_count(); j++) {
+              GetMutableSuiteCase(j)->Skip();
+            }
+            break;
+          }
+        }
+      } else if (Test::HasFatalFailure()) {
+        // If there was a fatal failure during the global setup then we know we
+        // aren't going to run any tests. Explicitly mark all of the tests as
+        // skipped to make this obvious in the output.
+        for (int test_index = 0; test_index < total_test_suite_count();
+             test_index++) {
+          GetMutableSuiteCase(test_index)->Skip();
+        }
+      }
+
+      // Tears down all environments in reverse order afterwards. If test
+      // environments aren't recreated for each iteration, only do so on the
+      // last iteration.
+      if (i == repeat - 1 || recreate_environments_when_repeating) {
+        repeater->OnEnvironmentsTearDownStart(*parent_);
+        std::for_each(environments_.rbegin(), environments_.rend(),
+                      TearDownEnvironment);
+        repeater->OnEnvironmentsTearDownEnd(*parent_);
+      }
+    }
+
+    elapsed_time_ = timer.Elapsed();
+
+    // Tells the unit test event listener that the tests have just finished.
+    repeater->OnTestIterationEnd(*parent_, i);
+
+    // Gets the result and clears it.
+    if (!Passed()) {
+      failed = true;
+    }
+
+    // Restores the original test order after the iteration.  This
+    // allows the user to quickly repro a failure that happens in the
+    // N-th iteration without repeating the first (N - 1) iterations.
+    // This is not enclosed in "if (GTEST_FLAG(shuffle)) { ... }", in
+    // case the user somehow changes the value of the flag somewhere
+    // (it's always safe to unshuffle the tests).
+    UnshuffleTests();
+
+    if (GTEST_FLAG_GET(shuffle)) {
+      // Picks a new random seed for each iteration.
+      random_seed_ = GetNextRandomSeed(random_seed_);
+    }
+  }
+
+  repeater->OnTestProgramEnd(*parent_);
+
+  if (!gtest_is_initialized_before_run_all_tests) {
+    ColoredPrintf(
+        GTestColor::kRed,
+        "\nIMPORTANT NOTICE - DO NOT IGNORE:\n"
+        "This test program did NOT call " GTEST_INIT_GOOGLE_TEST_NAME_
+        "() before calling RUN_ALL_TESTS(). This is INVALID. Soon " GTEST_NAME_
+        " will start to enforce the valid usage. "
+        "Please fix it ASAP, or IT WILL START TO FAIL.\n");  // NOLINT
+#if GTEST_FOR_GOOGLE_
+    ColoredPrintf(GTestColor::kRed,
+                  "For more details, see http://wiki/Main/ValidGUnitMain.\n");
+#endif  // GTEST_FOR_GOOGLE_
+  }
+
+  return !failed;
+}
+
+// Reads the GTEST_SHARD_STATUS_FILE environment variable, and creates the file
+// if the variable is present. If a file already exists at this location, this
+// function will write over it. If the variable is present, but the file cannot
+// be created, prints an error and exits.
+void WriteToShardStatusFileIfNeeded() {
+  const char* const test_shard_file = posix::GetEnv(kTestShardStatusFile);
+  if (test_shard_file != nullptr) {
+    FILE* const file = posix::FOpen(test_shard_file, "w");
+    if (file == nullptr) {
+      ColoredPrintf(GTestColor::kRed,
+                    "Could not write to the test shard status file \"%s\" "
+                    "specified by the %s environment variable.\n",
+                    test_shard_file, kTestShardStatusFile);
+      fflush(stdout);
+      exit(EXIT_FAILURE);
+    }
+    fclose(file);
+  }
+}
+
+// Checks whether sharding is enabled by examining the relevant
+// environment variable values. If the variables are present,
+// but inconsistent (i.e., shard_index >= total_shards), prints
+// an error and exits. If in_subprocess_for_death_test, sharding is
+// disabled because it must only be applied to the original test
+// process. Otherwise, we could filter out death tests we intended to execute.
+bool ShouldShard(const char* total_shards_env, const char* shard_index_env,
+                 bool in_subprocess_for_death_test) {
+  if (in_subprocess_for_death_test) {
+    return false;
+  }
+
+  const int32_t total_shards = Int32FromEnvOrDie(total_shards_env, -1);
+  const int32_t shard_index = Int32FromEnvOrDie(shard_index_env, -1);
+
+  if (total_shards == -1 && shard_index == -1) {
+    return false;
+  } else if (total_shards == -1 && shard_index != -1) {
+    const Message msg = Message() << "Invalid environment variables: you have "
+                                  << kTestShardIndex << " = " << shard_index
+                                  << ", but have left " << kTestTotalShards
+                                  << " unset.\n";
+    ColoredPrintf(GTestColor::kRed, "%s", msg.GetString().c_str());
+    fflush(stdout);
+    exit(EXIT_FAILURE);
+  } else if (total_shards != -1 && shard_index == -1) {
+    const Message msg = Message()
+                        << "Invalid environment variables: you have "
+                        << kTestTotalShards << " = " << total_shards
+                        << ", but have left " << kTestShardIndex << " unset.\n";
+    ColoredPrintf(GTestColor::kRed, "%s", msg.GetString().c_str());
+    fflush(stdout);
+    exit(EXIT_FAILURE);
+  } else if (shard_index < 0 || shard_index >= total_shards) {
+    const Message msg =
+        Message() << "Invalid environment variables: we require 0 <= "
+                  << kTestShardIndex << " < " << kTestTotalShards
+                  << ", but you have " << kTestShardIndex << "=" << shard_index
+                  << ", " << kTestTotalShards << "=" << total_shards << ".\n";
+    ColoredPrintf(GTestColor::kRed, "%s", msg.GetString().c_str());
+    fflush(stdout);
+    exit(EXIT_FAILURE);
+  }
+
+  return total_shards > 1;
+}
+
+// Parses the environment variable var as an Int32. If it is unset,
+// returns default_val. If it is not an Int32, prints an error
+// and aborts.
+int32_t Int32FromEnvOrDie(const char* var, int32_t default_val) {
+  const char* str_val = posix::GetEnv(var);
+  if (str_val == nullptr) {
+    return default_val;
+  }
+
+  int32_t result;
+  if (!ParseInt32(Message() << "The value of environment variable " << var,
+                  str_val, &result)) {
+    exit(EXIT_FAILURE);
+  }
+  return result;
+}
+
+// Given the total number of shards, the shard index, and the test id,
+// returns true if and only if the test should be run on this shard. The test id
+// is some arbitrary but unique non-negative integer assigned to each test
+// method. Assumes that 0 <= shard_index < total_shards.
+bool ShouldRunTestOnShard(int total_shards, int shard_index, int test_id) {
+  return (test_id % total_shards) == shard_index;
+}
+
+// Compares the name of each test with the user-specified filter to
+// decide whether the test should be run, then records the result in
+// each TestSuite and TestInfo object.
+// If shard_tests == true, further filters tests based on sharding
+// variables in the environment - see
+// https://github.com/google/googletest/blob/master/googletest/docs/advanced.md
+// . Returns the number of tests that should run.
+int UnitTestImpl::FilterTests(ReactionToSharding shard_tests) {
+  const int32_t total_shards = shard_tests == HONOR_SHARDING_PROTOCOL
+                                   ? Int32FromEnvOrDie(kTestTotalShards, -1)
+                                   : -1;
+  const int32_t shard_index = shard_tests == HONOR_SHARDING_PROTOCOL
+                                  ? Int32FromEnvOrDie(kTestShardIndex, -1)
+                                  : -1;
+
+  const PositiveAndNegativeUnitTestFilter gtest_flag_filter(
+      GTEST_FLAG_GET(filter));
+  const UnitTestFilter disable_test_filter(kDisableTestFilter);
+  // num_runnable_tests are the number of tests that will
+  // run across all shards (i.e., match filter and are not disabled).
+  // num_selected_tests are the number of tests to be run on
+  // this shard.
+  int num_runnable_tests = 0;
+  int num_selected_tests = 0;
+  for (auto* test_suite : test_suites_) {
+    const std::string& test_suite_name = test_suite->name();
+    test_suite->set_should_run(false);
+
+    for (size_t j = 0; j < test_suite->test_info_list().size(); j++) {
+      TestInfo* const test_info = test_suite->test_info_list()[j];
+      const std::string test_name(test_info->name());
+      // A test is disabled if test suite name or test name matches
+      // kDisableTestFilter.
+      const bool is_disabled =
+          disable_test_filter.MatchesName(test_suite_name) ||
+          disable_test_filter.MatchesName(test_name);
+      test_info->is_disabled_ = is_disabled;
+
+      const bool matches_filter =
+          gtest_flag_filter.MatchesTest(test_suite_name, test_name);
+      test_info->matches_filter_ = matches_filter;
+
+      const bool is_runnable =
+          (GTEST_FLAG_GET(also_run_disabled_tests) || !is_disabled) &&
+          matches_filter;
+
+      const bool is_in_another_shard =
+          shard_tests != IGNORE_SHARDING_PROTOCOL &&
+          !ShouldRunTestOnShard(total_shards, shard_index, num_runnable_tests);
+      test_info->is_in_another_shard_ = is_in_another_shard;
+      const bool is_selected = is_runnable && !is_in_another_shard;
+
+      num_runnable_tests += is_runnable;
+      num_selected_tests += is_selected;
+
+      test_info->should_run_ = is_selected;
+      test_suite->set_should_run(test_suite->should_run() || is_selected);
+    }
+  }
+  return num_selected_tests;
+}
+
+// Prints the given C-string on a single line by replacing all '\n'
+// characters with string "\\n".  If the output takes more than
+// max_length characters, only prints the first max_length characters
+// and "...".
+static void PrintOnOneLine(const char* str, int max_length) {
+  if (str != nullptr) {
+    for (int i = 0; *str != '\0'; ++str) {
+      if (i >= max_length) {
+        printf("...");
+        break;
+      }
+      if (*str == '\n') {
+        printf("\\n");
+        i += 2;
+      } else {
+        printf("%c", *str);
+        ++i;
+      }
+    }
+  }
+}
+
+// Prints the names of the tests matching the user-specified filter flag.
+void UnitTestImpl::ListTestsMatchingFilter() {
+  // Print at most this many characters for each type/value parameter.
+  const int kMaxParamLength = 250;
+
+  for (auto* test_suite : test_suites_) {
+    bool printed_test_suite_name = false;
+
+    for (size_t j = 0; j < test_suite->test_info_list().size(); j++) {
+      const TestInfo* const test_info = test_suite->test_info_list()[j];
+      if (test_info->matches_filter_) {
+        if (!printed_test_suite_name) {
+          printed_test_suite_name = true;
+          printf("%s.", test_suite->name());
+          if (test_suite->type_param() != nullptr) {
+            printf("  # %s = ", kTypeParamLabel);
+            // We print the type parameter on a single line to make
+            // the output easy to parse by a program.
+            PrintOnOneLine(test_suite->type_param(), kMaxParamLength);
+          }
+          printf("\n");
+        }
+        printf("  %s", test_info->name());
+        if (test_info->value_param() != nullptr) {
+          printf("  # %s = ", kValueParamLabel);
+          // We print the value parameter on a single line to make the
+          // output easy to parse by a program.
+          PrintOnOneLine(test_info->value_param(), kMaxParamLength);
+        }
+        printf("\n");
+      }
+    }
+  }
+  fflush(stdout);
+  const std::string& output_format = UnitTestOptions::GetOutputFormat();
+  if (output_format == "xml" || output_format == "json") {
+    FILE* fileout = OpenFileForWriting(
+        UnitTestOptions::GetAbsolutePathToOutputFile().c_str());
+    std::stringstream stream;
+    if (output_format == "xml") {
+      XmlUnitTestResultPrinter(
+          UnitTestOptions::GetAbsolutePathToOutputFile().c_str())
+          .PrintXmlTestsList(&stream, test_suites_);
+    } else if (output_format == "json") {
+      JsonUnitTestResultPrinter(
+          UnitTestOptions::GetAbsolutePathToOutputFile().c_str())
+          .PrintJsonTestList(&stream, test_suites_);
+    }
+    fprintf(fileout, "%s", StringStreamToString(&stream).c_str());
+    fclose(fileout);
+  }
+}
+
+// Sets the OS stack trace getter.
+//
+// Does nothing if the input and the current OS stack trace getter are
+// the same; otherwise, deletes the old getter and makes the input the
+// current getter.
+void UnitTestImpl::set_os_stack_trace_getter(
+    OsStackTraceGetterInterface* getter) {
+  if (os_stack_trace_getter_ != getter) {
+    delete os_stack_trace_getter_;
+    os_stack_trace_getter_ = getter;
+  }
+}
+
+// Returns the current OS stack trace getter if it is not NULL;
+// otherwise, creates an OsStackTraceGetter, makes it the current
+// getter, and returns it.
+OsStackTraceGetterInterface* UnitTestImpl::os_stack_trace_getter() {
+  if (os_stack_trace_getter_ == nullptr) {
+#ifdef GTEST_OS_STACK_TRACE_GETTER_
+    os_stack_trace_getter_ = new GTEST_OS_STACK_TRACE_GETTER_;
+#else
+    os_stack_trace_getter_ = new OsStackTraceGetter;
+#endif  // GTEST_OS_STACK_TRACE_GETTER_
+  }
+
+  return os_stack_trace_getter_;
+}
+
+// Returns the most specific TestResult currently running.
+TestResult* UnitTestImpl::current_test_result() {
+  if (current_test_info_ != nullptr) {
+    return &current_test_info_->result_;
+  }
+  if (current_test_suite_ != nullptr) {
+    return &current_test_suite_->ad_hoc_test_result_;
+  }
+  return &ad_hoc_test_result_;
+}
+
+// Shuffles all test suites, and the tests within each test suite,
+// making sure that death tests are still run first.
+void UnitTestImpl::ShuffleTests() {
+  // Shuffles the death test suites.
+  ShuffleRange(random(), 0, last_death_test_suite_ + 1, &test_suite_indices_);
+
+  // Shuffles the non-death test suites.
+  ShuffleRange(random(), last_death_test_suite_ + 1,
+               static_cast<int>(test_suites_.size()), &test_suite_indices_);
+
+  // Shuffles the tests inside each test suite.
+  for (auto& test_suite : test_suites_) {
+    test_suite->ShuffleTests(random());
+  }
+}
+
+// Restores the test suites and tests to their order before the first shuffle.
+void UnitTestImpl::UnshuffleTests() {
+  for (size_t i = 0; i < test_suites_.size(); i++) {
+    // Unshuffles the tests in each test suite.
+    test_suites_[i]->UnshuffleTests();
+    // Resets the index of each test suite.
+    test_suite_indices_[i] = static_cast<int>(i);
+  }
+}
+
+// Returns the current OS stack trace as an std::string.
+//
+// The maximum number of stack frames to be included is specified by
+// the gtest_stack_trace_depth flag.  The skip_count parameter
+// specifies the number of top frames to be skipped, which doesn't
+// count against the number of frames to be included.
+//
+// For example, if Foo() calls Bar(), which in turn calls
+// GetCurrentOsStackTraceExceptTop(..., 1), Foo() will be included in
+// the trace but Bar() and GetCurrentOsStackTraceExceptTop() won't.
+GTEST_NO_INLINE_ GTEST_NO_TAIL_CALL_ std::string
+GetCurrentOsStackTraceExceptTop(UnitTest* /*unit_test*/, int skip_count) {
+  // We pass skip_count + 1 to skip this wrapper function in addition
+  // to what the user really wants to skip.
+  return GetUnitTestImpl()->CurrentOsStackTraceExceptTop(skip_count + 1);
+}
+
+// Used by the GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_ macro to
+// suppress unreachable code warnings.
+namespace {
+class ClassUniqueToAlwaysTrue {};
+}  // namespace
+
+bool IsTrue(bool condition) { return condition; }
+
+bool AlwaysTrue() {
+#if GTEST_HAS_EXCEPTIONS
+  // This condition is always false so AlwaysTrue() never actually throws,
+  // but it makes the compiler think that it may throw.
+  if (IsTrue(false)) throw ClassUniqueToAlwaysTrue();
+#endif  // GTEST_HAS_EXCEPTIONS
+  return true;
+}
+
+// If *pstr starts with the given prefix, modifies *pstr to be right
+// past the prefix and returns true; otherwise leaves *pstr unchanged
+// and returns false.  None of pstr, *pstr, and prefix can be NULL.
+bool SkipPrefix(const char* prefix, const char** pstr) {
+  const size_t prefix_len = strlen(prefix);
+  if (strncmp(*pstr, prefix, prefix_len) == 0) {
+    *pstr += prefix_len;
+    return true;
+  }
+  return false;
+}
+
+// Parses a string as a command line flag.  The string should have
+// the format "--flag=value".  When def_optional is true, the "=value"
+// part can be omitted.
+//
+// Returns the value of the flag, or NULL if the parsing failed.
+static const char* ParseFlagValue(const char* str, const char* flag_name,
+                                  bool def_optional) {
+  // str and flag must not be NULL.
+  if (str == nullptr || flag_name == nullptr) return nullptr;
+
+  // The flag must start with "--" followed by GTEST_FLAG_PREFIX_.
+  const std::string flag_str =
+      std::string("--") + GTEST_FLAG_PREFIX_ + flag_name;
+  const size_t flag_len = flag_str.length();
+  if (strncmp(str, flag_str.c_str(), flag_len) != 0) return nullptr;
+
+  // Skips the flag name.
+  const char* flag_end = str + flag_len;
+
+  // When def_optional is true, it's OK to not have a "=value" part.
+  if (def_optional && (flag_end[0] == '\0')) {
+    return flag_end;
+  }
+
+  // If def_optional is true and there are more characters after the
+  // flag name, or if def_optional is false, there must be a '=' after
+  // the flag name.
+  if (flag_end[0] != '=') return nullptr;
+
+  // Returns the string after "=".
+  return flag_end + 1;
+}
+
+// Parses a string for a bool flag, in the form of either
+// "--flag=value" or "--flag".
+//
+// In the former case, the value is taken as true as long as it does
+// not start with '0', 'f', or 'F'.
+//
+// In the latter case, the value is taken as true.
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+static bool ParseFlag(const char* str, const char* flag_name, bool* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseFlagValue(str, flag_name, true);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Converts the string value to a bool.
+  *value = !(*value_str == '0' || *value_str == 'f' || *value_str == 'F');
+  return true;
+}
+
+// Parses a string for an int32_t flag, in the form of "--flag=value".
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+bool ParseFlag(const char* str, const char* flag_name, int32_t* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseFlagValue(str, flag_name, false);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Sets *value to the value of the flag.
+  return ParseInt32(Message() << "The value of flag --" << flag_name, value_str,
+                    value);
+}
+
+// Parses a string for a string flag, in the form of "--flag=value".
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+template <typename String>
+static bool ParseFlag(const char* str, const char* flag_name, String* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseFlagValue(str, flag_name, false);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Sets *value to the value of the flag.
+  *value = value_str;
+  return true;
+}
+
+// Determines whether a string has a prefix that Google Test uses for its
+// flags, i.e., starts with GTEST_FLAG_PREFIX_ or GTEST_FLAG_PREFIX_DASH_.
+// If Google Test detects that a command line flag has its prefix but is not
+// recognized, it will print its help message. Flags starting with
+// GTEST_INTERNAL_PREFIX_ followed by "internal_" are considered Google Test
+// internal flags and do not trigger the help message.
+static bool HasGoogleTestFlagPrefix(const char* str) {
+  return (SkipPrefix("--", &str) || SkipPrefix("-", &str) ||
+          SkipPrefix("/", &str)) &&
+         !SkipPrefix(GTEST_FLAG_PREFIX_ "internal_", &str) &&
+         (SkipPrefix(GTEST_FLAG_PREFIX_, &str) ||
+          SkipPrefix(GTEST_FLAG_PREFIX_DASH_, &str));
+}
+
+// Prints a string containing code-encoded text.  The following escape
+// sequences can be used in the string to control the text color:
+//
+//   @@    prints a single '@' character.
+//   @R    changes the color to red.
+//   @G    changes the color to green.
+//   @Y    changes the color to yellow.
+//   @D    changes to the default terminal text color.
+//
+static void PrintColorEncoded(const char* str) {
+  GTestColor color = GTestColor::kDefault;  // The current color.
+
+  // Conceptually, we split the string into segments divided by escape
+  // sequences.  Then we print one segment at a time.  At the end of
+  // each iteration, the str pointer advances to the beginning of the
+  // next segment.
+  for (;;) {
+    const char* p = strchr(str, '@');
+    if (p == nullptr) {
+      ColoredPrintf(color, "%s", str);
+      return;
+    }
+
+    ColoredPrintf(color, "%s", std::string(str, p).c_str());
+
+    const char ch = p[1];
+    str = p + 2;
+    if (ch == '@') {
+      ColoredPrintf(color, "@");
+    } else if (ch == 'D') {
+      color = GTestColor::kDefault;
+    } else if (ch == 'R') {
+      color = GTestColor::kRed;
+    } else if (ch == 'G') {
+      color = GTestColor::kGreen;
+    } else if (ch == 'Y') {
+      color = GTestColor::kYellow;
+    } else {
+      --str;
+    }
+  }
+}
+
+static const char kColorEncodedHelpMessage[] =
+    "This program contains tests written using " GTEST_NAME_
+    ". You can use the\n"
+    "following command line flags to control its behavior:\n"
+    "\n"
+    "Test Selection:\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "list_tests@D\n"
+    "      List the names of all tests instead of running them. The name of\n"
+    "      TEST(Foo, Bar) is \"Foo.Bar\".\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "filter=@YPOSITIVE_PATTERNS"
+    "[@G-@YNEGATIVE_PATTERNS]@D\n"
+    "      Run only the tests whose name matches one of the positive patterns "
+    "but\n"
+    "      none of the negative patterns. '?' matches any single character; "
+    "'*'\n"
+    "      matches any substring; ':' separates two patterns.\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "also_run_disabled_tests@D\n"
+    "      Run all disabled tests too.\n"
+    "\n"
+    "Test Execution:\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "repeat=@Y[COUNT]@D\n"
+    "      Run the tests repeatedly; use a negative count to repeat forever.\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "shuffle@D\n"
+    "      Randomize tests' orders on every iteration.\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "random_seed=@Y[NUMBER]@D\n"
+    "      Random number seed to use for shuffling test orders (between 1 and\n"
+    "      99999, or 0 to use a seed based on the current time).\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "recreate_environments_when_repeating@D\n"
+    "      Sets up and tears down the global test environment on each repeat\n"
+    "      of the test.\n"
+    "\n"
+    "Test Output:\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "color=@Y(@Gyes@Y|@Gno@Y|@Gauto@Y)@D\n"
+    "      Enable/disable colored output. The default is @Gauto@D.\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "brief=1@D\n"
+    "      Only print test failures.\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "print_time=0@D\n"
+    "      Don't print the elapsed time of each test.\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "output=@Y(@Gjson@Y|@Gxml@Y)[@G:@YDIRECTORY_PATH@G" GTEST_PATH_SEP_
+    "@Y|@G:@YFILE_PATH]@D\n"
+    "      Generate a JSON or XML report in the given directory or with the "
+    "given\n"
+    "      file name. @YFILE_PATH@D defaults to @Gtest_detail.xml@D.\n"
+#if GTEST_CAN_STREAM_RESULTS_
+    "  @G--" GTEST_FLAG_PREFIX_
+    "stream_result_to=@YHOST@G:@YPORT@D\n"
+    "      Stream test results to the given server.\n"
+#endif  // GTEST_CAN_STREAM_RESULTS_
+    "\n"
+    "Assertion Behavior:\n"
+#if GTEST_HAS_DEATH_TEST && !GTEST_OS_WINDOWS
+    "  @G--" GTEST_FLAG_PREFIX_
+    "death_test_style=@Y(@Gfast@Y|@Gthreadsafe@Y)@D\n"
+    "      Set the default death test style.\n"
+#endif  // GTEST_HAS_DEATH_TEST && !GTEST_OS_WINDOWS
+    "  @G--" GTEST_FLAG_PREFIX_
+    "break_on_failure@D\n"
+    "      Turn assertion failures into debugger break-points.\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "throw_on_failure@D\n"
+    "      Turn assertion failures into C++ exceptions for use by an external\n"
+    "      test framework.\n"
+    "  @G--" GTEST_FLAG_PREFIX_
+    "catch_exceptions=0@D\n"
+    "      Do not report exceptions as test failures. Instead, allow them\n"
+    "      to crash the program or throw a pop-up (on Windows).\n"
+    "\n"
+    "Except for @G--" GTEST_FLAG_PREFIX_
+    "list_tests@D, you can alternatively set "
+    "the corresponding\n"
+    "environment variable of a flag (all letters in upper-case). For example, "
+    "to\n"
+    "disable colored text output, you can either specify "
+    "@G--" GTEST_FLAG_PREFIX_
+    "color=no@D or set\n"
+    "the @G" GTEST_FLAG_PREFIX_UPPER_
+    "COLOR@D environment variable to @Gno@D.\n"
+    "\n"
+    "For more information, please read the " GTEST_NAME_
+    " documentation at\n"
+    "@G" GTEST_PROJECT_URL_ "@D. If you find a bug in " GTEST_NAME_
+    "\n"
+    "(not one in your own code or tests), please report it to\n"
+    "@G<" GTEST_DEV_EMAIL_ ">@D.\n";
+
+static bool ParseGoogleTestFlag(const char* const arg) {
+#define GTEST_INTERNAL_PARSE_FLAG(flag_name)  \
+  do {                                        \
+    auto value = GTEST_FLAG_GET(flag_name);   \
+    if (ParseFlag(arg, #flag_name, &value)) { \
+      GTEST_FLAG_SET(flag_name, value);       \
+      return true;                            \
+    }                                         \
+  } while (false)
+
+  GTEST_INTERNAL_PARSE_FLAG(also_run_disabled_tests);
+  GTEST_INTERNAL_PARSE_FLAG(break_on_failure);
+  GTEST_INTERNAL_PARSE_FLAG(catch_exceptions);
+  GTEST_INTERNAL_PARSE_FLAG(color);
+  GTEST_INTERNAL_PARSE_FLAG(death_test_style);
+  GTEST_INTERNAL_PARSE_FLAG(death_test_use_fork);
+  GTEST_INTERNAL_PARSE_FLAG(fail_fast);
+  GTEST_INTERNAL_PARSE_FLAG(filter);
+  GTEST_INTERNAL_PARSE_FLAG(internal_run_death_test);
+  GTEST_INTERNAL_PARSE_FLAG(list_tests);
+  GTEST_INTERNAL_PARSE_FLAG(output);
+  GTEST_INTERNAL_PARSE_FLAG(brief);
+  GTEST_INTERNAL_PARSE_FLAG(print_time);
+  GTEST_INTERNAL_PARSE_FLAG(print_utf8);
+  GTEST_INTERNAL_PARSE_FLAG(random_seed);
+  GTEST_INTERNAL_PARSE_FLAG(repeat);
+  GTEST_INTERNAL_PARSE_FLAG(recreate_environments_when_repeating);
+  GTEST_INTERNAL_PARSE_FLAG(shuffle);
+  GTEST_INTERNAL_PARSE_FLAG(stack_trace_depth);
+  GTEST_INTERNAL_PARSE_FLAG(stream_result_to);
+  GTEST_INTERNAL_PARSE_FLAG(throw_on_failure);
+  return false;
+}
+
+#if GTEST_USE_OWN_FLAGFILE_FLAG_
+static void LoadFlagsFromFile(const std::string& path) {
+  FILE* flagfile = posix::FOpen(path.c_str(), "r");
+  if (!flagfile) {
+    GTEST_LOG_(FATAL) << "Unable to open file \"" << GTEST_FLAG_GET(flagfile)
+                      << "\"";
+  }
+  std::string contents(ReadEntireFile(flagfile));
+  posix::FClose(flagfile);
+  std::vector<std::string> lines;
+  SplitString(contents, '\n', &lines);
+  for (size_t i = 0; i < lines.size(); ++i) {
+    if (lines[i].empty()) continue;
+    if (!ParseGoogleTestFlag(lines[i].c_str())) g_help_flag = true;
+  }
+}
+#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
+
+// Parses the command line for Google Test flags, without initializing
+// other parts of Google Test.  The type parameter CharType can be
+// instantiated to either char or wchar_t.
+template <typename CharType>
+void ParseGoogleTestFlagsOnlyImpl(int* argc, CharType** argv) {
+  std::string flagfile_value;
+  for (int i = 1; i < *argc; i++) {
+    const std::string arg_string = StreamableToString(argv[i]);
+    const char* const arg = arg_string.c_str();
+
+    using internal::ParseFlag;
+
+    bool remove_flag = false;
+    if (ParseGoogleTestFlag(arg)) {
+      remove_flag = true;
+#if GTEST_USE_OWN_FLAGFILE_FLAG_
+    } else if (ParseFlag(arg, "flagfile", &flagfile_value)) {
+      GTEST_FLAG_SET(flagfile, flagfile_value);
+      LoadFlagsFromFile(flagfile_value);
+      remove_flag = true;
+#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
+    } else if (arg_string == "--help" || HasGoogleTestFlagPrefix(arg)) {
+      // Both help flag and unrecognized Google Test flags (excluding
+      // internal ones) trigger help display.
+      g_help_flag = true;
+    }
+
+    if (remove_flag) {
+      // Shift the remainder of the argv list left by one.  Note
+      // that argv has (*argc + 1) elements, the last one always being
+      // NULL.  The following loop moves the trailing NULL element as
+      // well.
+      for (int j = i; j != *argc; j++) {
+        argv[j] = argv[j + 1];
+      }
+
+      // Decrements the argument count.
+      (*argc)--;
+
+      // We also need to decrement the iterator as we just removed
+      // an element.
+      i--;
+    }
+  }
+
+  if (g_help_flag) {
+    // We print the help here instead of in RUN_ALL_TESTS(), as the
+    // latter may not be called at all if the user is using Google
+    // Test with another testing framework.
+    PrintColorEncoded(kColorEncodedHelpMessage);
+  }
+}
+
+// Parses the command line for Google Test flags, without initializing
+// other parts of Google Test.
+void ParseGoogleTestFlagsOnly(int* argc, char** argv) {
+#if GTEST_HAS_ABSL
+  if (*argc > 0) {
+    // absl::ParseCommandLine() requires *argc > 0.
+    auto positional_args = absl::flags_internal::ParseCommandLineImpl(
+        *argc, argv, absl::flags_internal::ArgvListAction::kRemoveParsedArgs,
+        absl::flags_internal::UsageFlagsAction::kHandleUsage,
+        absl::flags_internal::OnUndefinedFlag::kReportUndefined);
+    // Any command-line positional arguments not part of any command-line flag
+    // (or arguments to a flag) are copied back out to argv, with the program
+    // invocation name at position 0, and argc is resized. This includes
+    // positional arguments after the flag-terminating delimiter '--'.
+    // See https://abseil.io/docs/cpp/guides/flags.
+    std::copy(positional_args.begin(), positional_args.end(), argv);
+    if (static_cast<int>(positional_args.size()) < *argc) {
+      argv[positional_args.size()] = nullptr;
+      *argc = static_cast<int>(positional_args.size());
+    }
+  }
+#else
+  ParseGoogleTestFlagsOnlyImpl(argc, argv);
+#endif
+
+  // Fix the value of *_NSGetArgc() on macOS, but if and only if
+  // *_NSGetArgv() == argv
+  // Only applicable to char** version of argv
+#if GTEST_OS_MAC
+#ifndef GTEST_OS_IOS
+  if (*_NSGetArgv() == argv) {
+    *_NSGetArgc() = *argc;
+  }
+#endif
+#endif
+}
+void ParseGoogleTestFlagsOnly(int* argc, wchar_t** argv) {
+  ParseGoogleTestFlagsOnlyImpl(argc, argv);
+}
+
+// The internal implementation of InitGoogleTest().
+//
+// The type parameter CharType can be instantiated to either char or
+// wchar_t.
+template <typename CharType>
+void InitGoogleTestImpl(int* argc, CharType** argv) {
+  // We don't want to run the initialization code twice.
+  if (GTestIsInitialized()) return;
+
+  if (*argc <= 0) return;
+
+  g_argvs.clear();
+  for (int i = 0; i != *argc; i++) {
+    g_argvs.push_back(StreamableToString(argv[i]));
+  }
+
+#if GTEST_HAS_ABSL
+  absl::InitializeSymbolizer(g_argvs[0].c_str());
+
+  // When using the Abseil Flags library, set the program usage message to the
+  // help message, but remove the color-encoding from the message first.
+  absl::SetProgramUsageMessage(absl::StrReplaceAll(
+      kColorEncodedHelpMessage,
+      {{"@D", ""}, {"@R", ""}, {"@G", ""}, {"@Y", ""}, {"@@", "@"}}));
+#endif  // GTEST_HAS_ABSL
+
+  ParseGoogleTestFlagsOnly(argc, argv);
+  GetUnitTestImpl()->PostFlagParsingInit();
+}
+
+}  // namespace internal
+
+// Initializes Google Test.  This must be called before calling
+// RUN_ALL_TESTS().  In particular, it parses a command line for the
+// flags that Google Test recognizes.  Whenever a Google Test flag is
+// seen, it is removed from argv, and *argc is decremented.
+//
+// No value is returned.  Instead, the Google Test flag variables are
+// updated.
+//
+// Calling the function for the second time has no user-visible effect.
+void InitGoogleTest(int* argc, char** argv) {
+#if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(argc, argv);
+#else   // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  internal::InitGoogleTestImpl(argc, argv);
+#endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+}
+
+// This overloaded version can be used in Windows programs compiled in
+// UNICODE mode.
+void InitGoogleTest(int* argc, wchar_t** argv) {
+#if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(argc, argv);
+#else   // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  internal::InitGoogleTestImpl(argc, argv);
+#endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+}
+
+// This overloaded version can be used on Arduino/embedded platforms where
+// there is no argc/argv.
+void InitGoogleTest() {
+  // Since Arduino doesn't have a command line, fake out the argc/argv arguments
+  int argc = 1;
+  const auto arg0 = "dummy";
+  char* argv0 = const_cast<char*>(arg0);
+  char** argv = &argv0;
+
+#if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(&argc, argv);
+#else   // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  internal::InitGoogleTestImpl(&argc, argv);
+#endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+}
+
+#if !defined(GTEST_CUSTOM_TEMPDIR_FUNCTION_)
+// Return value of first environment variable that is set and contains
+// a non-empty string. If there are none, return the "fallback" string.
+// Since we like the temporary directory to have a directory separator suffix,
+// add it if not provided in the environment variable value.
+static std::string GetTempDirFromEnv(
+    std::initializer_list<const char*> environment_variables,
+    const char* fallback, char separator) {
+  for (const char* variable_name : environment_variables) {
+    const char* value = internal::posix::GetEnv(variable_name);
+    if (value != nullptr && value[0] != '\0') {
+      if (value[strlen(value) - 1] != separator) {
+        return std::string(value).append(1, separator);
+      }
+      return value;
+    }
+  }
+  return fallback;
+}
+#endif
+
+std::string TempDir() {
+#if defined(GTEST_CUSTOM_TEMPDIR_FUNCTION_)
+  return GTEST_CUSTOM_TEMPDIR_FUNCTION_();
+#elif GTEST_OS_WINDOWS || GTEST_OS_WINDOWS_MOBILE
+  return GetTempDirFromEnv({"TEST_TMPDIR", "TEMP"}, "\\temp\\", '\\');
+#elif GTEST_OS_LINUX_ANDROID
+  return GetTempDirFromEnv({"TEST_TMPDIR", "TMPDIR"}, "/data/local/tmp/", '/');
+#else
+  return GetTempDirFromEnv({"TEST_TMPDIR", "TMPDIR"}, "/tmp/", '/');
+#endif
+}
+
+// Class ScopedTrace
+
+// Pushes the given source file location and message onto a per-thread
+// trace stack maintained by Google Test.
+void ScopedTrace::PushTrace(const char* file, int line, std::string message) {
+  internal::TraceInfo trace;
+  trace.file = file;
+  trace.line = line;
+  trace.message.swap(message);
+
+  UnitTest::GetInstance()->PushGTestTrace(trace);
+}
+
+// Pops the info pushed by the c'tor.
+ScopedTrace::~ScopedTrace() GTEST_LOCK_EXCLUDED_(&UnitTest::mutex_) {
+  UnitTest::GetInstance()->PopGTestTrace();
+}
+
+}  // namespace testing
diff --git a/test/gtest/gtest_main.cc b/test/gtest/src/gtest_main.cc
similarity index 97%
rename from test/gtest/gtest_main.cc
rename to test/gtest/src/gtest_main.cc
index 46b27c3..4497637 100644
--- a/test/gtest/gtest_main.cc
+++ b/test/gtest/src/gtest_main.cc
@@ -28,15 +28,14 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <cstdio>
+
 #include "gtest/gtest.h"
 
 #if GTEST_OS_ESP8266 || GTEST_OS_ESP32
 #if GTEST_OS_ESP8266
 extern "C" {
 #endif
-void setup() {
-  testing::InitGoogleTest();
-}
+void setup() { testing::InitGoogleTest(); }
 
 void loop() { RUN_ALL_TESTS(); }
 
diff --git a/test/include_windows_h.cc b/test/include_windows_h.cc
new file mode 100644
index 0000000..44f541f
--- /dev/null
+++ b/test/include_windows_h.cc
@@ -0,0 +1,6 @@
+// Test if including windows.h conflicts with httplib.h
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#include <httplib.h>
diff --git a/test/make-shared-library.sh b/test/make-shared-library.sh
new file mode 100755
index 0000000..04f2fc0
--- /dev/null
+++ b/test/make-shared-library.sh
@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+if [ "$#" -ne 1 ]; then
+    echo "Usage: $0 build_dir"
+    exit 1
+fi
+
+BUILD_DIR=$1
+
+# Make the build directory
+rm -rf $BUILD_DIR
+mkdir -p $BUILD_DIR/out
+
+cd $BUILD_DIR
+
+# Build the version
+git checkout $BUILD_DIR -q
+
+cmake \
+  -DCMAKE_BUILD_TYPE=Debug \
+  -DCMAKE_CXX_FLAGS="-g -Og" \
+  -DBUILD_SHARED_LIBS=ON \
+  -DHTTPLIB_COMPILE=ON \
+  -DCMAKE_INSTALL_PREFIX=./out \
+  ../..
+
+cmake --build . --target install
+cmake --build . --target clean
+
diff --git a/test/test.cc b/test/test.cc
index ebc50f6..a57b7c9 100644
--- a/test/test.cc
+++ b/test/test.cc
@@ -9,6 +9,7 @@
 
 #include <atomic>
 #include <chrono>
+#include <fstream>
 #include <future>
 #include <limits>
 #include <memory>
@@ -42,6 +43,10 @@ const int PORT = 1234;
 const string LONG_QUERY_VALUE = string(25000, '@');
 const string LONG_QUERY_URL = "/long-query-value?key=" + LONG_QUERY_VALUE;
 
+const string TOO_LONG_QUERY_VALUE = string(35000, '@');
+const string TOO_LONG_QUERY_URL =
+    "/too-long-query-value?key=" + TOO_LONG_QUERY_VALUE;
+
 const std::string JSON_DATA = "{\"hello\":\"world\"}";
 
 const string LARGE_DATA = string(1024 * 1024 * 100, '@'); // 100MB
@@ -59,7 +64,16 @@ MultipartFormData &get_file_value(MultipartFormDataItems &files,
 #endif
 }
 
-#ifndef _WIN32
+static void read_file(const std::string &path, std::string &out) {
+  std::ifstream fs(path, std::ios_base::binary);
+  if (!fs) throw std::runtime_error("File not found: " + path);
+  fs.seekg(0, std::ios_base::end);
+  auto size = fs.tellg();
+  fs.seekg(0);
+  out.resize(static_cast<size_t>(size));
+  fs.read(&out[0], static_cast<std::streamsize>(size));
+}
+
 class UnixSocketTest : public ::testing::Test {
 protected:
   void TearDown() override { std::remove(pathname_.c_str()); }
@@ -156,27 +170,29 @@ TEST_F(UnixSocketTest, abstract) {
 }
 #endif
 
-TEST(SocketStream, is_writable_UNIX) {
+#ifndef _WIN32
+TEST(SocketStream, wait_writable_UNIX) {
   int fds[2];
   ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM, 0, fds));
 
   const auto asSocketStream = [&](socket_t fd,
                                   std::function<bool(Stream &)> func) {
-    return detail::process_client_socket(fd, 0, 0, 0, 0, func);
+    return detail::process_client_socket(
+        fd, 0, 0, 0, 0, 0, std::chrono::steady_clock::time_point::min(), func);
   };
   asSocketStream(fds[0], [&](Stream &s0) {
     EXPECT_EQ(s0.socket(), fds[0]);
-    EXPECT_TRUE(s0.is_writable());
+    EXPECT_TRUE(s0.wait_writable());
 
     EXPECT_EQ(0, close(fds[1]));
-    EXPECT_FALSE(s0.is_writable());
+    EXPECT_FALSE(s0.wait_writable());
 
     return true;
   });
   EXPECT_EQ(0, close(fds[0]));
 }
 
-TEST(SocketStream, is_writable_INET) {
+TEST(SocketStream, wait_writable_INET) {
   sockaddr_in addr;
   memset(&addr, 0, sizeof(addr));
   addr.sin_family = AF_INET;
@@ -206,11 +222,12 @@ TEST(SocketStream, is_writable_INET) {
 
   const auto asSocketStream = [&](socket_t fd,
                                   std::function<bool(Stream &)> func) {
-    return detail::process_client_socket(fd, 0, 0, 0, 0, func);
+    return detail::process_client_socket(
+        fd, 0, 0, 0, 0, 0, std::chrono::steady_clock::time_point::min(), func);
   };
   asSocketStream(disconnected_svr_sock, [&](Stream &ss) {
     EXPECT_EQ(ss.socket(), disconnected_svr_sock);
-    EXPECT_FALSE(ss.is_writable());
+    EXPECT_FALSE(ss.wait_writable());
 
     return true;
   });
@@ -511,6 +528,15 @@ TEST(GetHeaderValueTest, RegularValueInt) {
   EXPECT_EQ(100ull, val);
 }
 
+TEST(GetHeaderValueTest, RegularInvalidValueInt) {
+  Headers headers = {{"Content-Length", "x"}};
+  auto is_invalid_value = false;
+  auto val = detail::get_header_value_u64(headers, "Content-Length", 0, 0,
+                                          is_invalid_value);
+  EXPECT_EQ(0ull, val);
+  EXPECT_TRUE(is_invalid_value);
+}
+
 TEST(GetHeaderValueTest, Range) {
   {
     Headers headers = {make_range_header({{1, -1}})};
@@ -646,7 +672,7 @@ TEST(ParseAcceptEncoding1, AcceptEncoding) {
 
 TEST(ParseAcceptEncoding2, AcceptEncoding) {
   Request req;
-  req.set_header("Accept-Encoding", "gzip, deflate, br");
+  req.set_header("Accept-Encoding", "gzip, deflate, br, zstd");
 
   Response res;
   res.set_header("Content-Type", "text/plain");
@@ -657,6 +683,8 @@ TEST(ParseAcceptEncoding2, AcceptEncoding) {
   EXPECT_TRUE(ret == detail::EncodingType::Brotli);
 #elif CPPHTTPLIB_ZLIB_SUPPORT
   EXPECT_TRUE(ret == detail::EncodingType::Gzip);
+#elif CPPHTTPLIB_ZSTD_SUPPORT
+  EXPECT_TRUE(ret == detail::EncodingType::Zstd);
 #else
   EXPECT_TRUE(ret == detail::EncodingType::None);
 #endif
@@ -664,7 +692,8 @@ TEST(ParseAcceptEncoding2, AcceptEncoding) {
 
 TEST(ParseAcceptEncoding3, AcceptEncoding) {
   Request req;
-  req.set_header("Accept-Encoding", "br;q=1.0, gzip;q=0.8, *;q=0.1");
+  req.set_header("Accept-Encoding",
+                 "br;q=1.0, gzip;q=0.8, zstd;q=0.8, *;q=0.1");
 
   Response res;
   res.set_header("Content-Type", "text/plain");
@@ -675,6 +704,8 @@ TEST(ParseAcceptEncoding3, AcceptEncoding) {
   EXPECT_TRUE(ret == detail::EncodingType::Brotli);
 #elif CPPHTTPLIB_ZLIB_SUPPORT
   EXPECT_TRUE(ret == detail::EncodingType::Gzip);
+#elif CPPHTTPLIB_ZSTD_SUPPORT
+  EXPECT_TRUE(ret == detail::EncodingType::Zstd);
 #else
   EXPECT_TRUE(ret == detail::EncodingType::None);
 #endif
@@ -718,7 +749,7 @@ TEST(ChunkedEncodingTest, FromHTTPWatch_Online) {
   ASSERT_TRUE(res);
 
   std::string out;
-  detail::read_file("./image.jpg", out);
+  read_file("./image.jpg", out);
 
   EXPECT_EQ(StatusCode::OK_200, res->status);
   EXPECT_EQ(out, res->body);
@@ -771,7 +802,7 @@ TEST(ChunkedEncodingTest, WithContentReceiver_Online) {
   ASSERT_TRUE(res);
 
   std::string out;
-  detail::read_file("./image.jpg", out);
+  read_file("./image.jpg", out);
 
   EXPECT_EQ(StatusCode::OK_200, res->status);
   EXPECT_EQ(out, body);
@@ -803,7 +834,7 @@ TEST(ChunkedEncodingTest, WithResponseHandlerAndContentReceiver_Online) {
   ASSERT_TRUE(res);
 
   std::string out;
-  detail::read_file("./image.jpg", out);
+  read_file("./image.jpg", out);
 
   EXPECT_EQ(StatusCode::OK_200, res->status);
   EXPECT_EQ(out, body);
@@ -1350,6 +1381,14 @@ TEST(CancelTest, WithCancelLargePayloadDelete) {
   EXPECT_EQ(Error::Canceled, res.error());
 }
 
+static std::string remove_whitespace(const std::string &input) {
+  std::string output;
+  output.reserve(input.size());
+  std::copy_if(input.begin(), input.end(), std::back_inserter(output),
+               [](unsigned char c) { return !std::isspace(c); });
+  return output;
+}
+
 TEST(BaseAuthTest, FromHTTPWatch_Online) {
 #ifdef CPPHTTPLIB_DEFAULT_HTTPBIN
   auto host = "httpbin.org";
@@ -1377,8 +1416,8 @@ TEST(BaseAuthTest, FromHTTPWatch_Online) {
     auto res =
         cli.Get(path, {make_basic_authentication_header("hello", "world")});
     ASSERT_TRUE(res);
-    EXPECT_EQ("{\n  \"authenticated\": true, \n  \"user\": \"hello\"\n}\n",
-              res->body);
+    EXPECT_EQ("{\"authenticated\":true,\"user\":\"hello\"}",
+              remove_whitespace(res->body));
     EXPECT_EQ(StatusCode::OK_200, res->status);
   }
 
@@ -1386,8 +1425,8 @@ TEST(BaseAuthTest, FromHTTPWatch_Online) {
     cli.set_basic_auth("hello", "world");
     auto res = cli.Get(path);
     ASSERT_TRUE(res);
-    EXPECT_EQ("{\n  \"authenticated\": true, \n  \"user\": \"hello\"\n}\n",
-              res->body);
+    EXPECT_EQ("{\"authenticated\":true,\"user\":\"hello\"}",
+              remove_whitespace(res->body));
     EXPECT_EQ(StatusCode::OK_200, res->status);
   }
 
@@ -1443,8 +1482,8 @@ TEST(DigestAuthTest, FromHTTPWatch_Online) {
     for (const auto &path : paths) {
       auto res = cli.Get(path.c_str());
       ASSERT_TRUE(res);
-      EXPECT_EQ("{\n  \"authenticated\": true, \n  \"user\": \"hello\"\n}\n",
-                res->body);
+      EXPECT_EQ("{\"authenticated\":true,\"user\":\"hello\"}",
+                remove_whitespace(res->body));
       EXPECT_EQ(StatusCode::OK_200, res->status);
     }
 
@@ -1575,36 +1614,40 @@ TEST(YahooRedirectTest, Redirect_Online) {
   EXPECT_EQ("https://www.yahoo.com/", res->location);
 }
 
+// Previously "nghttp2.org" "/httpbin/redirect-to"
+#define REDIR_HOST "httpbingo.org"
+#define REDIR_PATH "/redirect-to"
+
 TEST(HttpsToHttpRedirectTest, Redirect_Online) {
-  SSLClient cli("nghttp2.org");
+  SSLClient cli(REDIR_HOST);
   cli.set_follow_location(true);
-  auto res = cli.Get(
-      "/httpbin/redirect-to?url=http%3A%2F%2Fwww.google.com&status_code=302");
+  auto res =
+      cli.Get(REDIR_PATH "?url=http%3A%2F%2Fexample.com&status_code=302");
   ASSERT_TRUE(res);
   EXPECT_EQ(StatusCode::OK_200, res->status);
 }
 
 TEST(HttpsToHttpRedirectTest2, Redirect_Online) {
-  SSLClient cli("nghttp2.org");
+  SSLClient cli(REDIR_HOST);
   cli.set_follow_location(true);
 
   Params params;
-  params.emplace("url", "http://www.google.com");
+  params.emplace("url", "http://example.com");
   params.emplace("status_code", "302");
 
-  auto res = cli.Get("/httpbin/redirect-to", params, Headers{});
+  auto res = cli.Get(REDIR_PATH, params, Headers{});
   ASSERT_TRUE(res);
   EXPECT_EQ(StatusCode::OK_200, res->status);
 }
 
 TEST(HttpsToHttpRedirectTest3, Redirect_Online) {
-  SSLClient cli("nghttp2.org");
+  SSLClient cli(REDIR_HOST);
   cli.set_follow_location(true);
 
   Params params;
-  params.emplace("url", "http://www.google.com");
+  params.emplace("url", "http://example.com");
 
-  auto res = cli.Get("/httpbin/redirect-to?status_code=302", params, Headers{});
+  auto res = cli.Get(REDIR_PATH "?status_code=302", params, Headers{});
   ASSERT_TRUE(res);
   EXPECT_EQ(StatusCode::OK_200, res->status);
 }
@@ -1854,6 +1897,32 @@ TEST(PathUrlEncodeTest, PathUrlEncode) {
   }
 }
 
+TEST(PathUrlEncodeTest, IncludePercentEncodingLF) {
+  Server svr;
+
+  svr.Get("/", [](const Request &req, Response &) {
+    EXPECT_EQ("\x0A", req.get_param_value("something"));
+  });
+
+  auto thread = std::thread([&]() { svr.listen(HOST, PORT); });
+  auto se = detail::scope_exit([&] {
+    svr.stop();
+    thread.join();
+    ASSERT_FALSE(svr.is_running());
+  });
+
+  svr.wait_until_ready();
+
+  {
+    Client cli(HOST, PORT);
+    cli.set_url_encode(false);
+
+    auto res = cli.Get("/?something=%0A");
+    ASSERT_TRUE(res);
+    EXPECT_EQ(StatusCode::OK_200, res->status);
+  }
+}
+
 TEST(BindServerTest, DISABLED_BindDualStack) {
   Server svr;
 
@@ -2802,6 +2871,11 @@ protected:
                EXPECT_EQ(LONG_QUERY_URL, req.target);
                EXPECT_EQ(LONG_QUERY_VALUE, req.get_param_value("key"));
              })
+        .Get("/too-long-query-value",
+             [&](const Request &req, Response & /*res*/) {
+               EXPECT_EQ(TOO_LONG_QUERY_URL, req.target);
+               EXPECT_EQ(TOO_LONG_QUERY_VALUE, req.get_param_value("key"));
+             })
         .Get("/array-param",
              [&](const Request &req, Response & /*res*/) {
                EXPECT_EQ(3u, req.get_param_value_count("array"));
@@ -2942,7 +3016,13 @@ protected:
                res.status = 401;
                res.set_header("WWW-Authenticate", "Basic realm=123456");
              })
-#if defined(CPPHTTPLIB_ZLIB_SUPPORT) || defined(CPPHTTPLIB_BROTLI_SUPPORT)
+        .Delete("/issue609",
+                [](const httplib::Request &, httplib::Response &res,
+                   const httplib::ContentReader &) {
+                  res.set_content("ok", "text/plain");
+                })
+#if defined(CPPHTTPLIB_ZLIB_SUPPORT) || defined(CPPHTTPLIB_BROTLI_SUPPORT) ||  \
+    defined(CPPHTTPLIB_ZSTD_SUPPORT)
         .Get("/compress",
              [&](const Request & /*req*/, Response &res) {
                res.set_content(
@@ -3499,7 +3579,7 @@ TEST_F(ServerTest, LongRequest) {
 
 TEST_F(ServerTest, TooLongRequest) {
   std::string request;
-  for (size_t i = 0; i < 545; i++) {
+  for (size_t i = 0; i < 546; i++) {
     request += "/TooLongRequest";
   }
   request += "_NG";
@@ -3510,6 +3590,19 @@ TEST_F(ServerTest, TooLongRequest) {
   EXPECT_EQ(StatusCode::UriTooLong_414, res->status);
 }
 
+TEST_F(ServerTest, AlmostTooLongRequest) {
+  // test for #2046 - URI length check shouldn't include other content on req
+  // line URI is max URI length, minus 14 other chars in req line (GET, space,
+  // leading /, space, HTTP/1.1)
+  std::string request =
+      "/" + string(CPPHTTPLIB_REQUEST_URI_MAX_LENGTH - 14, 'A');
+
+  auto res = cli_.Get(request.c_str());
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(StatusCode::NotFound_404, res->status);
+}
+
 TEST_F(ServerTest, LongHeader) {
   Request req;
   req.method = "GET";
@@ -3571,6 +3664,13 @@ TEST_F(ServerTest, LongQueryValue) {
   EXPECT_EQ(StatusCode::UriTooLong_414, res->status);
 }
 
+TEST_F(ServerTest, TooLongQueryValue) {
+  auto res = cli_.Get(TOO_LONG_QUERY_URL.c_str());
+
+  ASSERT_FALSE(res);
+  EXPECT_EQ(Error::Read, res.error());
+}
+
 TEST_F(ServerTest, TooLongHeader) {
   Request req;
   req.method = "GET";
@@ -4013,6 +4113,13 @@ TEST_F(ServerTest, Issue1772) {
   EXPECT_EQ(StatusCode::Unauthorized_401, res->status);
 }
 
+TEST_F(ServerTest, Issue609) {
+  auto res = cli_.Delete("/issue609");
+  ASSERT_TRUE(res);
+  EXPECT_EQ(StatusCode::OK_200, res->status);
+  EXPECT_EQ(std::string("ok"), res->body);
+}
+
 TEST_F(ServerTest, GetStreamedChunked) {
   auto res = cli_.Get("/streamed-chunked");
   ASSERT_TRUE(res);
@@ -4843,6 +4950,245 @@ TEST_F(ServerTest, Brotli) {
 }
 #endif
 
+#ifdef CPPHTTPLIB_ZSTD_SUPPORT
+TEST_F(ServerTest, Zstd) {
+  Headers headers;
+  headers.emplace("Accept-Encoding", "zstd");
+  auto res = cli_.Get("/compress", headers);
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ("zstd", res->get_header_value("Content-Encoding"));
+  EXPECT_EQ("text/plain", res->get_header_value("Content-Type"));
+  EXPECT_EQ("26", res->get_header_value("Content-Length"));
+  EXPECT_EQ("123456789012345678901234567890123456789012345678901234567890123456"
+            "7890123456789012345678901234567890",
+            res->body);
+  EXPECT_EQ(StatusCode::OK_200, res->status);
+}
+
+TEST_F(ServerTest, ZstdWithoutAcceptEncoding) {
+  Headers headers;
+  headers.emplace("Accept-Encoding", "");
+  auto res = cli_.Get("/compress", headers);
+
+  ASSERT_TRUE(res);
+  EXPECT_TRUE(res->get_header_value("Content-Encoding").empty());
+  EXPECT_EQ("text/plain", res->get_header_value("Content-Type"));
+  EXPECT_EQ("100", res->get_header_value("Content-Length"));
+  EXPECT_EQ("123456789012345678901234567890123456789012345678901234567890123456"
+            "7890123456789012345678901234567890",
+            res->body);
+  EXPECT_EQ(StatusCode::OK_200, res->status);
+}
+
+TEST_F(ServerTest, ZstdWithContentReceiver) {
+  Headers headers;
+  headers.emplace("Accept-Encoding", "zstd");
+  std::string body;
+  auto res = cli_.Get("/compress", headers,
+                      [&](const char *data, uint64_t data_length) {
+                        EXPECT_EQ(100U, data_length);
+                        body.append(data, data_length);
+                        return true;
+                      });
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ("zstd", res->get_header_value("Content-Encoding"));
+  EXPECT_EQ("text/plain", res->get_header_value("Content-Type"));
+  EXPECT_EQ("26", res->get_header_value("Content-Length"));
+  EXPECT_EQ("123456789012345678901234567890123456789012345678901234567890123456"
+            "7890123456789012345678901234567890",
+            body);
+  EXPECT_EQ(StatusCode::OK_200, res->status);
+}
+
+TEST_F(ServerTest, ZstdWithoutDecompressing) {
+  Headers headers;
+  headers.emplace("Accept-Encoding", "zstd");
+
+  cli_.set_decompress(false);
+  auto res = cli_.Get("/compress", headers);
+
+  unsigned char compressed[26] = {0x28, 0xb5, 0x2f, 0xfd, 0x20, 0x64, 0x8d,
+                                  0x00, 0x00, 0x50, 0x31, 0x32, 0x33, 0x34,
+                                  0x35, 0x36, 0x37, 0x38, 0x39, 0x30, 0x01,
+                                  0x00, 0xd7, 0xa9, 0x20, 0x01};
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ("zstd", res->get_header_value("Content-Encoding"));
+  EXPECT_EQ("text/plain", res->get_header_value("Content-Type"));
+  EXPECT_EQ("26", res->get_header_value("Content-Length"));
+  EXPECT_EQ(StatusCode::OK_200, res->status);
+  ASSERT_EQ(26U, res->body.size());
+  EXPECT_TRUE(std::memcmp(compressed, res->body.data(), sizeof(compressed)) ==
+              0);
+}
+
+TEST_F(ServerTest, ZstdWithContentReceiverWithoutAcceptEncoding) {
+  Headers headers;
+  headers.emplace("Accept-Encoding", "");
+
+  std::string body;
+  auto res = cli_.Get("/compress", headers,
+                      [&](const char *data, uint64_t data_length) {
+                        EXPECT_EQ(100U, data_length);
+                        body.append(data, data_length);
+                        return true;
+                      });
+
+  ASSERT_TRUE(res);
+  EXPECT_TRUE(res->get_header_value("Content-Encoding").empty());
+  EXPECT_EQ("text/plain", res->get_header_value("Content-Type"));
+  EXPECT_EQ("100", res->get_header_value("Content-Length"));
+  EXPECT_EQ("123456789012345678901234567890123456789012345678901234567890123456"
+            "7890123456789012345678901234567890",
+            body);
+  EXPECT_EQ(StatusCode::OK_200, res->status);
+}
+
+TEST_F(ServerTest, NoZstd) {
+  Headers headers;
+  headers.emplace("Accept-Encoding", "zstd");
+  auto res = cli_.Get("/nocompress", headers);
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(false, res->has_header("Content-Encoding"));
+  EXPECT_EQ("application/octet-stream", res->get_header_value("Content-Type"));
+  EXPECT_EQ("100", res->get_header_value("Content-Length"));
+  EXPECT_EQ("123456789012345678901234567890123456789012345678901234567890123456"
+            "7890123456789012345678901234567890",
+            res->body);
+  EXPECT_EQ(StatusCode::OK_200, res->status);
+}
+
+TEST_F(ServerTest, NoZstdWithContentReceiver) {
+  Headers headers;
+  headers.emplace("Accept-Encoding", "zstd");
+  std::string body;
+  auto res = cli_.Get("/nocompress", headers,
+                      [&](const char *data, uint64_t data_length) {
+                        EXPECT_EQ(100U, data_length);
+                        body.append(data, data_length);
+                        return true;
+                      });
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(false, res->has_header("Content-Encoding"));
+  EXPECT_EQ("application/octet-stream", res->get_header_value("Content-Type"));
+  EXPECT_EQ("100", res->get_header_value("Content-Length"));
+  EXPECT_EQ("123456789012345678901234567890123456789012345678901234567890123456"
+            "7890123456789012345678901234567890",
+            body);
+  EXPECT_EQ(StatusCode::OK_200, res->status);
+}
+
+// TODO: How to enable zstd ??
+TEST_F(ServerTest, MultipartFormDataZstd) {
+  MultipartFormDataItems items = {
+      {"key1", "test", "", ""},
+      {"key2", "--abcdefg123", "", ""},
+  };
+  Headers headers;
+  headers.emplace("Accept-Encoding", "zstd");
+
+  cli_.set_compress(true);
+  auto res = cli_.Post("/compress-multipart", headers, items);
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(StatusCode::OK_200, res->status);
+}
+
+TEST_F(ServerTest, PutWithContentProviderWithZstd) {
+  Headers headers;
+  headers.emplace("Accept-Encoding", "zstd");
+
+  cli_.set_compress(true);
+  auto res = cli_.Put(
+      "/put", headers, 3,
+      [](size_t /*offset*/, size_t /*length*/, DataSink &sink) {
+        sink.os << "PUT";
+        return true;
+      },
+      "text/plain");
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(StatusCode::OK_200, res->status);
+  EXPECT_EQ("PUT", res->body);
+}
+
+TEST(ZstdDecompressor, ChunkedDecompression) {
+  std::string data;
+  for (size_t i = 0; i < 32 * 1024; ++i) {
+    data.push_back(static_cast<char>('a' + i % 26));
+  }
+
+  std::string compressed_data;
+  {
+    httplib::detail::zstd_compressor compressor;
+    bool result = compressor.compress(
+        data.data(), data.size(),
+        /*last=*/true,
+        [&](const char *compressed_data_chunk, size_t compressed_data_size) {
+          compressed_data.insert(compressed_data.size(), compressed_data_chunk,
+                                 compressed_data_size);
+          return true;
+        });
+    ASSERT_TRUE(result);
+  }
+
+  std::string decompressed_data;
+  {
+    httplib::detail::zstd_decompressor decompressor;
+
+    // Chunk size is chosen specifically to have a decompressed chunk size equal
+    // to 16384 bytes 16384 bytes is the size of decompressor output buffer
+    size_t chunk_size = 130;
+    for (size_t chunk_begin = 0; chunk_begin < compressed_data.size();
+         chunk_begin += chunk_size) {
+      size_t current_chunk_size =
+          std::min(compressed_data.size() - chunk_begin, chunk_size);
+      bool result = decompressor.decompress(
+          compressed_data.data() + chunk_begin, current_chunk_size,
+          [&](const char *decompressed_data_chunk,
+              size_t decompressed_data_chunk_size) {
+            decompressed_data.insert(decompressed_data.size(),
+                                     decompressed_data_chunk,
+                                     decompressed_data_chunk_size);
+            return true;
+          });
+      ASSERT_TRUE(result);
+    }
+  }
+  ASSERT_EQ(data, decompressed_data);
+}
+
+TEST(ZstdDecompressor, Decompress) {
+  std::string original_text = "Compressed with ZSTD";
+  unsigned char data[29] = {0x28, 0xb5, 0x2f, 0xfd, 0x20, 0x14, 0xa1, 0x00,
+                            0x00, 0x43, 0x6f, 0x6d, 0x70, 0x72, 0x65, 0x73,
+                            0x73, 0x65, 0x64, 0x20, 0x77, 0x69, 0x74, 0x68,
+                            0x20, 0x5a, 0x53, 0x54, 0x44};
+  std::string compressed_data(data, data + sizeof(data) / sizeof(data[0]));
+
+  std::string decompressed_data;
+  {
+    httplib::detail::zstd_decompressor decompressor;
+
+    bool result = decompressor.decompress(
+        compressed_data.data(), compressed_data.size(),
+        [&](const char *decompressed_data_chunk,
+            size_t decompressed_data_chunk_size) {
+          decompressed_data.insert(decompressed_data.size(),
+                                   decompressed_data_chunk,
+                                   decompressed_data_chunk_size);
+          return true;
+        });
+    ASSERT_TRUE(result);
+  }
+  ASSERT_EQ(original_text, decompressed_data);
+}
+#endif
+
 // Sends a raw request to a server listening at HOST:PORT.
 static bool send_request(time_t read_timeout_sec, const std::string &req,
                          std::string *resp = nullptr) {
@@ -4857,7 +5203,8 @@ static bool send_request(time_t read_timeout_sec, const std::string &req,
   if (client_sock == INVALID_SOCKET) { return false; }
 
   auto ret = detail::process_client_socket(
-      client_sock, read_timeout_sec, 0, 0, 0, [&](Stream &strm) {
+      client_sock, read_timeout_sec, 0, 0, 0, 0,
+      std::chrono::steady_clock::time_point::min(), [&](Stream &strm) {
         if (req.size() !=
             static_cast<size_t>(strm.write(req.data(), req.size()))) {
           return false;
@@ -4901,8 +5248,10 @@ TEST(ServerRequestParsingTest, TrimWhitespaceFromHeaderValues) {
                           "Connection: close\r\n"
                           "\r\n";
 
-  ASSERT_TRUE(send_request(5, req));
-  EXPECT_EQ(header_value, "\v bar \x1B");
+  std::string res;
+  ASSERT_TRUE(send_request(5, req, &res));
+  EXPECT_EQ(header_value, "");
+  EXPECT_EQ("HTTP/1.1 400 Bad Request", res.substr(0, 24));
 }
 
 // Sends a raw request and verifies that there isn't a crash or exception.
@@ -5060,6 +5409,22 @@ TEST(ServerRequestParsingTest, InvalidFieldValueContains_CR_LF_NUL) {
   EXPECT_EQ("HTTP/1.1 400 Bad Request", out.substr(0, 24));
 }
 
+TEST(ServerRequestParsingTest, InvalidFieldValueContains_LF) {
+  std::string out;
+  std::string request(
+      "GET /header_field_value_check HTTP/1.1\r\nTest: [\n\n\n]\r\n\r\n", 55);
+  test_raw_request(request, &out);
+  EXPECT_EQ("HTTP/1.1 400 Bad Request", out.substr(0, 24));
+}
+
+TEST(ServerRequestParsingTest, InvalidFieldNameContains_PreceedingSpaces) {
+  std::string out;
+  std::string request(
+      "GET /header_field_value_check HTTP/1.1\r\n  Test: val\r\n\r\n", 55);
+  test_raw_request(request, &out);
+  EXPECT_EQ("HTTP/1.1 400 Bad Request", out.substr(0, 24));
+}
+
 TEST(ServerRequestParsingTest, EmptyFieldValue) {
   std::string out;
 
@@ -5222,6 +5587,9 @@ TEST(StreamingTest, NoContentLengthStreaming) {
           s += std::string(data, len);
           return true;
         });
+
+    ASSERT_TRUE(res);
+    EXPECT_EQ(StatusCode::OK_200, res->status);
     EXPECT_EQ("aaabbb", s);
   });
   auto get_se = detail::scope_exit([&] { get_thread.join(); });
@@ -6091,7 +6459,7 @@ TEST(SSLClientTest, ServerCertificateVerification4) {
 
 TEST(SSLClientTest, ServerCertificateVerification5_Online) {
   std::string cert;
-  detail::read_file(CA_CERT_FILE, cert);
+  read_file(CA_CERT_FILE, cert);
 
   SSLClient cli("google.com");
   cli.load_ca_cert_store(cert.data(), cert.size());
@@ -6144,7 +6512,7 @@ TEST(SSLClientTest, WildcardHostNameMatch_Online) {
   ASSERT_EQ(StatusCode::OK_200, res->status);
 }
 
-TEST(SSLClientTest, Issue2004) {
+TEST(SSLClientTest, Issue2004_Online) {
   Client client("https://google.com");
   client.set_follow_location(true);
 
@@ -6736,38 +7104,41 @@ TEST(DecodeWithChunkedEncoding, BrotliEncoding_Online) {
 }
 #endif
 
+// Previously "https://nghttp2.org" "/httpbin/redirect-to"
+#undef REDIR_HOST // Silence compiler warning
+#define REDIR_HOST "https://httpbingo.org"
+
 TEST(HttpsToHttpRedirectTest, SimpleInterface_Online) {
-  Client cli("https://nghttp2.org");
+  Client cli(REDIR_HOST);
   cli.set_follow_location(true);
   auto res =
-      cli.Get("/httpbin/"
-              "redirect-to?url=http%3A%2F%2Fwww.google.com&status_code=302");
+      cli.Get(REDIR_PATH "?url=http%3A%2F%2Fexample.com&status_code=302");
 
   ASSERT_TRUE(res);
   EXPECT_EQ(StatusCode::OK_200, res->status);
 }
 
 TEST(HttpsToHttpRedirectTest2, SimpleInterface_Online) {
-  Client cli("https://nghttp2.org");
+  Client cli(REDIR_HOST);
   cli.set_follow_location(true);
 
   Params params;
-  params.emplace("url", "http://www.google.com");
+  params.emplace("url", "http://example.com");
   params.emplace("status_code", "302");
 
-  auto res = cli.Get("/httpbin/redirect-to", params, Headers{});
+  auto res = cli.Get(REDIR_PATH, params, Headers{});
   ASSERT_TRUE(res);
   EXPECT_EQ(StatusCode::OK_200, res->status);
 }
 
 TEST(HttpsToHttpRedirectTest3, SimpleInterface_Online) {
-  Client cli("https://nghttp2.org");
+  Client cli(REDIR_HOST);
   cli.set_follow_location(true);
 
   Params params;
-  params.emplace("url", "http://www.google.com");
+  params.emplace("url", "http://example.com");
 
-  auto res = cli.Get("/httpbin/redirect-to?status_code=302", params, Headers{});
+  auto res = cli.Get(REDIR_PATH "?status_code=302", params, Headers{});
   ASSERT_TRUE(res);
   EXPECT_EQ(StatusCode::OK_200, res->status);
 }
@@ -7496,9 +7867,9 @@ TEST(MultipartFormDataTest, CloseDelimiterWithoutCRLF) {
              "text2"
              "\r\n------------";
 
-  std::string resonse;
-  ASSERT_TRUE(send_request(1, req, &resonse));
-  ASSERT_EQ("200", resonse.substr(9, 3));
+  std::string response;
+  ASSERT_TRUE(send_request(1, req, &response));
+  ASSERT_EQ("200", response.substr(9, 3));
 }
 
 TEST(MultipartFormDataTest, ContentLength) {
@@ -7543,11 +7914,10 @@ TEST(MultipartFormDataTest, ContentLength) {
              "text2"
              "\r\n------------\r\n";
 
-  std::string resonse;
-  ASSERT_TRUE(send_request(1, req, &resonse));
-  ASSERT_EQ("200", resonse.substr(9, 3));
+  std::string response;
+  ASSERT_TRUE(send_request(1, req, &response));
+  ASSERT_EQ("200", response.substr(9, 3));
 }
-
 #endif
 
 TEST(TaskQueueTest, IncreaseAtomicInteger) {
@@ -7950,7 +8320,7 @@ TEST(InvalidHeaderCharsTest, is_field_value) {
   EXPECT_FALSE(detail::fields::is_field_value(" example_token"));
   EXPECT_FALSE(detail::fields::is_field_value("example_token "));
   EXPECT_TRUE(detail::fields::is_field_value("token@123"));
-  EXPECT_FALSE(detail::fields::is_field_value(""));
+  EXPECT_TRUE(detail::fields::is_field_value(""));
   EXPECT_FALSE(detail::fields::is_field_value("example\rtoken"));
   EXPECT_FALSE(detail::fields::is_field_value("example\ntoken"));
   EXPECT_FALSE(detail::fields::is_field_value(std::string("\0", 1)));
@@ -8007,6 +8377,32 @@ TEST(InvalidHeaderCharsTest, OnServer) {
   }
 }
 
+TEST(InvalidHeaderValueTest, InvalidContentLength) {
+  auto handled = false;
+
+  Server svr;
+  svr.Post("/test", [&](const Request &, Response &) { handled = true; });
+
+  thread t = thread([&] { svr.listen(HOST, PORT); });
+  auto se = detail::scope_exit([&] {
+    svr.stop();
+    t.join();
+    ASSERT_FALSE(svr.is_running());
+    ASSERT_FALSE(handled);
+  });
+
+  svr.wait_until_ready();
+
+  auto req = "POST /test HTTP/1.1\r\n"
+             "Content-Length: x\r\n"
+             "\r\n";
+
+  std::string response;
+  ASSERT_TRUE(send_request(1, req, &response));
+  ASSERT_EQ("HTTP/1.1 400 Bad Request",
+            response.substr(0, response.find("\r\n")));
+}
+
 #ifndef _WIN32
 TEST(Expect100ContinueTest, ServerClosesConnection) {
   static constexpr char reject[] = "Unauthorized";
@@ -8108,3 +8504,231 @@ TEST(Expect100ContinueTest, ServerClosesConnection) {
   }
 }
 #endif
+
+template <typename S, typename C>
+inline void max_timeout_test(S &svr, C &cli, time_t timeout, time_t threshold) {
+  svr.Get("/stream", [&](const Request &, Response &res) {
+    auto data = new std::string("01234567890123456789");
+
+    res.set_content_provider(
+        data->size(), "text/plain",
+        [&, data](size_t offset, size_t length, DataSink &sink) {
+          const size_t DATA_CHUNK_SIZE = 4;
+          const auto &d = *data;
+          std::this_thread::sleep_for(std::chrono::seconds(1));
+          sink.write(&d[offset], std::min(length, DATA_CHUNK_SIZE));
+          return true;
+        },
+        [data](bool success) {
+          EXPECT_FALSE(success);
+          delete data;
+        });
+  });
+
+  svr.Get("/stream_without_length", [&](const Request &, Response &res) {
+    auto i = new size_t(0);
+
+    res.set_content_provider(
+        "text/plain",
+        [i](size_t, DataSink &sink) {
+          if (*i < 5) {
+            std::this_thread::sleep_for(std::chrono::seconds(1));
+            sink.write("abcd", 4);
+            (*i)++;
+          } else {
+            sink.done();
+          }
+          return true;
+        },
+        [i](bool success) {
+          EXPECT_FALSE(success);
+          delete i;
+        });
+  });
+
+  svr.Get("/chunked", [&](const Request &, Response &res) {
+    auto i = new size_t(0);
+
+    res.set_chunked_content_provider(
+        "text/plain",
+        [i](size_t, DataSink &sink) {
+          if (*i < 5) {
+            std::this_thread::sleep_for(std::chrono::seconds(1));
+            sink.os << "abcd";
+            (*i)++;
+          } else {
+            sink.done();
+          }
+          return true;
+        },
+        [i](bool success) {
+          EXPECT_FALSE(success);
+          delete i;
+        });
+  });
+
+  auto listen_thread = std::thread([&svr]() { svr.listen("localhost", PORT); });
+  auto se = detail::scope_exit([&] {
+    svr.stop();
+    listen_thread.join();
+    ASSERT_FALSE(svr.is_running());
+  });
+
+  svr.wait_until_ready();
+
+  cli.set_max_timeout(std::chrono::milliseconds(timeout));
+
+  {
+    auto start = std::chrono::steady_clock::now();
+
+    auto res = cli.Get("/stream");
+
+    auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(
+                       std::chrono::steady_clock::now() - start)
+                       .count();
+
+    ASSERT_FALSE(res);
+    EXPECT_EQ(Error::Read, res.error());
+    EXPECT_TRUE(timeout <= elapsed && elapsed < timeout + threshold)
+        << "Timeout exceeded by " << (elapsed - timeout) << "ms";
+  }
+
+  {
+    auto start = std::chrono::steady_clock::now();
+
+    auto res = cli.Get("/stream_without_length");
+
+    auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(
+                       std::chrono::steady_clock::now() - start)
+                       .count();
+
+    ASSERT_FALSE(res);
+    EXPECT_EQ(Error::Read, res.error());
+    EXPECT_TRUE(timeout <= elapsed && elapsed < timeout + threshold)
+        << "Timeout exceeded by " << (elapsed - timeout) << "ms";
+  }
+
+  {
+    auto start = std::chrono::steady_clock::now();
+
+    auto res = cli.Get("/chunked", [&](const char *data, size_t data_length) {
+      EXPECT_EQ("abcd", string(data, data_length));
+      return true;
+    });
+
+    auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(
+                       std::chrono::steady_clock::now() - start)
+                       .count();
+
+    ASSERT_FALSE(res);
+    EXPECT_EQ(Error::Read, res.error());
+    EXPECT_TRUE(timeout <= elapsed && elapsed < timeout + threshold)
+        << "Timeout exceeded by " << (elapsed - timeout) << "ms";
+  }
+}
+
+TEST(MaxTimeoutTest, ContentStream) {
+  time_t timeout = 2000;
+  time_t threshold = 200;
+
+  Server svr;
+  Client cli("localhost", PORT);
+  max_timeout_test(svr, cli, timeout, threshold);
+}
+
+#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
+TEST(MaxTimeoutTest, ContentStreamSSL) {
+  time_t timeout = 2000;
+  time_t threshold = 1200; // SSL_shutdown is slow on some operating systems.
+
+  SSLServer svr(SERVER_CERT_FILE, SERVER_PRIVATE_KEY_FILE);
+
+  SSLClient cli("localhost", PORT);
+  cli.enable_server_certificate_verification(false);
+
+  max_timeout_test(svr, cli, timeout, threshold);
+}
+#endif
+
+class EventDispatcher {
+public:
+  EventDispatcher() {}
+
+  void wait_event(DataSink *sink) {
+    unique_lock<mutex> lk(m_);
+    int id = id_;
+    cv_.wait(lk, [&] { return cid_ == id; });
+    sink->write(message_.data(), message_.size());
+  }
+
+  void send_event(const string &message) {
+    lock_guard<mutex> lk(m_);
+    cid_ = id_++;
+    message_ = message;
+    cv_.notify_all();
+  }
+
+private:
+  mutex m_;
+  condition_variable cv_;
+  atomic_int id_{0};
+  atomic_int cid_{-1};
+  string message_;
+};
+
+TEST(ClientInThreadTest, Issue2068) {
+  EventDispatcher ed;
+
+  Server svr;
+  svr.Get("/event1", [&](const Request & /*req*/, Response &res) {
+    res.set_chunked_content_provider("text/event-stream",
+                                     [&](size_t /*offset*/, DataSink &sink) {
+                                       ed.wait_event(&sink);
+                                       return true;
+                                     });
+  });
+
+  auto listen_thread = std::thread([&svr]() { svr.listen(HOST, PORT); });
+
+  svr.wait_until_ready();
+
+  thread event_thread([&] {
+    int id = 0;
+    while (svr.is_running()) {
+      this_thread::sleep_for(chrono::milliseconds(500));
+
+      std::stringstream ss;
+      ss << "data: " << id << "\n\n";
+      ed.send_event(ss.str());
+      id++;
+    }
+  });
+
+  auto se = detail::scope_exit([&] {
+    svr.stop();
+
+    listen_thread.join();
+    event_thread.join();
+
+    ASSERT_FALSE(svr.is_running());
+  });
+
+  {
+    auto client = detail::make_unique<Client>(HOST, PORT);
+    client->set_read_timeout(std::chrono::minutes(10));
+
+    std::atomic<bool> stop{false};
+
+    std::thread t([&] {
+      client->Get("/event1",
+                  [&](const char *, size_t) -> bool { return !stop; });
+    });
+
+    std::this_thread::sleep_for(std::chrono::seconds(2));
+    stop = true;
+    client->stop();
+    client.reset();
+
+    t.join();
+  }
+}
diff --git a/test/test_proxy.cc b/test/test_proxy.cc
index 88a8ba9..672bcce 100644
--- a/test/test_proxy.cc
+++ b/test/test_proxy.cc
@@ -5,8 +5,7 @@
 using namespace std;
 using namespace httplib;
 
-template <typename T>
-void ProxyTest(T& cli, bool basic) {
+template <typename T> void ProxyTest(T &cli, bool basic) {
   cli.set_proxy("localhost", basic ? 3128 : 3129);
   auto res = cli.Get("/httpbin/get");
   ASSERT_TRUE(res != nullptr);
@@ -38,7 +37,7 @@ TEST(ProxyTest, SSLDigest) {
 // ----------------------------------------------------------------------------
 
 template <typename T>
-void RedirectProxyText(T& cli, const char *path, bool basic) {
+void RedirectProxyText(T &cli, const char *path, bool basic) {
   cli.set_proxy("localhost", basic ? 3128 : 3129);
   if (basic) {
     cli.set_proxy_basic_auth("hello", "world");
@@ -100,8 +99,7 @@ TEST(RedirectTest, YouTubeSSLDigest) {
 
 // ----------------------------------------------------------------------------
 
-template <typename T>
-void BaseAuthTestFromHTTPWatch(T& cli) {
+template <typename T> void BaseAuthTestFromHTTPWatch(T &cli) {
   cli.set_proxy("localhost", 3128);
   cli.set_proxy_basic_auth("hello", "world");
 
@@ -112,11 +110,11 @@ void BaseAuthTestFromHTTPWatch(T& cli) {
   }
 
   {
-    auto res =
-        cli.Get("/basic-auth/hello/world",
-                {make_basic_authentication_header("hello", "world")});
+    auto res = cli.Get("/basic-auth/hello/world",
+                       {make_basic_authentication_header("hello", "world")});
     ASSERT_TRUE(res != nullptr);
-    EXPECT_EQ("{\n  \"authenticated\": true, \n  \"user\": \"hello\"\n}\n", res->body);
+    EXPECT_EQ("{\n  \"authenticated\": true, \n  \"user\": \"hello\"\n}\n",
+              res->body);
     EXPECT_EQ(StatusCode::OK_200, res->status);
   }
 
@@ -124,7 +122,8 @@ void BaseAuthTestFromHTTPWatch(T& cli) {
     cli.set_basic_auth("hello", "world");
     auto res = cli.Get("/basic-auth/hello/world");
     ASSERT_TRUE(res != nullptr);
-    EXPECT_EQ("{\n  \"authenticated\": true, \n  \"user\": \"hello\"\n}\n", res->body);
+    EXPECT_EQ("{\n  \"authenticated\": true, \n  \"user\": \"hello\"\n}\n",
+              res->body);
     EXPECT_EQ(StatusCode::OK_200, res->status);
   }
 
@@ -158,8 +157,7 @@ TEST(BaseAuthTest, SSL) {
 // ----------------------------------------------------------------------------
 
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
-template <typename T>
-void DigestAuthTestFromHTTPWatch(T& cli) {
+template <typename T> void DigestAuthTestFromHTTPWatch(T &cli) {
   cli.set_proxy("localhost", 3129);
   cli.set_proxy_digest_auth("hello", "world");
 
@@ -181,7 +179,8 @@ void DigestAuthTestFromHTTPWatch(T& cli) {
     for (auto path : paths) {
       auto res = cli.Get(path.c_str());
       ASSERT_TRUE(res != nullptr);
-      EXPECT_EQ("{\n  \"authenticated\": true, \n  \"user\": \"hello\"\n}\n", res->body);
+      EXPECT_EQ("{\n  \"authenticated\": true, \n  \"user\": \"hello\"\n}\n",
+                res->body);
       EXPECT_EQ(StatusCode::OK_200, res->status);
     }
 
@@ -216,8 +215,7 @@ TEST(DigestAuthTest, NoSSL) {
 
 // ----------------------------------------------------------------------------
 
-template <typename T>
-void KeepAliveTest(T& cli, bool basic) {
+template <typename T> void KeepAliveTest(T &cli, bool basic) {
   cli.set_proxy("localhost", basic ? 3128 : 3129);
   if (basic) {
     cli.set_proxy_basic_auth("hello", "world");
@@ -249,9 +247,10 @@ void KeepAliveTest(T& cli, bool basic) {
         "/httpbin/digest-auth/auth-int/hello/world/MD5",
     };
 
-    for (auto path: paths) {
+    for (auto path : paths) {
       auto res = cli.Get(path.c_str());
-      EXPECT_EQ("{\n  \"authenticated\": true, \n  \"user\": \"hello\"\n}\n", res->body);
+      EXPECT_EQ("{\n  \"authenticated\": true, \n  \"user\": \"hello\"\n}\n",
+                res->body);
       EXPECT_EQ(StatusCode::OK_200, res->status);
     }
   }
diff --git a/test/www/meson.build b/test/www/meson.build
index ed3d357..be2b047 100644
--- a/test/www/meson.build
+++ b/test/www/meson.build
@@ -5,3 +5,4 @@
 configure_file(input: 'empty_file', output: 'empty_file', copy: true)
 configure_file(input: 'file',       output: 'file',       copy: true)
 subdir('dir')
+subdir('日本語Dir')
diff --git a/test/www/日本語Dir/meson.build b/test/www/日本語Dir/meson.build
new file mode 100644
index 0000000..4cd4150
--- /dev/null
+++ b/test/www/日本語Dir/meson.build
@@ -0,0 +1,4 @@
+# SPDX-FileCopyrightText: 2025 Andrea Pappacoda
+# SPDX-License-Identifier: MIT
+
+configure_file(input: '日本語File.txt', output: '日本語File.txt', copy: true)