Base64 encoder decoder + Stack allocator

include/jwt/impl/stack_alloc.ipp

@@ -0,0 +1,63 @@
+#ifndef STACK_ALLOC_IPP
+#define STACK_ALLOC_IPP
+
+namespace jwt {
+
+template <size_t N, size_t alignment>
+template <size_t reqested_alignment>
+char* Arena<N, alignment>::allocate(size_t n) noexcept
+{
+  static_assert (reqested_alignment <= alignment,
+      "Requested alignment is too small for this arena");
+
+  assert (pointer_in_storage(ptr_) &&
+      "No more space in the arena or it has outgrown its capacity");
+
+  n = align_up(n);
+
+  if ((ptr_ + n) <= (buf_ + N)) {
+    char* ret = ptr_;
+    ptr_ += n;
+
+    return ret;
+  }
+
+  assert (0 && "Code should not reach here");
+
+  return nullptr;
+}
+
+template <size_t N, size_t alignment>
+void Arena<N, alignment>::deallocate(char* p, size_t n) noexcept
+{
+  assert (pointer_in_storage(p) &&
+      "The address to de deleted does not lie inside the storage");
+
+  n = align_up(n);
+
+  if ((p + n) == ptr_) {
+    ptr_ = p;
+  }
+
+  return;
+}
+
+template <typename T, size_t N, size_t alignment>
+T* stack_alloc<T, N, alignment>::allocate(size_t n) noexcept
+{
+  return reinterpret_cast<T*>(
+      arena_.template allocate<alignof(T)>(n * sizeof(T))
+  );
+}
+
+template <typename T, size_t N, size_t alignment>
+void stack_alloc<T, N, alignment>::deallocate(T* p, size_t n) noexcept
+{
+  arena_.deallocate(reinterpret_cast<char*>(p), n);
+  return;
+}
+
+}
+
+
+#endif