In theory the copy is cheap (couple of pointers change), but tests
are usually compiled in Debug mode/with minimal optimizations, which
means that most users will still have to pay the cost for those
function calls.
Also adds `Predicate` helper function to create `PredicateMatcher`.
Because of limitations in type inference it needs to be explicitly
typed, like so
`Predicate<std::string>([](std::string const& str) { ... })`.
It also takes an optional second argument for description of the
predicate.
It is possible to infer the argument with sufficient TMP, see
43561563 (43561563)
but I don't think that the magic is worth introducing ATM.
Closes#1236
- this file excluded from the CATCH_CONFIG_DISABLE_MATCHERS path.
- matchers are always compiled in to the impl file
- _THROWS_WITH macros are still available with matchers disabled - but only the ones that take a string
- tests that use matchers have #ifdefs, so the whole SelfTest project can compile with matchers disable.
