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.
- 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.
