Experimental support for coroutines. Use CO_RETURN (or LR_CO_RETURN) for a member function that has a coroutine return type. Use CO_THROW (or LR_CO_THROW) to throw from a coroutine. Use as many CO_YIELD (or LR_CO_YIELD) from a coroutine function as you like, as long as the promise type supports it.

The experimental support must be explicitly enabled with

  #define TROMPELOEIL_EXPERIMENTAL_COROUTINES
  #include <trompeloeil.hpp>

trompeloeil::stream_tracer does not produce correct result for coroutines

Corrected output of input-range like types. Thank you @DNKpp for the fix.

The self test program "custom_recursive_mutex" now says that it's succeeded. Thank you @yurivict for reporting the confusion.

Self test programs are only build when explicitly setting -DTROMPELOEIL_BUILD_TESTS=yes to the CMake command line.

The self test programs require a higher version of CMake (3.19 currently)