cmake COMPILER_HAS_STD_CXX20 examples

Jackarain/proxy CMakeLists.txt :181 

CHECK_CXX_COMPILER_FLAG(/std:c++20 COMPILER_HAS_STD_CXX20)

Jackarain/proxy CMakeLists.txt :201 

CHECK_CXX_COMPILER_FLAG(-std=c++20 COMPILER_HAS_STD_CXX20)