# check for std::optional because macos is broke af sometimes set(std_optional_code [[ #include int main() { std::optional maybe; maybe = 1; return *maybe == 1; } ]]) check_cxx_source_compiles("${std_optional_code}" was_compiled) if(was_compiled) message(STATUS "we have std::optional") else() message(FATAL_ERROR "we dont have std::optional your compiler is broke af") endif()