// # __cplusplus

//

// Defined only if using C++ compiler.

//

// Its value is the actual C++ version in use

// in a similar way to __STDC_VERSION__

//

// C99 says that the C compiler must not define it.

//

// GCC 6.4 has the -std=c++17 option early, even before

// __cplusplus == 201703L was reached.

{

std::cout << "__cplusplus = " << __cplusplus << std::endl;

#if __cplusplus == 199711L

std::cout << "C++98" << std::endl;

#endif

#if __cplusplus == 201103L

std::cout << "C++11" << std::endl;

#endif

#if __cplusplus == 201402L

std::cout << "C++14" << std::endl;

#endif

#if __cplusplus == 201703L

std::cout << "C++17" << std::endl;

#endif

}

#ifdef __STDCPP_THREADS__

// TODO why not defined even though I do have multithreading?

std::cout << "__STDCPP_THREADS__" << __cplusplus << std::endl;

assert(__STDCPP_THREADS__ == 1);

#endif