Endianness at compile-time

endianness.cpp

// """"Should"""" work with any C+14 compiler
// (And yes, there is a beautiful UB in this code)

#include <iostream>

struct Endianness
{
	constexpr static bool isBig() 
	{
		union 
		{
			unsigned int i = 0x01000000;
			char c[4];
		};
		return c[0];
	}
};

int main() 
{
	std::cout << Endianness::isBig() << std::endl;
	return 0;
}