C++ compile-time генератор id

#include <iostream>

using it_t = unsigned int;


constexpr id_t getId()
{
	static id_t nId = 0;
	return ++nId;
}


int main()
{
	constexpr id_t nA = getId();
	constexpr id_t nB = getId();
	constexpr id_t nC = getId();

	std::cout << nA << std::endl;
	std::cout << nB << std::endl;
	std::cout << nC << std::endl;
	return 0;
}