Every C++ compiler suite I'm aware of supports the preprocessor macro
__COUNTER__.

So if I do the following:

#include <iostream>

auto main(void) -> int
{
    std::cout << __COUNTER__ << std::endl;
    std::cout << __COUNTER__ << std::endl;
    std::cout << __COUNTER__ << std::endl;
    std::cout << __COUNTER__ << std::endl;
}

Then it prints:
0
1
2
3

I see that in C++20 we have "std::source_location" which can probably
take the place of __FILE__, __LINE__, and maybe also __COUNTER__ in
some scenarios, but I still think __COUNTER__ should be standard C++.