std::source_location polyfill for C++17(and C++14, but please!) compilers

source_location.h

// std::source_location polyfill for C++17(and C++14, but please!) compilers.
//
// This polyfill does deviate a bit from the standard, as there is no consteval,
// but besides that, it should be nearly drop in replacement from this -> C++20.
// 
// License details:
// Use this however you like.

// REQUIREMENTS:
// Your compiler must have the follwing intrinsic functions:
//
// __builtin_FILE()
// __builtin_LINE()
// __builtin_FUNCTION()
//
// On MSVC, you also need __builtin_COLUMN().

namespace std {

	struct source_location {
		
		static constexpr source_location current(
			const unsigned int line = __builtin_LINE(), 
#ifdef _MSC_VER
			// MSVC helpfully provides the __builtin_COLUMN() intrinisic.
			const unsigned int column = __builtin_COLUMN(),
#else
			const unsigned int column = 0,
#endif
			const char* filename = __builtin_FILE(), 
			const char* function_name = __builtin_FUNCTION()) noexcept {
			source_location loc {};
			
			loc._filename = filename;
			loc._function_name = function_name;
			loc._line = line;
			loc._column = column;
			return loc;
		}
		
		constexpr unsigned int line() const noexcept {
			return _line;
		}
		
		constexpr unsigned int column() const noexcept {
			return _column;
		}
		
		constexpr const char* file_name() const noexcept {
			return _filename;
		}
		
		constexpr const char* function_name() const noexcept {
			return _function_name;
		}
		
	private:
		unsigned int _line;
		unsigned int _column;
		const char* _filename;
		const char* _function_name;
	};

} // namespace std