#include <stdint.h>
#include <utility>

template<class T>
class GLFunctor;

template<class Result, class... Args>
class GLFunctor<Result (Args...)>
{
	using GLFunc = Result (*)(Args...);

public:
	Result operator()(Args... args) const
	{
		using WinAPIGLFunc = __attribute__((ms_abi)) GLFunc;
		return reinterpret_cast<WinAPIGLFunc>(glProc)(std::forward<Args>(args)...);
	}
private:
	GLFunc glProc = nullptr;
};

GLFunctor<void (int pname)> test_functor;

void Test()
{
    test_functor(0);
}