black_magic

main.cpp

#include <iostream>
#include <type_traits>

template<typename T, typename U>
struct lambda_check {
	static constexpr bool value = !std::is_same<T, U>::value;
};

template <typename fun1, typename fun2>
constexpr bool is_lambda_(fun1, fun2) {
	return lambda_check<fun1, fun2>::value;
}

#define is_lambda(f) is_lambda_(f, f)

void f() {}

int main(int argc, char *argv[]) {
	std::cout << is_lambda(f) << std::endl;
	std::cout << is_lambda([](){}) << std::endl;
	auto g = [](){};
	std::cout << is_lambda(g);
	
	return EXIT_SUCCESS;
}