struct meow {
	void f(int, char, float) { }
};

template <typename FType>
void test() {
	using FTypeTraits = function_traits<FType>;
	
	static_assert(typename FTypeTraits::arity() == 3, "fail");

	static_assert(std::is_same<typename FTypeTraits::result_type, void>(), "fail");
	static_assert(std::is_same<typename FTypeTraits::template arg_type<0>, int>(), "fail");
	static_assert(std::is_same<typename FTypeTraits::template arg_type<1>, char>(), "fail");
	static_assert(std::is_same<typename FTypeTraits::template arg_type<2>, float>(), "fail");
}

void test1() {
	using FType = void(int, char, float);
	
	test<FType>();
}

void test2() {
	using FType = function_type<decltype(&meow::f)>::type;
	
	test<FType>();
}

void test3() {
	using FType = function_type<void(* const volatile &)(int, char, float)>::type;
	
	test<FType>();
}

void test4() {
	using FType = function_type<std::function<void(int, char, float)>>::type;
	
	test<FType>();
}