struct Object {
	virtual ~Object() = default;
	virtual void a() {}
};

struct B : public Object {
	void a() override {}
};

struct C : public B {
	void a() override {}
	__attribute__ ((noinline)) void test() {}
};

struct CF final : public B {
	void a() override {}
	__attribute__ ((noinline)) void test() {}
};

template <typename T>
static T *cast_to(Object *p_object) {
	if constexpr (std::is_final_v<T>) {
		return (p_object && typeid(*p_object) == typeid(T)) ? static_cast<T *>(p_object) : nullptr;
	} else
	{
		return dynamic_cast<T *>(p_object);
	}
}

template <typename T>
__attribute__ ((noinline)) void test(Object *a) {
	for (int i = 0; i < 100000000; ++i) {
		__attribute__ ((noinline)) T *c = cast_to<T>(a);
		if (c) {
			c->test();
		}
	}
}

template <typename T>
static T *cast_to_old(Object *p_object) {
	return dynamic_cast<T *>(p_object);
}

template <typename T>
__attribute__ ((noinline)) void test_old(Object *a) {
	for (int i = 0; i < 100000000; ++i) {
		T *c = cast_to_old<T>(a);
		if (c) {
			c->test();
		}
	}
}

int main()
{
	{
		auto t0 = std::chrono::high_resolution_clock::now();
		test<C>(new C());
		auto t1 = std::chrono::high_resolution_clock::now();
		std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0).count() << "ms\n";
	}
	{
		auto t0 = std::chrono::high_resolution_clock::now();
		test<C>(new B());
		auto t1 = std::chrono::high_resolution_clock::now();
		std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0).count() << "ms\n";
	}
	{
		auto t0 = std::chrono::high_resolution_clock::now();
		test<CF>(new CF());
		auto t1 = std::chrono::high_resolution_clock::now();
		std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0).count() << "ms\n";
	}
	{
		auto t0 = std::chrono::high_resolution_clock::now();
		test<CF>(new B());
		auto t1 = std::chrono::high_resolution_clock::now();
		std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0).count() << "ms\n";
	}

	{
		auto t0 = std::chrono::high_resolution_clock::now();
		test_old<C>(new C());
		auto t1 = std::chrono::high_resolution_clock::now();
		std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0).count() << "ms\n";
	}
	{
		auto t0 = std::chrono::high_resolution_clock::now();
		test_old<C>(new B());
		auto t1 = std::chrono::high_resolution_clock::now();
		std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0).count() << "ms\n";
	}
	{
		auto t0 = std::chrono::high_resolution_clock::now();
		test_old<CF>(new CF());
		auto t1 = std::chrono::high_resolution_clock::now();
		std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0).count() << "ms\n";
	}
	{
		auto t0 = std::chrono::high_resolution_clock::now();
		test_old<CF>(new B());
		auto t1 = std::chrono::high_resolution_clock::now();
		std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0).count() << "ms\n";
	}
}