function实现原理

void fun(int a)
{
	cout << "fun" << endl;
}
void add(int a, int b)
{
	cout << "add" << endl;
}

template<typename T, typename ...Ty>
class myfunction
{
};

template<typename T, typename ...Ty>
class myfunction<T(Ty...)>
{
public:
	using PFUN = T(*)(Ty...);

	myfunction(PFUN pf) :pfunc(pf) { cout << "构造" << endl; }
	T operator()(Ty... ty)
	{

		cout << "()" << endl;
		return pfunc(ty ...);
	}
private:
	PFUN pfunc;
};


int main()
{
	cout << "start" << endl;
	myfunction<void(int)>func = fun;
	func(1);
	myfunction<void(int, int)>fund = add;
	fund(1,2);

	cout << "end" << endl;
}

// 定义日志打印宏
#define LOG(fmt, ...) printf("[%s:%s:%d] " fmt "\n", __FILE__, __func__, __LINE__, ##__VA_ARGS__)

void foo() {
    LOG("Inside foo");
}

void bar() {
    LOG("Inside bar");
}

int main() {
    LOG("Inside main");
    foo();
    bar();
    return 0;
}