C++ 折叠参数包详解(悄然增强编程效率)

template <typename _Ty>
void print(_Ty data) 
{
	cout << data << endl;
}
template <typename _Ty,typename ...Args>
void print(_Ty data, Args ...args) 
{
	cout << data << "\t";
	print(args...);
}

template <typename _Ty>
void printData(_Ty data) {
	cout << data << "\t";
}
template <typename ...Args>
void printArgs(Args ...args)
{
	initializer_list<int>{(printData(args), 0)...};
	cout << endl;
}

class Test 
{
public:
	void printk() 
	{
		if (func) func();
	}
	template <typename Func,typename ...Args>
	void connect(Func&& f, Args&& ...args)    //右值引用
	{
		func = bind(forward<Func>(f), forward<Args>(args)...);
	}
protected:
	function<void()> func;
};
void sum(int a, int b) 
{
	cout<< a + b;
}
int main() 
{
	Test test;
	test.connect(sum, 1, 2);
	test.printk();
	test.connect([](int a, int b) {cout << endl << a + b; }, 3, 8);
	test.printk();
	return 0;
}

template <typename ...Args>
class Test;
template<>
class Test<> {};
template <typename _Ty, typename ...Args>
class Test<_Ty, Args...> :public Test<Args...>
{
public:
	Test() {}
	Test(_Ty data, Args ...args) :data(data), Test<Args...>(args...) {}
	Test<Args...>& getObject() { return *this; }
	_Ty& getData() { return data; }
protected:
	_Ty data;
};
void testOne() 
{
	Test<string, int, double> test("fsdjf", 32, 3.23);
	cout << test.getData() << "\t" << test.getObject().getData() << "\t" << test.getObject().getObject().getData() << endl;
}

template <typename ...Args>
class my_tuple;
template<>
class my_tuple<> {};
template <typename _Ty, typename ...Args>
class my_tuple<_Ty, Args...>
{
public:
	my_tuple() {}
	my_tuple(_Ty data, Args ...args) :data(data),args(args...) {}
	_Ty& getData() { return data; }
	my_tuple<Args...>& getObject() { return *this; }
protected:
	_Ty data;
	my_tuple<Args...> args;
};
void testTwo() 
{
	Test<string, int, double> test("fsdjf", 32, 3.23);
	cout << test.getData() << "\t" << test.getObject().getData() << "\t" << test.getObject().getObject().getData() << endl;
}