浅析C++元组tuple类型

#include <tuple>

tuple<int,string,vector<int>> test{1,"hello,world",{4,5,6}};

tuple<int, string,vector<int>> test(1,"hello,world",{4,5,6});

tuple<size_t, size_t> test;	//每个成员的值为0

tuple<size_t, size_t> test;	//每个成员的值为0
test = tuple<size_t, size_t>(1,2);	//第一个成员的值为1，第二个成员的值为2

auto test2 = make_tuple(3.14,"wasd");

//错误写法
auto test2 = make_tuple(3.14,"wasd",{ 3,4,5 });
//正确写法
vector<int> nums = { 3,4,5 };
auto test2 = make_tuple(3.14,"wasd",nums);

tuple<int, string, vector<int>> test{ 1,"hello,world",{4,5,6} };
cout << get<0>(test) << endl;		//打印test第一个成员，其类型为int
cout << get<1>(test) << endl;		//打印test第二个成员，其类型为string
cout << get<2>(test)[0] << endl;	//打印test第三个成员vector<int>的第一个元素

tuple<int, double, vector<string>> test{ 1,1.23,{"123","456"}};
//获取tuple成员个数
size_t num = tuple_size<decltype(test)>::value;
//利用tuple某个成员类型来声明变量（以第0个成员为例）
tuple_element<0, decltype(test)>::type n = get<0>(test);

tuple<int, int, int> test(1,2,3);
tuple<int, int, int> test2(4,5,6);
tuple<int, int, int> test3(7,8,9);
//拼接
auto new_tup = tuple_cat(test, test2, test3);

tuple<int, int, int> test(1,2,3);
tuple<int, int, int> test2(4,5,6);
//交换
test.swap(test2);

tuple<int,int> test{2,8};
tuple<int,int> test2{2,8,6};
int a, b;
//解包
tie(a, b) = test;
//ignore占位的情况
tie(a, b, ignore) = test2;

//有如下四个tuple
tuple<string, string> test{"1","2"};
tuple<int, int, int> test2{ 1,2,3 };
tuple<int,int> test3{1,2};
tuple<int, int> test4{ 4,5 };
test == test2;	//报错，string与int类型不能比较
test2 < test3;	//报错，test2与test3成员数量不同
test3 < test4;	//正确，该语句值为True

#include <iostream>
#include <tuple>
#include <array>
#include <utility>
using namespace std;
template<class Tuple, size_t N>
struct PrintTuple
{
	static void Printf(const Tuple& Value)
	{
		PrintTuple<Tuple, N - 1>::Printf(Value);
		cout << "," << get<N - 1>(Value);
	}
};
template<class Tuple>
struct PrintTuple<Tuple, 1>
{
	static void Printf(const Tuple& Value)
	{
	     cout << get<0>(Value);
	}
};
template<class... Args>
void PrintfMyTuple(const tuple<Args...>& vlaue)
{
      PrintTuple<decltype(vlaue), sizeof...(Args)>::Printf(vlaue);
}
int main()
{
	tuple<int, int, int, int> a(2, 3, 1, 4);
	PrintfMyTuple(a);
	system("pause");

	return 0;
}