c++11——tuple元组

1. make_tupe
tuple<const char*, int> tp = make_tuple(sendPack, nSendSize);//构造tuple
2. tie 函数（创建一个元组的左值引用）
auto tp = std::tie(1, "aa", 2.2); //tp 实际类型为 std::tuple<int&, string&, int&>

1. get<x>()
const char* data = tp.get<0>();
int a = tp.get<1>();
2. tie
int x, y;
string a;
std::tie(x, a, y) = tp; //则自动赋值到三个变量
也可以只解析第三个值：
std::tie(std::ignore, std::ignore, y) = tp; //std::ignore为占位符

int main(){
std::tuple<int, std::string, float> t1(10, "test", 3.14);
int n = 7;
auto t2 = std::tuple_cat(t1, std::make_pair("Foo", "nar"), t1, std::tie(n));
n = 10;
//t2 = {10, "test", 3.14, "Foo", "nar", 10}; //n为10，因为tie中存放的为引用
return 0;
}