C++ 像Python一样使用元组tuple - std::tuple

std::tuple

std::tuple是C++11中引入的数据结构，可以将不同类型的值放到一起，类似python中的tuple

常用方法：

std::get 按索引获取值，如类型不是const，也可以用来设置值，如：std::get<0>(tuple) = value;

std::tuple_size 获取长度

std::tie 挨个将元素存入变量，需要类型一致

示例：

#include <iostream>
#include <string>
#include <functional>
#include <vector>
#include <tuple>

int main() 
{
    using tuple_student = std::tuple<int, std::string, int, double>;
    
    tuple_student tuple_1 = std::make_tuple(1, "Tom", 180, 71.2);
    tuple_student tuple_2 = std::make_tuple(2, "Rick", 188, 72.4);
    tuple_student tuple_3 = std::make_tuple(3, "Bob", 166, 68.0);
    std::cout << std::tuple_size<tuple_student>::value << '\n';
    
    std::vector<tuple_student> vStudents{ tuple_1, tuple_2, tuple_3 };

    for (tuple_student t : vStudents)
    {
        std::cout << "No: " << std::get<0>(t) << '\n' <<
            "Name: " << std::get<1>(t) << '\n' <<
            "Height: " << std::get<2>(t) << '\n' <<
            "Weight: " << std::get<3>(t) << '\n' << std::endl;
    }

    for (tuple_student t: vStudents)
    {
        int No; std::string name; int height; double weight;
        std::tie(No, name, height, weight) = t;
        std::cout << "No: " << No << '\n' <<
            "Name: " << name << '\n' <<
            "Height: " << height << '\n' <<
            "Weight: " << weight << '\n' << std::endl;
    }

    //C++17 new bind operation
    for (tuple_student t : vStudents)
    {
        auto [ No, name, height, weight ] = t;
        std::cout << "No: " << No << '\n' <<
            "Name: " << name << '\n' <<
            "Height: " << height << '\n' <<
            "Weight: " << weight << '\n' << std::endl;
    }

    return 0;
}