Function main

code/4/4.3.cpp:45–77

}

int main()
{
    auto student = get_student(0);
    std::cout << "ID: 0, "
    << "GPA: " << std::get<0>(student) << ", "
    << "成绩: " << std::get<1>(student) << ", "
    << "姓名: " << std::get<2>(student) << '\n';
    
    double gpa;
    char grade;
    std::string name;
    
    // 元组进行拆包
    std::tie(gpa, grade, name) = get_student(1);
    std::cout << "ID: 1, "
    << "GPA: " << gpa << ", "
    << "成绩: " << grade << ", "
    << "姓名: " << name << '\n';
    
    
    std::tuple<std::string, double, double, int> t("123", 4.5, 6.7, 8);
    std::cout << std::get<std::string>(t) << std::endl;
    // std::cout << std::get<double>(t) << std::endl;   // 非法, 引发编译期错误
    std::cout << std::get<3>(t) << std::endl;
    
    // 拼接元组
    auto new_tuple = std::tuple_cat(get_student(1), std::move(t));
    
    // 迭代
    for(int i = 0; i != tuple_len(new_tuple); ++i)
        // 运行期索引
        std::cout << tuple_index(i, new_tuple) << std::endl;
}