对std::tuple进行“迭代”，并访问所有构造函数

#include <iostream>
#include <tuple>
#include <type_traits>

// 递归终止条件
template <std::size_t I, typename... Types>
typename std::enable_if<I == sizeof...(Types)>::type
iterate_tuple(const std::tuple<Types...>& t) {
    // 递归结束，不做任何操作
}

// 访问tuple中的元素并检查构造函数
template <std::size_t I, typename... Types>
typename std::enable_if<I < sizeof...(Types)>::type
iterate_tuple(const std::tuple<Types...>& t) {
    std::cout << "Element " << I << ":" << std::endl;
    
    // 访问元素
    const auto& element = std::get<I>(t);
    
    // 检查构造函数
    if (std::is_constructible<decltype(element)>::value) {
        std::cout << "Has constructor" << std::endl;
    } else {
        std::cout << "Does not have constructor" << std::endl;
    }
    
    // 递归调用下一个元素
    iterate_tuple<I + 1>(t);
}

int main() {
    std::tuple<int, double, std::string> my_tuple(42, 3.14, "hello");
    
    iterate_tuple<0>(my_tuple);
    
    return 0;
}

Element 0:
Has constructor
Element 1:
Has constructor
Element 2:
Has constructor