c++ for each 遍历tuple

#include <iostream>
#include <tuple>

//c++11写法

namespace detail
{
    template<int... Is>
    struct seq { };

    template<int N, int... Is>
    struct gen_seq : gen_seq<N - 1, N - 1, Is...> { };

    template<int... Is>
    struct gen_seq<0, Is...> : seq<Is...> { };
}


namespace detail
{
    template<typename T, typename F, int... Is>
    void for_each_c11(T&& t, F f, seq<Is...>)
    {
        auto l = { (f(std::get<Is>(t)),0)... };
    }
}

template<typename... Ts, typename F>
void for_each_in_tuple_c11(std::tuple<Ts...> const& t, F f)
{
    detail::for_each_c11(t, f, detail::gen_seq<sizeof...(Ts)>());
}

//c++14
template<typename T, typename F, int... Is>
void for_each_c14(T&& t, F f,std::integer_sequence<int,Is...>)
{
    auto l = { (f(std::get<Is>(t)),0)... };
}

template<typename... Ts, typename F>
void for_each_in_tuple_c14(std::tuple<Ts...> const& t, F f)
{
    for_each_c14(t, f,std::make_integer_sequence<int,sizeof...(Ts)>());
}

int main()
{
    auto datas = std::make_tuple<int>(1, 2, 3, 4);
    std::apply([](auto&& ... args) {
        ((std::cout << args << std::endl),...);
        }, datas);

    std::cout << "....." << std::endl;
    for_each_in_tuple_c11(datas,[](auto value) {
        std::cout << value << std::endl;
        });

    std::cout << "....." << std::endl;
    for_each_in_tuple_c14(datas, [](auto value) {
        std::cout << value << std::endl;
        });
}

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转载自blog.csdn.net/qq_53332653/article/details/114921481