通过变长模版参数创建一个模版参数类型都是std::vector<T>的tuple

链接：https://www.zhihu.com/question/38949490/answer/78918985

template <typename ...Types>
struct store
{};

template <>
struct store<>
{
    using type = std::tuple<>;
};

template <typename First>
struct store<First>
{
    using first = std::vector<First>;
    using type = std::tuple<first>;
};

template <typename First,typename ...Types>
struct store<First,Types...>
{
    using first = std::vector<First>;
    using type = std::tuple<first,typename store<Types...>::first>;
};

int main()
{
    store<>::type;
    store<int>::type;
    store<int,double>::type;

    return 0;
}