#include <iostream>
#include <tuple>

int main()
{
    std::tuple<int, std::string, bool> foo { 10, "Hello, world!", false };

    auto foo_ext = std::tuple_cat(foo, std::make_tuple('a'));

    std::cout << std::get<0>(foo_ext) << "\n"
              << std::get<1>(foo_ext) << "\n"
              << std::get<2>(foo_ext) << "\n"
              << std::get<3>(foo_ext) << "\n";
}