libcxx/test/std/utilities/tuple/tuple.tuple/tuple.creation/make_tuple.pass.cpp

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// <tuple>

// template <class... Types> class tuple;

// template<class... Types>
//   tuple<VTypes...> make_tuple(Types&&... t);

// UNSUPPORTED: c++98, c++03

#include <tuple>
#include <functional>
#include <cassert>

#include "test_macros.h"

int main(int, char**)
{
    {
        int i = 0;
        float j = 0;
        std::tuple<int, int&, float&> t = std::make_tuple(1, std::ref(i),
                                                          std::ref(j));
        assert(std::get<0>(t) == 1);
        assert(std::get<1>(t) == 0);
        assert(std::get<2>(t) == 0);
        i = 2;
        j = 3.5;
        assert(std::get<0>(t) == 1);
        assert(std::get<1>(t) == 2);
        assert(std::get<2>(t) == 3.5);
        std::get<1>(t) = 0;
        std::get<2>(t) = 0;
        assert(i == 0);
        assert(j == 0);
    }
#if TEST_STD_VER > 11
    {
        constexpr auto t1 = std::make_tuple(0, 1, 3.14);
        constexpr int i1 = std::get<1>(t1);
        constexpr double d1 = std::get<2>(t1);
        static_assert (i1 == 1, "" );
        static_assert (d1 == 3.14, "" );
    }
#endif

  return 0;
}