libstdc++-v3/testsuite/experimental/array/make_array.cc

// { dg-do compile { target c++14 } }

// Copyright (C) 2015-2021 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3.  If not see
// <http://www.gnu.org/licenses/>.

#include <experimental/array>
#include <functional> // for std::ref and std::reference_wrapper

struct MoveOnly
{
  MoveOnly() = default;
  MoveOnly(MoveOnly&&) = default;
  MoveOnly& operator=(MoveOnly&&) = default;
};

void test01()
{
  char x[42];
  std::array<char, 42> y = std::experimental::to_array(x);
  std::array<int, 5> z = std::experimental::make_array(1,2,3,4,5);
  std::array<long, 3> zz = std::experimental::make_array(1,2L, 3);
  std::array<MoveOnly, 1> zzz = std::experimental::make_array(MoveOnly{});
  int dummy;
  auto good = std::experimental::make_array<
    std::reference_wrapper<int>>(std::ref(dummy));
  constexpr char x2[42]{};
  constexpr std::array<char, 42> y2 = std::experimental::to_array(x2);
  constexpr std::array<int, 5> z2 =
    std::experimental::make_array(1,2,3,4,5);
  constexpr std::array<long, 3> zz2
    = std::experimental::make_array(1,2L, 3);
  constexpr std::array<MoveOnly, 1> zzz2 = std::experimental::make_array(MoveOnly{});
}

void test02()
{
  // PR libstdc++/79195
  struct A {};
  struct B : A {};
  struct C : A {};
  auto arr = std::experimental::make_array<A>(B{}, C{});
  static_assert(std::is_same<decltype(arr), std::array<A, 2>>::value, "");
}