libstdc++-v3/testsuite/25_algorithms/swap/constexpr.cc

   1 // Copyright (C) 2019-2020 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-options "-std=gnu++2a" }
  19 // { dg-do compile { target c++2a } }
  20
  21 #include <algorithm>
  22
  23 constexpr bool
  24 test()
  25 {
  26   auto ok = true;
  27
  28   double asc = 3.1415;
  29   double bsc = 2.7182;
  30   std::swap(asc, bsc);
  31   ok = ok && asc == 2.7182 && bsc == 3.1415;
  32
  33   float arr[5]{0.0f, 1.0f, 2.0f, 3.0f, 4.0f};
  34   float brr[5]{5.0f, 6.0f, 7.0f, 8.0f, 9.0f};
  35   std::swap(arr, brr);
  36   ok = ok && arr[2] == 7.0f && brr[2] == 2.0f;
  37
  38   return ok;
  39 }
  40
  41 static_assert(test());