libstdc++-v3/testsuite/20_util/tuple/swap_cxx17.cc

   1 // { dg-options "-std=gnu++17" }
   2 // { dg-do compile }
   3
   4 // Copyright (C) 2016-2020 Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING3.  If not see
  19 // <http://www.gnu.org/licenses/>.
  20
  21
  22 // NOTE: This makes use of the fact that we know how moveable
  23 // is implemented on tuple.  If the implementation changed
  24 // this test may begin to fail.
  25
  26 #include <tuple>
  27
  28 // Not swappable, and tuple not swappable via the generic std::swap.
  29 struct C { };
  30 void swap(C&, C&) = delete;
  31
  32 static_assert( !std::is_swappable_v<std::tuple<int, C>> );
  33 static_assert( !std::is_swappable_v<std::tuple<C, int>> );
  34 static_assert( !std::is_swappable_v<std::tuple<int, int, C>> );
  35 static_assert( !std::is_swappable_v<std::tuple<C, int, int>> );
  36
  37 // Not swappable, and tuple not swappable via the generic std::swap.
  38 struct D { D(D&&) = delete; };
  39
  40 static_assert( !std::is_swappable_v<std::tuple<int, D>> );
  41 static_assert( !std::is_swappable_v<std::tuple<D, int>> );
  42 static_assert( !std::is_swappable_v<std::tuple<int, int, D>> );
  43 static_assert( !std::is_swappable_v<std::tuple<D, int, int>> );