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

   1 // { dg-do compile { target c++17 } }
   2
   3 // Copyright (C) 2016-2024 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20
  21 // NOTE: This makes use of the fact that we know how moveable
  22 // is implemented on tuple.  If the implementation changed
  23 // this test may begin to fail.
  24
  25 #include <tuple>
  26
  27 // Not swappable, and tuple not swappable via the generic std::swap.
  28 struct C { };
  29 void swap(C&, C&) = delete;
  30
  31 static_assert( !std::is_swappable_v<std::tuple<int, C>> );
  32 static_assert( !std::is_swappable_v<std::tuple<C, int>> );
  33 static_assert( !std::is_swappable_v<std::tuple<int, int, C>> );
  34 static_assert( !std::is_swappable_v<std::tuple<C, int, int>> );
  35
  36 // Not swappable, and tuple not swappable via the generic std::swap.
  37 struct D { D(D&&) = delete; };
  38
  39 static_assert( !std::is_swappable_v<std::tuple<int, D>> );
  40 static_assert( !std::is_swappable_v<std::tuple<D, int>> );
  41 static_assert( !std::is_swappable_v<std::tuple<int, int, D>> );
  42 static_assert( !std::is_swappable_v<std::tuple<D, int, int>> );