libstdc++-v3/testsuite/20_util/logical_traits/83134.cc

   1 // Copyright (C) 2017-2023 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-do compile { target c++17 } }
  19
  20 #include <type_traits>
  21
  22 struct X {
  23   constexpr operator bool() const { return false; }
  24   constexpr bool operator!() const = delete;
  25 };
  26
  27 struct Y {
  28   static constexpr X value{};
  29 };
  30
  31 static_assert(std::negation<Y>::value);  // PR libstdc++/83134