libstdc++-v3/testsuite/20_util/hash/nullptr.cc

   1 // Copyright (C) 2019-2021 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++17" }
  19 // { dg-do run { target c++17 } }
  20
  21 #include <functional>
  22 #include <testsuite_hooks.h>
  23
  24 void
  25 test01()
  26 {
  27   auto h1 = std::hash<std::nullptr_t>{}(nullptr);
  28   static_assert(std::is_same_v<decltype(h1), std::size_t>);
  29   auto h2 = std::hash<std::nullptr_t>{}(nullptr);
  30   VERIFY( h1 == h2 );
  31 }
  32
  33 int
  34 main()
  35 {
  36   test01();
  37 }