libstdc++-v3/testsuite/29_atomics/atomic_flag/test/explicit.cc

   1 // { dg-options "-std=gnu++2a" }
   2 // { dg-do run { target c++2a } }
   3 // { dg-require-thread-fence "" }
   4
   5 // Copyright (C) 2008-2023 Free Software Foundation, Inc.
   6 //
   7 // This file is part of the GNU ISO C++ Library.  This library is free
   8 // software; you can redistribute it and/or modify it under the
   9 // terms of the GNU General Public License as published by the
  10 // Free Software Foundation; either version 3, or (at your option)
  11 // any later version.
  12
  13 // This library is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License along
  19 // with this library; see the file COPYING3.  If not see
  20 // <http://www.gnu.org/licenses/>.
  21
  22 #include <atomic>
  23 #include <testsuite_hooks.h>
  24
  25 int main()
  26 {
  27   using namespace std;
  28
  29   atomic_flag af0 = ATOMIC_FLAG_INIT;
  30   VERIFY( ! af0.test(memory_order_acquire) );
  31
  32   atomic_flag af{true};
  33   const atomic_flag& caf = af;
  34
  35   VERIFY( af.test(memory_order_acquire) );
  36   VERIFY( caf.test(memory_order_acquire) );
  37   af.clear(memory_order_release);
  38   VERIFY( ! af.test(memory_order_acquire) );
  39   VERIFY( ! caf.test(memory_order_acquire) );
  40 }