libstdc++-v3/testsuite/30_threads/call_once/60497.cc

   1 // { dg-do compile { target *-*-freebsd* *-*-dragonfly* *-*-netbsd* *-*-linux* *-*-gnu* *-*-solaris* *-*-cygwin *-*-rtems* *-*-darwin* powerpc-ibm-aix* } }
   2 // { dg-options "-pthread" { target *-*-freebsd* *-*-dragonfly* *-*-netbsd* *-*-linux* *-*-gnu* *-*-solaris* powerpc-ibm-aix* } }
   3 // { dg-require-effective-target c++11 }
   4 // { dg-require-cstdint "" }
   5 // { dg-require-gthreads "" }
   6
   7 // Copyright (C) 2014-2017 Free Software Foundation, Inc.
   8 //
   9 // This file is part of the GNU ISO C++ Library.  This library is free
  10 // software; you can redistribute it and/or modify it under the
  11 // terms of the GNU General Public License as published by the
  12 // Free Software Foundation; either version 3, or (at your option)
  13 // any later version.
  14
  15 // This library is distributed in the hope that it will be useful,
  16 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 // GNU General Public License for more details.
  19
  20 // You should have received a copy of the GNU General Public License along
  21 // with this library; see the file COPYING3.  If not see
  22 // <http://www.gnu.org/licenses/>.
  23
  24 // libstdc++/60497
  25
  26 #include <mutex>
  27 #include <memory>
  28 #include <functional>
  29
  30 struct A;
  31 template<typename T> struct B { T t; };
  32
  33 using UP = std::unique_ptr<B<A>>;
  34
  35 void f(UP&) { }
  36
  37 void g(UP& p)
  38 {
  39   std::once_flag o;
  40   std::call_once(o, f, std::ref(p));
  41 }