libstdc++-v3/testsuite/20_util/enable_shared_from_this/members/reinit.cc

   1 // Copyright (C) 2015-2020 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 run { target c++11 } }
  19
  20 #include <memory>
  21 #include <testsuite_hooks.h>
  22
  23 struct X : public std::enable_shared_from_this<X> { };
  24
  25 bool
  26 share_ownership(const std::shared_ptr<X>& p1, const std::shared_ptr<X>& p2)
  27 {
  28   return !p1.owner_before(p2) && !p2.owner_before(p1);
  29 }
  30
  31 void
  32 test01()
  33 {
  34   std::shared_ptr<X> p1(new X);
  35   VERIFY( share_ownership( p1->shared_from_this(), p1 ) );
  36   {
  37     std::shared_ptr<X> p2(p1.get(), [](X*){});
  38     // The weak_ptr member of the enable_shared_from_this base should not
  39     // be reset by creating a second control block that owns the pointer.
  40     VERIFY( share_ownership( p2->shared_from_this(), p1 ) );
  41   }
  42   VERIFY( share_ownership( p1->shared_from_this(), p1 ) );
  43 }
  44
  45 int
  46 main()
  47 {
  48   test01();
  49 }