libstdc++-v3/testsuite/20_util/shared_ptr/observers/use_count.cc

   1 // { dg-do run { target c++11 } }
   2
   3 // Copyright (C) 2005-2018 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20 // 20.6.6.2 Template class shared_ptr [util.smartptr.shared]
  21
  22 #include <memory>
  23 #include <testsuite_hooks.h>
  24
  25 struct A { };
  26 struct B : A { };
  27
  28 // 20.6.6.2.5 shared_ptr observers [util.smartptr.shared.obs]
  29
  30 // use_count
  31 void
  32 test01()
  33 {
  34   const std::shared_ptr<A> p1;
  35   VERIFY( p1.use_count() == 0 );
  36   const std::shared_ptr<A> p2(p1);
  37   VERIFY( p1.use_count() == 0 );
  38 }
  39
  40 void
  41 test02()
  42 {
  43   std::shared_ptr<A> p1(new A);
  44   std::shared_ptr<A> p2(p1);
  45   p1.reset();
  46   VERIFY( p1.use_count() == 0 );
  47   VERIFY( p2.use_count() == 1 );
  48 }
  49
  50 void
  51 test03()
  52 {
  53   std::shared_ptr<A> p1(new A);
  54   std::shared_ptr<A> p2(p1);
  55   p2.reset(new B);
  56   VERIFY( p1.use_count() == 1 );
  57   VERIFY( p2.use_count() == 1 );
  58 }
  59
  60
  61 int
  62 main()
  63 {
  64   test01();
  65   test02();
  66   test03();
  67   return 0;
  68 }