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

   1 // { dg-options "-std=gnu++0x" }
   2
   3 // Copyright (C) 2005-2013 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   bool test __attribute__((unused)) = true;
  35
  36   const std::shared_ptr<A> p1;
  37   VERIFY( p1.use_count() == 0 );
  38   const std::shared_ptr<A> p2(p1);
  39   VERIFY( p1.use_count() == 0 );
  40 }
  41
  42 void
  43 test02()
  44 {
  45   bool test __attribute__((unused)) = true;
  46
  47   std::shared_ptr<A> p1(new A);
  48   std::shared_ptr<A> p2(p1);
  49   p1.reset();
  50   VERIFY( p1.use_count() == 0 );
  51   VERIFY( p2.use_count() == 1 );
  52 }
  53
  54 void
  55 test03()
  56 {
  57   bool test __attribute__((unused)) = true;
  58
  59   std::shared_ptr<A> p1(new A);
  60   std::shared_ptr<A> p2(p1);
  61   p2.reset(new B);
  62   VERIFY( p1.use_count() == 1 );
  63   VERIFY( p2.use_count() == 1 );
  64 }
  65
  66
  67 int
  68 main()
  69 {
  70   test01();
  71   test02();
  72   test03();
  73   return 0;
  74 }