libstdc++-v3/testsuite/20_util/shared_ptr/cons/alias-rval.cc

   1 // { dg-do run { target c++20 } }
   2 // { dg-require-effective-target hosted }
   3
   4 // Copyright (C) 2019-2023 Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING3.  If not see
  19 // <http://www.gnu.org/licenses/>.
  20
  21 // Template class shared_ptr [util.smartptr.shared]
  22
  23 #include <memory>
  24 #include <testsuite_hooks.h>
  25
  26 struct A
  27 {
  28   A() : i() { }
  29   virtual ~A() { }
  30   int i;
  31 };
  32
  33 struct B : A
  34 {
  35   B() : A(), a() { }
  36   virtual ~B() { }
  37   A a;
  38 };
  39
  40 // 20.6.6.2.1 shared_ptr constructors [util.smartptr.shared.const]
  41
  42 // Aliasing constructors
  43
  44 void
  45 test01()
  46 {
  47   bool test = true;
  48
  49   std::shared_ptr<A> a;
  50   std::shared_ptr<bool> b1(std::move(a), &test);
  51   VERIFY( b1.use_count() == 0 );
  52   VERIFY( b1.get() == &test );
  53   VERIFY( a.use_count() == 0 );
  54   VERIFY( a == nullptr );
  55
  56   std::shared_ptr<bool> b2(b1);
  57   VERIFY( b2.use_count() == 0 );
  58   VERIFY( b1 == b2 );
  59 }
  60
  61 void
  62 test02()
  63 {
  64   A* ptr = new A;
  65   ptr->i = 100;
  66   std::shared_ptr<A> a(ptr);
  67   std::shared_ptr<int> i1(std::move(a), &a->i);
  68   VERIFY( i1.use_count() == 1 );
  69   VERIFY( *i1 == 100 );
  70   VERIFY( a.use_count() == 0 );
  71   VERIFY( a == nullptr );
  72
  73   std::shared_ptr<int> i2(i1);
  74   VERIFY( i2.use_count() == 2 );
  75   VERIFY( i2.get() == &ptr->i );
  76 }
  77
  78 void
  79 test03()
  80 {
  81   std::shared_ptr<B> b1(new B);
  82   b1->i = 100;
  83   b1->a.i = 200;
  84   std::shared_ptr<B> b2(b1);
  85   std::shared_ptr<A> a1(std::move(b1), b1.get());
  86   std::shared_ptr<A> a2(std::move(b2), &b2->a);
  87   VERIFY( a1.use_count() == 2 );
  88   VERIFY( a2.use_count() == 2 );
  89   VERIFY( a1->i == 100 );
  90   VERIFY( a2->i == 200 );
  91   VERIFY( b1.use_count() == 0 );
  92   VERIFY( b2.use_count() == 0 );
  93   VERIFY( b1 == nullptr );
  94   VERIFY( b2 == nullptr );
  95 }
  96
  97 int
  98 main()
  99 {
 100   test01();
 101   test02();
 102   test03();
 103 }