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

   1 // { dg-do run { target c++11 } }
   2 // { dg-require-effective-target hosted }
   3
   4 // Copyright (C) 2008-2024 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 // 20.7.2.2 Class template shared_ptr [util.smartptr.shared]
  22
  23 #include <memory>
  24 #include <testsuite_hooks.h>
  25
  26 struct A { };
  27
  28 int destroyed = 0;
  29 struct B : A { ~B() { ++destroyed; } };
  30
  31 // 20.7.2.2.1 shared_ptr constructors [util.smartptr.shared.const]
  32
  33 // Construction from unique_ptr
  34
  35 template<typename From, typename To>
  36 constexpr bool constructible()
  37 {
  38   using namespace std;
  39   return is_constructible<shared_ptr<To>, unique_ptr<From>>::value
  40     && is_constructible<shared_ptr<const To>, unique_ptr<From>>::value
  41     && is_constructible<shared_ptr<const To>, unique_ptr<const From>>::value;
  42 }
  43
  44 static_assert(  constructible< A,   A    >(), "A -> A compatible" );
  45 static_assert(  constructible< B,   A    >(), "B -> A compatible" );
  46 static_assert(  constructible< int, int  >(), "int -> int compatible" );
  47 static_assert( !constructible< int, long >(), "int -> long not compatible" );
  48
  49 void
  50 test01()
  51 {
  52   std::unique_ptr<A> up(new A);
  53   std::shared_ptr<A> sp(std::move(up));
  54   VERIFY( up.get() == 0 );
  55   VERIFY( sp.get() != 0 );
  56   VERIFY( sp.use_count() == 1 );
  57 }
  58
  59 void
  60 test02()
  61 {
  62   std::unique_ptr<B> b(new B);
  63   std::shared_ptr<A> a(std::move(b));
  64   VERIFY( b.get() == 0 );
  65   VERIFY( a.get() != 0 );
  66   VERIFY( a.use_count() == 1 );
  67   a.reset();
  68   VERIFY( destroyed == 1 );
  69 }
  70
  71 int
  72 main()
  73 {
  74   test01();
  75   test02();
  76   return 0;
  77 }