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

   1 // { dg-do run { target c++11 } }
   2
   3 // Copyright (C) 2008-2022 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 // 20.7.2.2 Class template shared_ptr [util.smartptr.shared]
  21
  22 #include <memory>
  23 #include <testsuite_hooks.h>
  24
  25 struct A { };
  26
  27 int destroyed = 0;
  28 struct B : A { ~B() { ++destroyed; } };
  29
  30 // 20.7.2.2.1 shared_ptr constructors [util.smartptr.shared.const]
  31
  32 // Construction from unique_ptr
  33
  34 template<typename From, typename To>
  35 constexpr bool constructible()
  36 {
  37   using namespace std;
  38   return is_constructible<shared_ptr<To>, unique_ptr<From>>::value
  39     && is_constructible<shared_ptr<const To>, unique_ptr<From>>::value
  40     && is_constructible<shared_ptr<const To>, unique_ptr<const From>>::value;
  41 }
  42
  43 static_assert(  constructible< A,   A    >(), "A -> A compatible" );
  44 static_assert(  constructible< B,   A    >(), "B -> A compatible" );
  45 static_assert(  constructible< int, int  >(), "int -> int compatible" );
  46 static_assert( !constructible< int, long >(), "int -> long not compatible" );
  47
  48 void
  49 test01()
  50 {
  51   std::unique_ptr<A> up(new A);
  52   std::shared_ptr<A> sp(std::move(up));
  53   VERIFY( up.get() == 0 );
  54   VERIFY( sp.get() != 0 );
  55   VERIFY( sp.use_count() == 1 );
  56 }
  57
  58 void
  59 test02()
  60 {
  61   std::unique_ptr<B> b(new B);
  62   std::shared_ptr<A> a(std::move(b));
  63   VERIFY( b.get() == 0 );
  64   VERIFY( a.get() != 0 );
  65   VERIFY( a.use_count() == 1 );
  66   a.reset();
  67   VERIFY( destroyed == 1 );
  68 }
  69
  70 int
  71 main()
  72 {
  73   test01();
  74   test02();
  75   return 0;
  76 }