libstdc++-v3/testsuite/20_util/enable_shared_from_this/members/unique_ptr.cc

   1 // { dg-do run { target c++11 } }
   2 // { dg-require-effective-target hosted }
   3
   4 // Copyright (C) 2013-2024 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 #include <memory>
  22 #include <ext/pointer.h>
  23 #include <testsuite_hooks.h>
  24
  25 struct X : public std::enable_shared_from_this<X> { };
  26
  27 void test01()
  28 {
  29   std::unique_ptr<X> up(new X);
  30   X* xp = up.get();
  31   std::shared_ptr<X> sp(std::move(up));
  32   VERIFY( xp->shared_from_this() != nullptr );
  33 }
  34
  35 using __gnu_cxx::_Pointer_adapter;
  36 using __gnu_cxx::_Std_pointer_impl;
  37
  38 struct Deleter
  39 {
  40   struct pointer : _Pointer_adapter<_Std_pointer_impl<X>>
  41   {
  42     using _Pointer_adapter::_Pointer_adapter;
  43     operator X*() const noexcept { return this->get(); }
  44   };
  45
  46   void operator()(pointer p) const noexcept { delete (X*)p; }
  47 };
  48
  49 void test02()
  50 {
  51   std::unique_ptr<X, Deleter> up(new X);
  52   Deleter::pointer xp = up.get();
  53   // Creating shared_ptr from unique_ptr with custom pointer is an extension:
  54   std::shared_ptr<X> sp(std::move(up));
  55   // but enable_shared_from_this should still work:
  56   VERIFY( xp->shared_from_this() != nullptr );
  57 }
  58
  59 int main()
  60 {
  61   test01();
  62   test02();
  63 }