cond_dealtor.hpp

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// -*- C++ -*-
 
// Copyright (C) 2005-2020 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the terms
// of the GNU General Public License as published by the Free Software
// Foundation; either version 3, or (at your option) any later
// version.
 
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.
 
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
 
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.
 
// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
 
// Permission to use, copy, modify, sell, and distribute this software
// is hereby granted without fee, provided that the above copyright
// notice appears in all copies, and that both that copyright notice
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/**
 * @file detail/cond_dealtor.hpp
 * Contains a conditional deallocator.
 */
 
#ifndef PB_DS_COND_DEALTOR_HPP
#define PB_DS_COND_DEALTOR_HPP
 
#include <ext/pb_ds/detail/types_traits.hpp>
 
namespace __gnu_pbds
{
  namespace detail
  {
    /// Conditional deallocate constructor argument.
    template<typename Entry, typename _Alloc>
      class cond_dealtor
      {
        typedef rebind_traits<_Alloc, Entry>    alloc_traits;
 
      public:
        typedef typename alloc_traits::allocator_type entry_allocator;
        typedef typename alloc_traits::pointer        entry_pointer;
 
        cond_dealtor(entry_pointer p_e)
        : m_p_e(p_e), m_no_action_destructor(false) { }
 
        ~cond_dealtor()
        {
          if (m_no_action_destructor)
            return;
          s_alloc.deallocate(m_p_e, 1);
        }
 
        void
        set_no_action()
        { m_no_action_destructor = true; }
 
      private:
        entry_pointer           m_p_e;
        bool                    m_no_action_destructor;
        static entry_allocator  s_alloc;
      };
 
    template<typename Entry, class _Alloc>
      typename cond_dealtor<Entry, _Alloc>::entry_allocator
      cond_dealtor<Entry, _Alloc>::s_alloc;
  } // namespace detail
} // namespace __gnu_pbds
 
#endif // #ifndef PB_DS_COND_DEALTOR_HPP