libstdc++
cond_dealtor.hpp
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00001 // -*- C++ -*-
00002 
00003 // Copyright (C) 2005, 2006, 2009, 2011 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the terms
00007 // of the GNU General Public License as published by the Free Software
00008 // Foundation; either version 3, or (at your option) any later
00009 // version.
00010 
00011 // This library is distributed in the hope that it will be useful, but
00012 // WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014 // General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
00026 
00027 // Permission to use, copy, modify, sell, and distribute this software
00028 // is hereby granted without fee, provided that the above copyright
00029 // notice appears in all copies, and that both that copyright notice
00030 // and this permission notice appear in supporting documentation. None
00031 // of the above authors, nor IBM Haifa Research Laboratories, make any
00032 // representation about the suitability of this software for any
00033 // purpose. It is provided "as is" without express or implied
00034 // warranty.
00035 
00036 /**
00037  * @file detail/cond_dealtor.hpp
00038  * Contains a conditional deallocator.
00039  */
00040 
00041 #ifndef PB_DS_COND_DEALTOR_HPP
00042 #define PB_DS_COND_DEALTOR_HPP
00043 
00044 namespace __gnu_pbds
00045 {
00046   namespace detail
00047   {
00048     /// Conditional deallocate constructor argument.
00049     template<typename Entry, typename _Alloc>
00050       class cond_dealtor
00051       {
00052     typedef typename _Alloc::template rebind<Entry> __rebind_e;
00053 
00054       public:
00055     typedef typename __rebind_e::other      entry_allocator;
00056     typedef typename entry_allocator::pointer   entry_pointer;
00057 
00058     cond_dealtor(entry_pointer p_e)
00059     : m_p_e(p_e), m_no_action_destructor(false) { }
00060 
00061     ~cond_dealtor()
00062     {
00063       if (m_no_action_destructor)
00064         return;
00065       s_alloc.deallocate(m_p_e, 1);
00066     }
00067 
00068     void
00069     set_no_action()
00070     { m_no_action_destructor = true; }
00071 
00072       private:
00073     entry_pointer       m_p_e;
00074     bool            m_no_action_destructor;
00075     static entry_allocator  s_alloc;
00076       };
00077 
00078     template<typename Entry, class _Alloc>
00079       typename cond_dealtor<Entry, _Alloc>::entry_allocator
00080       cond_dealtor<Entry, _Alloc>::s_alloc;
00081   } // namespace detail
00082 } // namespace __gnu_pbds
00083 
00084 #endif // #ifndef PB_DS_COND_DEALTOR_HPP