libstdc++
cond_key_dtor_entry_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 cc_hash_table_map_/cond_key_dtor_entry_dealtor.hpp
00038  * Contains a conditional key destructor, used for exception handling.
00039  */
00040 
00041 namespace __gnu_pbds
00042 {
00043   namespace detail
00044   {
00045     /// Conditional dey destructor, cc_hash.
00046     template<typename HT_Map>
00047     class cond_dealtor
00048     {
00049     public:
00050       typedef typename HT_Map::entry        entry;
00051       typedef typename HT_Map::entry_allocator  entry_allocator;
00052       typedef typename HT_Map::key_type     key_type;
00053 
00054       cond_dealtor(entry_allocator* p_a, entry* p_e)
00055       : m_p_a(p_a), m_p_e(p_e), m_key_destruct(false),
00056     m_no_action_destructor(false)
00057       { }
00058 
00059       inline
00060       ~cond_dealtor();
00061 
00062       void
00063       set_key_destruct()
00064       { m_key_destruct = true; }
00065 
00066       void
00067       set_no_action_destructor()
00068       { m_no_action_destructor = true; }
00069 
00070     protected:
00071       entry_allocator* const            m_p_a;
00072       entry* const              m_p_e;
00073 
00074       bool                  m_key_destruct;
00075       bool                  m_no_action_destructor;
00076     };
00077 
00078     template<typename HT_Map>
00079     inline
00080     cond_dealtor<HT_Map>::
00081     ~cond_dealtor()
00082     {
00083       if (m_no_action_destructor)
00084     return;
00085       if (m_key_destruct)
00086     m_p_e->m_value.first.~key_type();
00087       m_p_a->deallocate(m_p_e, 1);
00088     }
00089   } // namespace detail
00090 } // namespace __gnu_pbds