libstdc++-v3/include/ext/pb_ds/detail/cc_hash_table_map_/cond_key_dtor_entry_dealtor.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2015 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 terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 3, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  26
  27 // Permission to use, copy, modify, sell, and distribute this software
  28 // is hereby granted without fee, provided that the above copyright
  29 // notice appears in all copies, and that both that copyright notice
  30 // and this permission notice appear in supporting documentation. None
  31 // of the above authors, nor IBM Haifa Research Laboratories, make any
  32 // representation about the suitability of this software for any
  33 // purpose. It is provided "as is" without express or implied
  34 // warranty.
  35
  36 /**
  37  * @file cc_hash_table_map_/cond_key_dtor_entry_dealtor.hpp
  38  * Contains a conditional key destructor, used for exception handling.
  39  */
  40
  41 namespace __gnu_pbds
  42 {
  43   namespace detail
  44   {
  45     /// Conditional dey destructor, cc_hash.
  46     template<typename HT_Map>
  47     class cond_dealtor
  48     {
  49     public:
  50       typedef typename HT_Map::entry            entry;
  51       typedef typename HT_Map::entry_allocator  entry_allocator;
  52       typedef typename HT_Map::key_type         key_type;
  53
  54       cond_dealtor(entry_allocator* p_a, entry* p_e)
  55       : m_p_a(p_a), m_p_e(p_e), m_key_destruct(false),
  56         m_no_action_destructor(false)
  57       { }
  58
  59       inline
  60       ~cond_dealtor();
  61
  62       void
  63       set_key_destruct()
  64       { m_key_destruct = true; }
  65
  66       void
  67       set_no_action_destructor()
  68       { m_no_action_destructor = true; }
  69
  70     protected:
  71       entry_allocator* const                    m_p_a;
  72       entry* const                              m_p_e;
  73
  74       bool                                      m_key_destruct;
  75       bool                                      m_no_action_destructor;
  76     };
  77
  78     template<typename HT_Map>
  79     inline
  80     cond_dealtor<HT_Map>::
  81     ~cond_dealtor()
  82     {
  83       if (m_no_action_destructor)
  84         return;
  85       if (m_key_destruct)
  86         m_p_e->m_value.first.~key_type();
  87       m_p_a->deallocate(m_p_e, 1);
  88     }
  89   } // namespace detail
  90 } // namespace __gnu_pbds