mingw/lib/gcc/mingw32/4.3.3/include/c++/ext/pb_ds/list_update_policy.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006, 2007 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 2, 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 // You should have received a copy of the GNU General Public License
  17 // along with this library; see the file COPYING.  If not, write to
  18 // the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
  19 // MA 02111-1307, USA.
  20
  21 // As a special exception, you may use this file as part of a free
  22 // software library without restriction.  Specifically, if other files
  23 // instantiate templates or use macros or inline functions from this
  24 // file, or you compile this file and link it with other files to
  25 // produce an executable, this file does not by itself cause the
  26 // resulting executable to be covered by the GNU General Public
  27 // License.  This exception does not however invalidate any other
  28 // reasons why the executable file might be covered by the GNU General
  29 // Public License.
  30
  31 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  32
  33 // Permission to use, copy, modify, sell, and distribute this software
  34 // is hereby granted without fee, provided that the above copyright
  35 // notice appears in all copies, and that both that copyright notice
  36 // and this permission notice appear in supporting documentation. None
  37 // of the above authors, nor IBM Haifa Research Laboratories, make any
  38 // representation about the suitability of this software for any
  39 // purpose. It is provided "as is" without express or implied
  40 // warranty.
  41
  42 /**
  43  * @file list_update_policy.hpp
  44  * Contains policies for list update containers.
  45  */
  46
  47 #ifndef PB_DS_LU_POLICY_HPP
  48 #define PB_DS_LU_POLICY_HPP
  49
  50 #include <cstdlib>
  51 #include <ext/pb_ds/detail/list_update_policy/counter_lu_metadata.hpp>
  52
  53 namespace __gnu_pbds
  54 {
  55   // A null type that means that each link in a list-based container
  56   // does not actually need metadata.
  57   struct null_lu_metadata
  58   { };
  59
  60 #define PB_DS_CLASS_T_DEC template<typename Allocator>
  61 #define PB_DS_CLASS_C_DEC move_to_front_lu_policy<Allocator>
  62
  63   // A list-update policy that unconditionally moves elements to the
  64   // front of the list.
  65   template<typename Allocator = std::allocator<char> >
  66   class move_to_front_lu_policy
  67   {
  68   public:
  69     typedef Allocator allocator;
  70
  71     // Metadata on which this functor operates.
  72     typedef null_lu_metadata metadata_type;
  73
  74     // Reference to metadata on which this functor operates.
  75     typedef typename allocator::template rebind<metadata_type>::other metadata_rebind;
  76     typedef typename metadata_rebind::reference metadata_reference;
  77
  78     // Creates a metadata object.
  79     metadata_type
  80     operator()() const;
  81
  82     // Decides whether a metadata object should be moved to the front
  83     // of the list.
  84     inline bool
  85     operator()(metadata_reference r_metadata) const;
  86
  87   private:
  88     static null_lu_metadata s_metadata;
  89   };
  90
  91 #include <ext/pb_ds/detail/list_update_policy/mtf_lu_policy_imp.hpp>
  92
  93 #undef PB_DS_CLASS_T_DEC
  94 #undef PB_DS_CLASS_C_DEC
  95
  96 #define PB_DS_CLASS_T_DEC template<size_t Max_Count, class Allocator>
  97 #define PB_DS_CLASS_C_DEC counter_lu_policy<Max_Count, Allocator>
  98
  99   // A list-update policy that moves elements to the front of the list
 100   // based on the counter algorithm.
 101   template<size_t Max_Count = 5, typename Allocator = std::allocator<char> >
 102   class counter_lu_policy
 103   : private detail::counter_lu_policy_base<typename Allocator::size_type>
 104   {
 105   public:
 106     typedef Allocator allocator;
 107
 108     enum
 109       {
 110         max_count = Max_Count
 111       };
 112
 113     typedef typename allocator::size_type size_type;
 114
 115     // Metadata on which this functor operates.
 116     typedef detail::counter_lu_metadata<size_type> metadata_type;
 117
 118     // Reference to metadata on which this functor operates.
 119     typedef typename Allocator::template rebind<metadata_type>::other metadata_rebind;
 120     typedef typename metadata_rebind::reference metadata_reference;
 121
 122     // Creates a metadata object.
 123     metadata_type
 124     operator()() const;
 125
 126     // Decides whether a metadata object should be moved to the front
 127     // of the list.
 128     bool
 129     operator()(metadata_reference r_metadata) const;
 130
 131   private:
 132     typedef detail::counter_lu_policy_base<typename Allocator::size_type> base_type;
 133   };
 134
 135 #include <ext/pb_ds/detail/list_update_policy/counter_lu_policy_imp.hpp>
 136
 137 #undef PB_DS_CLASS_T_DEC
 138 #undef PB_DS_CLASS_C_DEC
 139
 140 } // namespace __gnu_pbds
 141
 142 #endif