1// -*- C++ -*- 2 3// Copyright (C) 2005, 2006 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 <ext/pb_ds/detail/list_update_policy/counter_lu_metadata.hpp> 51 52namespace pb_ds 53{ 54 // A null type that means that each link in a list-based container 55 // does not actually need metadata. 56 struct null_lu_metadata 57 { }; 58 59#define PB_DS_CLASS_T_DEC template<typename Allocator> 60#define PB_DS_CLASS_C_DEC move_to_front_lu_policy<Allocator> 61 62 // A list-update policy that unconditionally moves elements to the 63 // front of the list. 64 template<typename Allocator = std::allocator<char> > 65 class move_to_front_lu_policy 66 { 67 public: 68 typedef Allocator allocator; 69 70 // Metadata on which this functor operates. 71 typedef null_lu_metadata metadata_type; 72 73 // Reference to metadata on which this functor operates. 74 typedef typename allocator::template rebind<metadata_type>::other metadata_rebind; 75 typedef typename metadata_rebind::reference metadata_reference; 76 77 // Creates a metadata object. 78 metadata_type 79 operator()() const; 80 81 // Decides whether a metadata object should be moved to the front 82 // of the list. 83 inline bool 84 operator()(metadata_reference r_metadata) const; 85 86 private: 87 static null_lu_metadata s_metadata; 88 }; 89 90#include <ext/pb_ds/detail/list_update_policy/mtf_lu_policy_imp.hpp> 91 92#undef PB_DS_CLASS_T_DEC 93#undef PB_DS_CLASS_C_DEC 94 95#define PB_DS_CLASS_T_DEC template<size_t Max_Count, class Allocator> 96#define PB_DS_CLASS_C_DEC counter_lu_policy<Max_Count, Allocator> 97 98 // A list-update policy that moves elements to the front of the list 99 // based on the counter algorithm. 100 template<size_t Max_Count = 5, typename Allocator = std::allocator<char> > 101 class counter_lu_policy 102 : private detail::counter_lu_policy_base<typename Allocator::size_type> 103 { 104 public: 105 typedef Allocator allocator; 106 107 enum 108 { 109 max_count = Max_Count 110 }; 111 112 typedef typename allocator::size_type size_type; 113 114 // Metadata on which this functor operates. 115 typedef detail::counter_lu_metadata<size_type> metadata_type; 116 117 // Reference to metadata on which this functor operates. 118 typedef typename Allocator::template rebind<metadata_type>::other metadata_rebind; 119 typedef typename metadata_rebind::reference metadata_reference; 120 121 // Creates a metadata object. 122 metadata_type 123 operator()() const; 124 125 // Decides whether a metadata object should be moved to the front 126 // of the list. 127 bool 128 operator()(metadata_reference r_metadata) const; 129 130 private: 131 typedef detail::counter_lu_policy_base<typename Allocator::size_type> base_type; 132 }; 133 134#include <ext/pb_ds/detail/list_update_policy/counter_lu_policy_imp.hpp> 135 136#undef PB_DS_CLASS_T_DEC 137#undef PB_DS_CLASS_C_DEC 138 139} // namespace pb_ds 140 141#endif 142