libstdc++-v3/include/ext/pb_ds/detail/eq_fn/hash_eq_fn.hpp

   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 hash_eq_fn.hpp
  44  * Contains 2 eqivalence functions, one employing a hash value,
  45  *    and one ignoring it.
  46  */
  47
  48 #ifndef PB_DS_HASH_EQ_FN_HPP
  49 #define PB_DS_HASH_EQ_FN_HPP
  50
  51 #include <utility>
  52 #include <debug/debug.h>
  53
  54 namespace pb_ds
  55 {
  56   namespace detail
  57   {
  58     template<typename Key, class Eq_Fn, class Allocator, bool Store_Hash>
  59     struct hash_eq_fn;
  60
  61 #define PB_DS_CLASS_T_DEC \
  62     template<typename Key, class Eq_Fn, class Allocator>
  63
  64 #define PB_DS_CLASS_C_DEC \
  65     hash_eq_fn<Key, Eq_Fn, Allocator, false>
  66
  67     /**
  68      * Specialization 1- The client requests that hash values not be stored.
  69      **/
  70     template<typename Key, class Eq_Fn, class Allocator>
  71     struct hash_eq_fn<Key, Eq_Fn, Allocator, false> : public Eq_Fn
  72     {
  73       typedef Eq_Fn eq_fn_base;
  74
  75       typedef typename Allocator::template rebind<Key>::other key_allocator;
  76
  77       typedef typename key_allocator::const_reference const_key_reference;
  78
  79       hash_eq_fn();
  80
  81       hash_eq_fn(const Eq_Fn& r_eq_fn);
  82
  83       inline bool
  84       operator()(const_key_reference r_lhs_key, const_key_reference r_rhs_key) const;
  85
  86       inline void
  87       swap(const PB_DS_CLASS_C_DEC& other);
  88     };
  89
  90     PB_DS_CLASS_T_DEC
  91     PB_DS_CLASS_C_DEC::
  92     hash_eq_fn()
  93     { }
  94
  95     PB_DS_CLASS_T_DEC
  96     inline void
  97     PB_DS_CLASS_C_DEC::
  98     swap(const PB_DS_CLASS_C_DEC& other)
  99     { std::swap((Eq_Fn& )(*this), (Eq_Fn& )other); }
 100
 101     PB_DS_CLASS_T_DEC
 102     PB_DS_CLASS_C_DEC::
 103     hash_eq_fn(const Eq_Fn& r_eq_fn) :
 104       Eq_Fn(r_eq_fn)
 105     { }
 106
 107     PB_DS_CLASS_T_DEC
 108     inline bool
 109     PB_DS_CLASS_C_DEC::
 110     operator()(const_key_reference r_lhs_key, const_key_reference r_rhs_key) const
 111     { return (eq_fn_base::operator()(r_lhs_key, r_rhs_key)); }
 112
 113 #undef PB_DS_CLASS_T_DEC
 114 #undef PB_DS_CLASS_C_DEC
 115
 116 #define PB_DS_CLASS_T_DEC \
 117     template<typename Key, class Eq_Fn, class Allocator>
 118
 119 #define PB_DS_CLASS_C_DEC \
 120     hash_eq_fn<Key, Eq_Fn, Allocator, true>
 121
 122     /**
 123      * Specialization 2- The client requests that hash values be stored.
 124      **/
 125     template<typename Key, class Eq_Fn, class Allocator>
 126     struct hash_eq_fn<Key, Eq_Fn, Allocator, true> :
 127       public Eq_Fn
 128     {
 129       typedef typename Allocator::size_type size_type;
 130
 131       typedef Eq_Fn eq_fn_base;
 132
 133       typedef typename Allocator::template rebind<Key>::other key_allocator;
 134
 135       typedef typename key_allocator::const_reference const_key_reference;
 136
 137       hash_eq_fn();
 138
 139       hash_eq_fn(const Eq_Fn& r_eq_fn);
 140
 141       inline bool
 142       operator()(const_key_reference r_lhs_key, size_type lhs_hash,
 143                  const_key_reference r_rhs_key, size_type rhs_hash) const;
 144
 145       inline void
 146       swap(const PB_DS_CLASS_C_DEC& other);
 147     };
 148
 149     PB_DS_CLASS_T_DEC
 150     PB_DS_CLASS_C_DEC::
 151     hash_eq_fn()
 152     { }
 153
 154     PB_DS_CLASS_T_DEC
 155     PB_DS_CLASS_C_DEC::
 156     hash_eq_fn(const Eq_Fn& r_eq_fn) :
 157       Eq_Fn(r_eq_fn)
 158     { }
 159
 160     PB_DS_CLASS_T_DEC
 161     inline bool
 162     PB_DS_CLASS_C_DEC::
 163     operator()(const_key_reference r_lhs_key, size_type lhs_hash,
 164                const_key_reference r_rhs_key, size_type rhs_hash) const
 165     {
 166       _GLIBCXX_DEBUG_ASSERT(!eq_fn_base::operator()(r_lhs_key, r_rhs_key)
 167                             || lhs_hash == rhs_hash);
 168
 169       return (lhs_hash == rhs_hash &&
 170               eq_fn_base::operator()(r_lhs_key, r_rhs_key));
 171     }
 172
 173     PB_DS_CLASS_T_DEC
 174     inline void
 175     PB_DS_CLASS_C_DEC::
 176     swap(const PB_DS_CLASS_C_DEC& other)
 177     { std::swap((Eq_Fn& )(*this), (Eq_Fn& )(other)); }
 178
 179 #undef PB_DS_CLASS_T_DEC
 180 #undef PB_DS_CLASS_C_DEC
 181
 182   } // namespace detail
 183 } // namespace pb_ds
 184
 185 #endif