libstdc++-v3/include/ext/pb_ds/detail/hash_fn/mod_based_range_hashing.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 mod_based_range_hashing.hpp
  44  * Contains a range hashing policy base.
  45  */
  46
  47 #ifndef PB_DS_MOD_BASED_RANGE_HASHING_HPP
  48 #define PB_DS_MOD_BASED_RANGE_HASHING_HPP
  49
  50 namespace __gnu_pbds
  51 {
  52
  53   namespace detail
  54   {
  55
  56 #define PB_DS_CLASS_T_DEC                       \
  57     template<typename Size_Type>
  58
  59 #define PB_DS_CLASS_C_DEC                                       \
  60     mod_based_range_hashing<                                    \
  61                                                 Size_Type>
  62
  63     template<typename Size_Type>
  64     class mod_based_range_hashing
  65     {
  66     protected:
  67       typedef Size_Type size_type;
  68
  69     protected:
  70       void
  71       swap(PB_DS_CLASS_C_DEC& other);
  72
  73       void
  74       notify_resized(size_type size);
  75
  76       inline size_type
  77       range_hash(size_type hash) const;
  78
  79     private:
  80       size_type m_size;
  81     };
  82
  83     PB_DS_CLASS_T_DEC
  84     void
  85     PB_DS_CLASS_C_DEC::
  86     swap(PB_DS_CLASS_C_DEC& other)
  87     {
  88       std::swap(m_size, other.m_size);
  89     }
  90
  91     PB_DS_CLASS_T_DEC
  92     void
  93     PB_DS_CLASS_C_DEC::
  94     notify_resized(size_type size)
  95     {
  96       m_size = size;
  97     }
  98
  99     PB_DS_CLASS_T_DEC
 100     inline typename PB_DS_CLASS_C_DEC::size_type
 101     PB_DS_CLASS_C_DEC::
 102     range_hash(size_type hash) const
 103     {
 104       return (hash % m_size);
 105     }
 106
 107 #undef PB_DS_CLASS_T_DEC
 108 #undef PB_DS_CLASS_C_DEC
 109
 110   } // namespace detail
 111
 112 } // namespace __gnu_pbds
 113
 114 #endif // #ifndef PB_DS_MOD_BASED_RANGE_HASHING_HPP