contrib/gcc-8.0/libstdc++-v3/include/backward/hash_fun.h

   1 // 'struct hash' from SGI -*- C++ -*-
   2
   3 // Copyright (C) 2001-2018 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
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU 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 /*
  26  * Copyright (c) 1996-1998
  27  * Silicon Graphics Computer Systems, Inc.
  28  *
  29  * Permission to use, copy, modify, distribute and sell this software
  30  * and its documentation for any purpose is hereby granted without fee,
  31  * provided that the above copyright notice appear in all copies and
  32  * that both that copyright notice and this permission notice appear
  33  * in supporting documentation.  Silicon Graphics makes no
  34  * representations about the suitability of this software for any
  35  * purpose.  It is provided "as is" without express or implied warranty.
  36  *
  37  *
  38  * Copyright (c) 1994
  39  * Hewlett-Packard Company
  40  *
  41  * Permission to use, copy, modify, distribute and sell this software
  42  * and its documentation for any purpose is hereby granted without fee,
  43  * provided that the above copyright notice appear in all copies and
  44  * that both that copyright notice and this permission notice appear
  45  * in supporting documentation.  Hewlett-Packard Company makes no
  46  * representations about the suitability of this software for any
  47  * purpose.  It is provided "as is" without express or implied warranty.
  48  *
  49  */
  50
  51 /** @file backward/hash_fun.h
  52  *  This file is a GNU extension to the Standard C++ Library (possibly
  53  *  containing extensions from the HP/SGI STL subset).
  54  */
  55
  56 #ifndef _BACKWARD_HASH_FUN_H
  57 #define _BACKWARD_HASH_FUN_H 1
  58
  59 #include <bits/c++config.h>
  60
  61 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  62 {
  63 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  64
  65   using std::size_t;
  66
  67   template<class _Key>
  68     struct hash { };
  69
  70   inline size_t
  71   __stl_hash_string(const char* __s)
  72   {
  73     unsigned long __h = 0;
  74     for ( ; *__s; ++__s)
  75       __h = 5 * __h + *__s;
  76     return size_t(__h);
  77   }
  78
  79   template<>
  80     struct hash<char*>
  81     {
  82       size_t
  83       operator()(const char* __s) const
  84       { return __stl_hash_string(__s); }
  85     };
  86
  87   template<>
  88     struct hash<const char*>
  89     {
  90       size_t
  91       operator()(const char* __s) const
  92       { return __stl_hash_string(__s); }
  93     };
  94
  95   template<>
  96     struct hash<char>
  97     {
  98       size_t
  99       operator()(char __x) const
 100       { return __x; }
 101     };
 102
 103   template<>
 104     struct hash<unsigned char>
 105     {
 106       size_t
 107       operator()(unsigned char __x) const
 108       { return __x; }
 109     };
 110
 111   template<>
 112     struct hash<signed char>
 113     {
 114       size_t
 115       operator()(unsigned char __x) const
 116       { return __x; }
 117     };
 118
 119   template<>
 120     struct hash<short>
 121     {
 122       size_t
 123       operator()(short __x) const
 124       { return __x; }
 125     };
 126
 127   template<>
 128     struct hash<unsigned short>
 129     {
 130       size_t
 131       operator()(unsigned short __x) const
 132       { return __x; }
 133     };
 134
 135   template<>
 136     struct hash<int>
 137     {
 138       size_t
 139       operator()(int __x) const
 140       { return __x; }
 141     };
 142
 143   template<>
 144     struct hash<unsigned int>
 145     {
 146       size_t
 147       operator()(unsigned int __x) const
 148       { return __x; }
 149     };
 150
 151   template<>
 152     struct hash<long>
 153     {
 154       size_t
 155       operator()(long __x) const
 156       { return __x; }
 157     };
 158
 159   template<>
 160     struct hash<unsigned long>
 161     {
 162       size_t
 163       operator()(unsigned long __x) const
 164       { return __x; }
 165     };
 166
 167 _GLIBCXX_END_NAMESPACE_VERSION
 168 } // namespace
 169
 170 #endif