1// 'struct hash' from SGI -*- C++ -*-
2
3// Copyright (C) 2001-2015 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
61namespace __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
171