1// 'struct hash' from SGI -*- C++ -*-
2
3// Copyright (C) 2001, 2002, 2003, 2004, 2005 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 2, 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// You should have received a copy of the GNU General Public License along
17// with this library; see the file COPYING.  If not, write to the Free
18// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
19// USA.
20
21// As a special exception, you may use this file as part of a free software
22// library without restriction.  Specifically, if other files instantiate
23// templates or use macros or inline functions from this file, or you compile
24// this file and link it with other files to produce an executable, this
25// file does not by itself cause the resulting executable to be covered by
26// the GNU General Public License.  This exception does not however
27// invalidate any other reasons why the executable file might be covered by
28// the GNU General Public License.
29
30/*
31 * Copyright (c) 1996-1998
32 * Silicon Graphics Computer Systems, Inc.
33 *
34 * Permission to use, copy, modify, distribute and sell this software
35 * and its documentation for any purpose is hereby granted without fee,
36 * provided that the above copyright notice appear in all copies and
37 * that both that copyright notice and this permission notice appear
38 * in supporting documentation.  Silicon Graphics makes no
39 * representations about the suitability of this software for any
40 * purpose.  It is provided "as is" without express or implied warranty.
41 *
42 *
43 * Copyright (c) 1994
44 * Hewlett-Packard Company
45 *
46 * Permission to use, copy, modify, distribute and sell this software
47 * and its documentation for any purpose is hereby granted without fee,
48 * provided that the above copyright notice appear in all copies and
49 * that both that copyright notice and this permission notice appear
50 * in supporting documentation.  Hewlett-Packard Company makes no
51 * representations about the suitability of this software for any
52 * purpose.  It is provided "as is" without express or implied warranty.
53 *
54 */
55
56/** @file ext/hash_fun.h
57 *  This file is a GNU extension to the Standard C++ Library (possibly
58 *  containing extensions from the HP/SGI STL subset).
59 */
60
61#ifndef _HASH_FUN_H
62#define _HASH_FUN_H 1
63
64#include <cstddef>
65
66_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
67
68  using std::size_t;
69
70  template<class _Key>
71    struct hash { };
72
73  inline size_t
74  __stl_hash_string(const char* __s)
75  {
76    unsigned long __h = 0;
77    for ( ; *__s; ++__s)
78      __h = 5 * __h + *__s;
79    return size_t(__h);
80  }
81
82  template<>
83    struct hash<char*>
84    {
85      size_t
86      operator()(const char* __s) const
87      { return __stl_hash_string(__s); }
88    };
89
90  template<>
91    struct hash<const char*>
92    {
93      size_t
94      operator()(const char* __s) const
95      { return __stl_hash_string(__s); }
96    };
97
98  template<>
99    struct hash<char>
100    {
101      size_t
102      operator()(char __x) const
103      { return __x; }
104    };
105
106  template<>
107    struct hash<unsigned char>
108    {
109      size_t
110      operator()(unsigned char __x) const
111      { return __x; }
112    };
113
114  template<>
115    struct hash<signed char>
116    {
117      size_t
118      operator()(unsigned char __x) const
119      { return __x; }
120    };
121
122  template<>
123    struct hash<short>
124    {
125      size_t
126      operator()(short __x) const
127      { return __x; }
128    };
129
130  template<>
131    struct hash<unsigned short>
132    {
133      size_t
134      operator()(unsigned short __x) const
135      { return __x; }
136    };
137
138  template<>
139    struct hash<int>
140    {
141      size_t
142      operator()(int __x) const
143      { return __x; }
144    };
145
146  template<>
147    struct hash<unsigned int>
148    {
149      size_t
150      operator()(unsigned int __x) const
151      { return __x; }
152    };
153
154  template<>
155    struct hash<long>
156    {
157      size_t
158      operator()(long __x) const
159      { return __x; }
160    };
161
162  template<>
163    struct hash<unsigned long>
164    {
165      size_t
166      operator()(unsigned long __x) const
167      { return __x; }
168    };
169
170_GLIBCXX_END_NAMESPACE
171
172#endif
173