1 : // 'struct hash' from SGI -*- C++ -*-
2 :
3 : // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2009, 2010
4 : // Free Software Foundation, Inc.
5 : //
6 : // This file is part of the GNU ISO C++ Library. This library is free
7 : // software; you can redistribute it and/or modify it under the
8 : // terms of the GNU General Public License as published by the
9 : // Free Software Foundation; either version 3, or (at your option)
10 : // any later version.
11 :
12 : // This library is distributed in the hope that it will be useful,
13 : // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 : // GNU General Public License for more details.
16 :
17 : // Under Section 7 of GPL version 3, you are granted additional
18 : // permissions described in the GCC Runtime Library Exception, version
19 : // 3.1, as published by the Free Software Foundation.
20 :
21 : // You should have received a copy of the GNU General Public License and
22 : // a copy of the GCC Runtime Library Exception along with this program;
23 : // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 : // <http://www.gnu.org/licenses/>.
25 :
26 : /*
27 : * Copyright (c) 1996-1998
28 : * Silicon Graphics Computer Systems, Inc.
29 : *
30 : * Permission to use, copy, modify, distribute and sell this software
31 : * and its documentation for any purpose is hereby granted without fee,
32 : * provided that the above copyright notice appear in all copies and
33 : * that both that copyright notice and this permission notice appear
34 : * in supporting documentation. Silicon Graphics makes no
35 : * representations about the suitability of this software for any
36 : * purpose. It is provided "as is" without express or implied warranty.
37 : *
38 : *
39 : * Copyright (c) 1994
40 : * Hewlett-Packard Company
41 : *
42 : * Permission to use, copy, modify, distribute and sell this software
43 : * and its documentation for any purpose is hereby granted without fee,
44 : * provided that the above copyright notice appear in all copies and
45 : * that both that copyright notice and this permission notice appear
46 : * in supporting documentation. Hewlett-Packard Company makes no
47 : * representations about the suitability of this software for any
48 : * purpose. It is provided "as is" without express or implied warranty.
49 : *
50 : */
51 :
52 : /** @file backward/hash_fun.h
53 : * This file is a GNU extension to the Standard C++ Library (possibly
54 : * containing extensions from the HP/SGI STL subset).
55 : */
56 :
57 : #ifndef _BACKWARD_HASH_FUN_H
58 : #define _BACKWARD_HASH_FUN_H 1
59 :
60 : #include <cstddef>
61 :
62 : _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
63 :
64 : using std::size_t;
65 :
66 : template<class _Key>
67 : struct hash { };
68 :
69 : inline size_t
70 : __stl_hash_string(const char* __s)
71 : {
72 : unsigned long __h = 0;
73 : for ( ; *__s; ++__s)
74 : __h = 5 * __h + *__s;
75 : return size_t(__h);
76 : }
77 :
78 : template<>
79 : struct hash<char*>
80 : {
81 : size_t
82 : operator()(const char* __s) const
83 : { return __stl_hash_string(__s); }
84 : };
85 :
86 : template<>
87 : struct hash<const char*>
88 : {
89 : size_t
90 : operator()(const char* __s) const
91 : { return __stl_hash_string(__s); }
92 : };
93 :
94 : template<>
95 : struct hash<char>
96 : {
97 : size_t
98 : operator()(char __x) const
99 : { return __x; }
100 : };
101 :
102 : template<>
103 : struct hash<unsigned char>
104 : {
105 : size_t
106 : operator()(unsigned char __x) const
107 : { return __x; }
108 : };
109 :
110 : template<>
111 : struct hash<signed char>
112 : {
113 : size_t
114 : operator()(unsigned char __x) const
115 : { return __x; }
116 : };
117 :
118 : template<>
119 : struct hash<short>
120 : {
121 : size_t
122 : operator()(short __x) const
123 : { return __x; }
124 : };
125 :
126 : template<>
127 : struct hash<unsigned short>
128 : {
129 : size_t
130 : operator()(unsigned short __x) const
131 : { return __x; }
132 : };
133 :
134 : template<>
135 : struct hash<int>
136 : {
137 : size_t
138 0 : operator()(int __x) const
139 0 : { return __x; }
140 : };
141 :
142 : template<>
143 : struct hash<unsigned int>
144 : {
145 : size_t
146 : operator()(unsigned int __x) const
147 : { return __x; }
148 : };
149 :
150 : template<>
151 : struct hash<long>
152 : {
153 : size_t
154 : operator()(long __x) const
155 : { return __x; }
156 : };
157 :
158 : template<>
159 : struct hash<unsigned long>
160 : {
161 : size_t
162 : operator()(unsigned long __x) const
163 : { return __x; }
164 : };
165 :
166 : _GLIBCXX_END_NAMESPACE
167 :
168 : #endif
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