xref: /openbsd-src/gnu/gcc/libstdc++-v3/include/ext/hash_fun.h (revision 404b540a9034ac75a6199ad1a32d1bbc7a0d4210)
1*404b540aSrobert // 'struct hash' from SGI -*- C++ -*-
2*404b540aSrobert 
3*404b540aSrobert // Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4*404b540aSrobert //
5*404b540aSrobert // This file is part of the GNU ISO C++ Library.  This library is free
6*404b540aSrobert // software; you can redistribute it and/or modify it under the
7*404b540aSrobert // terms of the GNU General Public License as published by the
8*404b540aSrobert // Free Software Foundation; either version 2, or (at your option)
9*404b540aSrobert // any later version.
10*404b540aSrobert 
11*404b540aSrobert // This library is distributed in the hope that it will be useful,
12*404b540aSrobert // but WITHOUT ANY WARRANTY; without even the implied warranty of
13*404b540aSrobert // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14*404b540aSrobert // GNU General Public License for more details.
15*404b540aSrobert 
16*404b540aSrobert // You should have received a copy of the GNU General Public License along
17*404b540aSrobert // with this library; see the file COPYING.  If not, write to the Free
18*404b540aSrobert // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
19*404b540aSrobert // USA.
20*404b540aSrobert 
21*404b540aSrobert // As a special exception, you may use this file as part of a free software
22*404b540aSrobert // library without restriction.  Specifically, if other files instantiate
23*404b540aSrobert // templates or use macros or inline functions from this file, or you compile
24*404b540aSrobert // this file and link it with other files to produce an executable, this
25*404b540aSrobert // file does not by itself cause the resulting executable to be covered by
26*404b540aSrobert // the GNU General Public License.  This exception does not however
27*404b540aSrobert // invalidate any other reasons why the executable file might be covered by
28*404b540aSrobert // the GNU General Public License.
29*404b540aSrobert 
30*404b540aSrobert /*
31*404b540aSrobert  * Copyright (c) 1996-1998
32*404b540aSrobert  * Silicon Graphics Computer Systems, Inc.
33*404b540aSrobert  *
34*404b540aSrobert  * Permission to use, copy, modify, distribute and sell this software
35*404b540aSrobert  * and its documentation for any purpose is hereby granted without fee,
36*404b540aSrobert  * provided that the above copyright notice appear in all copies and
37*404b540aSrobert  * that both that copyright notice and this permission notice appear
38*404b540aSrobert  * in supporting documentation.  Silicon Graphics makes no
39*404b540aSrobert  * representations about the suitability of this software for any
40*404b540aSrobert  * purpose.  It is provided "as is" without express or implied warranty.
41*404b540aSrobert  *
42*404b540aSrobert  *
43*404b540aSrobert  * Copyright (c) 1994
44*404b540aSrobert  * Hewlett-Packard Company
45*404b540aSrobert  *
46*404b540aSrobert  * Permission to use, copy, modify, distribute and sell this software
47*404b540aSrobert  * and its documentation for any purpose is hereby granted without fee,
48*404b540aSrobert  * provided that the above copyright notice appear in all copies and
49*404b540aSrobert  * that both that copyright notice and this permission notice appear
50*404b540aSrobert  * in supporting documentation.  Hewlett-Packard Company makes no
51*404b540aSrobert  * representations about the suitability of this software for any
52*404b540aSrobert  * purpose.  It is provided "as is" without express or implied warranty.
53*404b540aSrobert  *
54*404b540aSrobert  */
55*404b540aSrobert 
56*404b540aSrobert /** @file ext/hash_fun.h
57*404b540aSrobert  *  This file is a GNU extension to the Standard C++ Library (possibly
58*404b540aSrobert  *  containing extensions from the HP/SGI STL subset).
59*404b540aSrobert  */
60*404b540aSrobert 
61*404b540aSrobert #ifndef _HASH_FUN_H
62*404b540aSrobert #define _HASH_FUN_H 1
63*404b540aSrobert 
64*404b540aSrobert #include <cstddef>
65*404b540aSrobert 
66*404b540aSrobert _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
67*404b540aSrobert 
68*404b540aSrobert   using std::size_t;
69*404b540aSrobert 
70*404b540aSrobert   template<class _Key>
71*404b540aSrobert     struct hash { };
72*404b540aSrobert 
73*404b540aSrobert   inline size_t
__stl_hash_string(const char * __s)74*404b540aSrobert   __stl_hash_string(const char* __s)
75*404b540aSrobert   {
76*404b540aSrobert     unsigned long __h = 0;
77*404b540aSrobert     for ( ; *__s; ++__s)
78*404b540aSrobert       __h = 5 * __h + *__s;
79*404b540aSrobert     return size_t(__h);
80*404b540aSrobert   }
81*404b540aSrobert 
82*404b540aSrobert   template<>
83*404b540aSrobert     struct hash<char*>
84*404b540aSrobert     {
85*404b540aSrobert       size_t
86*404b540aSrobert       operator()(const char* __s) const
87*404b540aSrobert       { return __stl_hash_string(__s); }
88*404b540aSrobert     };
89*404b540aSrobert 
90*404b540aSrobert   template<>
91*404b540aSrobert     struct hash<const char*>
92*404b540aSrobert     {
93*404b540aSrobert       size_t
94*404b540aSrobert       operator()(const char* __s) const
95*404b540aSrobert       { return __stl_hash_string(__s); }
96*404b540aSrobert     };
97*404b540aSrobert 
98*404b540aSrobert   template<>
99*404b540aSrobert     struct hash<char>
100*404b540aSrobert     {
101*404b540aSrobert       size_t
102*404b540aSrobert       operator()(char __x) const
103*404b540aSrobert       { return __x; }
104*404b540aSrobert     };
105*404b540aSrobert 
106*404b540aSrobert   template<>
107*404b540aSrobert     struct hash<unsigned char>
108*404b540aSrobert     {
109*404b540aSrobert       size_t
110*404b540aSrobert       operator()(unsigned char __x) const
111*404b540aSrobert       { return __x; }
112*404b540aSrobert     };
113*404b540aSrobert 
114*404b540aSrobert   template<>
115*404b540aSrobert     struct hash<signed char>
116*404b540aSrobert     {
117*404b540aSrobert       size_t
118*404b540aSrobert       operator()(unsigned char __x) const
119*404b540aSrobert       { return __x; }
120*404b540aSrobert     };
121*404b540aSrobert 
122*404b540aSrobert   template<>
123*404b540aSrobert     struct hash<short>
124*404b540aSrobert     {
125*404b540aSrobert       size_t
126*404b540aSrobert       operator()(short __x) const
127*404b540aSrobert       { return __x; }
128*404b540aSrobert     };
129*404b540aSrobert 
130*404b540aSrobert   template<>
131*404b540aSrobert     struct hash<unsigned short>
132*404b540aSrobert     {
133*404b540aSrobert       size_t
134*404b540aSrobert       operator()(unsigned short __x) const
135*404b540aSrobert       { return __x; }
136*404b540aSrobert     };
137*404b540aSrobert 
138*404b540aSrobert   template<>
139*404b540aSrobert     struct hash<int>
140*404b540aSrobert     {
141*404b540aSrobert       size_t
142*404b540aSrobert       operator()(int __x) const
143*404b540aSrobert       { return __x; }
144*404b540aSrobert     };
145*404b540aSrobert 
146*404b540aSrobert   template<>
147*404b540aSrobert     struct hash<unsigned int>
148*404b540aSrobert     {
149*404b540aSrobert       size_t
150*404b540aSrobert       operator()(unsigned int __x) const
151*404b540aSrobert       { return __x; }
152*404b540aSrobert     };
153*404b540aSrobert 
154*404b540aSrobert   template<>
155*404b540aSrobert     struct hash<long>
156*404b540aSrobert     {
157*404b540aSrobert       size_t
158*404b540aSrobert       operator()(long __x) const
159*404b540aSrobert       { return __x; }
160*404b540aSrobert     };
161*404b540aSrobert 
162*404b540aSrobert   template<>
163*404b540aSrobert     struct hash<unsigned long>
164*404b540aSrobert     {
165*404b540aSrobert       size_t
166*404b540aSrobert       operator()(unsigned long __x) const
167*404b540aSrobert       { return __x; }
168*404b540aSrobert     };
169*404b540aSrobert 
170*404b540aSrobert _GLIBCXX_END_NAMESPACE
171*404b540aSrobert 
172*404b540aSrobert #endif
173