00001 // 'struct hash' from SGI -*- C++ -*- 00002 00003 // Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 2, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // You should have received a copy of the GNU General Public License along 00017 // with this library; see the file COPYING. If not, write to the Free 00018 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 00019 // USA. 00020 00021 // As a special exception, you may use this file as part of a free software 00022 // library without restriction. Specifically, if other files instantiate 00023 // templates or use macros or inline functions from this file, or you compile 00024 // this file and link it with other files to produce an executable, this 00025 // file does not by itself cause the resulting executable to be covered by 00026 // the GNU General Public License. This exception does not however 00027 // invalidate any other reasons why the executable file might be covered by 00028 // the GNU General Public License. 00029 00030 /* 00031 * Copyright (c) 1996-1998 00032 * Silicon Graphics Computer Systems, Inc. 00033 * 00034 * Permission to use, copy, modify, distribute and sell this software 00035 * and its documentation for any purpose is hereby granted without fee, 00036 * provided that the above copyright notice appear in all copies and 00037 * that both that copyright notice and this permission notice appear 00038 * in supporting documentation. Silicon Graphics makes no 00039 * representations about the suitability of this software for any 00040 * purpose. It is provided "as is" without express or implied warranty. 00041 * 00042 * 00043 * Copyright (c) 1994 00044 * Hewlett-Packard Company 00045 * 00046 * Permission to use, copy, modify, distribute and sell this software 00047 * and its documentation for any purpose is hereby granted without fee, 00048 * provided that the above copyright notice appear in all copies and 00049 * that both that copyright notice and this permission notice appear 00050 * in supporting documentation. Hewlett-Packard Company makes no 00051 * representations about the suitability of this software for any 00052 * purpose. It is provided "as is" without express or implied warranty. 00053 * 00054 */ 00055 00061 #ifndef _HASH_FUN_H 00062 #define _HASH_FUN_H 1 00063 00064 #include <cstddef> 00065 00066 namespace __gnu_cxx 00067 { 00068 using std::size_t; 00069 00070 template<class _Key> 00071 struct hash { }; 00072 00073 inline size_t 00074 __stl_hash_string(const char* __s) 00075 { 00076 unsigned long __h = 0; 00077 for ( ; *__s; ++__s) 00078 __h = 5 * __h + *__s; 00079 return size_t(__h); 00080 } 00081 00082 template<> 00083 struct hash<char*> 00084 { 00085 size_t 00086 operator()(const char* __s) const 00087 { return __stl_hash_string(__s); } 00088 }; 00089 00090 template<> 00091 struct hash<const char*> 00092 { 00093 size_t 00094 operator()(const char* __s) const 00095 { return __stl_hash_string(__s); } 00096 }; 00097 00098 template<> 00099 struct hash<char> 00100 { 00101 size_t 00102 operator()(char __x) const 00103 { return __x; } 00104 }; 00105 00106 template<> 00107 struct hash<unsigned char> 00108 { 00109 size_t 00110 operator()(unsigned char __x) const 00111 { return __x; } 00112 }; 00113 00114 template<> 00115 struct hash<signed char> 00116 { 00117 size_t 00118 operator()(unsigned char __x) const 00119 { return __x; } 00120 }; 00121 00122 template<> 00123 struct hash<short> 00124 { 00125 size_t 00126 operator()(short __x) const 00127 { return __x; } 00128 }; 00129 00130 template<> 00131 struct hash<unsigned short> 00132 { 00133 size_t 00134 operator()(unsigned short __x) const 00135 { return __x; } 00136 }; 00137 00138 template<> 00139 struct hash<int> 00140 { 00141 size_t 00142 operator()(int __x) const 00143 { return __x; } 00144 }; 00145 00146 template<> 00147 struct hash<unsigned int> 00148 { 00149 size_t 00150 operator()(unsigned int __x) const 00151 { return __x; } 00152 }; 00153 00154 template<> 00155 struct hash<long> 00156 { 00157 size_t 00158 operator()(long __x) const 00159 { return __x; } 00160 }; 00161 00162 template<> 00163 struct hash<unsigned long> 00164 { 00165 size_t 00166 operator()(unsigned long __x) const 00167 { return __x; } 00168 }; 00169 } // namespace __gnu_cxx 00170 00171 #endif