1 // 'struct hash' from SGI -*- C++ -*- 2 3 // Copyright (C) 2001, 2002, 2003 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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). You should only 59 * include this header if you are using GCC 3 or later. 60 */ 61 62 #ifndef _HASH_FUN_H 63 #define _HASH_FUN_H 1 64 65 #include <cstddef> 66 67 namespace __gnu_cxx 68 { 69 using std::size_t; 70 71 template <class _Key> struct hash { }; 72 73 inline size_t __stl_hash_string(const char * __s)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<> struct hash<char*> 83 { 84 size_t operator()(const char* __s) const 85 { return __stl_hash_string(__s); } 86 }; 87 88 template<> struct hash<const char*> 89 { 90 size_t operator()(const char* __s) const 91 { return __stl_hash_string(__s); } 92 }; 93 94 template<> struct hash<char> 95 { size_t operator()(char __x) const { return __x; } }; 96 97 template<> struct hash<unsigned char> 98 { size_t operator()(unsigned char __x) const { return __x; } }; 99 100 template<> struct hash<signed char> 101 { size_t operator()(unsigned char __x) const { return __x; } }; 102 103 template<> struct hash<short> 104 { size_t operator()(short __x) const { return __x; } }; 105 106 template<> struct hash<unsigned short> 107 { size_t operator()(unsigned short __x) const { return __x; } }; 108 109 template<> struct hash<int> 110 { size_t operator()(int __x) const { return __x; } }; 111 112 template<> struct hash<unsigned int> 113 { size_t operator()(unsigned int __x) const { return __x; } }; 114 115 template<> struct hash<long> 116 { size_t operator()(long __x) const { return __x; } }; 117 118 template<> struct hash<unsigned long> 119 { size_t operator()(unsigned long __x) const { return __x; } }; 120 } // namespace __gnu_cxx 121 122 #endif 123