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1 | // -*- C++ -*- |
2 | ||
3 | // Copyright (C) 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 | |
83f51799 | 18 | // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, |
fd1e1726 BK |
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 | // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL. | |
31 | ||
32 | // Permission to use, copy, modify, sell, and distribute this software | |
33 | // is hereby granted without fee, provided that the above copyright | |
34 | // notice appears in all copies, and that both that copyright notice and | |
35 | // this permission notice appear in supporting documentation. None of | |
36 | // the above authors, nor IBM Haifa Research Laboratories, make any | |
37 | // representation about the suitability of this software for any | |
38 | // purpose. It is provided "as is" without express or implied warranty. | |
39 | ||
40 | /** | |
41 | * @file hash_mod_example.cpp | |
42 | * An example showing how to use cc_ht_map with alternative policies. | |
43 | */ | |
44 | ||
45 | // For cc_hash_assoc_cntnr. | |
46 | #include <ext/pb_assoc/assoc_cntnr.hpp> | |
47 | // For direct_mask_range_hashing and hash_standard_resize_policy. | |
48 | #include <ext/pb_assoc/hash_policy.hpp> | |
49 | // For unary_function, binary_function. | |
50 | #include <functional> | |
51 | // For string. | |
52 | #include <string> | |
53 | ||
54 | /* | |
55 | * A string hash functor | |
56 | */ | |
57 | struct string_hash : public std::unary_function< | |
58 | std::string, | |
59 | size_t> | |
60 | { | |
61 | inline size_t | |
62 | operator()(std::string str) const | |
63 | { | |
64 | std::string::const_iterator b = str.begin(); | |
65 | ||
66 | std::string::const_iterator e = str.end(); | |
67 | ||
68 | size_t hash = 0; | |
69 | ||
70 | while (b != e) | |
71 | { | |
72 | hash *= 5; | |
73 | ||
74 | hash += static_cast<size_t>(*b); | |
75 | ||
76 | ++b; | |
77 | } | |
78 | ||
79 | return (hash); | |
80 | } | |
81 | }; | |
82 | ||
83 | int | |
84 | main() | |
85 | { | |
86 | /* | |
87 | * A collision-chaining hash table mapping strings to ints. | |
88 | */ | |
89 | typedef | |
90 | pb_assoc::cc_hash_assoc_cntnr< | |
91 | std::string, | |
92 | int, | |
93 | // Hash function. | |
94 | string_hash, | |
95 | // Equivalence function. | |
96 | std::equal_to< | |
97 | std::string>, | |
98 | // Range hashing function. | |
99 | pb_assoc::direct_mask_range_hashing<>, | |
100 | // Resize policy. | |
101 | pb_assoc::hash_standard_resize_policy<>, | |
102 | // Store the hash value with each entry. | |
103 | true> | |
104 | map_t; | |
105 | ||
106 | map_t h; | |
107 | ||
108 | h["Hello, "] = 0; | |
109 | h["world"] = 1; | |
110 | } | |
111 |