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1 | ///////////////////////////////////////////////////////////////////////////// |
2 | // Name: hashset.h | |
e54c96f1 | 3 | // Purpose: interface of wxHashSet |
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4 | // Author: wxWidgets team |
5 | // RCS-ID: $Id$ | |
6 | // Licence: wxWindows license | |
7 | ///////////////////////////////////////////////////////////////////////////// | |
8 | ||
9 | /** | |
10 | @class wxHashSet | |
7c913512 | 11 | |
23324ae1 | 12 | This is a simple, type-safe, and reasonably efficient hash set class, |
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13 | whose interface is a subset of the interface of STL containers. |
14 | In particular, the interface is modeled after std::set, and the various, | |
23324ae1 | 15 | non-standard, std::hash_map. |
7c913512 | 16 | |
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17 | Example: |
18 | @code | |
19 | class MyClass { ... }; | |
20 | ||
21 | // same, with MyClass* keys (only uses pointer equality!) | |
22 | WX_DECLARE_HASH_SET( MyClass*, wxPointerHash, wxPointerEqual, MySet1 ); | |
23 | // same, with int keys | |
24 | WX_DECLARE_HASH_SET( int, wxIntegerHash, wxIntegerEqual, MySet2 ); | |
25 | // declare a hash set with string keys | |
26 | WX_DECLARE_HASH_SET( wxString, wxStringHash, wxStringEqual, MySet3 ); | |
27 | ||
28 | MySet1 h1; | |
29 | MySet2 h1; | |
30 | MySet3 h3; | |
31 | ||
32 | // store and retrieve values | |
33 | h1.insert( new MyClass( 1 ) ); | |
34 | ||
35 | h3.insert( "foo" ); | |
36 | h3.insert( "bar" ); | |
37 | h3.insert( "baz" ); | |
38 | ||
39 | int size = h3.size(); // now is three | |
40 | bool has_foo = h3.find( "foo" ) != h3.end(); | |
41 | ||
42 | h3.insert( "bar" ); // still has size three | |
43 | ||
44 | // iterate over all the elements in the class | |
45 | MySet3::iterator it; | |
46 | for( it = h3.begin(); it != h3.end(); ++it ) | |
47 | { | |
48 | wxString key = *it; | |
49 | // do something useful with key | |
50 | } | |
51 | @endcode | |
52 | ||
53 | ||
54 | @section hashset_declaringnew Declaring new hash set types | |
55 | ||
56 | @code | |
57 | WX_DECLARE_HASH_SET( KEY_T, // type of the keys | |
58 | HASH_T, // hasher | |
59 | KEY_EQ_T, // key equality predicate | |
60 | CLASSNAME); // name of the class | |
61 | @endcode | |
62 | The HASH_T and KEY_EQ_T are the types used for the hashing function and key | |
63 | comparison. wxWidgets provides three predefined hashing functions: | |
64 | wxIntegerHash for integer types ( int, long, short, and their unsigned counterparts ), | |
65 | wxStringHash for strings ( wxString, wxChar*, char* ), and wxPointerHash for | |
66 | any kind of pointer. | |
67 | Similarly three equality predicates: wxIntegerEqual, wxStringEqual, wxPointerEqual | |
68 | are provided. Using this you could declare a hash set using int values like this: | |
69 | ||
70 | @code | |
71 | WX_DECLARE_HASH_SET( int, | |
72 | wxIntegerHash, | |
73 | wxIntegerEqual, | |
74 | MySet ); | |
75 | ||
76 | // using an user-defined class for keys | |
77 | class MyKey { ... }; | |
78 | ||
79 | // hashing function | |
80 | class MyKeyHash | |
81 | { | |
82 | public: | |
83 | MyKeyHash() { } | |
84 | ||
85 | unsigned long operator()( const MyKey& k ) const | |
86 | { | |
87 | // compute the hash | |
88 | } | |
89 | ||
90 | MyKeyHash& operator=(const MyKeyHash&) { return *this; } | |
91 | }; | |
92 | ||
93 | // comparison operator | |
94 | class MyKeyEqual | |
95 | { | |
96 | public: | |
97 | MyKeyEqual() { } | |
98 | bool operator()( const MyKey& a, const MyKey& b ) const | |
99 | { | |
100 | // compare for equality | |
101 | } | |
102 | ||
103 | MyKeyEqual& operator=(const MyKeyEqual&) { return *this; } | |
104 | }; | |
105 | ||
106 | WX_DECLARE_HASH_SET( MyKey, // type of the keys | |
107 | MyKeyHash, // hasher | |
108 | MyKeyEqual, // key equality predicate | |
109 | CLASSNAME); // name of the class | |
110 | @endcode | |
111 | ||
112 | ||
113 | @section hashset_types Types | |
114 | ||
115 | In the documentation below you should replace wxHashSet with the name you | |
116 | used in the class declaration. | |
117 | ||
118 | - wxHashSet::key_type: Type of the hash keys | |
119 | - wxHashSet::mapped_type: Type of hash keys | |
120 | - wxHashSet::value_type: Type of hash keys | |
121 | - wxHashSet::iterator: Used to enumerate all the elements in a hash set; | |
122 | it is similar to a value_type* | |
123 | - wxHashSet::const_iterator: Used to enumerate all the elements in a constant | |
124 | hash set; it is similar to a const value_type* | |
125 | - wxHashSet::size_type: Used for sizes | |
126 | - wxHashSet::Insert_Result: The return value for insert() | |
127 | ||
128 | ||
129 | @section hashset_iter Iterators | |
130 | ||
131 | An iterator is similar to a pointer, and so you can use the usual pointer | |
132 | operations: ++it ( and it++ ) to move to the next element, *it to access the | |
133 | element pointed to, *it to access the value of the element pointed to. | |
134 | Hash sets provide forward only iterators, this means that you can't use --it, | |
135 | it + 3, it1 - it2. | |
136 | ||
23324ae1 | 137 | @library{wxbase} |
9cc56d1f | 138 | @category{containers} |
23324ae1 | 139 | */ |
7c913512 | 140 | class wxHashSet |
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141 | { |
142 | public: | |
23324ae1 | 143 | /** |
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144 | The size parameter is just a hint, the table will resize automatically |
145 | to preserve performance. | |
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146 | */ |
147 | wxHashSet(size_type size = 10); | |
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148 | |
149 | /** | |
150 | Copy constructor. | |
151 | */ | |
7c913512 | 152 | wxHashSet(const wxHashSet& set); |
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153 | |
154 | //@{ | |
155 | /** | |
156 | Returns an iterator pointing at the first element of the hash set. | |
157 | Please remember that hash sets do not guarantee ordering. | |
158 | */ | |
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159 | const_iterator begin() const; |
160 | iterator begin(); | |
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161 | //@} |
162 | ||
163 | /** | |
164 | Removes all elements from the hash set. | |
165 | */ | |
166 | void clear(); | |
167 | ||
168 | /** | |
169 | Counts the number of elements with the given key present in the set. | |
170 | This function returns only 0 or 1. | |
171 | */ | |
328f5751 | 172 | size_type count(const key_type& key) const; |
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173 | |
174 | /** | |
175 | Returns @true if the hash set does not contain any elements, @false otherwise. | |
176 | */ | |
328f5751 | 177 | bool empty() const; |
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178 | |
179 | //@{ | |
180 | /** | |
181 | Returns an iterator pointing at the one-after-the-last element of the hash set. | |
182 | Please remember that hash sets do not guarantee ordering. | |
183 | */ | |
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184 | const_iterator end() const; |
185 | iterator end(); | |
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186 | //@} |
187 | ||
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188 | /** |
189 | Erases the element with the given key, and returns the number of elements | |
190 | erased (either 0 or 1). | |
191 | */ | |
192 | size_type erase(const key_type& key); | |
193 | ||
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194 | //@{ |
195 | /** | |
196 | Erases the element pointed to by the iterator. After the deletion | |
197 | the iterator is no longer valid and must not be used. | |
198 | */ | |
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199 | void erase(iterator it); |
200 | void erase(const_iterator it); | |
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201 | //@} |
202 | ||
203 | //@{ | |
204 | /** | |
205 | If an element with the given key is present, the functions returns | |
206 | an iterator pointing at that element, otherwise an invalid iterator | |
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207 | is returned; i.e. |
208 | @code | |
209 | hashset.find( non_existent_key ) == hashset.end() | |
210 | @endcode | |
23324ae1 | 211 | */ |
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212 | iterator find(const key_type& key) const; |
213 | const_iterator find(const key_type& key) const; | |
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214 | //@} |
215 | ||
216 | /** | |
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217 | Inserts the given value in the hash set. |
218 | The return value is equivalent to a | |
219 | @code std::pair<wxHashMap::iterator, bool> @endcode | |
220 | The iterator points to the inserted element, the boolean value is @true | |
221 | if @a v was actually inserted. | |
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222 | */ |
223 | Insert_Result insert(const value_type& v); | |
224 | ||
225 | /** | |
226 | Returns the number of elements in the set. | |
227 | */ | |
328f5751 | 228 | size_type size() const; |
23324ae1 | 229 | }; |
e54c96f1 | 230 |