| 1 | ///////////////////////////////////////////////////////////////////////////// |
| 2 | // Name: hashset.h |
| 3 | // Purpose: interface of wxHashSet |
| 4 | // Author: wxWidgets team |
| 5 | // RCS-ID: $Id$ |
| 6 | // Licence: wxWindows licence |
| 7 | ///////////////////////////////////////////////////////////////////////////// |
| 8 | |
| 9 | /** |
| 10 | @class wxHashSet |
| 11 | |
| 12 | This is a simple, type-safe, and reasonably efficient hash set class, |
| 13 | whose interface is a subset of the interface of STL containers. |
| 14 | |
| 15 | The interface is similar to std::tr1::hash_set or std::set classes but |
| 16 | notice that, unlike std::set, the contents of a hash set is not sorted. |
| 17 | |
| 18 | Example: |
| 19 | @code |
| 20 | class MyClass { ... }; |
| 21 | |
| 22 | // same, with MyClass* keys (only uses pointer equality!) |
| 23 | WX_DECLARE_HASH_SET( MyClass*, wxPointerHash, wxPointerEqual, MySet1 ); |
| 24 | // same, with int keys |
| 25 | WX_DECLARE_HASH_SET( int, wxIntegerHash, wxIntegerEqual, MySet2 ); |
| 26 | // declare a hash set with string keys |
| 27 | WX_DECLARE_HASH_SET( wxString, wxStringHash, wxStringEqual, MySet3 ); |
| 28 | |
| 29 | MySet1 h1; |
| 30 | MySet2 h1; |
| 31 | MySet3 h3; |
| 32 | |
| 33 | // store and retrieve values |
| 34 | h1.insert( new MyClass( 1 ) ); |
| 35 | |
| 36 | h3.insert( "foo" ); |
| 37 | h3.insert( "bar" ); |
| 38 | h3.insert( "baz" ); |
| 39 | |
| 40 | int size = h3.size(); // now is three |
| 41 | bool has_foo = h3.find( "foo" ) != h3.end(); |
| 42 | |
| 43 | h3.insert( "bar" ); // still has size three |
| 44 | |
| 45 | // iterate over all the elements in the class |
| 46 | MySet3::iterator it; |
| 47 | for( it = h3.begin(); it != h3.end(); ++it ) |
| 48 | { |
| 49 | wxString key = *it; |
| 50 | // do something useful with key |
| 51 | } |
| 52 | @endcode |
| 53 | |
| 54 | |
| 55 | @section hashset_declaringnew Declaring new hash set types |
| 56 | |
| 57 | @code |
| 58 | WX_DECLARE_HASH_SET( KEY_T, // type of the keys |
| 59 | HASH_T, // hasher |
| 60 | KEY_EQ_T, // key equality predicate |
| 61 | CLASSNAME); // name of the class |
| 62 | @endcode |
| 63 | The HASH_T and KEY_EQ_T are the types used for the hashing function and key |
| 64 | comparison. wxWidgets provides three predefined hashing functions: |
| 65 | wxIntegerHash for integer types ( int, long, short, and their unsigned counterparts ), |
| 66 | wxStringHash for strings ( wxString, wxChar*, char* ), and wxPointerHash for |
| 67 | any kind of pointer. |
| 68 | Similarly three equality predicates: wxIntegerEqual, wxStringEqual, wxPointerEqual |
| 69 | are provided. Using this you could declare a hash set using int values like this: |
| 70 | |
| 71 | @code |
| 72 | WX_DECLARE_HASH_SET( int, |
| 73 | wxIntegerHash, |
| 74 | wxIntegerEqual, |
| 75 | MySet ); |
| 76 | |
| 77 | // using an user-defined class for keys |
| 78 | class MyKey { ... }; |
| 79 | |
| 80 | // hashing function |
| 81 | class MyKeyHash |
| 82 | { |
| 83 | public: |
| 84 | MyKeyHash() { } |
| 85 | |
| 86 | unsigned long operator()( const MyKey& k ) const |
| 87 | { |
| 88 | // compute the hash |
| 89 | } |
| 90 | |
| 91 | MyKeyHash& operator=(const MyKeyHash&) { return *this; } |
| 92 | }; |
| 93 | |
| 94 | // comparison operator |
| 95 | class MyKeyEqual |
| 96 | { |
| 97 | public: |
| 98 | MyKeyEqual() { } |
| 99 | bool operator()( const MyKey& a, const MyKey& b ) const |
| 100 | { |
| 101 | // compare for equality |
| 102 | } |
| 103 | |
| 104 | MyKeyEqual& operator=(const MyKeyEqual&) { return *this; } |
| 105 | }; |
| 106 | |
| 107 | WX_DECLARE_HASH_SET( MyKey, // type of the keys |
| 108 | MyKeyHash, // hasher |
| 109 | MyKeyEqual, // key equality predicate |
| 110 | CLASSNAME); // name of the class |
| 111 | @endcode |
| 112 | |
| 113 | |
| 114 | @section hashset_types Types |
| 115 | |
| 116 | In the documentation below you should replace wxHashSet with the name you |
| 117 | used in the class declaration. |
| 118 | |
| 119 | - wxHashSet::key_type: Type of the hash keys |
| 120 | - wxHashSet::mapped_type: Type of hash keys |
| 121 | - wxHashSet::value_type: Type of hash keys |
| 122 | - wxHashSet::iterator: Used to enumerate all the elements in a hash set; |
| 123 | it is similar to a value_type* |
| 124 | - wxHashSet::const_iterator: Used to enumerate all the elements in a constant |
| 125 | hash set; it is similar to a const value_type* |
| 126 | - wxHashSet::size_type: Used for sizes |
| 127 | - wxHashSet::Insert_Result: The return value for insert() |
| 128 | |
| 129 | |
| 130 | @section hashset_iter Iterators |
| 131 | |
| 132 | An iterator is similar to a pointer, and so you can use the usual pointer |
| 133 | operations: ++it ( and it++ ) to move to the next element, *it to access the |
| 134 | element pointed to, *it to access the value of the element pointed to. |
| 135 | Hash sets provide forward only iterators, this means that you can't use --it, |
| 136 | it + 3, it1 - it2. |
| 137 | |
| 138 | @library{wxbase} |
| 139 | @category{containers} |
| 140 | */ |
| 141 | class wxHashSet |
| 142 | { |
| 143 | public: |
| 144 | /** |
| 145 | The size parameter is just a hint, the table will resize automatically |
| 146 | to preserve performance. |
| 147 | */ |
| 148 | wxHashSet(size_type size = 10); |
| 149 | |
| 150 | /** |
| 151 | Copy constructor. |
| 152 | */ |
| 153 | wxHashSet(const wxHashSet& set); |
| 154 | |
| 155 | //@{ |
| 156 | /** |
| 157 | Returns an iterator pointing at the first element of the hash set. |
| 158 | Please remember that hash sets do not guarantee ordering. |
| 159 | */ |
| 160 | const_iterator begin() const; |
| 161 | iterator begin(); |
| 162 | //@} |
| 163 | |
| 164 | /** |
| 165 | Removes all elements from the hash set. |
| 166 | */ |
| 167 | void clear(); |
| 168 | |
| 169 | /** |
| 170 | Counts the number of elements with the given key present in the set. |
| 171 | This function returns only 0 or 1. |
| 172 | */ |
| 173 | size_type count(const key_type& key) const; |
| 174 | |
| 175 | /** |
| 176 | Returns @true if the hash set does not contain any elements, @false otherwise. |
| 177 | */ |
| 178 | bool empty() const; |
| 179 | |
| 180 | //@{ |
| 181 | /** |
| 182 | Returns an iterator pointing at the one-after-the-last element of the hash set. |
| 183 | Please remember that hash sets do not guarantee ordering. |
| 184 | */ |
| 185 | const_iterator end() const; |
| 186 | iterator end(); |
| 187 | //@} |
| 188 | |
| 189 | /** |
| 190 | Erases the element with the given key, and returns the number of elements |
| 191 | erased (either 0 or 1). |
| 192 | */ |
| 193 | size_type erase(const key_type& key); |
| 194 | |
| 195 | //@{ |
| 196 | /** |
| 197 | Erases the element pointed to by the iterator. After the deletion |
| 198 | the iterator is no longer valid and must not be used. |
| 199 | */ |
| 200 | void erase(iterator it); |
| 201 | void erase(const_iterator it); |
| 202 | //@} |
| 203 | |
| 204 | //@{ |
| 205 | /** |
| 206 | If an element with the given key is present, the functions returns |
| 207 | an iterator pointing at that element, otherwise an invalid iterator |
| 208 | is returned; i.e. |
| 209 | @code |
| 210 | hashset.find( non_existent_key ) == hashset.end() |
| 211 | @endcode |
| 212 | */ |
| 213 | iterator find(const key_type& key) const; |
| 214 | const_iterator find(const key_type& key) const; |
| 215 | //@} |
| 216 | |
| 217 | /** |
| 218 | Inserts the given value in the hash set. |
| 219 | The return value is equivalent to a |
| 220 | @code std::pair<wxHashMap::iterator, bool> @endcode |
| 221 | The iterator points to the inserted element, the boolean value is @true |
| 222 | if @a v was actually inserted. |
| 223 | */ |
| 224 | Insert_Result insert(const value_type& v); |
| 225 | |
| 226 | /** |
| 227 | Returns the number of elements in the set. |
| 228 | */ |
| 229 | size_type size() const; |
| 230 | }; |
| 231 | |