@class wxHashSet
This is a simple, type-safe, and reasonably efficient hash set class,
- whose interface is a subset of the interface of STL containers. In
- particular, the interface is modeled after std::set, and the various,
+ whose interface is a subset of the interface of STL containers.
+ In particular, the interface is modeled after std::set, and the various,
non-standard, std::hash_map.
+ Example:
+ @code
+ class MyClass { ... };
+
+ // same, with MyClass* keys (only uses pointer equality!)
+ WX_DECLARE_HASH_SET( MyClass*, wxPointerHash, wxPointerEqual, MySet1 );
+ // same, with int keys
+ WX_DECLARE_HASH_SET( int, wxIntegerHash, wxIntegerEqual, MySet2 );
+ // declare a hash set with string keys
+ WX_DECLARE_HASH_SET( wxString, wxStringHash, wxStringEqual, MySet3 );
+
+ MySet1 h1;
+ MySet2 h1;
+ MySet3 h3;
+
+ // store and retrieve values
+ h1.insert( new MyClass( 1 ) );
+
+ h3.insert( "foo" );
+ h3.insert( "bar" );
+ h3.insert( "baz" );
+
+ int size = h3.size(); // now is three
+ bool has_foo = h3.find( "foo" ) != h3.end();
+
+ h3.insert( "bar" ); // still has size three
+
+ // iterate over all the elements in the class
+ MySet3::iterator it;
+ for( it = h3.begin(); it != h3.end(); ++it )
+ {
+ wxString key = *it;
+ // do something useful with key
+ }
+ @endcode
+
+
+ @section hashset_declaringnew Declaring new hash set types
+
+ @code
+ WX_DECLARE_HASH_SET( KEY_T, // type of the keys
+ HASH_T, // hasher
+ KEY_EQ_T, // key equality predicate
+ CLASSNAME); // name of the class
+ @endcode
+ The HASH_T and KEY_EQ_T are the types used for the hashing function and key
+ comparison. wxWidgets provides three predefined hashing functions:
+ wxIntegerHash for integer types ( int, long, short, and their unsigned counterparts ),
+ wxStringHash for strings ( wxString, wxChar*, char* ), and wxPointerHash for
+ any kind of pointer.
+ Similarly three equality predicates: wxIntegerEqual, wxStringEqual, wxPointerEqual
+ are provided. Using this you could declare a hash set using int values like this:
+
+ @code
+ WX_DECLARE_HASH_SET( int,
+ wxIntegerHash,
+ wxIntegerEqual,
+ MySet );
+
+ // using an user-defined class for keys
+ class MyKey { ... };
+
+ // hashing function
+ class MyKeyHash
+ {
+ public:
+ MyKeyHash() { }
+
+ unsigned long operator()( const MyKey& k ) const
+ {
+ // compute the hash
+ }
+
+ MyKeyHash& operator=(const MyKeyHash&) { return *this; }
+ };
+
+ // comparison operator
+ class MyKeyEqual
+ {
+ public:
+ MyKeyEqual() { }
+ bool operator()( const MyKey& a, const MyKey& b ) const
+ {
+ // compare for equality
+ }
+
+ MyKeyEqual& operator=(const MyKeyEqual&) { return *this; }
+ };
+
+ WX_DECLARE_HASH_SET( MyKey, // type of the keys
+ MyKeyHash, // hasher
+ MyKeyEqual, // key equality predicate
+ CLASSNAME); // name of the class
+ @endcode
+
+
+ @section hashset_types Types
+
+ In the documentation below you should replace wxHashSet with the name you
+ used in the class declaration.
+
+ - wxHashSet::key_type: Type of the hash keys
+ - wxHashSet::mapped_type: Type of hash keys
+ - wxHashSet::value_type: Type of hash keys
+ - wxHashSet::iterator: Used to enumerate all the elements in a hash set;
+ it is similar to a value_type*
+ - wxHashSet::const_iterator: Used to enumerate all the elements in a constant
+ hash set; it is similar to a const value_type*
+ - wxHashSet::size_type: Used for sizes
+ - wxHashSet::Insert_Result: The return value for insert()
+
+
+ @section hashset_iter Iterators
+
+ An iterator is similar to a pointer, and so you can use the usual pointer
+ operations: ++it ( and it++ ) to move to the next element, *it to access the
+ element pointed to, *it to access the value of the element pointed to.
+ Hash sets provide forward only iterators, this means that you can't use --it,
+ it + 3, it1 - it2.
+
@library{wxbase}
- @category{FIXME}
+ @category{containers}
*/
class wxHashSet
{
public:
- //@{
/**
- Copy constructor.
+ The size parameter is just a hint, the table will resize automatically
+ to preserve performance.
*/
wxHashSet(size_type size = 10);
+
+ /**
+ Copy constructor.
+ */
wxHashSet(const wxHashSet& set);
- //@}
//@{
/**
Returns an iterator pointing at the first element of the hash set.
Please remember that hash sets do not guarantee ordering.
*/
- const_iterator begin();
- const iterator begin();
+ const_iterator begin() const;
+ iterator begin();
//@}
/**
Returns an iterator pointing at the one-after-the-last element of the hash set.
Please remember that hash sets do not guarantee ordering.
*/
- const_iterator end();
- const iterator end();
+ const_iterator end() const;
+ iterator end();
//@}
+ /**
+ Erases the element with the given key, and returns the number of elements
+ erased (either 0 or 1).
+ */
+ size_type erase(const key_type& key);
+
//@{
/**
Erases the element pointed to by the iterator. After the deletion
the iterator is no longer valid and must not be used.
*/
- size_type erase(const key_type& key);
void erase(iterator it);
void erase(const_iterator it);
//@}
/**
If an element with the given key is present, the functions returns
an iterator pointing at that element, otherwise an invalid iterator
- is returned (i.e. hashset.find( non_existent_key ) == hashset.end()).
+ is returned; i.e.
+ @code
+ hashset.find( non_existent_key ) == hashset.end()
+ @endcode
*/
iterator find(const key_type& key) const;
const_iterator find(const key_type& key) const;
//@}
/**
- Inserts the given value in the hash set. The return value is
- equivalent to a @c std::pairwxHashMap::iterator, bool;
- the iterator points to the inserted element, the boolean value
- is @true if @c v was actually inserted.
+ Inserts the given value in the hash set.
+ The return value is equivalent to a
+ @code std::pair<wxHashMap::iterator, bool> @endcode
+ The iterator points to the inserted element, the boolean value is @true
+ if @a v was actually inserted.
*/
Insert_Result insert(const value_type& v);
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