1QMapIterator(3qt)                                            QMapIterator(3qt)
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NAME

6       QMapIterator - Iterator for QMap
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SYNOPSIS

9       #include <qmap.h>
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11   Public Members
12       typedef std::bidirectional_iterator_tag iterator_category
13       typedef T value_type
14       typedef T * pointer
15       typedef T & reference
16       QMapIterator ()
17       QMapIterator ( QMapNode<K, T> * p )
18       QMapIterator ( const QMapIterator<K, T> & it )
19       bool operator== ( const QMapIterator<K, T> & it ) const
20       bool operator!= ( const QMapIterator<K, T> & it ) const
21       T & operator* ()
22       const T & operator* () const
23       const K & key () const
24       T & data ()
25       const T & data () const
26       QMapIterator<K, T> & operator++ ()
27       QMapIterator<K, T> operator++ ( int )
28       QMapIterator<K, T> & operator-- ()
29       QMapIterator<K, T> operator-- ( int )
30

DESCRIPTION

32       The QMapIterator class provides an iterator for QMap.
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34       You cannot create an iterator by yourself. Instead, you must ask a map
35       to give you one. An iterator is as big as a pointer; on 32-bit machines
36       that means 4 bytes, on 64-bit machines, 8 bytes. That makes copying
37       iterators very fast. Iterators behave in a similar way to pointers, and
38       they are almost as fast as pointers. See the QMap example.
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40       QMap is highly optimized for performance and memory usage, but the
41       trade-off is that you must be more careful. The only way to traverse a
42       map is to use iterators. QMap does not know about its iterators, and
43       the iterators don't even know to which map they belong. That makes
44       things fast but a bit dangerous because it is up to you to make sure
45       that the iterators you are using are still valid. QDictIterator will be
46       able to give warnings, whereas QMapIterator may end up in an undefined
47       state.
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49       For every Iterator there is also a ConstIterator. You must use the
50       ConstIterator to access a QMap in a const environment or if the
51       reference or pointer to the map is itself const. Its semantics are the
52       same, but it only returns const references to the item it points to.
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54       See also QMap, QMapConstIterator, Qt Template Library Classes, and Non-
55       GUI Classes.
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57   Member Type Documentation

QMapIterator::iterator_category

59       The type of iterator category, std::bidirectional_iterator_tag.
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QMapIterator::pointer

62       Pointer to value_type.
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QMapIterator::reference

65       Reference to value_type.
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QMapIterator::value_type

68       The type of value.
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MEMBER FUNCTION DOCUMENTATION

QMapIterator::QMapIterator ()

72       Creates an uninitialized iterator.
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QMapIterator::QMapIterator ( QMapNode<K, T> * p )

75       Constructs an iterator starting at node p.
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QMapIterator::QMapIterator ( const QMapIterator<K, T> & it )

78       Constructs a copy of the iterator, it.
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T & QMapIterator::data ()

81       Returns a reference to the current item's data.
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const T & QMapIterator::data () const

84       This is an overloaded member function, provided for convenience. It
85       behaves essentially like the above function.
86
87       Returns a const reference to the current item's data.
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const K & QMapIterator::key () const

90       Returns a const reference to the current item's key.
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bool QMapIterator::operator!= ( const QMapIterator<K, T> & it ) const

93       Compares the iterator to the it iterator and returns FALSE if they
94       point to the same item; otherwise returns TRUE.
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T & QMapIterator::operator* ()

97       Dereference operator. Returns a reference to the current item's data.
98       The same as data().
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const T & QMapIterator::operator* () const

101       This is an overloaded member function, provided for convenience. It
102       behaves essentially like the above function.
103
104       Dereference operator. Returns a const reference to the current item's
105       data. The same as data().
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QMapIterator<K, T> & QMapIterator::operator++ ()

108       Prefix ++ makes the succeeding item current and returns an iterator
109       pointing to the new current item. The iterator cannot check whether it
110       reached the end of the map. Incrementing the iterator returned by end()
111       causes undefined results.
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QMapIterator<K, T> QMapIterator::operator++ ( int )

114       This is an overloaded member function, provided for convenience. It
115       behaves essentially like the above function.
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117       Postfix ++ makes the succeeding item current and returns an iterator
118       pointing to the new current item. The iterator cannot check whether it
119       reached the end of the map. Incrementing the iterator returned by end()
120       causes undefined results.
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QMapIterator<K, T> & QMapIterator::operator-- ()

123       Prefix -- makes the previous item current and returns an iterator
124       pointing to the new current item. The iterator cannot check whether it
125       reached the beginning of the map. Decrementing the iterator returned by
126       begin() causes undefined results.
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QMapIterator<K, T> QMapIterator::operator-- ( int )

129       This is an overloaded member function, provided for convenience. It
130       behaves essentially like the above function.
131
132       Postfix -- makes the previous item current and returns an iterator
133       pointing to the new current item. The iterator cannot check whether it
134       reached the beginning of the map. Decrementing the iterator returned by
135       begin() causes undefined results.
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bool QMapIterator::operator== ( const QMapIterator<K, T> & it ) const

138       Compares the iterator to the it iterator and returns TRUE if they point
139       to the same item; otherwise returns FALSE.
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141

SEE ALSO

143       http://doc.trolltech.com/qmapiterator.html
144       http://www.trolltech.com/faq/tech.html
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147       Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com.  See the
148       license file included in the distribution for a complete license
149       statement.
150

AUTHOR

152       Generated automatically from the source code.
153

BUGS

155       If you find a bug in Qt, please report it as described in
156       http://doc.trolltech.com/bughowto.html.  Good bug reports help us to
157       help you. Thank you.
158
159       The definitive Qt documentation is provided in HTML format; it is
160       located at $QTDIR/doc/html and can be read using Qt Assistant or with a
161       web browser. This man page is provided as a convenience for those users
162       who prefer man pages, although this format is not officially supported
163       by Trolltech.
164
165       If you find errors in this manual page, please report them to qt-
166       bugs@trolltech.com.  Please include the name of the manual page
167       (qmapiterator.3qt) and the Qt version (3.3.8).
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171Trolltech AS                    2 February 2007              QMapIterator(3qt)
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