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32	<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QMap Class Reference</h1>
33
34	<p>The QMap class is a value-based template class that
35	provides a dictionary.
36	<a href="#details">More...</a>
37	<p><tt>#include <<a href="qmap-h.html">qmap.h</a>></tt>
38	<p><a href="qmap-members.html">List of all member functions.</a>
39	<h2>Public Members</h2>
40	<ul>
41	<li class=fn>typedef Key <a href="#key_type"><b>key_type</b></a></li>
42	<li class=fn>typedef T <a href="#mapped_type"><b>mapped_type</b></a></li>
43	<li class=fn>typedef QPair<const key_type, mapped_type> <a href="#value_type"><b>value_type</b></a></li>
44	<li class=fn>typedef value_type * <a href="#pointer"><b>pointer</b></a></li>
45	<li class=fn>typedef const value_type * <a href="#const_pointer"><b>const_pointer</b></a></li>
46	<li class=fn>typedef value_type & <a href="#reference"><b>reference</b></a></li>
47	<li class=fn>typedef const value_type & <a href="#const_reference"><b>const_reference</b></a></li>
48	<li class=fn>typedef size_t <a href="#size_type"><b>size_type</b></a></li>
49	<li class=fn>typedef QMapIterator<Key, T> <a href="#iterator"><b>iterator</b></a></li>
50	<li class=fn>typedef QMapConstIterator<Key, T> <a href="#const_iterator"><b>const_iterator</b></a></li>
51	<li class=fn>typedef QPair<iterator, bool> <b>insert_pair</b></li>
52	<li class=fn>typedef QMapIterator<Key, T> <a href="#Iterator"><b>Iterator</b></a></li>
53	<li class=fn>typedef QMapConstIterator<Key, T> <a href="#ConstIterator"><b>ConstIterator</b></a></li>
54	<li class=fn>typedef T <a href="#ValueType"><b>ValueType</b></a></li>
55	<li class=fn><a href="#QMap"><b>QMap</b></a> ()</li>
56	<li class=fn><a href="#QMap-2"><b>QMap</b></a> ( const QMap<Key, T> & m )</li>
57	<li class=fn><a href="#QMap-3"><b>QMap</b></a> ( const std::map<Key, T> & m )</li>
58	<li class=fn><a href="#~QMap"><b>~QMap</b></a> ()</li>
59	<li class=fn>QMap<Key, T> & <a href="#operator-eq"><b>operator=</b></a> ( const QMap<Key, T> & m )</li>
60	<li class=fn>QMap<Key, T> & <a href="#operator-eq-2"><b>operator=</b></a> ( const std::map<Key, T> & m )</li>
61	<li class=fn>iterator <a href="#begin"><b>begin</b></a> ()</li>
62	<li class=fn>iterator <a href="#end"><b>end</b></a> ()</li>
63	<li class=fn>const_iterator <a href="#begin-2"><b>begin</b></a> () const</li>
64	<li class=fn>const_iterator <a href="#end-2"><b>end</b></a> () const</li>
65	<li class=fn>const_iterator <a href="#constBegin"><b>constBegin</b></a> () const</li>
66	<li class=fn>const_iterator <a href="#constEnd"><b>constEnd</b></a> () const</li>
67	<li class=fn>iterator <a href="#replace"><b>replace</b></a> ( const Key & k, const T & v )</li>
68	<li class=fn>size_type <a href="#size"><b>size</b></a> () const</li>
69	<li class=fn>bool <a href="#empty"><b>empty</b></a> () const</li>
70	<li class=fn>QPair<iterator, bool> <a href="#insert-2"><b>insert</b></a> ( const value_type & x )</li>
71	<li class=fn>void <a href="#erase"><b>erase</b></a> ( iterator it )</li>
72	<li class=fn>void <a href="#erase-2"><b>erase</b></a> ( const key_type & k )</li>
73	<li class=fn>size_type <a href="#count"><b>count</b></a> ( const key_type & k ) const</li>
74	<li class=fn>T & <a href="#operator[]"><b>operator[]</b></a> ( const Key & k )</li>
75	<li class=fn>void <a href="#clear"><b>clear</b></a> ()</li>
76	<li class=fn>iterator <a href="#find"><b>find</b></a> ( const Key & k )</li>
77	<li class=fn>const_iterator <a href="#find-2"><b>find</b></a> ( const Key & k ) const</li>
78	<li class=fn>const T & <a href="#operator[]-2"><b>operator[]</b></a> ( const Key & k ) const</li>
79	<li class=fn>bool <a href="#contains"><b>contains</b></a> ( const Key & k ) const</li>
80	<li class=fn>size_type <a href="#count-2"><b>count</b></a> () const</li>
81	<li class=fn>QValueList<Key> <a href="#keys"><b>keys</b></a> () const</li>
82	<li class=fn>QValueList<T> <a href="#values"><b>values</b></a> () const</li>
83	<li class=fn>bool <a href="#isEmpty"><b>isEmpty</b></a> () const</li>
84	<li class=fn>iterator <a href="#insert"><b>insert</b></a> ( const Key & key, const T & value, bool overwrite = TRUE )</li>
85	<li class=fn>void <a href="#remove"><b>remove</b></a> ( iterator it )</li>
86	<li class=fn>void <a href="#remove-2"><b>remove</b></a> ( const Key & k )</li>
87	</ul>
88	<h2>Protected Members</h2>
89	<ul>
90	<li class=fn>void <a href="#detach"><b>detach</b></a> ()</li>
91	</ul>
92	<h2>Related Functions</h2>
93	<ul>
94	<li class=fn>QDataStream & <a href="#operator-gt-gt"><b>operator>></b></a> ( QDataStream & s, QMap<Key, T> & m )</li>
95	<li class=fn>QDataStream & <a href="#operator-lt-lt"><b>operator<<</b></a> ( QDataStream & s, const QMap<Key, T> & m )</li>
96	</ul>
97	<hr><a name="details"></a><h2>Detailed Description</h2>
98
99
100	The QMap class is a value-based template class that
101	provides a dictionary.
102	<p>
103
104
105
106	<p> QMap is a Qt implementation of an STL-like map container. It can
107	be used in your application if the standard <tt>map</tt> is not
108	available on all your target platforms. QMap is part of the <a href="qtl.html">Qt Template Library</a>.
109	<p> QMap<Key, Data> defines a template instance to create a
110	dictionary with keys of type Key and values of type Data. QMap
111	does not store pointers to the members of the map; instead, it
112	holds a copy of every member. For this reason, QMap is
113	value-based, whereas <a href="qptrlist.html">QPtrList</a> and <a href="qdict.html">QDict</a> are pointer-based.
114	<p> QMap contains and manages a collection of objects of type Data
115	with associated key values of type Key and provides iterators that
116	allow the contained objects to be addressed. QMap owns the
117	contained items.
118	<p> Some classes cannot be used within a QMap. For example everything
119	derived from <a href="qobject.html">QObject</a> and thus all classes that implement widgets.
120	Only values can be used in a QMap. To qualify as a value, the
121	class must provide
122	<p> <ul>
123	<li> A copy constructor
124	<li> An assignment operator
125	<li> A default constructor, i.e. a constructor that does not take
126	any arguments.
127	</ul>
128	<p> Note that C++ defaults to field-by-field assignment operators and
129	copy constructors if no explicit version is supplied. In many
130	cases, this is sufficient.
131	<p> The class used for the key requires that the <tt>operator<</tt> is
132	implemented to define ordering of the keys.
133	<p> QMap's function naming is consistent with the other Qt classes
134	(e.g., <a href="#count">count</a>(), <a href="#isEmpty">isEmpty</a>()). QMap also provides extra functions for
135	compatibility with STL algorithms, such as <a href="#size">size</a>() and <a href="#empty">empty</a>().
136	Programmers already familiar with the STL <tt>map</tt> can use these
137	the STL-like functions if preferred.
138	<p> Example:
139	<a name="qmap-eg"></a>
140	<pre>
141	#include <<a href="qstring-h.html">qstring.h</a>>
142	#include <<a href="qmap-h.html">qmap.h</a>>
143	#include <<a href="qstring-h.html">qstring.h</a>>
144
145	class Employee
146	{
147	public:
148	Employee(): sn(0) {}
149	Employee( const <a href="qstring.html">QString</a>& forename, const <a href="qstring.html">QString</a>& surname, int salary )
150	: fn(forename), sn(surname), sal(salary)
151	{ }
152
153	<a href="qstring.html">QString</a> forename() const { return fn; }
154	<a href="qstring.html">QString</a> surname() const { return sn; }
155	int salary() const { return sal; }
156	void setSalary( int salary ) { sal = salary; }
157
158	private:
159	<a href="qstring.html">QString</a> fn;
160	<a href="qstring.html">QString</a> sn;
161	int sal;
162	};
163
164	int main(int argc, char **argv)
165	{
166	<a href="qapplication.html">QApplication</a> app( argc, argv );
167
168	typedef QMap<QString, Employee> EmployeeMap;
169	EmployeeMap map;
170
171	map["JD001"] = Employee("John", "Doe", 50000);
172	map["JW002"] = Employee("Jane", "Williams", 80000);
173	map["TJ001"] = Employee("Tom", "Jones", 60000);
174
175	Employee sasha( "Sasha", "Hind", 50000 );
176	map["SH001"] = sasha;
177	sasha.setSalary( 40000 );
178
179	EmployeeMap::<a href="#Iterator">Iterator</a> it;
180	for ( it = map.begin(); it != map.end(); ++it ) {
181	printf( "%s: %s, %s earns %d\n",
182	it.key().latin1(),
183	it.data().surname().latin1(),
184	it.data().forename().latin1(),
185	it.data().salary() );
186	}
187	return 0;
188	}
189	</pre>
190
191	<p> Program output:
192	<pre>
193	JD001: Doe, John earns 50000
194	JW002: Williams, Jane earns 80000
195	SH001: Hind, Sasha earns 50000
196	TJ001: Jones, Tom earns 60000
197	</pre>
198
199	<p> The latest changes to Sasha's salary did not affect the value in
200	the list because the map created a copy of Sasha's entry. In
201	addition, notice that the items are sorted alphabetically (by key)
202	when iterating over the map.
203	<p> There are several ways to find items in a map. The <a href="#begin">begin</a>() and
204	<a href="#end">end</a>() functions return iterators to the beginning and end of the
205	map. The advantage of using an iterator is that you can move
206	forward or backward by incrementing/decrementing the iterator.
207	The iterator returned by end() points to the element which is one
208	past the last element in the container. The past-the-end iterator
209	is still associated with the map it belongs to, however it is <em>not</em> dereferenceable; <a href="qsize.html#operator-4">operator</a>() will not return a well-defined
210	value. If the map is empty, the iterator returned by begin() will
211	equal the iterator returned by end().
212	<p> Another way to find an element in the map is by using the <a href="#find">find</a>()
213	function. This returns an iterator pointing to the desired item or
214	to the end() iterator if no such element exists.
215	<p> Another approach uses the operator[]. But be warned: if the map
216	does not contain an entry for the element you are looking for,
217	operator[] inserts a default value. If you do not know that the
218	element you are searching for is really in the list, you should
219	not use operator[]. The following example illustrates this:
220	<p> <pre>
221	QMap<QString,QString> map;
222	map["Clinton"] = "Bill";
223	str << map["Clinton"] << map["Bush"] << endl;
224	</pre>
225
226	<p> The code fragment will print out "Clinton", "". Since the value
227	associated with the "Bush" key did not exist, the map inserted a
228	default value (in this case, an empty string). If you are not
229	sure whether a certain element is in the map, you should use
230	find() and iterators instead.
231	<p> If you just want to know whether a certain key is contained in the
232	map, use the <a href="#contains">contains</a>() function. In addition, <a href="#count">count</a>() tells you
233	how many keys are in the map.
234	<p> It is safe to have multiple iterators at the same time. If some
235	member of the map is removed, only iterators pointing to the
236	removed member become invalid; inserting in the map does not
237	invalidate any iterators.
238	<p> Since QMap is value-based, there is no need to be concerned about
239	deleting items in the map. The map holds its own copies and will
240	free them if the corresponding member or the map itself is
241	deleted.
242	<p> QMap is <a href="shclass.html#implicitly-shared">implicitly shared</a>. This means you can just make copies of
243	the map in time O(1). If multiple QMap instances share the same
244	data and one is modifying the map's data, this modifying instance
245	makes a copy and modifies its private copy: so it does not affect
246	other instances. If a QMap is being used in a multi-threaded
247	program, you must protect all access to the map. See <a href="qmutex.html">QMutex</a>.
248	<p> There are a couple of ways of inserting new items into the map.
249	One uses the <a href="#insert">insert</a>() method; the other uses operator[]:
250	<pre>
251	QMap<QString, QString> map;
252	map["Clinton"] = "Bill";
253	map.<a href="#insert">insert</a>( "Bush", "George" );
254	</pre>
255
256	<p> Items can also be removed from the map in several ways. One way is
257	to pass an iterator to <a href="#remove">remove</a>(). Another way is to pass a key
258	value to remove(), which will delete the entry with the requested
259	key. In addition you can clear the entire map using the <a href="#clear">clear</a>()
260	method.
261	<p> <p>See also <a href="qmapiterator.html">QMapIterator</a>, <a href="qtl.html">Qt Template Library Classes</a>, <a href="shared.html">Implicitly and Explicitly Shared Classes</a>, and <a href="tools.html">Non-GUI Classes</a>.
262
263	<hr><h2>Member Type Documentation</h2>
264	<h3 class=fn><a name="ConstIterator"></a>QMap::ConstIterator</h3>
265	The map's const iterator type, Qt style.
266	<h3 class=fn><a name="Iterator"></a>QMap::Iterator</h3>
267	The map's iterator type, Qt style.
268	<h3 class=fn><a name="ValueType"></a>QMap::ValueType</h3>
269	Corresponds to <a href="qpair.html">QPair</a><key_type, mapped_type>, Qt style.
270	<h3 class=fn><a name="const_iterator"></a>QMap::const_iterator</h3>
271	The map's const iterator type.
272	<h3 class=fn><a name="const_pointer"></a>QMap::const_pointer</h3>
273	Const pointer to value_type.
274	<h3 class=fn><a name="const_reference"></a>QMap::const_reference</h3>
275	Const reference to value_type.
276	<h3 class=fn><a name="iterator"></a>QMap::iterator</h3>
277	The map's iterator type.
278	<h3 class=fn><a name="key_type"></a>QMap::key_type</h3>
279	The map's key type.
280	<h3 class=fn><a name="mapped_type"></a>QMap::mapped_type</h3>
281	The map's data type.
282	<h3 class=fn><a name="pointer"></a>QMap::pointer</h3>
283	Pointer to value_type.
284	<h3 class=fn><a name="reference"></a>QMap::reference</h3>
285	Reference to value_type.
286	<h3 class=fn><a name="size_type"></a>QMap::size_type</h3>
287	An unsigned integral type, used to represent various sizes.
288	<h3 class=fn><a name="value_type"></a>QMap::value_type</h3>
289	Corresponds to <a href="qpair.html">QPair</a><key_type, mapped_type>.
290	<hr><h2>Member Function Documentation</h2>
291	<h3 class=fn><a name="QMap"></a>QMap::QMap ()
292	</h3>
293
294	<p> Constructs an empty map.
295
296	<h3 class=fn><a name="QMap-2"></a>QMap::QMap ( const <a href="qmap.html">QMap</a><Key, T> & m )
297	</h3>
298
299	<p> Constructs a copy of <em>m</em>.
300	<p> This operation costs O(1) time because QMap is <a href="shclass.html#implicitly-shared">implicitly shared</a>.
301	This makes returning a QMap from a function very fast. If a shared
302	instance is modified, it will be copied (copy-on-write), and this
303	takes O(n) time.
304
305	<h3 class=fn><a name="QMap-3"></a>QMap::QMap ( const std::map<Key, T> & m )
306	</h3>
307
308	<p> Constructs a copy of <em>m</em>.
309
310	<h3 class=fn><a name="~QMap"></a>QMap::~QMap ()
311	</h3>
312
313	<p> Destroys the map. References to the values in the map and all
314	iterators of this map become invalidated. Since QMap is highly
315	tuned for performance you won't see warnings if you use invalid
316	iterators, because it is not possible for an iterator to check
317	whether it is valid or not.
318
319	<h3 class=fn><a href="qmap.html#iterator">iterator</a> <a name="begin"></a>QMap::begin ()
320	</h3>
321
322	<p> Returns an iterator pointing to the first element in the map. This
323	iterator equals <a href="#end">end</a>() if the map is empty.
324	<p> The items in the map are traversed in the order defined by
325	operator<(Key, Key).
326	<p> <p>See also <a href="#end">end</a>() and <a href="qmapiterator.html">QMapIterator</a>.
327
328	<h3 class=fn><a href="qmap.html#const_iterator">const_iterator</a> <a name="begin-2"></a>QMap::begin () const
329	</h3>
330
331	<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
332	<p> <p>See also <a href="#end">end</a>() and <a href="qmapconstiterator.html">QMapConstIterator</a>.
333
334	<h3 class=fn>void <a name="clear"></a>QMap::clear ()
335	</h3>
336
337	<p> Removes all items from the map.
338	<p> <p>See also <a href="#remove">remove</a>().
339
340	<h3 class=fn><a href="qmap.html#const_iterator">const_iterator</a> <a name="constBegin"></a>QMap::constBegin () const
341	</h3>
342
343	<p> Returns an iterator pointing to the first element in the map. This
344	iterator equals <a href="#end">end</a>() if the map is empty.
345	<p> The items in the map are traversed in the order defined by
346	operator<(Key, Key).
347	<p> <p>See also <a href="#constEnd">constEnd</a>() and <a href="qmapconstiterator.html">QMapConstIterator</a>.
348
349	<h3 class=fn><a href="qmap.html#const_iterator">const_iterator</a> <a name="constEnd"></a>QMap::constEnd () const
350	</h3>
351
352	<p> The iterator returned by <a href="#end">end</a>() points to the element which is one
353	past the last element in the container. The past-the-end iterator
354	is still associated with the map it belongs to, but it is <em>not</em>
355	dereferenceable; <a href="qsize.html#operator-4">operator</a>() will not return a well-defined value.
356	<p> This iterator equals <a href="#constBegin">constBegin</a>() if the map is empty.
357	<p> <p>See also <a href="#constBegin">constBegin</a>() and <a href="qmapconstiterator.html">QMapConstIterator</a>.
358
359	<h3 class=fn>bool <a name="contains"></a>QMap::contains ( const Key & k ) const
360	</h3>
361
362	<p> Returns TRUE if the map contains an item with key <em>k</em>; otherwise
363	returns FALSE.
364
365	<h3 class=fn><a href="qmap.html#size_type">size_type</a> <a name="count"></a>QMap::count ( const <a href="qmap.html#key_type">key_type</a> & k ) const
366	</h3>
367
368	<p> Returns the number of items whose key is <em>k</em>. Since QMap does not
369	allow duplicate keys, the return value is always 0 or 1.
370	<p> This function is provided for STL compatibility.
371
372	<h3 class=fn><a href="qmap.html#size_type">size_type</a> <a name="count-2"></a>QMap::count () const
373	</h3>
374
375	<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
376	<p> Returns the number of items in the map.
377	<p> <p>See also <a href="#isEmpty">isEmpty</a>().
378
379	<h3 class=fn>void <a name="detach"></a>QMap::detach ()<tt> [protected]</tt>
380	</h3>
381
382	<p> If the map does not share its data with another QMap instance,
383	nothing happens; otherwise the function creates a new copy of this
384	map and detaches from the shared one. This function is called
385	whenever the map is modified. The <a href="shclass.html#implicit-sharing">implicit sharing</a> mechanism is
386	implemented this way.
387
388	<h3 class=fn>bool <a name="empty"></a>QMap::empty () const
389	</h3>
390
391	<p> Returns TRUE if the map contains no items; otherwise returns
392	FALSE.
393	<p> This function is provided for STL compatibility. It is equivalent
394	to <a href="#isEmpty">isEmpty</a>().
395	<p> <p>See also <a href="#size">size</a>().
396
397	<h3 class=fn><a href="qmap.html#iterator">iterator</a> <a name="end"></a>QMap::end ()
398	</h3>
399
400	<p> The iterator returned by <a href="#end">end</a>() points to the element which is one
401	past the last element in the container. The past-the-end iterator
402	is still associated with the map it belongs to, but it is <em>not</em>
403	dereferenceable; <a href="qsize.html#operator-4">operator</a>() will not return a well-defined value.
404	<p> This iterator equals <a href="#begin">begin</a>() if the map is empty.
405	<p> <p>See also <a href="#begin">begin</a>() and <a href="qmapiterator.html">QMapIterator</a>.
406
407	<h3 class=fn><a href="qmap.html#const_iterator">const_iterator</a> <a name="end-2"></a>QMap::end () const
408	</h3>
409
410	<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
411	<p>
412	<h3 class=fn>void <a name="erase"></a>QMap::erase ( <a href="qmap.html#iterator">iterator</a> it )
413	</h3>
414
415	<p> Removes the item associated with the iterator <em>it</em> from the map.
416	<p> This function is provided for STL compatibility. It is equivalent
417	to <a href="#remove">remove</a>().
418	<p> <p>See also <a href="#clear">clear</a>().
419
420	<h3 class=fn>void <a name="erase-2"></a>QMap::erase ( const <a href="qmap.html#key_type">key_type</a> & k )
421	</h3>
422
423	<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
424	<p> Removes the item with the key <em>k</em> from the map.
425
426	<h3 class=fn><a href="qmap.html#iterator">iterator</a> <a name="find"></a>QMap::find ( const Key & k )
427	</h3>
428
429	<p> Returns an iterator pointing to the element with key <em>k</em> in the
430	map.
431	<p> Returns <a href="#end">end</a>() if no key matched.
432	<p> <p>See also <a href="qmapiterator.html">QMapIterator</a>.
433
434	<h3 class=fn><a href="qmap.html#const_iterator">const_iterator</a> <a name="find-2"></a>QMap::find ( const Key & k ) const
435	</h3>
436
437	<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
438	<p> Returns an iterator pointing to the element with key <em>k</em> in the
439	map.
440	<p> Returns <a href="#end">end</a>() if no key matched.
441	<p> <p>See also <a href="qmapconstiterator.html">QMapConstIterator</a>.
442
443	<h3 class=fn><a href="qmap.html#iterator">iterator</a> <a name="insert"></a>QMap::insert ( const Key & key, const T & value, bool overwrite = TRUE )
444	</h3>
445
446	<p> Inserts a new item with the key, <em>key</em>, and a value of <em>value</em>.
447	If there is already an item whose key is <em>key</em>, that item's value
448	is replaced with <em>value</em>, unless <em>overwrite</em> is FALSE (it is
449	TRUE by default). In this case an iterator to this item is
450	returned, else an iterator to the new item is returned.
451	<p>
452	<h3 class=fn><a href="qpair.html">QPair</a><iterator, bool> <a name="insert-2"></a>QMap::insert ( const <a href="qmap.html#value_type">value_type</a> & x )
453	</h3>
454
455	<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
456	<p> Inserts the (key, value) pair <em>x</em> into the map. <em>x</em> is a <a href="qpair.html">QPair</a>
457	whose <tt>first</tt> element is a key to be inserted and whose <tt>second</tt>
458	element is the associated value to be inserted. Returns a pair
459	whose <tt>first</tt> element is an iterator pointing to the inserted
460	item and whose <tt>second</tt> element is a bool indicating TRUE if <em>x</em>
461	was inserted and FALSE if it was not inserted, e.g. because it was
462	already present.
463	<p> <p>See also <a href="#replace">replace</a>().
464
465	<h3 class=fn>bool <a name="isEmpty"></a>QMap::isEmpty () const
466	</h3>
467
468	<p> Returns TRUE if the map contains no items; otherwise returns
469	FALSE.
470	<p> <p>See also <a href="#count">count</a>().
471
472	<h3 class=fn><a href="qvaluelist.html">QValueList</a><Key> <a name="keys"></a>QMap::keys () const
473	</h3>
474
475	<p> Returns a list of all the keys in the map, in order.
476
477	<h3 class=fn><a href="qmap.html">QMap</a><Key, T> & <a name="operator-eq"></a>QMap::operator= ( const <a href="qmap.html">QMap</a><Key, T> & m )
478	</h3>
479
480	<p> Assigns <em>m</em> to this map and returns a reference to this map.
481	<p> All iterators of the current map become invalidated by this
482	operation. The cost of such an assignment is O(1), because QMap is
483	<a href="shclass.html#implicitly-shared">implicitly shared</a>.
484
485	<h3 class=fn><a href="qmap.html">QMap</a><Key, T> & <a name="operator-eq-2"></a>QMap::operator= ( const std::map<Key, T> & m )
486	</h3>
487
488	<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
489	<p> Assigns <em>m</em> to this map and returns a reference to this map.
490	<p> All iterators of the current map become invalidated by this
491	operation.
492
493	<h3 class=fn>T & <a name="operator[]"></a>QMap::operator[] ( const Key & k )
494	</h3>
495
496	<p> Returns the value associated with the key <em>k</em>. If no such key is
497	present, an empty item is inserted with this key and a reference
498	to the empty item is returned.
499	<p> You can use this operator both for reading and writing:
500	<pre>
501	QMap<QString, QString> map;
502	map["Clinton"] = "Bill";
503	stream << map["Clinton"];
504	</pre>
505
506
507	<h3 class=fn>const T & <a name="operator[]-2"></a>QMap::operator[] ( const Key & k ) const
508	</h3>
509
510	<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
511	<p> <b>Warning:</b> This function differs from the non-const version of the
512	same function. It will <em>not</em> insert an empty value if the key <em>k</em> does not exist. This may lead to logic errors in your program.
513	You should check if the element exists before calling this
514	function.
515	<p> Returns the value associated with the key <em>k</em>. If no such key is
516	present, a reference to an empty item is returned.
517
518	<h3 class=fn>void <a name="remove"></a>QMap::remove ( <a href="qmap.html#iterator">iterator</a> it )
519	</h3>
520
521	<p> Removes the item associated with the iterator <em>it</em> from the map.
522	<p> <p>See also <a href="#clear">clear</a>().
523
524	<h3 class=fn>void <a name="remove-2"></a>QMap::remove ( const Key & k )
525	</h3>
526
527	<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
528	<p> Removes the item with the key <em>k</em> from the map.
529
530	<h3 class=fn><a href="qmap.html#iterator">iterator</a> <a name="replace"></a>QMap::replace ( const Key & k, const T & v )
531	</h3>
532
533	<p> Replaces the value of the element with key <em>k</em>, with the value <em>v</em>.
534	<p> <p>See also <a href="#insert">insert</a>() and <a href="#remove">remove</a>().
535
536	<h3 class=fn><a href="qmap.html#size_type">size_type</a> <a name="size"></a>QMap::size () const
537	</h3>
538
539	<p> Returns the number of items in the map.
540	<p> This function is provided for STL compatibility. It is equivalent
541	to <a href="#count">count</a>().
542	<p> <p>See also <a href="#empty">empty</a>().
543
544	<h3 class=fn><a href="qvaluelist.html">QValueList</a><T> <a name="values"></a>QMap::values () const
545	</h3>
546
547	<p> Returns a list of all the values in the map, in key order.
548
549	<hr><h2>Related Functions</h2>
550	<h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="operator-lt-lt"></a>operator<< ( <a href="qdatastream.html">QDataStream</a> & s, const <a href="qmap.html">QMap</a><Key, T> & m )
551	</h3>
552
553	<p>
554	<p> Writes the map <em>m</em> to the stream <em>s</em>. The types <em>Key</em> and <em>T</em>
555	must implement the streaming operator as well.
556
557	<h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="operator-gt-gt"></a>operator>> ( <a href="qdatastream.html">QDataStream</a> & s, <a href="qmap.html">QMap</a><Key, T> & m )
558	</h3>
559
560	<p>
561	<p> Reads the map <em>m</em> from the stream <em>s</em>. The types <em>Key</em> and <em>T</em>
562	must implement the streaming operator as well.
563
564	<!-- eof -->
565	<hr><p>
566	This file is part of the <a href="index.html">Qt toolkit</a>.
567	Copyright © 1995-2007
568	<a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center>
569	<table width=100% cellspacing=0 border=0><tr>
570	<td>Copyright © 2007
571	<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a>
572	<td align=right><div align=right>Qt 3.3.8</div>
573	</table></div></address></body>
574	</html>

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