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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>QBitArray Class Reference</h1>
33
34	<p>The QBitArray class provides an array of bits.
35	<a href="#details">More...</a>
36	<p>All the functions in this class are <a href="threads.html#reentrant">reentrant</a> when Qt is built with thread support.</p>
37	<p><tt>#include <<a href="qbitarray-h.html">qbitarray.h</a>></tt>
38	<p>Inherits <a href="qbytearray.html">QByteArray</a>.
39	<p><a href="qbitarray-members.html">List of all member functions.</a>
40	<h2>Public Members</h2>
41	<ul>
42	<li class=fn><a href="#QBitArray"><b>QBitArray</b></a> ()</li>
43	<li class=fn><a href="#QBitArray-2"><b>QBitArray</b></a> ( uint size )</li>
44	<li class=fn><a href="#QBitArray-3"><b>QBitArray</b></a> ( const QBitArray & a )</li>
45	<li class=fn>QBitArray & <a href="#operator-eq"><b>operator=</b></a> ( const QBitArray & a )</li>
46	<li class=fn>uint <a href="#size"><b>size</b></a> () const</li>
47	<li class=fn>bool <a href="#resize"><b>resize</b></a> ( uint size )</li>
48	<li class=fn>bool <a href="#fill"><b>fill</b></a> ( bool v, int size = -1 )</li>
49	<li class=fn>virtual void <a href="#detach"><b>detach</b></a> ()</li>
50	<li class=fn>QBitArray <a href="#copy"><b>copy</b></a> () const</li>
51	<li class=fn>bool <a href="#testBit"><b>testBit</b></a> ( uint index ) const</li>
52	<li class=fn>void <a href="#setBit-2"><b>setBit</b></a> ( uint index )</li>
53	<li class=fn>void <a href="#setBit"><b>setBit</b></a> ( uint index, bool value )</li>
54	<li class=fn>void <a href="#clearBit"><b>clearBit</b></a> ( uint index )</li>
55	<li class=fn>bool <a href="#toggleBit"><b>toggleBit</b></a> ( uint index )</li>
56	<li class=fn>bool <a href="#at"><b>at</b></a> ( uint index ) const</li>
57	<li class=fn>QBitVal <a href="#operator[]"><b>operator[]</b></a> ( int index )</li>
58	<li class=fn>bool <a href="#operator[]-2"><b>operator[]</b></a> ( int index ) const</li>
59	<li class=fn>QBitArray & <a href="#operator-and-eq"><b>operator&=</b></a> ( const QBitArray & a )</li>
60	<li class=fn>QBitArray & <a href="#operator\|-eq"><b>operator\|=</b></a> ( const QBitArray & a )</li>
61	<li class=fn>QBitArray & <a href="#operator^-eq"><b>operator^=</b></a> ( const QBitArray & a )</li>
62	<li class=fn>QBitArray <a href="#operator~"><b>operator~</b></a> () const</li>
63	</ul>
64	<h2>Related Functions</h2>
65	<ul>
66	<li class=fn>QBitArray <a href="#operator-and"><b>operator&</b></a> ( const QBitArray & a1, const QBitArray & a2 )</li>
67	<li class=fn>QBitArray <a href="#operator\|"><b>operator\|</b></a> ( const QBitArray & a1, const QBitArray & a2 )</li>
68	<li class=fn>QBitArray <a href="#operator^"><b>operator^</b></a> ( const QBitArray & a1, const QBitArray & a2 )</li>
69	<li class=fn>QDataStream & <a href="#operator-lt-lt"><b>operator<<</b></a> ( QDataStream & s, const QBitArray & a )</li>
70	<li class=fn>QDataStream & <a href="#operator-gt-gt"><b>operator>></b></a> ( QDataStream & s, QBitArray & a )</li>
71	</ul>
72	<hr><a name="details"></a><h2>Detailed Description</h2>
73
74
75
76	The QBitArray class provides an array of bits.
77	<p>
78
79
80	<p> Because QBitArray is a <a href="qmemarray.html">QMemArray</a>, it uses explicit <a href="shclass.html">sharing</a> with a reference count.
81	<p> A QBitArray is a special byte array that can access individual
82	bits and perform bit-operations (AND, OR, XOR and NOT) on entire
83	arrays or bits.
84	<p> Bits can be manipulated by the <a href="#setBit">setBit</a>() and <a href="#clearBit">clearBit</a>() functions,
85	but it is also possible to use the indexing [] operator to test
86	and set individual bits. The [] operator is a little slower than
87	setBit() and clearBit() because some tricks are required to
88	implement single-bit assignments.
89	<p> Example:
90	<pre>
91	QBitArray a(3);
92	a.<a href="#setBit">setBit</a>( 0 );
93	a.<a href="#clearBit">clearBit</a>( 1 );
94	a.<a href="#setBit">setBit</a>( 2 ); // a = [1 0 1]
95
96	QBitArray b(3);
97	b[0] = 1;
98	b[1] = 1;
99	b[2] = 0; // b = [1 1 0]
100
101	QBitArray c;
102	c = ~a & b; // c = [0 1 0]
103	</pre>
104
105	<p> When a QBitArray is constructed the bits are uninitialized. Use
106	<a href="#fill">fill</a>() to set all the bits to 0 or 1. The array can be resized
107	with <a href="#resize">resize</a>() and copied with <a href="#copy">copy</a>(). Bits can be set with
108	setBit() and cleared with clearBit(). Bits can be toggled with
109	<a href="#toggleBit">toggleBit</a>(). A bit's value can be obtained with <a href="#testBit">testBit</a>() and with
110	<a href="#at">at</a>().
111	<p> QBitArray supports the & (AND), \| (OR), ^ (XOR) and ~ (NOT)
112	operators.
113	<p>See also <a href="collection.html">Collection Classes</a>, <a href="shared.html">Implicitly and Explicitly Shared Classes</a>, and <a href="tools.html">Non-GUI Classes</a>.
114
115	<hr><h2>Member Function Documentation</h2>
116	<h3 class=fn><a name="QBitArray"></a>QBitArray::QBitArray ()
117	</h3>
118	Constructs an empty bit array.
119
120	<h3 class=fn><a name="QBitArray-2"></a>QBitArray::QBitArray ( uint size )
121	</h3>
122	Constructs a bit array of <em>size</em> bits. The bits are uninitialized.
123	<p> <p>See also <a href="#fill">fill</a>().
124
125	<h3 class=fn><a name="QBitArray-3"></a>QBitArray::QBitArray ( const <a href="qbitarray.html">QBitArray</a> & a )
126	</h3>
127
128	<p> Constructs a <a href="shclass.html#shallow-copy">shallow copy</a> of <em>a</em>.
129
130	<h3 class=fn>bool <a name="at"></a>QBitArray::at ( uint index ) const
131	</h3>
132
133	<p> Returns the value (0 or 1) of the bit at position <em>index</em>.
134	<p> <p>See also <a href="#operator[]">operator[]</a>().
135
136	<h3 class=fn>void <a name="clearBit"></a>QBitArray::clearBit ( uint index )
137	</h3>
138	Clears the bit at position <em>index</em>, i.e. sets it to 0.
139	<p> <p>See also <a href="#setBit">setBit</a>() and <a href="#toggleBit">toggleBit</a>().
140
141	<h3 class=fn><a href="qbitarray.html">QBitArray</a> <a name="copy"></a>QBitArray::copy () const
142	</h3>
143	Returns a <a href="shclass.html#deep-copy">deep copy</a> of the bit array.
144	<p> <p>See also <a href="#detach">detach</a>().
145
146	<h3 class=fn>void <a name="detach"></a>QBitArray::detach ()<tt> [virtual]</tt>
147	</h3>
148	Detaches from shared bit array data and makes sure that this bit
149	array is the only one referring to the data.
150	<p> If multiple bit arrays share common data, this bit array
151	dereferences the data and gets a copy of the data. Nothing happens
152	if there is only a single reference.
153	<p> <p>See also <a href="#copy">copy</a>().
154
155	<p>Reimplemented from <a href="qmemarray.html#detach">QMemArray</a>.
156	<h3 class=fn>bool <a name="fill"></a>QBitArray::fill ( bool v, int size = -1 )
157	</h3>
158	Fills the bit array with <em>v</em> (1's if <em>v</em> is TRUE, or 0's if <em>v</em>
159	is FALSE).
160	<p> <a href="#fill">fill</a>() resizes the bit array to <em>size</em> bits if <em>size</em> is
161	nonnegative.
162	<p> Returns FALSE if a nonnegative <em>size</em> was specified and the bit
163	array could not be resized; otherwise returns TRUE.
164	<p> <p>See also <a href="#resize">resize</a>().
165
166	<h3 class=fn><a href="qbitarray.html">QBitArray</a> & <a name="operator-and-eq"></a>QBitArray::operator&= ( const <a href="qbitarray.html">QBitArray</a> & a )
167	</h3>
168	Performs the AND operation between all bits in this bit array and
169	<em>a</em>. Returns a reference to this bit array.
170	<p> The result has the length of the longest of the two bit arrays,
171	with any missing bits (i.e. if one array is shorter than the
172	other), taken to be 0.
173	<pre>
174	QBitArray a( 3 ), b( 2 );
175	a[0] = 1; a[1] = 0; a[2] = 1; // a = [1 0 1]
176	b[0] = 1; b[1] = 0; // b = [1 0]
177	a &= b; // a = [1 0 0]
178	</pre>
179
180	<p> <p>See also <a href="#operator\|-eq">operator\|=</a>(), <a href="#operator^-eq">operator^=</a>(), and <a href="#operator~">operator~</a>().
181
182	<h3 class=fn><a href="qbitarray.html">QBitArray</a> & <a name="operator-eq"></a>QBitArray::operator= ( const <a href="qbitarray.html">QBitArray</a> & a )
183	</h3>
184
185	<p> Assigns a <a href="shclass.html#shallow-copy">shallow copy</a> of <em>a</em> to this bit array and returns a
186	reference to this array.
187
188	<h3 class=fn><a href="qbitval.html">QBitVal</a> <a name="operator[]"></a>QBitArray::operator[] ( int index )
189	</h3>
190
191	<p> Implements the [] operator for bit arrays.
192	<p> The returned <a href="qbitval.html">QBitVal</a> is a context object. It makes it possible to
193	get and set a single bit value by its <em>index</em> position.
194	<p> Example:
195	<pre>
196	QBitArray a( 3 );
197	a[0] = 0;
198	a[1] = 1;
199	a[2] = a[0] ^ a[1];
200	</pre>
201
202	<p> The functions <a href="#testBit">testBit</a>(), <a href="#setBit">setBit</a>() and <a href="#clearBit">clearBit</a>() are faster.
203	<p> <p>See also <a href="#at">at</a>().
204
205	<h3 class=fn>bool <a name="operator[]-2"></a>QBitArray::operator[] ( int index ) const
206	</h3>
207	This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
208	<p> Implements the [] operator for constant bit arrays.
209
210	<h3 class=fn><a href="qbitarray.html">QBitArray</a> & <a name="operator^-eq"></a>QBitArray::operator^= ( const <a href="qbitarray.html">QBitArray</a> & a )
211	</h3>
212	Performs the XOR operation between all bits in this bit array and
213	<em>a</em>. Returns a reference to this bit array.
214	<p> The result has the length of the longest of the two bit arrays,
215	with any missing bits (i.e. if one array is shorter than the
216	other), taken to be 0.
217	<pre>
218	QBitArray a( 3 ), b( 2 );
219	a[0] = 1; a[1] = 0; a[2] = 1; // a = [1 0 1]
220	b[0] = 1; b[1] = 0; // b = [1 0]
221	a ^= b; // a = [0 0 1]
222	</pre>
223
224	<p> <p>See also <a href="#operator-and-eq">operator&=</a>(), <a href="#operator\|-eq">operator\|=</a>(), and <a href="#operator~">operator~</a>().
225
226	<h3 class=fn><a href="qbitarray.html">QBitArray</a> & <a name="operator\|-eq"></a>QBitArray::operator\|= ( const <a href="qbitarray.html">QBitArray</a> & a )
227	</h3>
228	Performs the OR operation between all bits in this bit array and
229	<em>a</em>. Returns a reference to this bit array.
230	<p> The result has the length of the longest of the two bit arrays,
231	with any missing bits (i.e. if one array is shorter than the
232	other), taken to be 0.
233	<pre>
234	QBitArray a( 3 ), b( 2 );
235	a[0] = 1; a[1] = 0; a[2] = 1; // a = [1 0 1]
236	b[0] = 1; b[1] = 0; // b = [1 0]
237	a \|= b; // a = [1 0 1]
238	</pre>
239
240	<p> <p>See also <a href="#operator-and-eq">operator&=</a>(), <a href="#operator^-eq">operator^=</a>(), and <a href="#operator~">operator~</a>().
241
242	<h3 class=fn><a href="qbitarray.html">QBitArray</a> <a name="operator~"></a>QBitArray::operator~ () const
243	</h3>
244	Returns a bit array that contains the inverted bits of this bit array.
245	<p> Example:
246	<pre>
247	QBitArray a( 3 ), b;
248	a[0] = 1; a[1] = 0; a[2] = 1; // a = [1 0 1]
249	b = ~a; // b = [0 1 0]
250	</pre>
251
252
253	<h3 class=fn>bool <a name="resize"></a>QBitArray::resize ( uint size )
254	</h3>
255	Resizes the bit array to <em>size</em> bits and returns TRUE if the bit
256	array could be resized; otherwise returns FALSE. The array becomes
257	a null array if <em>size</em> == 0.
258	<p> If the array is expanded, the new bits are set to 0.
259	<p> <p>See also <a href="#size">size</a>().
260
261	<h3 class=fn>void <a name="setBit"></a>QBitArray::setBit ( uint index, bool value )
262	</h3>
263
264	<p> Sets the bit at position <em>index</em> to <em>value</em>.
265	<p> Equivalent to:
266	<pre>
267	if ( value )
268	<a href="#setBit">setBit</a>( index );
269	else
270	<a href="#clearBit">clearBit</a>( index );
271	</pre>
272
273	<p> <p>See also <a href="#clearBit">clearBit</a>() and <a href="#toggleBit">toggleBit</a>().
274
275	<h3 class=fn>void <a name="setBit-2"></a>QBitArray::setBit ( uint index )
276	</h3>
277	This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
278	<p> Sets the bit at position <em>index</em> to 1.
279	<p> <p>See also <a href="#clearBit">clearBit</a>() and <a href="#toggleBit">toggleBit</a>().
280
281	<h3 class=fn>uint <a name="size"></a>QBitArray::size () const
282	</h3>
283
284	<p> Returns the bit array's size (number of bits).
285	<p> <p>See also <a href="#resize">resize</a>().
286
287	<h3 class=fn>bool <a name="testBit"></a>QBitArray::testBit ( uint index ) const
288	</h3>
289	Returns TRUE if the bit at position <em>index</em> is set, i.e. is 1;
290	otherwise returns FALSE.
291	<p> <p>See also <a href="#setBit">setBit</a>() and <a href="#clearBit">clearBit</a>().
292
293	<h3 class=fn>bool <a name="toggleBit"></a>QBitArray::toggleBit ( uint index )
294	</h3>
295	Toggles the bit at position <em>index</em>.
296	<p> If the previous value was 0, the new value will be 1. If the
297	previous value was 1, the new value will be 0.
298	<p> <p>See also <a href="#setBit">setBit</a>() and <a href="#clearBit">clearBit</a>().
299
300	<hr><h2>Related Functions</h2>
301	<h3 class=fn><a href="qbitarray.html">QBitArray</a> <a name="operator-and"></a>operator& ( const <a href="qbitarray.html">QBitArray</a> & a1, const <a href="qbitarray.html">QBitArray</a> & a2 )
302	</h3>
303
304	<p> Returns the AND result between the bit arrays <em>a1</em> and <em>a2</em>.
305	<p> The result has the length of the longest of the two bit arrays,
306	with any missing bits (i.e. if one array is shorter than the
307	other), taken to be 0.
308	<p> <p>See also <a href="#operator-and-eq">QBitArray::operator&=</a>().
309
310	<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="qbitarray.html">QBitArray</a> & a )
311	</h3>
312
313	<p> Writes bit array <em>a</em> to stream <em>s</em>.
314	<p> <p>See also <a href="datastreamformat.html">Format of the QDataStream operators</a>.
315
316	<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="qbitarray.html">QBitArray</a> & a )
317	</h3>
318
319	<p> Reads a bit array into <em>a</em> from stream <em>s</em>.
320	<p> <p>See also <a href="datastreamformat.html">Format of the QDataStream operators</a>.
321
322	<h3 class=fn><a href="qbitarray.html">QBitArray</a> <a name="operator^"></a>operator^ ( const <a href="qbitarray.html">QBitArray</a> & a1, const <a href="qbitarray.html">QBitArray</a> & a2 )
323	</h3>
324
325	<p> Returns the XOR result between the bit arrays <em>a1</em> and <em>a2</em>.
326	<p> The result has the length of the longest of the two bit arrays,
327	with any missing bits (i.e. if one array is shorter than the
328	other), taken to be 0.
329	<p> <p>See also <a href="#operator^">QBitArray::operator^</a>().
330
331	<h3 class=fn><a href="qbitarray.html">QBitArray</a> <a name="operator\|"></a>operator\| ( const <a href="qbitarray.html">QBitArray</a> & a1, const <a href="qbitarray.html">QBitArray</a> & a2 )
332	</h3>
333
334	<p> Returns the OR result between the bit arrays <em>a1</em> and <em>a2</em>.
335	<p> The result has the length of the longest of the two bit arrays,
336	with any missing bits (i.e. if one array is shorter than the
337	other), taken to be 0.
338	<p> <p>See also <a href="#operator\|-eq">QBitArray::operator\|=</a>().
339
340	<!-- eof -->
341	<hr><p>
342	This file is part of the <a href="index.html">Qt toolkit</a>.
343	Copyright © 1995-2007
344	<a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center>
345	<table width=100% cellspacing=0 border=0><tr>
346	<td>Copyright © 2007
347	<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a>
348	<td align=right><div align=right>Qt 3.3.8</div>
349	</table></div></address></body>
350	</html>

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