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<td width="1"> </td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a> · <a href="classes.html"><font color="#004faf">All Classes</font></a> · <a href="mainclasses.html"><font color="#004faf">Main Classes</font></a> · <a href="groups.html"><font color="#004faf">Grouped Classes</font></a> · <a href="modules.html"><font color="#004faf">Modules</font></a> · <a href="functions.html"><font color="#004faf">Functions</font></a></td>
<td align="right" valign="top" width="230"><a href="http://www.trolltech.com"><img src="images/trolltech-logo.png" align="right" width="203" height="32" border="0" /></a></td></tr></table><h1 align="center">QQueue Class Reference<br /><sup><sup>[<a href="qtcore.html">QtCore</a> module]</sup></sup></h1>
<p>The QQueue class is a generic container that provides a queue. <a href="#details">More...</a></p>
<pre> #include <QQueue></pre><p>Inherits <a href="qlist.html">QList<T></a>.</p>
<p><b>Note:</b> All the functions in this class are <a href="threads.html#reentrant">reentrant</a>.</p>
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<li><a href="qqueue-members.html">List of all members, including inherited members</a></li>
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<h3>Public Functions</h3>
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<li><div class="fn"/><b><a href="qqueue.html#QQueue">QQueue</a></b> ()</li>
<li><div class="fn"/><b><a href="qqueue.html#dtor.QQueue">~QQueue</a></b> ()</li>
<li><div class="fn"/>T <b><a href="qqueue.html#dequeue">dequeue</a></b> ()</li>
<li><div class="fn"/>void <b><a href="qqueue.html#enqueue">enqueue</a></b> ( const T & <i>t</i> )</li>
<li><div class="fn"/>T & <b><a href="qqueue.html#head">head</a></b> ()</li>
<li><div class="fn"/>const T & <b><a href="qqueue.html#head-2">head</a></b> () const</li>
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<ul>
<li><div class="fn"/>60 public functions inherited from <a href="qlist.html#public-functions">QList</a></li>
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<h3>Additional Inherited Members</h3>
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<li><div class="fn"/>3 static public members inherited from <a href="qlist.html#static-public-members">QList</a></li>
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<h2>Detailed Description</h2>
<p>The QQueue class is a generic container that provides a queue.</p>
<p>QQueue<T> is one of Qt's generic <a href="containers.html#container-classes">container classes</a>. It implements a queue data structure for items of a same type.</p>
<p>A queue is a first in, first out (FIFO) structure. Items are added to the tail of the queue using <a href="qqueue.html#enqueue">enqueue</a>() and retrieved from the head using <a href="qqueue.html#dequeue">dequeue</a>(). The <a href="qqueue.html#head">head</a>() function provides access to the head item without removing it.</p>
<p>Example:</p>
<pre> QQueue<int> queue;
queue.enqueue(1);
queue.enqueue(2);
queue.enqueue(3);
while (!queue.isEmpty())
cout << queue.dequeue() << endl;</pre>
<p>The example will output 1, 2, 3 in that order.</p>
<p>QQueue inherits from <a href="qlist.html">QList</a>. All of <a href="qlist.html">QList</a>'s functionality also applies to QQueue. For example, you can use <a href="qlist.html#isEmpty">isEmpty</a>() to test whether the queue is empty, and you can traverse a QQueue using <a href="qlist.html">QList</a>'s iterator classes (for example, <a href="qlistiterator.html">QListIterator</a>). But in addition, QQueue provides three convenience functions that make it easy to implement FIFO semantics: <a href="qqueue.html#enqueue">enqueue</a>(), <a href="qqueue.html#dequeue">dequeue</a>(), and <a href="qqueue.html#head">head</a>().</p>
<p>QQueue's value type must be an <a href="containers.html#assignable-data-types">assignable data type</a>. This covers most data types that are commonly used, but the compiler won't let you, for example, store a <a href="qwidget.html">QWidget</a> as a value; instead, store a <a href="qwidget.html">QWidget</a> *.</p>
<p>See also <a href="qlist.html">QList</a> and <a href="qstack.html">QStack</a>.</p>
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<h2>Member Function Documentation</h2>
<h3 class="fn"><a name="QQueue"></a>QQueue::QQueue ()</h3>
<p>Constructs an empty queue.</p>
<h3 class="fn"><a name="dtor.QQueue"></a>QQueue::~QQueue ()</h3>
<p>Destroys the queue. References to the values in the queue, and all iterators over this queue, become invalid.</p>
<h3 class="fn"><a name="dequeue"></a>T QQueue::dequeue ()</h3>
<p>Removes the head item in the queue and returns it. This function assumes that the queue isn't empty.</p>
<p>This is the same as <a href="qlist.html#takeFirst">QList::takeFirst</a>().</p>
<p>See also <a href="qqueue.html#head">head</a>(), <a href="qqueue.html#enqueue">enqueue</a>(), and <a href="qlist.html#isEmpty">isEmpty</a>().</p>
<h3 class="fn"><a name="enqueue"></a>void QQueue::enqueue ( const T & <i>t</i> )</h3>
<p>Adds value <i>t</i> to the tail of the queue.</p>
<p>This is the same as <a href="qlist.html#append">QList::append</a>().</p>
<p>See also <a href="qqueue.html#dequeue">dequeue</a>() and <a href="qqueue.html#head">head</a>().</p>
<h3 class="fn"><a name="head"></a>T & QQueue::head ()</h3>
<p>Returns a reference to the queue's head item. This function assumes that the queue isn't empty.</p>
<p>This is the same as <a href="qlist.html#first">QList::first</a>().</p>
<p>See also <a href="qqueue.html#dequeue">dequeue</a>(), <a href="qqueue.html#enqueue">enqueue</a>(), and <a href="qlist.html#isEmpty">isEmpty</a>().</p>
<h3 class="fn"><a name="head-2"></a>const T & QQueue::head () const</h3>
<p>This is an overloaded member function, provided for convenience.</p>
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