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<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">QSet::const_iterator Class Reference<br /><sup><sup>[<a href="qtcore.html">QtCore</a> module]</sup></sup></h1>
<p>The QSet::const_iterator class provides an STL-style const iterator for <a href="qset.html">QSet</a>. <a href="#details">More...</a></p>
<pre> #include <<a href="qset.html">QSet</a>></pre><p>This class was introduced in Qt 4.2.</p>
<ul>
<li><a href="qset-const-iterator-members.html">List of all members, including inherited members</a></li>
</ul>
<a name="public-functions"></a>
<h3>Public Functions</h3>
<ul>
<li><div class="fn"/><b><a href="qset-const-iterator.html#const_iterator">const_iterator</a></b> ()</li>
<li><div class="fn"/><b><a href="qset-const-iterator.html#const_iterator-3">const_iterator</a></b> ( const const_iterator & <i>other</i> )</li>
<li><div class="fn"/><b><a href="qset-const-iterator.html#const_iterator-4">const_iterator</a></b> ( const iterator & <i>other</i> )</li>
<li><div class="fn"/>bool <b><a href="qset-const-iterator.html#operator-not-eq">operator!=</a></b> ( const const_iterator & <i>other</i> ) const</li>
<li><div class="fn"/>const T & <b><a href="qset-const-iterator.html#operator-2a">operator*</a></b> () const</li>
<li><div class="fn"/>const_iterator <b><a href="qset-const-iterator.html#operator-2b">operator+</a></b> ( int <i>j</i> ) const</li>
<li><div class="fn"/>const_iterator & <b><a href="qset-const-iterator.html#operator-2b-2b">operator++</a></b> ()</li>
<li><div class="fn"/>const_iterator <b><a href="qset-const-iterator.html#operator-2b-2b-2">operator++</a></b> ( int )</li>
<li><div class="fn"/>const_iterator & <b><a href="qset-const-iterator.html#operator-2b-eq">operator+=</a></b> ( int <i>j</i> )</li>
<li><div class="fn"/>const_iterator <b><a href="qset-const-iterator.html#operator-">operator-</a></b> ( int <i>j</i> ) const</li>
<li><div class="fn"/>const_iterator & <b><a href="qset-const-iterator.html#operator--">operator--</a></b> ()</li>
<li><div class="fn"/>const_iterator <b><a href="qset-const-iterator.html#operator---2">operator--</a></b> ( int )</li>
<li><div class="fn"/>const_iterator & <b><a href="qset-const-iterator.html#operator--eq">operator-=</a></b> ( int <i>j</i> )</li>
<li><div class="fn"/>const T * <b><a href="qset-const-iterator.html#operator--gt">operator-></a></b> () const</li>
<li><div class="fn"/>const_iterator & <b><a href="qset-const-iterator.html#operator-eq">operator=</a></b> ( const const_iterator & <i>other</i> )</li>
<li><div class="fn"/>bool <b><a href="qset-const-iterator.html#operator-eq-eq">operator==</a></b> ( const const_iterator & <i>other</i> ) const</li>
</ul>
<a name="details"></a>
<hr />
<h2>Detailed Description</h2>
<p>The QSet::const_iterator class provides an STL-style const iterator for <a href="qset.html">QSet</a>.</p>
<p><a href="qset.html">QSet</a> features both <a href="containers.html#stl-style-iterators">STL-style iterators</a> and <a href="containers.html#java-style-iterators">Java-style iterators</a>. The STL-style iterators are more low-level and more cumbersome to use; on the other hand, they are slightly faster and, for developers who already know STL, have the advantage of familiarity.</p>
<p><a href="qset.html">QSet</a><Key, T>::const_iterator allows you to iterate over a <a href="qset.html">QSet</a>. If you want to modify the <a href="qset.html">QSet</a> as you iterate over it, you must use <a href="qset-iterator.html">QSet::iterator</a> instead. It is generally good practice to use QSet::const_iterator on a non-const <a href="qset.html">QSet</a> as well, unless you need to change the <a href="qset.html">QSet</a> through the iterator. Const iterators are slightly faster, and can improve code readability.</p>
<p>The default QSet::const_iterator constructor creates an uninitialized iterator. You must initialize it using a function like <a href="qset.html#begin">QSet::begin</a>(), <a href="qset.html#end">QSet::end</a>(), or <a href="qset.html#insert">QSet::insert</a>() before you can start iterating. Here's a typical loop that prints all the items stored in a set:</p>
<pre> QSet<QString> set;
set << "January" << "February" << ... << "December";
QSet<QString>::const_iterator i;
for (i = set.begin(); i != set.end(); ++i)
qDebug() << *i;</pre>
<p>STL-style iterators can be used as arguments to <a href="qtalgorithms.html">generic algorithms</a>. For example, here's how to find an item in the set using the <a href="qtalgorithms.html#qFind">qFind</a>() algorithm:</p>
<pre> QSet<QString> set;
...
QSet<QString>::iterator it = qFind(set.begin(), set.end(), "Jeanette");
if (it != set.constEnd())
cout << "Found Jeanette" << endl;</pre>
<p>Multiple iterators can be used on the same set. However, you may not attempt to modify the container while iterating on it.</p>
<p>See also <a href="qset-iterator.html">QSet::iterator</a> and <a href="qsetiterator.html">QSetIterator</a>.</p>
<hr />
<h2>Member Function Documentation</h2>
<h3 class="fn"><a name="const_iterator"></a>const_iterator::const_iterator ()</h3>
<p>Constructs an uninitialized iterator.</p>
<p>Functions like operator*() and operator++() should not be called on an uninitialized iterator. Use operator=() to assign a value to it before using it.</p>
<p>See also <a href="qset.html#begin">QSet::begin</a>() and <a href="qset.html#end">QSet::end</a>().</p>
<h3 class="fn"><a name="const_iterator-3"></a>const_iterator::const_iterator ( const const_iterator & <i>other</i> )</h3>
<p>Constructs a copy of <i>other</i>.</p>
<h3 class="fn"><a name="const_iterator-4"></a>const_iterator::const_iterator ( const <a href="qset-iterator.html">iterator</a> & <i>other</i> )</h3>
<p>Constructs a copy of <i>other</i>.</p>
<p>This function was introduced in Qt 4.2.</p>
<h3 class="fn"><a name="operator-not-eq"></a>bool const_iterator::operator!= ( const const_iterator & <i>other</i> ) const</h3>
<p>Returns true if <i>other</i> points to a different item than this iterator; otherwise returns false.</p>
<p>See also <a href="qset-const-iterator.html#operator-eq-eq">operator==</a>().</p>
<h3 class="fn"><a name="operator-2a"></a>const T & const_iterator::operator* () const</h3>
<p>Returns a reference to the current item.</p>
<p>See also <a href="qset-const-iterator.html#operator--gt">operator-></a>().</p>
<h3 class="fn"><a name="operator-2b"></a>const_iterator const_iterator::operator+ ( int <i>j</i> ) const</h3>
<p>Returns an iterator to the item at <i>j</i> positions forward from this iterator. (If <i>j</i> is negative, the iterator goes backward.)</p>
<p>This operation can be slow for large <i>j</i> values.</p>
<p>See also <a href="qset-const-iterator.html#operator-">operator-</a>().</p>
<h3 class="fn"><a name="operator-2b-2b"></a>const_iterator & const_iterator::operator++ ()</h3>
<p>The prefix ++ operator (<tt>++it</tt>) advances the iterator to the next item in the set and returns an iterator to the new current item.</p>
<p>Calling this function on <a href="qset.html#constEnd">QSet::constEnd</a>() leads to undefined results.</p>
<p>See also <a href="qset-const-iterator.html#operator--">operator--</a>().</p>
<h3 class="fn"><a name="operator-2b-2b-2"></a>const_iterator const_iterator::operator++ ( int )</h3>
<p>This is an overloaded member function, provided for convenience.</p>
<p>The postfix ++ operator (<tt>it++</tt>) advances the iterator to the next item in the set and returns an iterator to the previously current item.</p>
<h3 class="fn"><a name="operator-2b-eq"></a>const_iterator & const_iterator::operator+= ( int <i>j</i> )</h3>
<p>Advances the iterator by <i>j</i> items. (If <i>j</i> is negative, the iterator goes backward.)</p>
<p>This operation can be slow for large <i>j</i> values.</p>
<p>See also <a href="qset-const-iterator.html#operator--eq">operator-=</a>() and <a href="qset-const-iterator.html#operator-2b">operator+</a>().</p>
<h3 class="fn"><a name="operator-"></a>const_iterator const_iterator::operator- ( int <i>j</i> ) const</h3>
<p>Returns an iterator to the item at <i>j</i> positions backward from this iterator. (If <i>j</i> is negative, the iterator goes forward.)</p>
<p>This operation can be slow for large <i>j</i> values.</p>
<p>See also <a href="qset-const-iterator.html#operator-2b">operator+</a>().</p>
<h3 class="fn"><a name="operator--"></a>const_iterator & const_iterator::operator-- ()</h3>
<p>The prefix -- operator (<tt>--it</tt>) makes the preceding item current and returns an iterator to the new current item.</p>
<p>Calling this function on <a href="qset.html#begin">QSet::begin</a>() leads to undefined results.</p>
<p>See also <a href="qset-const-iterator.html#operator-2b-2b">operator++</a>().</p>
<h3 class="fn"><a name="operator---2"></a>const_iterator const_iterator::operator-- ( int )</h3>
<p>This is an overloaded member function, provided for convenience.</p>
<p>The postfix -- operator (<tt>it--</tt>) makes the preceding item current and returns an iterator to the previously current item.</p>
<h3 class="fn"><a name="operator--eq"></a>const_iterator & const_iterator::operator-= ( int <i>j</i> )</h3>
<p>Makes the iterator go back by <i>j</i> items. (If <i>j</i> is negative, the iterator goes forward.)</p>
<p>This operation can be slow for large <i>j</i> values.</p>
<p>See also <a href="qset-const-iterator.html#operator-2b-eq">operator+=</a>() and <a href="qset-const-iterator.html#operator-">operator-</a>().</p>
<h3 class="fn"><a name="operator--gt"></a>const T * const_iterator::operator-> () const</h3>
<p>Returns a pointer to the current item.</p>
<p>See also <a href="qset-const-iterator.html#operator-2a">operator*</a>().</p>
<h3 class="fn"><a name="operator-eq"></a>const_iterator & const_iterator::operator= ( const const_iterator & <i>other</i> )</h3>
<p>Assigns <i>other</i> to this iterator.</p>
<h3 class="fn"><a name="operator-eq-eq"></a>bool const_iterator::operator== ( const const_iterator & <i>other</i> ) const</h3>
<p>Returns true if <i>other</i> points to the same item as this iterator; otherwise returns false.</p>
<p>See also <a href="qset-const-iterator.html#operator-not-eq">operator!=</a>().</p>
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