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Breadcrumbs go here --> <li><a href="modules.html">Modules</a></li> <li><a href="qtcore.html">QtCore</a></li> <li>const_iterator</li> </ul> </div> <div class="toolbuttons toolblock"> <ul> <li id="smallA" class="t_button">A</li> <li id="medA" class="t_button active">A</li> <li id="bigA" class="t_button">A</li> <li id="print" class="t_button"><a href="javascript:this.print();"> <span>Print</span></a></li> </ul> </div> </div> <div class="content mainContent"> <div class="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#public-types">Public Types</a></li> <li class="level1"><a href="#public-functions">Public Functions</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <h1 class="title">const_iterator Class Reference</h1> <span class="small-subtitle">(QFuture::const_iterator)<br/></span> <!-- $$$const_iterator-brief --> <p>The QFuture::const_iterator class provides an STL-style const iterator for <a href="qfuture.html">QFuture</a>. <a href="#details">More...</a></p> <!-- @@@const_iterator --> <pre class="cpp"> <span class="preprocessor">#include <<a href="qfuture.html">QFuture</a>></span></pre><p><b>Note:</b> All functions in this class are <a href="threads-reentrancy.html#reentrant">reentrant</a>.</p> <p>This class was introduced in Qt 4.4.</p> <ul> <li><a href="qfuture-const-iterator-members.html">List of all members, including inherited members</a></li> </ul> <a name="public-types"></a> <h2>Public Types</h2> <table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> typedef </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#difference_type-typedef">difference_type</a></b></td></tr> <tr><td class="memItemLeft rightAlign topAlign"> typedef </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#iterator_category-typedef">iterator_category</a></b></td></tr> <tr><td class="memItemLeft rightAlign topAlign"> typedef </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#pointer-typedef">pointer</a></b></td></tr> <tr><td class="memItemLeft rightAlign topAlign"> typedef </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#reference-typedef">reference</a></b></td></tr> <tr><td class="memItemLeft rightAlign topAlign"> typedef </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#value_type-typedef">value_type</a></b></td></tr> </table> <a name="public-functions"></a> <h2>Public Functions</h2> <table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#const_iterator">const_iterator</a></b> ()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#const_iterator-3">const_iterator</a></b> ( const const_iterator & <i>other</i> )</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator-not-eq">operator!=</a></b> ( const const_iterator & <i>other</i> ) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> const T & </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator-2a">operator*</a></b> () const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> const_iterator </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator-2b">operator+</a></b> ( int <i>j</i> ) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> const_iterator & </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator-2b-2b">operator++</a></b> ()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> const_iterator </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator-2b-2b-2">operator++</a></b> ( int )</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> const_iterator & </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator-2b-eq">operator+=</a></b> ( int <i>j</i> )</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> const_iterator </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator-">operator-</a></b> ( int <i>j</i> ) const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> const_iterator & </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator--">operator--</a></b> ()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> const_iterator </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator---2">operator--</a></b> ( int )</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> const_iterator & </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator--eq">operator-=</a></b> ( int <i>j</i> )</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> const T * </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator--gt">operator-></a></b> () const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> const_iterator & </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator-eq">operator=</a></b> ( const const_iterator & <i>other</i> )</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qfuture-const-iterator.html#operator-eq-eq">operator==</a></b> ( const const_iterator & <i>other</i> ) const</td></tr> </table> <a name="details"></a> <!-- $$$const_iterator-description --> <div class="descr"> <h2>Detailed Description</h2> <p>The QFuture::const_iterator class provides an STL-style const iterator for <a href="qfuture.html">QFuture</a>.</p> <p><a href="qfuture.html">QFuture</a> provides 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>The default QFuture::const_iterator constructor creates an uninitialized iterator. You must initialize it using a <a href="qfuture.html">QFuture</a> function like <a href="qfuture.html#constBegin">QFuture::constBegin</a>() or <a href="qfuture.html#constEnd">QFuture::constEnd</a>() before you start iterating. Here's a typical loop that prints all the results available in a future:</p> <pre class="cpp"> <span class="type"><a href="qfuture.html">QFuture</a></span><span class="operator"><</span><span class="type"><a href="qstring.html">QString</a></span><span class="operator">></span> future <span class="operator">=</span> <span class="operator">.</span><span class="operator">.</span><span class="operator">.</span>; <span class="type"><a href="qfuture.html">QFuture</a></span><span class="operator"><</span><span class="type"><a href="qstring.html">QString</a></span><span class="operator">></span><span class="operator">::</span>const_iterator i; <span class="keyword">for</span> (i <span class="operator">=</span> future<span class="operator">.</span>constBegin(); i <span class="operator">!</span><span class="operator">=</span> future<span class="operator">.</span>constEnd(); <span class="operator">+</span><span class="operator">+</span>i) cout <span class="operator"><</span><span class="operator"><</span> <span class="operator">*</span>i <span class="operator"><</span><span class="operator"><</span> endl;</pre> </div> <p><b>See also </b><a href="qfutureiterator.html">QFutureIterator</a> and <a href="qfuture.html">QFuture</a>.</p> <!-- @@@const_iterator --> <div class="types"> <h2>Member Type Documentation</h2> <!-- $$$difference_type --> <h3 class="fn"><a name="difference_type-typedef"></a>typedef const_iterator::<span class="name">difference_type</span></h3> <p>Typedef for ptrdiff_t. Provided for STL compatibility.</p> <!-- @@@difference_type --> <!-- $$$iterator_category --> <h3 class="fn"><a name="iterator_category-typedef"></a>typedef const_iterator::<span class="name">iterator_category</span></h3> <p>Typedef for std::bidirectional_iterator_tag. Provided for STL compatibility.</p> <!-- @@@iterator_category --> <!-- $$$pointer --> <h3 class="fn"><a name="pointer-typedef"></a>typedef const_iterator::<span class="name">pointer</span></h3> <p>Typedef for const T *. Provided for STL compatibility.</p> <!-- @@@pointer --> <!-- $$$reference --> <h3 class="fn"><a name="reference-typedef"></a>typedef const_iterator::<span class="name">reference</span></h3> <p>Typedef for const T &. Provided for STL compatibility.</p> <!-- @@@reference --> <!-- $$$value_type --> <h3 class="fn"><a name="value_type-typedef"></a>typedef const_iterator::<span class="name">value_type</span></h3> <p>Typedef for T. Provided for STL compatibility.</p> <!-- @@@value_type --> </div> <div class="func"> <h2>Member Function Documentation</h2> <!-- $$$const_iterator[overload1]$$$const_iterator --> <h3 class="fn"><a name="const_iterator"></a>const_iterator::<span class="name">const_iterator</span> ()</h3> <p>Constructs an uninitialized iterator.</p> <p>Functions like operator*() and operator++() should not be called on an uninitialized iterartor. Use operator=() to assign a value to it before using it.</p> <p><b>See also </b><a href="qfuture.html#constBegin">QFuture::constBegin</a>() and <a href="qfuture.html#constEnd">QFuture::constEnd</a>().</p> <!-- @@@const_iterator --> <!-- $$$const_iterator$$$const_iteratorconstconst_iterator& --> <h3 class="fn"><a name="const_iterator-3"></a>const_iterator::<span class="name">const_iterator</span> ( const <span class="type">const_iterator</span> & <i>other</i> )</h3> <p>Constructs a copy of <i>other</i>.</p> <!-- @@@const_iterator --> <!-- $$$operator!=[overload1]$$$operator!=constconst_iterator& --> <h3 class="fn"><a name="operator-not-eq"></a><span class="type">bool</span> const_iterator::<span class="name">operator!=</span> ( const <span class="type">const_iterator</span> & <i>other</i> ) const</h3> <p>Returns true if <i>other</i> points to a different result than this iterator; otherwise returns false.</p> <p><b>See also </b><a href="qfuture-const-iterator.html#operator-eq-eq">operator==</a>().</p> <!-- @@@operator!= --> <!-- $$$operator*[overload1]$$$operator* --> <h3 class="fn"><a name="operator-2a"></a>const <span class="type">T</span> & const_iterator::<span class="name">operator*</span> () const</h3> <p>Returns the current result.</p> <!-- @@@operator* --> <!-- $$$operator+[overload1]$$$operator+int --> <h3 class="fn"><a name="operator-2b"></a><span class="type">const_iterator</span> const_iterator::<span class="name">operator+</span> ( <span class="type">int</span> <i>j</i> ) const</h3> <p>Returns an iterator to the results at <i>j</i> positions forward from this iterator. (If <i>j</i> is negative, the iterator goes backward.)</p> <p><b>See also </b><a href="qfuture-const-iterator.html#operator-">operator-</a>() and <a href="qfuture-const-iterator.html#operator-2b-eq">operator+=</a>().</p> <!-- @@@operator+ --> <!-- $$$operator++[overload1]$$$operator++ --> <h3 class="fn"><a name="operator-2b-2b"></a><span class="type">const_iterator</span> & const_iterator::<span class="name">operator++</span> ()</h3> <p>The prefix ++ operator (<tt>++it</tt>) advances the iterator to the next result in the future and returns an iterator to the new current result.</p> <p>Calling this function on <a href="qfuture.html#constEnd">QFuture::constEnd</a>() leads to undefined results.</p> <p><b>See also </b><a href="qfuture-const-iterator.html#operator--">operator--</a>().</p> <!-- @@@operator++ --> <!-- $$$operator++$$$operator++int --> <h3 class="fn"><a name="operator-2b-2b-2"></a><span class="type">const_iterator</span> const_iterator::<span class="name">operator++</span> ( <span class="type">int</span> )</h3> <p>This is an overloaded function.</p> <p>The postfix ++ operator (<tt>it++</tt>) advances the iterator to the next result in the future and returns an iterator to the previously current result.</p> <!-- @@@operator++ --> <!-- $$$operator+=[overload1]$$$operator+=int --> <h3 class="fn"><a name="operator-2b-eq"></a><span class="type">const_iterator</span> & const_iterator::<span class="name">operator+=</span> ( <span class="type">int</span> <i>j</i> )</h3> <p>Advances the iterator by <i>j</i> results. (If <i>j</i> is negative, the iterator goes backward.)</p> <p><b>See also </b><a href="qfuture-const-iterator.html#operator--eq">operator-=</a>() and <a href="qfuture-const-iterator.html#operator-2b">operator+</a>().</p> <!-- @@@operator+= --> <!-- $$$operator-[overload1]$$$operator-int --> <h3 class="fn"><a name="operator-"></a><span class="type">const_iterator</span> const_iterator::<span class="name">operator-</span> ( <span class="type">int</span> <i>j</i> ) const</h3> <p>Returns an iterator to the result at <i>j</i> positions backward from this iterator. (If <i>j</i> is negative, the iterator goes forward.)</p> <p><b>See also </b><a href="qfuture-const-iterator.html#operator-2b">operator+</a>() and <a href="qfuture-const-iterator.html#operator--eq">operator-=</a>().</p> <!-- @@@operator- --> <!-- $$$operator--[overload1]$$$operator-- --> <h3 class="fn"><a name="operator--"></a><span class="type">const_iterator</span> & const_iterator::<span class="name">operator--</span> ()</h3> <p>The prefix -- operator (<tt>--it</tt>) makes the preceding result current and returns an iterator to the new current result.</p> <p>Calling this function on <a href="qfuture.html#constBegin">QFuture::constBegin</a>() leads to undefined results.</p> <p><b>See also </b><a href="qfuture-const-iterator.html#operator-2b-2b">operator++</a>().</p> <!-- @@@operator-- --> <!-- $$$operator--$$$operator--int --> <h3 class="fn"><a name="operator---2"></a><span class="type">const_iterator</span> const_iterator::<span class="name">operator--</span> ( <span class="type">int</span> )</h3> <p>This is an overloaded function.</p> <p>The postfix -- operator (<tt>it--</tt>) makes the preceding result current and returns an iterator to the previously current result.</p> <!-- @@@operator-- --> <!-- $$$operator-=[overload1]$$$operator-=int --> <h3 class="fn"><a name="operator--eq"></a><span class="type">const_iterator</span> & const_iterator::<span class="name">operator-=</span> ( <span class="type">int</span> <i>j</i> )</h3> <p>Makes the iterator go back by <i>j</i> results. (If <i>j</i> is negative, the iterator goes forward.)</p> <p><b>See also </b><a href="qfuture-const-iterator.html#operator-2b-eq">operator+=</a>() and <a href="qfuture-const-iterator.html#operator-">operator-</a>().</p> <!-- @@@operator-= --> <!-- $$$operator->[overload1]$$$operator-> --> <h3 class="fn"><a name="operator--gt"></a>const <span class="type">T</span> * const_iterator::<span class="name">operator-></span> () const</h3> <p>Returns a pointer to the current result.</p> <!-- @@@operator-> --> <!-- $$$operator=[overload1]$$$operator=constconst_iterator& --> <h3 class="fn"><a name="operator-eq"></a><span class="type">const_iterator</span> & const_iterator::<span class="name">operator=</span> ( const <span class="type">const_iterator</span> & <i>other</i> )</h3> <p>Assigns <i>other</i> to this iterator.</p> <!-- @@@operator= --> <!-- $$$operator==[overload1]$$$operator==constconst_iterator& --> <h3 class="fn"><a name="operator-eq-eq"></a><span class="type">bool</span> const_iterator::<span class="name">operator==</span> ( const <span class="type">const_iterator</span> & <i>other</i> ) const</h3> <p>Returns true if <i>other</i> points to the same result as this iterator; otherwise returns false.</p> <p><b>See also </b><a href="qfuture-const-iterator.html#operator-not-eq">operator!=</a>().</p> <!-- @@@operator== --> </div> </div> </div> </div> <div class="ft"> <span></span> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2015 The Qt Company Ltd. 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