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<h1 align="center">Qt Object Model<br /><small></small></h1>
<p>The standard C++ object model provides very efficient runtime support for the object paradigm. But its static nature is inflexibile in certain problem domains. Graphical user interface programming is a domain that requires both runtime efficiency and a high level of flexibility. Qt provides this, by combining the speed of C++ with the flexibility of the Qt Object Model.</p>
<p>Qt adds these features to C++:</p>
<ul>
<li>a very powerful mechanism for seamless object communication called <a href="qtjambi-signalsandslots.html">signals and slots</tt></a></li>
<li>queryable and designable <a href="properties.html">object properties</tt></a></li>
<li>powerful <a href="eventsandfilters.html">events and event filters</tt></a></li>
<li>contextual string translation for internationalization</tt></li>
<li>sophisticated interval driven <a href="timers.html">timers</tt></a> that make it possible to elegantly integrate many tasks in an event-driven GUI</li>
<li>hierarchical and queryable <a href="objecttrees.html">object trees</tt></a> that organize object ownership in a natural way</li>
<li>guarded pointers (QPointer) that are automatically set to 0 when the referenced object is destroyed, unlike normal C++ pointers which become dangling pointers when their objects are destroyed</li>
<li>a <a href="metaobjects.html#qobjectcast">dynamic cast</tt></a> that works across library boundaries.</li>
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<p>Many of these Qt features are implemented with standard C++ techniques, based on inheritance from <a href="core/QObject.html"><tt>QObject</tt></a>. Others, like the object communication mechanism and the dynamic property system, require the <a href="metaobjects.html">Meta-Object System</tt></a> provided by Qt's own <a href="moc.html#moc">Meta-Object Compiler (moc)</tt></a>.</p>
<p>The meta-object system is a C++ extension that makes the language better suited to true component GUI programming. Although templates can be used to extend C++, the meta-object system provides benefits using standard C++ that cannot be achieved with templates; see <a href="templates.html">Why Doesn't Qt Use Templates for Signals and Slots?</tt></a></p>
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