<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Casting</title> <link rel="stylesheet" href="style.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.1"> <link rel="home" href="index.html" title="Programming with gtkmm"> <link rel="up" href="chapter-refptr.html" title="Appendix A. The RefPtr smartpointer"> <link rel="prev" href="sec-refptr-dereferencing.html" title="Dereferencing"> <link rel="next" href="sec-refptr-checking-for-null.html" title="Checking for null"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr><th colspan="3" align="center">Casting</th></tr> <tr> <td width="20%" align="left"> <a accesskey="p" href="sec-refptr-dereferencing.html"><img src="icons/prev.png" alt="Prev"></a> </td> <th width="60%" align="center">Appendix A. The RefPtr smartpointer</th> <td width="20%" align="right"> <a accesskey="n" href="sec-refptr-checking-for-null.html"><img src="icons/next.png" alt="Next"></a> </td> </tr> </table> <hr> </div> <div class="sect1" title="Casting"> <div class="titlepage"><div><div><h2 class="title" style="clear: both"> <a name="sec-refptr-casting"></a>Casting</h2></div></div></div> <p> You can cast <code class="classname">RefPtrs</code> to base types, just like normal pointers. </p> <p> </p> <pre class="programlisting"> Glib::RefPtr<Gtk::TreeStore> refStore = Gtk::TreeStore::create(columns); Glib::RefPtr<Gtk::TreeModel> refModel = refStore; </pre> <p> </p> <p>This means that any method which takes a <span class="type">const Glib::RefPtr<BaseType></span> argument can also take a <span class="type">const Glib::RefPtr<DerivedType></span>. The cast is implicit, just as it would be for a normal pointer.</p> <p>You can also cast to a derived type, but the syntax is a little different than with a normal pointer. </p> <p> </p> <pre class="programlisting"> Glib::RefPtr<Gtk::TreeStore> refStore = Glib::RefPtr<Gtk::TreeStore>::cast_dynamic(refModel); Glib::RefPtr<Gtk::TreeStore> refStore2 = Glib::RefPtr<Gtk::TreeStore>::cast_static(refModel); </pre> <p> </p> </div> <div class="navfooter"> <hr> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"> <a accesskey="p" href="sec-refptr-dereferencing.html"><img src="icons/prev.png" alt="Prev"></a> </td> <td width="20%" align="center"><a accesskey="u" href="chapter-refptr.html"><img src="icons/up.png" alt="Up"></a></td> <td width="40%" align="right"> <a accesskey="n" href="sec-refptr-checking-for-null.html"><img src="icons/next.png" alt="Next"></a> </td> </tr> <tr> <td width="40%" align="left" valign="top">Dereferencing </td> <td width="20%" align="center"><a accesskey="h" href="index.html"><img src="icons/home.png" alt="Home"></a></td> <td width="40%" align="right" valign="top"> Checking for null</td> </tr> </table> </div> </body> </html>
