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<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Dereferencing</title><meta name="generator" content="DocBook XSL Stylesheets V1.64.1"><link rel="home" href="index.html" title="Programming with gtkmm2"><link rel="up" href="apa.html" title="AppendixA.The RefPtr smartpointer"><link rel="previous" href="apa.html" title="AppendixA.The RefPtr smartpointer"><link rel="next" href="apas03.html" title="Casting"></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">Dereferencing</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="apa.html">Prev</a></td><th width="60%" align="center">AppendixA.The RefPtr smartpointer</th><td width="20%" align="right"><a accesskey="n" href="apas03.html">Next</a></td></tr></table><hr></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2520502"></a>Dereferencing</h2></div></div><div></div></div><p>You can dereference a smartpointer with the -> operator, to
call the methods of the underlying instance, just like a normal pointer.
</p><p>
</p><pre class="programlisting">
Glib::RefPtr<Gdk::Bitmap> refBitmap = Gdk::Bitmap::create(window,
data, width, height);
int depth = refBitmap->get_depth();
</pre><p>
</p><p>But unlike most smartpointers, you can't use the * operator to
access the underlying instance.
</p><p>
</p><pre class="programlisting">
Glib::RefPtr<Gdk::Bitmap> refBitmap = Gdk::Bitmap::create(window,
data, width, height);
Gdk::Bitmap* underlying = *refBitmap; //Syntax error - will not compile.
</pre><p>
</p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="apa.html">Prev</a></td><td width="20%" align="center"><a accesskey="u" href="apa.html">Up</a></td><td width="40%" align="right"><a accesskey="n" href="apas03.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">AppendixA.The RefPtr smartpointer</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">Casting</td></tr></table></div></body></html>
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