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<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Retyping</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="LibSigC++" /><link rel="up" href="ch04.html" title="Chapter 4. Advanced topics" /><link rel="prev" href="ch04.html" title="Chapter 4. Advanced topics" /><link rel="next" href="ch04s03.html" title="Marshallers" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Retyping</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch04.html">Prev</a> </td><th width="60%" align="center">Chapter 4. Advanced topics</th><td width="20%" align="right"> <a accesskey="n" href="ch04s03.html">Next</a></td></tr></table><hr /></div><div class="sect1" title="Retyping"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="id3047474"></a>Retyping</h2></div></div></div><p>A similar topic is retyping. Perhaps you have a signal that takes an <code class="literal">int</code>, but
you want to connect a function that takes a <code class="literal">double</code>.</p><p>This can be achieved with the <code class="literal">retype</code> template. <code class="literal">retype</code> has template arguments
just like <code class="literal">Signal</code> - return value, signal types.</p><p>It's a function template that takes a <code class="literal">slot</code>, and returns a <code class="literal">slot</code>. eg.</p><pre class="programlisting">
void dostuff(double foo)
{
}
SigC::Signal1<void,int> asignal;
asignal.connect( retype<void,int>( slot(&dostuff) ) );
</pre><p>If you only want to change the return type, you can use <code class="literal">retype_return</code>.
<code class="literal">retype_return</code> needs only one template argument.</p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch04.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch04.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ch04s03.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 4. Advanced topics </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Marshallers</td></tr></table></div></body></html>
