tt>) describes how callback classes
can swap ownership relationship with their Python wrappers.</li>
<li><a class="reference" href="http://aspn.activestate.com/ASPN/Mail/Message/c++-sig/1860301">http://aspn.activestate.com/ASPN/Mail/Message/c++-sig/1860301</a>
describes how this can also be used to considerably simplify
callback classes, solve some &quot;dangling reference&quot; problems, and
optimize the calling of non-overridden virtual functions.</li>
</ul>
</div>
</div>
<div class="section">
<h1><a clas