fault will be reimplemented
to automatically track classes used as virtual bases).</i> This 
situation is demonstrated by 
<a href="../test/test_diamond.cpp" target="test_diamond_cpp">test_diamond.cpp</a>
included with the library.

<h3><a name="export">Export Key</a></h3>

When serializing a derived class through a virtual base class pointer,
two issues may arise.
<ul>
<li> The code in the derived class might never be explicitly
referred to.  Such code will never be instantiated.
<p>
This is addressed by i