 in fact abstract.  This will guarentee that
<code style="white-space: normal">BOOST_IS_ABSTRACT</code>
will return the correct value for all compilers.

<h3><a name="typeinfo">Type Information Implementation</a></h3>
This last trait is also related to the serialization of objects
through a base class pointer.  The implementation of this facility
requires the ability to determine at run time the true type of the
object that a base class pointer points to.  Different serialization
systems do this in differen