🚀 go-pugleaf

In article <445k3k$18p@isoit109.bbn.hp.com> Jean-Rene Bouvier <jr@isoit109.bbn.hp.com> writes:

> 2. what is the reason for this restriction, or rather, is there any reason to
>    keep this restriction (apart from the fact that a DerviedObject*& bears no
>    inheritance relationship to an Object*&) ?

The real problem is that a DerivedObject* might not have the same
internal representation (i.e. bit pattern) as an Object*, because
there is no reason to believe that the Object part of a DerivedObject
is at the beginning of the DerivedObject.  In the presence of multiple
inheritance, we can guarantee that a DerivedObject* will have a
different representation from a pointer to at least one of its
base classes.
-- 
				--Andrew Koenig
				  ark@research.att.com


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