smob design

[Dan Eble]

The Smob code is sending me mixed messages.  On one hand, it looks like 
multiple levels of derivation will not work, e.g. creating a subclass of Book, 
because
Book::Book() would call smobify_self() before the subclass constructor runs
scm_gc_register_collectable_memory() would sizeof(Book) rather than 
sizeof(derived class)
etc.?

On the other hand, Book uses the macro VIRTUAL_COPY_CONSTRUCTOR to define a 
virtual clone() method, as if derivation were intended.

Am I confused because the code is confusing, or for no particular reason?  If 
the code could be cleaned up, which direction should it move in?

Thanks,
— 
Dan