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Chap 3 question: Class of allocated instances.
I'm wondering why one can't count on the following being true:
(eq (find-class 'foo) (class-of (allocate-instance 'foo)))
Presumably, if a programmer defined a method on 'allocate-instance'
he could have it return any old sort of widget (rather than a "foo").
Is this useful? Is it still useful if the constraint is added that
(subtype (class-of (allocate-instance 'foo)) 'foo)
Without some such constraint, it might be possible for
(typep (allocate-instance 'foo) 'foo)
to be false. It was similar such problems that led to the
"cleanup" proposal ARRAY-TYPE-ELEMENT-TYPE-SEMANTICS -- that often
one could have the following turn out false:
(typep (make-array <n> :element-type '(array <some-type>))
-- JonL --