[racket] equal? with classes and contracts

I think something like this has come up before but I can't find the
thread. Given:

(define A%
  (class object% (inspect #f) (super-new)))
(define/contract B%
  (class/c )
  (class object% (inspect #f) (super-new)))

How can I get around the problem that:
    (equal? (new A%) (new A%))
but
    (not (equal? (new B%) (new B%)))

I want to be able to compare objects of the same contracted class for
structural equality.



And another question: is there something similar to struct-copy for
objects? Or a way to easily clone them?



--- nadeem