(when (use-dispatch-dfun-p generic-function)
(return-from make-checking-dfun (make-dispatch-dfun generic-function))))
(multiple-value-bind (nreq applyp metatypes nkeys)
(when (use-dispatch-dfun-p generic-function)
(return-from make-checking-dfun (make-dispatch-dfun generic-function))))
(multiple-value-bind (nreq applyp metatypes nkeys)