(values element-type
(when (eq *wild-type* element-type)
(apply #'type-union element-supertypes)))))
+ (member-type
+ ;; Convert member-type to an union-type.
+ (array-type-upgraded-element-type
+ (apply #'type-union (mapcar #'ctype-of (member-type-members type)))))
(t
;; KLUDGE: there is no good answer here, but at least
;; *wild-type* won't cause HAIRY-DATA-VECTOR-{REF,SET} to be