Plaster

(defun foo (new-value cons) (declare (inline rplaca cadr)) (check-type cons (cons t (cons cons))) (rplaca (cadr cons) new-value) new-value) ; in: DEFUN FOO ; (RPLACA (CONSTRICTOR:CADR CONS) CONSTRICTOR::NEW-VALUE) ; ; caught WARNING: ; Derived type of #:N-X5 is ; (VALUES NULL &OPTIONAL), ; conflicting with its asserted type ; CONS. ; See also: ; The SBCL Manual, Node "Handling of Types" ;