anchor.diff:          (type nil)
           (named nil)
           (slot-offsets nil)
  -        (sealed nil))
  +        (sealed nil)
  +        (slot-locations nil))
       (when (not (listp name-and-options))
         (setf name-and-options (list name-and-options)))
       (setf name (first name-and-options))
  
positive.code:         ((and (eql (first option) :sealed)
                (null (rest option)))
           (setf sealed t))
          (t (error "Unsupported DEFSTRUCT option ~S" option))))
      (values name
              (if conc-namep
                  (intern (string (or conc-name
  
negative.code:          (setf area (second option)))
          ;; (:slot-offsets)
          ;; Generate constants of the form +conc-name-slot-name+
          ;; that contain the indices of the slots.
          ((and (eql (first option) :slot-offsets)
                (null (rest option)))
           (setf slot-offsets t))
  