anchor.diff:              new-value (class-of object) object slot-name))))
   
   (defun std-slot-boundp (instance slot-name)
  -  (when (not (symbolp slot-name))
  -    (setf slot-name (slot-definition-name slot-name)))
  -  (let ((location (slot-location (class-of instance) slot-name))
  -        (slots (std-instance-slots instance)))
  -    (not (eq secret-unbound-value (slot-contents slots location)))))
  -(defun fc-std-slot-boundp (instance slot-name)
  -  (when (not (symbolp slot-name))
  -    (setf slot-name (slot-definition-name slot-name)))
  -  (let ((location (slot-location (class-of instance) slot-name))
  -        (slots (funcallable-std-instance-slots instance)))
  +  (multiple-value-bind (slots location)
  +      (slot-location-in-instance instance slot-name)
       (not (eq secret-unbound-value (slot-contents slots location)))))
   (defun slot-boundp (object slot-name)
  -  (cond ((eq (class-of (class-of object)) the-class-standard-class)
  -         (std-slot-boundp object slot-name))
  -        ((eq (class-of (class-of object)) the-class-funcallable-standard-class)
  -         (fc-std-slot-boundp object slot-name))
  -        (t (slot-boundp-using-class (class-of object) object slot-name))))
  +  (let ((metaclass (class-of (class-of object))))
  +    (cond ((or (eq metaclass the-class-standard-class)
  +               (eq metaclass the-class-funcallable-standard-class))
  +           (std-slot-boundp object slot-name))
  +          (t (slot-boundp-using-class (class-of object) object slot-name)))))
   
   (defun std-slot-makunbound (instance slot-name)
  -  (when (not (symbolp slot-name))
  -    (setf slot-name (slot-definition-name slot-name)))
  -  (let ((location (slot-location (class-of instance) slot-name))
  -        (slots (std-instance-slots instance)))
  -    (setf (slot-contents slots location) secret-unbound-value))
  -  instance)
  -(defun fc-std-slot-makunbound (instance slot-name)
  -  (when (not (symbolp slot-name))
  -    (setf slot-name (slot-definition-name slot-name)))
  -  (let ((location (slot-location (class-of instance) slot-name))
  -        (slots (funcallable-std-instance-slots instance)))
  +  (multiple-value-bind (slots location)
  +      (slot-location-in-instance instance slot-name)
       (setf (slot-contents slots location) secret-unbound-value))
     instance)
   (defun slot-makunbound (object slot-name)
  -  (cond ((eq (class-of (class-of object)) the-class-standard-class)
  -         (std-slot-makunbound object slot-name))
  -        ((eq (class-of (class-of object)) the-class-funcallable-standard-class)
  -         (fc-std-slot-makunbound object slot-name))
  -        (t (slot-makunbound-using-class (class-of object) object slot-name))))
  +  (let ((metaclass (class-of (class-of object))))
  +    (cond ((or (eq metaclass the-class-standard-class)
  +               (eq metaclass the-class-funcallable-standard-class))
  +           (std-slot-makunbound object slot-name))
  +          (t (slot-makunbound-using-class (class-of object) object slot-name)))))
   
   (defun std-slot-exists-p (instance slot-name)
     (when (not (symbolp slot-name))
  
positive.code:     (let* ((location (or (fast-sv-position slot-name layout)
                           (error "The slot ~S is missing from the class ~S."
                                  slot-name (class-of instance)))))
        (setf (svref slots location) value))))
  
  (defun (setf slot-value) (new-value object slot-name)
    (cond ((or (eq (class-of (class-of object)) the-class-standard-class)
               (eq (class-of (class-of object)) the-class-funcallable-standard-class))
  
negative.code:   (not (null (find slot-name (class-slots (class-of instance))
                     :key #'slot-definition-name))))
  (defun slot-exists-p (object slot-name)
    (let ((metaclass (class-of (class-of object))))
      (cond ((or (eq metaclass the-class-standard-class)
                 (eq metaclass the-class-funcallable-standard-class))
             (std-slot-exists-p object slot-name))
            (t (slot-exists-p-using-class (class-of object) object slot-name)))))
  
  ;;; class-of
  
  