-(defmethod (setf slot-value-using-class) (value (class virtual-slots-class)
- (object virtual-slots-object)
- (slotd effective-virtual-slot-definition))
- (unless (slot-boundp slotd 'setter)
- (setf (slot-value slotd 'setter) (compute-slot-writer-function slotd)))
- (funcall (slot-value slotd 'setter) value object))
-