(error "You can't change the class of ~S to ~S~@
because it isn't already an instance with metaclass ~S."
instance new-class 'standard-class))
(defmethod change-class ((instance funcallable-standard-object)
(error "You can't change the class of ~S to ~S~@
because it isn't already an instance with metaclass ~S."
instance new-class 'standard-class))
(defmethod change-class ((instance funcallable-standard-object)