(unless (some (lambda (method)
(let* ((specs (method-specializers method))
(message-spec (car specs))
(unless (some (lambda (method)
(let* ((specs (method-specializers method))
(message-spec (car specs))
(unless (c-type-equal-p (c-type-subtype ,type)
,want-type)
(error "Messages with `~(~A~)' combination ~
(unless (c-type-equal-p (c-type-subtype ,type)
,want-type)
(error "Messages with `~(~A~)' combination ~