+;;; ... or default-initargs when the location was already initialized
+(defvar *definitargs-counter* 0)
+(defclass definitargs-class ()
+ ((a :initarg :a :initarg :a2))
+ (:default-initargs :a2 (incf *definitargs-counter*)))
+(assert (= (slot-value (make-instance 'definitargs-class) 'a) 1))
+(assert (= (slot-value (make-instance 'definitargs-class :a 0) 'a) 0))
+(assert (= *definitargs-counter* 2))