car-safe

Object -> Object

リストでなくてもエラーにならないcar

code: data.c

DEFUN ("car-safe", Fcar_safe, Scar_safe, 1, 1, 0,

doc: /* Return the car of OBJECT if it is a cons cell, or else nil. */)

(Lisp_Object object)

{

return CAR_SAFE (object);

}

code: example.el

(car-safe 1)

;; => nil