fill-pointer vector => fill-pointer
(setf ( fill-pointer vector) new-fill-pointer)
vector—a vector with a fill pointer.
fill-pointer, new-fill-pointer—a valid fill pointer for the vector.
Accesses the fill pointer of vector.
(setq a (make-array 8 :fill-pointer 4)) => #(NIL NIL NIL NIL)
(fill-pointer a) => 4
(dotimes (i (length a)) (setf (aref a i) (* i i))) => NIL
a => #(0 1 4 9)
(setf (fill-pointer a) 3) => 3
(fill-pointer a) => 3
a => #(0 1 4)
(setf (fill-pointer a) 8) => 8
a => #(0 1 4 9 NIL NIL NIL NIL)
Should signal an error of type type-error if vector is not a vector with a fill pointer.
There is no operator that will remove a vector's fill pointer.