setf

setf is an autoloaded Lisp macro in `gv.el'.

(setf PLACE VAL PLACE VAL ...)

Set each PLACE to the value of its VAL.
This is a generalized version of `setq'; the PLACEs may be symbolic
references such as (car x) or (aref x i), as well as plain symbols.
For example, (setf (cadr x) y) is equivalent to (setcar (cdr x) y).
The return value is the last VAL in the list.