cl-multiple-value-bind is an autoloaded Lisp macro in `cl-macs.el'.

(cl-multiple-value-bind (SYM...) FORM BODY)

Collect multiple return values.
FORM must return a list; the BODY is then executed with the first N elements
of this list bound (`let'-style) to each of the symbols SYM in turn. This
is analogous to the Common Lisp `multiple-value-bind' macro, using lists to
simulate true multiple return values. For compatibility, (cl-values A B C) is
a synonym for (list A B C).