Returning variable "references" under lexical binding

[Sean McAfee <eefacm@gmail.com>]

I recently tried writing my first non-toy code that employs lexical
binding.  It's a routine that sets up a series of idle timers, storing
each successive timer object into the same lexical variable.

I want my routine to return an object that can be used to cancel the
most recently set timer.  If I were writing this code in the days prior
to lexical binding, I might have dono something like this:

(defun start-my-timer ()
  (let ((timer (gensym)))
    ;; ... (set timer (make-timer ...)) ...
    timer))

(defun cancel-my-timer (timer)
  (cancel-timer (symbol-value timer)))

The documenentation for lexical variables cautions against treating them
as symbols, specifically stating that functions like symbol-value will
not work.  So I wrote my routine to return a closure:

(defun start-my-timer ()
  (let (timer)
    ;; ... (setq timer (make-timer ...)) ...
    (lambda () timer)))

(defun cancel-my-timer (timer)
  (cancel-timer (funcall timer)))

This works, but is it the "correct" way to do this?