> From: Philipp Stephani <p.stephani2@gmail.com>
> Date: Sat, 20 Aug 2016 15:59:54 +0000
> Cc: emacs-devel@gnu.org
>
>  If we want to give advice like that, IMO we should also give such an
>  advice for when BUFFER is non-nil.
>
> OK, then I'd append ", and to count the number of characters
> in some other BUFFER, use
> `(with-current-buffer BUFFER (- (point-max) (point-min)))'.".

Fine with me, thanks.