I’ve seen the following code used hundreds of times:

(buffer-local-value 'major-mode buffer)

(with-current-buffer buffer ‘major-mode)

Why don’t we add the following function to Emacs and simplify a bit the lives of Elisp hackers:

(defun buffer-mode (buffer)
  "Return the major mode associated with BUFFER."
  (buffer-local-value ‘major-mode buffer))

Trivial, but useful.

Cheers,

Bozhidar