How to check if a buffer is empty?

Question

How to check if a buffer is empty? Checking if count-lines gives 0 is over-killing for this I think.

UPDATE: Yeah, phils's answer should work. Write it out:

(defun buffer-empty-p (&optional buffer)
  (= (buffer-size buffer) 0))

Answer 1

buffer-size is a built-in function in `C source code'.

(buffer-size &optional BUFFER)

Return the number of characters in the current buffer.
If BUFFER, return the number of characters in that buffer instead.