Comment or uncomment region or current line

comment-or-uncomment-region-or-line.el

(defun tkareine/active-region-or-line ()
  (if mark-active (list (region-beginning) (region-end))
    (list (line-beginning-position)
          (line-beginning-position 2))))

(defun tkareine/comment-or-uncomment-region-or-line ()
  (interactive)
  (let ((region (tkareine/active-region-or-line)))
    (when region
      (let ((rbegin (car region))
            (rend (cadr region)))
        (comment-or-uncomment-region rbegin rend)))))

(global-set-key (kbd "C-c c") 'tkareine/comment-or-uncomment-region-or-line)