gtk:radio-button-join-group (button group)

button -- a gtk:radio-button widget
group -- a gtk:radio-button widget whose group we are joining, or nil to remove the radio button from its group

Joins a radio button to the group of another radio button widget. Use this in language bindings instead of the the gtk:radio-button-get-group and gtk:radio-button-set-group functions. A common way to set up a group of radio buttons with a label is the following:

(let (button lastbutton)
  ;; Add three buttons to a group
  (dolist (label '("First Button" "Second Button" "Third Button"))
    (setf button (gtk:radio-button-new-with-label nil label))
    (gtk:radio-button-join-group button lastbutton)
    (setf lastbutton button)))