gtk:center-box-start-widget (object)

object -- a gtk:center-box widget
child -- a gtk:widget start widget

Accessor of the start-widget slot of the gtk:center-box class. The gtk:center-box-start-widget function gets the start widget, or nil if there is none. The (setf gtk:center-box-start-widget) function sets the start widget. To remove the existing start widget, pass nil.