gtk:tool-item-group-child-position (container child)

container -- a gtk:tool-item-group widget
child -- a gtk:widget child object
position -- an integer for the position of the item within the group

The accessor for the position child property gets or sets the position of item in the list of children of container starting with 0. Returns -1 if item is no child of container. Setting the position -1 means the end of the list of children.