Creating toolbar menubuttons via UI Manager

[Krzysztof Kosiński <tweenk pl gmail com>]

Hello all

I found a post that describes how to create toolbar menubuttons
(GtkMenuToolButton) on toolbars with GTK's GtkUIManager.
http://www.gtkforums.com/viewtopic.php?t=4215
The solution is rather messy and involves deriving a new GType from
GtkAction and setting the toolbar_item_type member of its
GtkActionClass to a different value.

Now my question is: is this possible at all with gtkmm?

Regards, Krzysztof