Gtk::Builder get_object

[Jonas Platte <jonasplatte myopera com>]

Hello,
I have one obvious question: How to use Gtk::Builder::get_object()? I've
got a simple glade file, with some scales that use Gtk::Adjustment's,
and I simply want to use these. But I can't use

    Gtk::Adjustment* pAdj = builder->get_object("adjustment1");

or something like that. The compiler always says it can't convert from
Glib::Object to Gtk::Adjustment. The only thing that I could compile
looked like this

    Glib::RefPtr<Gtk::Adjustment> pAdj;
    pAdj.cast_dynamic(builder->get_object("adjustment1"));

or similar. But that didn't get me a valid Adjustment. How am I supposed
to use get_object?