Window destroy event

[Fabio Rafael da Rosa <fabiorafael rosa gmail com>]

On other bindings (and plain C gtk) we have two signals for handling a
window being destroyed: destroy and delete event. 
As far as I understood, destroy is a GTK specific signal inherited from
GtkWidget, right? The delete_event, on the other hand, is and event from
the Windowing System (x11 event) . 
Is that correct ?
On GTKmm, I could not find a way to connect a callback to the destroy
signal. I have a Gtk::Window::signal_delete_event, but I could not find
a Gtk::Window::signal_destroy . 
How do I connect something to destroy ?

Thanks in advance
Regards
--
Fabio Rafael da Rosa