GtkAction - no gtk_action_set_sensitive()?

[Matthew Walton <matthew alledora co uk>]

I've been experimenting with GtkAction via the gtkmm C++ bindings, and 
was quite surprised to find that gtkmm doesn't provide a 
Gtk::Action::set_sensitive() method. Upon investigation I discovered 
that this is because GTK+ doesn't provide gtk_action_set_sensitive().

Without this method, I can't see how the programmer is supposed to set 
the sensitivity of the Action's controls - if I'm understanding the API 
right, setting the Action to be insensitive should disable all the 
buttons and menu items associated with it. Yes, it can be done by the 
property, but given that there's a gtk_action_get_sensitive(), I'm 
surprised to find that there isn't one for setting sensitivity.

Am I barking up entirely the wrong tree here? Obviously gtkmm can 
provide set_sensitive quite easily, but we were wondering if there was a 
particular reason why GTK+ doesn't provide one.

Thanks

Matthew