Re: virtual inheritance and Glib::Interface

[Murray Cumming <murrayc murrayc com>]

On Wed, 2006-04-05 at 13:14 -0500, Jonathon Jongsma wrote:
> I was looking at Gtk::ListStore and noticed that it used multiple
> inheritance.  Specifically:
> class ListStore :
>   public Glib::Object,
>   public TreeModel,
>   public TreeSortable,
>   public TreeDragSource,
>   public TreeDragDest
> 
> TreeModel, TreeSortable, TreeDragSource, and TreeDragDest all inherit
> from Glib::Interface.  I noticed that Glib::Interface inherits
> virtually from Glib::ObjectBase (as does Glib::Object), but TreeModel,
> TreeSortable, TreeDragSource, and TreeDragDest don't inherit virtually
> from Glib::Interface.  It seems that we're probably creating multiple
> Glib::Interface objects whenever we create a Gtk::ListStore (and by
> extension Gtk::TreeStore).  There may very well be more cases where
> this is true, but I haven't looked any farther yet.  Is there any
> reason why we wouldn't want want to inherit virtually from
> Glib::Interface in these cases?

I don't think that's true, and it's not what the doxygen diagrams show,
though they could be wrong. You could confirm it by putting some
std::cout in the constructors.

-- 
Murray Cumming
murrayc murrayc com
www.murrayc.com
www.openismus.com