[gtkmm] Shouldn't Gtk::CellRenderer::_property_renderable() pure virtual?

[Frank Naumann <fnaumann cs uni-magdeburg de>]

Hello!

If I understand it right Gtk::CellRenderer is just a base class and should
not instantiated itself. If this is true it make much more sense if
the _property_renderable method is pure virtual instead of core dumping
the application.


Regards,
Frank Naumann