How to forward accesses from model attributes to other class attributes

[Markus Elfring <Markus Elfring web de>]

Hello!

I have got the impression that model attributes like a "Gtk::TreeModelColumn" 
store their information completely themselves so far.
http://developer.gnome.org/gtkmm/3.2/classGtk_1_1TreeModelColumn.html

Some models contain also additional class attributes (with reusable details) 
that do not provide a model column interface. Now I am looking for an adapter 
which supports efficient data exchange.
(I hope that unneeded data copying can be avoided with a direct connection from 
the data source to the target column by an appropriate model adapter.)

Can read/write accesses be forwarded from a model column to a different attribute?
http://en.wikipedia.org/wiki/Adapter_pattern

How do you think about opportunities for improvements in the gtkmm template 
class library?

Regards,
Markus