Re: [gtkmm] gtkmm 2.4 questions

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

Hello!

> > > > You would expect get_size() to be const. Therefore the implementation
> > > > should probably be const.
> > >
> > > Following your argumentation render_vfunc must be const too (as it just
> > > display something, it don't change the instance).
> >
> > It kind of changes whether or not its rendered.
>
> If you mean that it renders _into_ one of the method's arguments, then
> yes, it might be a candidate for constness. However, I'm not sure what
> it actually does.

Sure, it renders to the widget and window method arguments.

> > > Or I'm wrong here (and if yes, why?).
> >
> > You don't understand the const or mutable keywords.

Until now I used const for all methods of an object that don't change the 
state or member data of it (e.g. methods that should be working on an 
const instance of that object).

I'm just curious that such complex tasks like get_size_vfunc and 
render_vfunc need to fullfill such requirements even if they are subject 
of object specialization (for a maximum of flexible usage).


Regards,
Frank