Re: [gtkmm] gtkmm 2.4 questions

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

Hello!

> From the user's perspective, if a method may be reasonably called upon a 
> constant object, it should be declared const. Whether it actually changes the 
> internal state is irrelevant; if it appears that it does not, then const it 
> should be. That's what mutable is for, as has been mentioned.

Then I don't see the difference against making all objects and 
methods constant and declare all member data mutable.

But to be honest, I never really understand for what mutable was 
introduced. I read the chapter about mutable in Stroustroup several times 
with getting the point.

> It's not good style, but had your code been written for gtkmm 2.4 to start 
> with, you would no doubt have developed a more elegant solution.

Maybe. But for dynamically calulated content I don't see a solution yet. 
Maybe there is a better solution for my problem now (I render directly 
from an internal and rather complex data structure the treeview; it's the 
wanted behaviour to recalculate the content every time a redraw is done; 
this was elegant to implement with a own specialized CellRenderer).

> I'm with Murray on it being right to have get_size_vfunc be const though.

Then my question, why is get_size_vfunc const? What's the difference 
compared to render_vfunc for example?


Regards,
Frank