Proposed improvements to the separate compilation model

[Dicebot]

On Sunday, 3 March 2013 at 11:03:55 UTC, deadalnix wrote:
> On Sunday, 3 March 2013 at 10:47:34 UTC, Dicebot wrote:
>> Regarding CTFE - it is a reason to not use this layout for 
>> generic algorithm libraries and similar stuff, but there is no 
>> point in allowing application module code for CTFE by an 
>> accident.
>
> It is the virtual vs final by default argument. You'll find 
> very good reason to do so, but it has drawback. I'm not sure if 
> one is really better than the other.

How so? virtual vs final is a lot about overriding by accident 
(or not overriding), VMT overhead and similar things that do make 
difference. CTFE is all about either giving access to source for 
evaluation or not. Where is the catch?