FYI my experience with D' version

[Tobias Pankrath]

> The biggest downside is if you add a function, you have to go 
> back
> to ALL the config files and add it in to make the project 
> compile.
>
> enum bool wantsNewFeature = false;
>
> which can be a hassle if you have like 20 config files. But, 
> this
> is good and bad because it does make you think about it at 
> least,
> not just silently doing the wrong thing if you forget.

Couldn't you make a template mixin that inserts default values if 
not yet defined?