Map one tuple to another Tuple of different type

[Vlad Levenfeld via Digitalmars-d-learn]

On Monday, 21 July 2014 at 19:02:59 UTC, H. S. Teoh via 
Digitalmars-d-learn wrote:
> functionality is desirable. Maybe we should rouse a racket on 
> the main D
> forum to either make staticIota public, or implement static 
> foreach. ;-)

static switch would be so sick. I frequently find myself doing 
some compile-time branching with more than 2 branches or with an 
enum (like for policies/strategies/whatever). Compile-time case 
labels would clean that code up, and final switch would be a 
maintenance improvement as well.

static while sounds cool, but how would it work? (as in use case, 
not implementation). The condition would have to be immutable, 
wouldn't it?