First life-signs of type functions

[Stefan Koch]

On Tuesday, 12 May 2020 at 16:12:42 UTC, Steven Schveighoffer 
wrote:

> to force a type function instead of using CTFE when you want to 
> manipulate a compile-time list of strings.
>
> It reminds me of what people would resort to for a static 
> foreach over a tuple when all they wanted was the index (before 
> static foreach existed).
>
> -Steve

There is no essentially no difference between a type function and 
CTFE.
Type functions are really just passing type as expressions to 
CTFE.
Well that and the ability to assign to alias.
Having a dummy alias parameter just means ctfeOnly.