using the full range of ubyte with iota

[Tobias Pankrath via Digitalmars-d-learn]

On Sunday, 25 January 2015 at 12:25:35 UTC, Dominikus Dittes 
Scherkl wrote:
>
> map!(x => fn(cast(ParameterTypeTuple!fn[0])x)
>
> but instead with
>
> map!(paramCast!fn)
>
> Because this is useful in more situations, e.g. in every place 
> where you know the values would fit into the parameter (and for 
> a single call would use a cast).
>
> But so far I couldn't manage to make this work :-/

http://dpaste.dzfl.pl/07b1fa3c2dad