variable x cannot be read at compile time (ctfe)

[bearophile]

maarten van damme:

> I always get "variable x cannot be read at compile time" in 
> this method :
>
> auto bitsetToRange(in SudokuCell x) {
>     return boardSide.iota().filter!(i => (x >> i) & 
> 1)().map!(x=>x+1)();
> }
>
> with SudokuCell beeing declared as:
> alias ushort SudokuCell;

Why don't you show us a little complete compilable program that 
contains your problem?

Bye,
bearophile