Re: variable x cannot be read at compile time (ctfe)

[monarch_dodra]

On Monday, 17 December 2012 at 09:42:50 UTC, maarten van damme 
wrote:
I finally got around trying to finish my sudoksolver and I'm 
pretty
happy with the result, except one little piece that screams for 
ctfe
but I never seem to get it working.
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;

I want to generate a dynamic array with all return values form 
this
method with x ranging from 0..sudokuCell.size.
Why is it complaining x cannot be read at compile time while it 
is
passed at compile time?

Probably because you declared "boardside" as an "auto"? You need 
to declare it as immutable or enum. Can't add much to it without 
some context.

FYI: As much as I love ufcs, "boardSide.iota()" makes no sense to 
me. It took me a minute to realize what was going on. I'd really 
write it as:
return iota(boardSide).filter!(i => (x >> i) & 
1)().map!(x=>x+1)();