Issue 7982 [1] is caused by iota.length() [2] not working
properly with unsigned values where the begin is greater than the
end (the larger value is subtracted from the smaller value
causing it to wrap around).
I asked Andrei in IRC if replacing:
return unsigned((pastLast - current) / step);
with:
return unsigned(((cast(Signed!Value)pastLast) -
(cast(Signed!Value)current)) / step);
was a sane approach. Although it does seem to fix the problem
(though I haven't tested thoroughly) Andrei said it wasn't sane.
I'm not sure what would be a better approach so I'm asking for
ideas here.
(why does std.traits have unsigned() to take advantage of IFTI
but no signed() equivalent?)
[1] http://d.puremagic.com/issues/show_bug.cgi?id=7982
[2]
https://github.com/D-Programming-Language/phobos/blob/master/std/range.d#L4383
Regards,
Brad Anderson
