On Monday, 5 February 2018 at 21:21:47 UTC, H. S. Teoh wrote:
On Mon, Feb 05, 2018 at 09:20:16PM +0000, Nick Sabalausky via
Digitalmars-d wrote:
But still, I thought we had value range propagation rules to
avoid this sort of nonsense when possible (such as the example
above)?
VRP doesn't help when the code doesn't have compile-time known
values, such as in the non-reduced code my example snippet was
reduced from.
If you were negating a byte, the code does have compile-time
known values, since there's a limit to what you can stuff into a
byte. If you weren't, the warning is warranted. I will admit the
case of -(-128) could throw it off, though.
--
Simen
