On Thursday, 20 February 2014 at 20:52:23 UTC, Xinok wrote:
The following statement prints false:
writeln(-1 < uint.max);
This came up in another topic recently. I think this is silly
and
an unnecessary source of bugs (it's bitten me before and
presumably many others as well). I'm making a proposal to add an
extra check so that comparisons of signed with unsigned types is
always correct. Simply, if the signed type is negative, it is by
default less than the unsigned value. The compiler has all the
information it needs at compile time to add this check where
necessary. I demonstrate the problem and solution here:
http://dpaste.dzfl.pl/acd819d1a9ea
Others have suggested disallowing comparing a signed type with
an
unsigned type. I think this is a better solution. Yes, it will
add a small bit of overhead, but I believe it's more important
for code to be correct than to be fast.
Any takers?
This will silently change the semantics of any C code compiled
with DMD (even if those semantics were extremely bug prone in the
first place). Is this a good or bad thing? I can't think of any C
code that would rely on such behaviour, but I think it'd just be
safer all-around to make it an error.
