On Friday, 9 August 2013 at 17:35:18 UTC, monarch_dodra wrote:
On Friday, 9 August 2013 at 15:28:10 UTC, Manfred Nowak wrote:
michaelc37 wrote:
WTF -> -1 is greater than 7 ????
From the docs:
It is an error to have one operand be signed and the other
unsigned for a
<, <=, > or >= expression.
-manfred
Interesting. I didn't know it was documented as being an
outright error, I thought it was just "surprising"...
I don't think Walter will ever accept to make it illegal
though, breaks too much code. If this was a change he was OK
with, I think we would have had it since day one, or at least,
years ago.
I remember hearing somewhere that D is about enforcing users to
write CORRECT code. I would really be disappointed with the
language if this sort of gotcha weren't eliminated.
If I look at this assert, I shouldn't be expecting it to pass.
static assert(-1 > cast(size_t)7);
IMHO, as long as this sort of comparison causes a compile-time
error, as the docs say they should, this kind of breaking change
is the of very good sort. The sort that reveals bugs in code.
(Like when they changed the NULL macro to mean 'nullptr' instead
of 0 in C++.) I couldn't imagine a programmer exploiting this
intentionally, as it serves no purpose.
Related: std.algorithm.max *is* sign aware, and you can use
code such as:
if (a == max(a, b))
I have an pull request which creates the premise of functional
"less"/"greater" operators, which are also sign aware:
https://github.com/D-Programming-Language/phobos/pull/1365/files
*If* it goes through, and *if* we make them public in
std.functional, then it allows code such as:
int a = -1;
size_t b = 7;
assert(a.less(b)); //Passes
That is pretty cool, but unless the comparison operators actually
use that code, (which they probably won't, since it's not a
library thing?) it will only provide a workaround to the problem.
