On Thursday, 23 January 2014 at 20:35:56 UTC, Andrei Alexandrescu
wrote:
byte a = -128;
auto b = -a;
What type should b get? (of course "byte" but the value
doesn't fit!)
The type will be int.
Ah, ok. Of course the small types always become int.
But the problem would be the same with
long a = long.min;
auto b = -a;
does this return ulong (which could hold the correct result) or
long (and a wrong result)?
integral types still suffer the same old flaws.
There are quite a few improvements for integrals, too, most
importantly of the kind that don't exact a speed penalty.
I can understand that speed is critical for unsigned types but
for me the main benefit of signed types is their "ease of use" -
like in the "hello world" program it should be easy to do it
right and work "out of the box". Errors like
int a = 2_000_000_000;
int b = a + a;
should not generate weird stuff like -294_967_296 (which it
actually does) but better produce NaN to indicate that the result
is not in the valid range or "int".
For addition that may be not to complicated to handle, but for
multiplication? There it would be very nice (and fast!!) to have
an implenetation that checks the carry and set the result to NaN
if carry is not 0. At the moment doing so requires the use of
inline assembler - not realy a newbi-thing to do...
