On 05-05-2012 13:06, bearophile wrote:
Alex Rønne Petersen:
I don't think the language really makes it clear whether overflows and
underflows are well-defined. Do we guarantee that for any integral
type T, T.max + 1 == T.min and T.min - 1 == T.max?
This is relevant in particular for GDC and LDC since they target a lot
of weird architectures.
In a good system language I'd like to see something better than what's
present in C#. So I'd like the language to offer the programmer the
choice of 3 or 4 different semantics in integral operations:
1) A shared standard semantics that overflows, as in Java;
2) A semantics that overflows, that adapts to the fastest available on
the CPU, as in C;
3) Shared standard overflows with unsigned values and run-time errors
when a signed value overflows (or goes out of its range).
4) Run-time errors when every signed or unsigned value overflows (or
goes out of its range), as in Ada.
Bye,
bearophile
Good point. The wrapping rule described in my OP should be the default
IMO. Then perhaps the other modes could be activated with an @attribute
of sorts?
--
- Alex
