[boost] Re: (boost) Re: A pure C/C++ question

From: Bill Seymour (bill-at-the-office_at_[hidden])
Date: 2002-08-22 12:54:54

Victor A. Wagner wrote:
>
> I'm one of those weirdos that thinks that "correct" is
> a lot more important than "fast".
>

Perhaps in your application domain.  Folk who write,
e.g., encryption routines would disagree.  They need
arithmetic to be fast and repeatable (gets the same
answer every time).  Whether it gets the "correct"
answer is totally irrelevant.

David Bergman wrote:
>
> [Integer] arithmetic is supposed to be module 2^n, ...
>

No, just unsigned integer arithmetic.  As others have
already said, signed integer overflow yields undefined
behavior.  That includes, but is not limited to, wrapping
modulo 2^n as if it were unsigned (MSVC and others),
INT_MAX + 1 == 1 (Borland, IIRC), hardware traps
(Unisys, Cray, IIRC), ...

--Bill Seymour