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Re: unsigned int

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Ike Naar <ike@iceland.freeshell.org> writes:

> On 2016-07-31, Tim Rentsch <txr@alumni.caltech.edu> wrote:
>> The most obvious difference between signed types and unsigned
>> types (not counting that only signed types can be negative) is
>> that operating on and converting to unsigned types is always
>> defined behavior, whereas operating on or converting to signed
>> types is sometimes undefined or implementation-defined behavior.
>
> Nit: a shift operation on unsigned types has undefined behavour if
> the value of the right operand is greater than or equal to the
> width of the promoted left operand (6.5.7p3).

Yes, and that is worth pointing out.  I subconsciously put
it in a different category, because the abstract operation
(or maybe I should say "abstract operation") isn't defined
for such shift values.  But it is undefined behavior, as
are divide by zero and remainder by zero.  Is that a complete
list?  Off the top of my head I can't think of any others.
Converting from floating point to an unsigned type can (IIANM)
give undefined behavior, but I don't think of that as an
operation on an unsigned type.

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Re: unsigned int Tim Rentsch <txr@alumni.caltech.edu> - 2016-07-31 16:36 -0700
  Re: unsigned int Ike Naar <ike@iceland.freeshell.org> - 2016-08-01 06:01 +0000
    Re: unsigned int Tim Rentsch <txr@alumni.caltech.edu> - 2016-08-01 07:27 -0700

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