More on semantics of opPow: return type

[Bill Baxter]

On Tue, Dec 8, 2009 at 10:18 AM, Bill Baxter <wbaxter at gmail.com> wrote:
>> I agree. Then at least why not make the type of the exponent unsigned? That
>> gives the type system a fighting chance (via e.g. value range propagation).
>> Give Willy a chance!
>
> Honestly, I don't really understand this concern with range
> propagation.   Seems to me that allowing a negative exponent doesn't
> much expand the range, if a truncation rule is used.  The result is
> either undefined, 0 or 1.  The range is much greater with a
> non-negative exponent.  Could be undefined, zero, or most any negative
> or positive number.

This was meant sincerely, by the way.  As in, I am ignorant about this
issue (the trouble with range propagation and negative exponents) and
would appreciate it if someone could explain it.

--bb