On Wed, 2005-07-06 at 15:54 +0300, Michael Veksler wrote:
> > most architectures have different bit representations for +0.0 and -0.0,
> > yet the two values compare equal.
> >
>
> Yet, their sign bit is observable through things like
> assert(a == 0.0);
> assert(b == 0.0);
> 1/(1/a+ 1/b)
> which would give either NaN or 0 depending on the sign
> of a and b.
>
> So do you want one or two copies in the set?
>
what matters is whether the sign bit is observable through the equality
predicate. in the case of the operator==(double, double), it is not
observable, so there should be only one copy in a set.
