Yes. They are different numbers. In a way, negative zero represents "a really small negative number" that can't be represented exactly using floating point.
On Saturday, July 9, 2016, Davide Lasagna <lasagnadav...@gmail.com> wrote: > Hi, > > I have just been bitten by a function hashing a custom type containing a > vector of floats. It turns out that hashing positive and negative floating > point zeros returns different hashes. > > Demo: > julia> hash(-0.0) > 0x3be7d0f7780de548 > > julia> hash(0.0) > 0x77cfa1eef01bca90 > > julia> hash(0) > 0x77cfa1eef01bca90 > > Is this expected behaviour? > >
