> Do people test equality of hashes very often? I, for one,
> do not.
> 
> For example, does anyone depend on these hashes being
> equal?
> 
>    x = {1=>2, 3=>4}
>    y = {3=>4, 1=>2}
>    x == y            #  => true
> 
> Or does anyone have code that depends in some other way
> on the fact that the ordering in a hash is NOT predictable?
> 

Where are you going with this?  There seem to be three unrelated things
here:

1. The question "does anyone use Hash.==(other)?"
2. The implication that you think the order in which pairs are added to
a hash is (or should be) significant.
3. The question of whether anyone depends on hashes not being "ordered"
in some sense

To see why this seems odd, let me recast your question in terms of
arrays:

<analogy>
Does anyone depend on these arrays being equal?

   x = Array.new; x[1] = 2; x[3] = 4
   y = Array.new; y[3] = 4; y[1] = 2
   x == y            #  => true

Or does anyone have code that depends in some other way on the fact that
the order in which items are added too an array is NOT significant?
</analogy>

-- MarkusQ