From: Stephen Bannasch <stephen.bannasch@...>
Date: 2007-09-18T05:06:28+09:00
Subject: [?] problem using set with hash objects

I'm using set in the ruby standard library to produce collections of 
unique objects from enumerable objects with duplicates but it's 
doesn't appear to work with hash objects.

$ ruby --version
ruby 1.8.5 (2006-12-25 patchlevel 12) [i686-darwin8.9.1]
$ irb
irb(main):001:0> require 'set'
=> true
irb(main):002:0> a = [1,1,2,3]
=> [1, 1, 2, 3]
irb(main):003:0> b = [{:a1 => "123"}, {:a1 => "123"}, {:b1 => "123"}]
=> [{:a1=>"123"}, {:a1=>"123"}, {:b1=>"123"}]
irb(main):004:0> seta = a.to_set
=> #<Set: {1, 2, 3}>
irb(main):005:0> setb = b.to_set
=> #<Set: {{:a1=>"123"}, {:a1=>"123"}, {:b1=>"123"}}>
irb(main):006:0> b[0] == b[1]
=> true

Am I doing something wrong?