gistfile1.txt

>> a = "foo"
=> "foo"
>> b = "bar"
=> "bar"
>> c = {}
=> {}
>> c[a] ||= :foo
=> :foo
>> c[b] ||= :bar
=> :bar
>> c
=> {"foo"=>:foo, "bar"=>:bar}
>> a.hash
=> 876516207
>> def a.hash; :zozozoz.hash; end
=> nil
>> def b.hash; :zozozoz.hash; end
=> nil
>> c = {}
=> {}
>> c[a] ||= :foo
=> :foo
>> c[b] ||= :bar
=> :bar
>> c
=> {"foo"=>:foo, "bar"=>:bar}