From: ts <decoux@...>
Date: 2002-03-14T00:27:24+09:00
Subject: Re: key comparision inside Hash

>>>>> "E" == Erik =?ISO-8859-1?Q?B=E5gfors?= <Erik> writes:

E> What's the best way to create such a hash-method btw??

 One way (and *not* the best) is to use XOR (or ADD). Something like this

   class A
      attr_reader :a, :b
      def initialize(a, b)
         @a, @b = a, b
      end
      def hash
         @a.hash ^ @b.hash
      end
      def eql?(o)
         o.kind_of?(A) && @a.eql?(o.a) && @b.eql?(o.b)
      end
   end

 but you'll have

   A.new(a, b).hash == A.new(b, a).hash


Guy Decoux