gistfile1.rb

class Enum < Hash
  def initialize(*members)
    super()
    @rev = {}
    members.each_with_index {|m,i| self[i] = m }
  end
  def [](k)
     super || @rev[k] # || raise ArgumentError, "#{k} is not a member of this enum"
  end
  def []=(k,v)
    @rev[v] = k
    super
  end
end