gistfile1.rb

Thing = Struct.new(:a, :b, :c) do
  def some_thing
  end
end
 
class Thing
  attr_accessor :d
  
  alias_method :old_brackets, :[]
  def [](m)
    if m.to_s == 'd'
      self.d
    else
      old_brackets(m)
    end
  end
  
  alias_method :old_brackets_equal, :[]=
  def []=(m, v)
    if m.to_s == 'd'
      self.d = v 
    else
      old_brackets_equal(m, v)
    end
  end
end