gistfile1.rb

module Delegatable
  def delegate(from_obj, from_method, to_obj, to_method)
    from_obj.extend Module.new{
      define_method(from_method) do |*arg|
        to_obj.__send__(to_method, *arg)
      end
    }
  end
end

class Test2
  def test
    puts self.class.to_s
  end
end

class Test1
  extend Delegatable
  @@t2 = Test2.new
  delegate self, :_test, @@t2, :test
end

Test1._test

o = Object.new
extend Delegatable
delegate o, :_hoge, Test1, :_test
o._hoge