Hi, At Wed, 1 Mar 2006 19:39:15 +0900, Tanaka Akira wrote in [ruby-core:07468]: > The performance issue exists. However I'm not sure that it > is significant because Kernel#object_id is used not so > common. ObjectSpace._id2ref is used rarely and it should > be. rb_obj_id() is used as Kernel#hash also. -- Nobu Nakada