Aaron D. Gifford wrote in post #992841: > What do you do when you see a need to be able to attach some data to > an object instance for later use somewhere else in a body of code? ... > require 'ostructmod' > class OpenSSL::PKey > include OpenStructModule > end You probably wouldn't want OpenStructModule even if it did exist because you wouldn't want NoMethodError to be suppressed. Perhaps you're looking for Object#extend. module UserId attr_accessor :user_id end thing = Object.new # whatever the thing is thing.extend(UserId).user_id = 123456 p thing.user_id #=>123456 -- Posted via http://www.ruby-forum.com/.