From: Rob Pitt Date: 2008-03-21T15:41:15+09:00 Subject: Re: get object from its object-specific class? > def instance_of_singleton_class_2(sc) not only is this method faster but it works in a situation where the ObjectSpace does not. Consider this rspec test pasted in from a personal introspection lib. It will work with this method but not with the ObjectSpace: def singleton class<