From: "Bartosz DziewoƄski" Date: 2013-02-21T03:24:47+09:00 Subject: Re: Fixnum: freeze status on ruby 2.0.0 rc2 It makes sense. A Fixnum is immutable, so it can be considered "frozen". There is an entry for this in the Ruby changelog: https://github.com/ruby/ruby/blob/trunk/ChangeLog#L8266 -- Matma Rex