Also check out https://www.snellman.net/blog/archive/2015-07-27-use-cases-for-change-class-in-common-lisp/ https://www.snellman.net/blog/archive/2015-07-27-use-

Also check out https://www.snellman.net/blog/archive/2015-07-27-use-cases-for-change-class-in-common-lisp/ https://www.snellman.net/blog/archive/2015-07-27-use-cases-f... for some really interesting, but niche, things you can do to classes.