Am I correct in assuming that any language with support for overloading functions for new types, instead of extending existing types with new members/methods, w

Am I correct in assuming that any language with support for overloading functions for new types, instead of extending existing types with new members/methods, would have a solution to such issues? This would then also cover: * anything CLOS-inspired: Common Lisp, Dylan, Factor, Clojure * but also presumably anything with C++- or Clay-like (http://tachyon.in/clay/ http://tachyon.in/clay/) generic programming, namely w.r.t generically using freely-overloadable functions. I believe Haskell achieves something similar to this using type classes.