We apply MacoCaml, an extension of OCaml with support for compile-time user-specified code generation, to the generic function problem. MacoCaml’s combination of macros with phase separation and code quotations neatly addresses what is a recurring challenge for OCaml developers: how to write safe and efficient functions over type representations?

Our solution to the challenge also illustrates some recently-established formal guarantees offered by MacoCaml, including soundness and phase distinction.