classTo define a new cp class, you just have to provide an implementation for the wrappers between your type
'a wrappers -> ?group:group -> string list -> ?short_name:string -> 'a -> string ->
fooand the type
Raw.cp. Once you have your wrappers
class foo_cp = [foo] cp_custom_type w
For further details, have a look at the commented .ml file,
section "predefined cp classes".