(* TEST
flags = " -w -a "
* setup-ocamlc.byte-build-env
** ocamlc.byte
*** check-ocamlc.byte-output
*)

module type S = sig
 type +'a t

 val foo : [`A] t -> unit
 val bar : [< `A | `B] t -> unit
end

module Make(T : S) = struct
 let f x =
   T.foo x;
   T.bar x;
   (x :> [`A | `C] T.t)
end