[@@js.enum] vs [@js.enum] with polymorphic variant.

[hhugo]

I'd like to write the following ( [@@js.enum] )

module String_or_number' : sig
  type t =
    [ `string of string [@js.default]
    | `Int of int    [@js.default]
    ]
  [@@js.enum]

  val t_to_js : t -> Ojs.t
  val t_of_js : Ojs.t -> t
end =
  [%js]

It fails with
Error: Sum types without js.* attribute not supported in this context

The way to do it is currently ([@js.enum])

module String_or_number' : sig
  type t =
    [ `string of string [@js.default]
    | `Int of int    [@js.default]
    ]
  [@js.enum]

  val t_to_js : t -> Ojs.t
  val t_of_js : Ojs.t -> t
end =
  [%js]

It would be nice to support the first version.