Original bug ID: 7828
Reporter: @trefis
Assigned to: @gasche
Status: resolved (set by @gasche on 2018-09-03T09:26:18Z)
Resolution: fixed
Priority: normal
Severity: minor
Version: 4.06.1
Fixed in version: 4.08.0+dev/beta1/beta2
Category: typing
Monitored by: @gasche @diml

Bug description

Noticed on 4.06 by Stefan Muenzel, reproduced on trunk.

    OCaml version 4.06.1

type t = I of int [@@unboxed] [@@Immediate];;

type t = I of int [@@Immediate] [@@unboxed]

external id : t -> t = "%identity";;

Characters 0-34:
external id : t -> t = "%identity";;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Warning 61: This primitive declaration uses type t, which is unannotated and
unboxable. The representation of such types may change in future
versions. You should annotate the declaration of t with [@@boxed]
or [@@unboxed].
Characters 0-34:
external id : t -> t = "%identity";;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Warning 61: This primitive declaration uses type t, which is unannotated and
unboxable. The representation of such types may change in future
versions. You should annotate the declaration of t with [@@boxed]
or [@@unboxed].
external id : t -> t = "%identity"

external id : (t [@unboxed]) -> (t [@unboxed]) = "%identity";;

Characters 15-16:
external id : (t [@unboxed]) -> (t [@unboxed]) = "%identity";;
^
Error: Don't know how to unbox this type. Only float, int32, int64 and nativeint can be unboxed