minor fixes

src/typing/operators.ml

@@ -935,8 +935,8 @@ let type_is ctx e t p_t p =
 			| TAbstractDecl { a_impl = Some c; a_is = Some (arg_t,cf) } ->
 				(* abstract with @:op(v is T) -> generate static call *)
 				let e_method = Texpr.Builder.make_static_field c cf (mk_zero_range_pos p) in
-				let e = AbstractCast.cast_or_unify ctx arg_t e p in
-				let t_ret = match cf.cf_type with TFun (_, t) -> t | _ -> die ~p "unexpected @:op(v is T) type" __LOC__ in
+				let e = AbstractCast.cast_or_unify ctx arg_t e e.epos in
+				let t_ret = match follow cf.cf_type with TFun (_, t) -> t | _ -> die ~p "unexpected @:op(v is T) type" __LOC__ in
 				mk (TCall (e_method, [e])) t_ret p
 
 			| _ ->