Matching Over Unions With Primitive Type Problem

[odersky]

Minimized example

object test:

  val x: Int | String = 1

  x match
    case _: Int =>
    case _: String =>

Output

-- Error: i8779.scala:6:9 ------------------------------------------------------
6 |    case _: Int =>
  |         ^
  |this case is unreachable since type Int | String is not a subclass of class Integer

Expectation

Should compile.