[Vala] case/when with enum

[Arc Riley <arcriley gmail com>]

error: Integer or string expression expected

on a case statement where:
  enum _message
    create
    resize
    title
    close
  _queue = new AsyncQueue of _message
  case _queue.pop()

Using case/when with enum values would seem extremely logical, was this
overlooked or is there a reason not to support it?