Scala3 example of switch low-level optimisation

import ProcessState.*

type ProcessState = Stop | Running | Idle
object ProcessState {
  type Stop = 1
  val Stop: Stop = 1
  type Running = 2
  val Running: Running = 2
  type Idle = 3
  val Idle: Idle = 3
}

import java.util.concurrent.atomic.AtomicInteger

opaque type AtomicProcessState = AtomicInteger
object AtomicProcessState {

  inline def apply(initial: ProcessState): AtomicProcessState = AtomicInteger(initial)

  extension (self: AtomicProcessState) {

    inline def compareAndSet(expected: ProcessState, newValue: ProcessState): Boolean =
      self.compareAndSet(expected, newValue)

    inline def set(value: ProcessState): Unit =
      self.set(value)

    inline def get(): ProcessState =
      self.get().asInstanceOf[ProcessState]

  }

}


  protected val state: AtomicProcessState = AtomicProcessState(ProcessState.Idle)
  private def tell(queue: ConcurrentLinkedQueue[T], message: T): Unit = {
    import ProcessState.*
    (state.get(): @switch) match {
      case Stop =>
        runtime.reportFailure(Undelivered(message))
      case Running =>
        queue.add(message)
      case Idle =>
        queue.add(message)
        continue()
    }
  }