ActorExample.swift

import Foundation

class CounterSortaActor {
  let queue = DispatchQueue(label: "CounterQueue")
  private var _count = 0

  var count: Int {
    get {
      queue.sync { _count }
    }
    set {
      queue.sync {
        _count += 1
       }
     }
   }
}

actor CounterActor {
  var count = 0

  func increment() {
    count += 1
  }
}