generic swift status AVPlayer

generics.swift

protocol StatusObservable: NSObject, Sendable {
  associatedtype Status: Equatable, Sendable
  var status: Status { get }
  var error: Error? { get }
}

extension AVPlayer: @retroactive Sendable {}
extension AVPlayer: StatusObservable {
  typealias Status = AVPlayer.Status
}

extension AVPlayerItem: @retroactive Sendable {}
extension AVPlayerItem: StatusObservable {
  typealias Status = AVPlayerItem.Status
}

// Then the function generic utilizing these protocols:

  func addStatusObserver<T: StatusObservable>(
    for observable: T,
    failedStatus: T.Status
  ) {
    keyValueObservers.append(
      observable.observe(
        \.status,
        options: [.initial, .new]
      ) { [unowned self] _, change in
        if change.newValue == failedStatus {
          Task { await self.reset(from: observable.error) }
        }
      }
    )
  }

// And the call sites

    addStatusObserver(
      for: avPlayer,
      failedStatus: .failed
    )
    addStatusObserver(
      for: avPlayerItem,
      failedStatus: .failed
    )