I have this code:

struct DailyRewardItem {}

@MainActor
protocol Plugin {
  var dailyRewardItems: [DailyRewardItem] { get }
}

enum MagicItemType: CaseIterable {
  case shuffle
  case hammer
  case rocket
  case bomb
  
  @MainActor
  var dailyRewardItem: DailyRewardItem {
    return DailyRewardItem()
  }
}

class MyPlugin: Plugin {
  let dailyRewardItems = MagicItemType.allCases.map(.dailyRewardItem)
}

I got this warning:

Cannot form key path to main actor-isolated property ‘dailyRewardItem’; this is an error in the Swift 6 language mode

Here MyPlugin is implicitly main actor because it extends Plugin. So MyPlugin::dailyRewardItems is also main actor. The keyPath is also in main actor. Not sure why this gives warning.

If I don’t use the keyPath, it is working fine without warning.

  let dailyRewardItems = MagicItemType.allCases.map { $0.dailyRewardItem }