Swift -Enum Redeclaration Error after updating to Xcode 11.4, Swift 5.2

Question

I have an enum that worked fine in Xcode 11.3, Swift 5.1. I just graded to Xcode 11.4 Swift 5.2 and now I get a redeclaration error:

I did a global search and there aren't any other enums with the same name nor any other classes or enums that use the method. It never occurred prior to my upgrade. I did a clean, deep clean, and cleared out derived data.

How can I fix this error?

enum ActivityType: String {

    case north
    case south
    case east
    case west
    case up
    case down
    case still

    static func value(from raw: String?) -> ActivityType {
        switch raw {
        case ActivityType.north.rawValue():
            return .north
        case ActivityType.south.rawValue():
            return .south
        case ActivityType.east.rawValue():
            return .east
        case ActivityType.west.rawValue():
            return .west
        case ActivityType.up.rawValue():
            return .up
        case ActivityType.down.rawValue():
            return .down
        case ActivityType.still.rawValue():
            return .still
        default:
            return .still
        }
    }

    func rawValue() -> String { // error occurs here
        switch self {
        case .north:
            return "north"
        case .south:
            return "south"
        case .east:
            return "east"
        case .west:
            return "west"
        case .up:
            return "up"
        case .down:
            return "down"
        case .still:
            return "still"
        }
    }
}

Answer 1

Since your enum already has String as the raw value type, you have an autogenerated rawValue property. It conflicts with your rawValue() function. However, it is unnecessary, since you can just use the autogenerated code:

enum ActivityType: String {

    case north, south, east, west, up, down, still

    static func value(from rawValue: String?) -> ActivityType {
        guard let rawValue = rawValue, let activityType = ActivityType(rawValue: rawValue) else {
            return .still
        }
        return activityType
    }

}

The above does the same as your code. Of course even that is largely unnecessary, since you could just use ActivityType(rawValue: myString)?? .still ActivityType(rawValue: myString)?? .still directly.

Answer 2

protocol RawRepresentableWithDefault: RawRepresentable {
  static var `default`: Self { get }
}

extension RawRepresentableWithDefault {
  init(rawValue: RawValue?) {
    self = rawValue.flatMap(Self.init) ?? .default
  }
}

enum ActivityType: String {
  case north, south, east, west, up, down, still
}

extension ActivityType: RawRepresentableWithDefault {
  static let `default` = still
}