//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2019 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

/// A class of types whose instances hold the value of an entity with stable identity.
@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
public protocol Identifiable {

  /// A type representing the stable identity of the entity associated with `self`.
  associatedtype ID: Hashable

  /// The stable identity of the entity associated with `self`.
  var id: ID { get }
}

@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
extension Identifiable where Self: AnyObject {
  public var id: ObjectIdentifier {
    return ObjectIdentifier(self)
  }
}