public let payload: Any?

struct User {
  let firstName: String
  let lastName: String
}

let user = User(firstName: "foo", lastName: "bar")

guard let location = Compass.parse(url, payload: user) else {
  return
}

// ...

if let user = location.payload as? User {
  print("\(user.firstName) \(user.lastName)")
}

guard let location = Compass.parse(url, payload: ["foo": "bar"]) else {
  return
}

// ...

if let payload = location.payload as? [String: String] {
  print(payload["foo"])
}

What do you think?

class ErrorRoute: ErrorRoutable {
  var error: ErrorType?

  func handle(routeError: ErrorType, from currentController: Controller) {
    error = routeError
  }
}

class ThrowableRoute: Routable {
  func navigate(to location: Location, from currentController: Controller) throws {
    throw RouteError.InvalidArguments(location)
  }
}

let router = Router()
let errorRoute = ErrorRoute()

router.errorRoute = errorRoute // errorRoute is an optional var
router.routes["throw"] = ThrowableRoute()
router.navigate(to: Location(path: "throw"), from: UIViewController())

print(errorRoute.error) // RouteError.InvalidArguments