// Define routes
struct UserIndex: Route {
    let path = "/users"

    func map(to url: URL, parameters: [String: String], queries: [String: String]) -> UIViewController {
        return UserIndexViewController()
    }
}

struct UserDetail: Route {
    let path = "/users/{id}"

    struct Parameters: Decodable {
        let id: Int
    }

    func map(to url: URL, parameters: Parameters, queries: [String: String]) -> UIViewController {
        return UserDetailViewController(id: parameters.id)
    }
}

// Use `Navigator` (for iOS)
Navigator.append(route: UserIndex())
Navigator.append(route: UserDetail())

Navigator.push(url: URL(string: "/users/42")!, animated: true)
Navigator.present(url: URL(string: "/users/42")!, animated: true)

// Use `Router`
let router = Router<UIViewController>()
router.append(route: UserIndex())
router.append(route: UserDetail())

router.push(url: URL(string: "/users/42")!) // Return `UserDetailViewController`