actix-web scope wrapper

redirect_if_unauthorized.rs

// These type signatures do not quite work.
fn redirect_if_unauthorized<T, R>(
  req: actix_web::dev::ServiceRequest,
  srv: &mut T::Service,
) -> impl future::Future<Output = Result<actix_web::dev::ServiceResponse, Error>> + Clone
where
  T: actix_service::ServiceFactory<
    Config = (),
    Request = actix_web::dev::ServiceRequest,
    Response = actix_web::dev::ServiceResponse,
    Error = Error,
    InitError = (),
  >,
{
  match req.get_identity() {
    Some(id) => {
      trace!("Found identity cookie {}", id);
      use actix_service::Service;
      srv.call(req)
    }
    None => future::Either::Right(future::ok(dev::ServiceResponse::new(
      req.into_parts().0,
      goto("/login"),
    ))),
  }
}

/*
Error: 
`match` arms have incompatible types

expected associated type, found enum `futures_util::future::either::Either`

note: expected type `<<T as actix_service::ServiceFactory>::Service as actix_service::Service>::Future`
         found enum `futures_util::future::either::Either<_, futures_util::future::ready::Ready<std::result::Result<actix_web::service::ServiceResponse, _>>>`rustc(E0308)
lib.rs(109, 5): consider calling `actix_service::Service::call`
main.rs(331, 3): `match` arms have incompatible types
main.rs(335, 7): this is found to be of type `<<T as actix_service::ServiceFactory>::Service as actix_service::Service>::Future`
main.rs(337, 13): expected associated type, found enum `futures_util::future::either::Either`
*/