Piping two channels together in Rust

pipe.rs

enum Xor<A, B> {
    Left(A),
    Right(B)
}

type PipeError<T> = Xor<RecvError, SendError<T>>;

fn pipe<T: 'static + Send, U: 'static + Send>(f: fn(T) -> U, from: Receiver<T>, to: Sender<U>) -> thread::JoinHandle<()> {
    thread::spawn(move || {
        loop {
            from.recv()
                .map(f).map_err(Xor::Left)
                .and_then(|msg| to.send(msg).map_err(Xor::Right));
        }
    })
}