Function sesh::select_mut

pub fn select_mut<T, S>(
    rs: &mut Vec<Recv<T, S>>
) -> Result<(T, S), Box<dyn Error>> where
    T: Send,
    S: Session, 

Selects the first active session. Receives from the selected session, and removes the endpoint from the input vector. Returns the received value and the continuation of the selected session.