fd.rs

// This version gives a "cannot move out of borrowed content error"
let ref fd = &self.fd.unwrap();

// But I guess that's fair game. Docs say it "moves" content, which
// is not what we want. How about expect?
let ref fd = &self.fd.expect("Invalid state: no fd found in Sync::Write");

// Nope, also doesn't work. This is the only version that works fine.
let fd = match &self.fd {
  &Some(ref fd) => fd,
  &None => panic!("Invalid state: no fd found in Sync::Write"),
};

Solution was to do:

    let fd = self.fd.as_ref().expect("self.fd was None.");

Which gives us a reference that can be moved by .expect(). Autoref prevents the need to then call it let ref fd =