Function unexpected

Source
pub fn unexpected<I, S>(message: S) -> Unexpected<I>
where I: Stream, S: Into<Info<I::Item>>,
Expand description

Always fails with message as the error. Never consumes any input.

let result = unexpected("token")
    .parse("a");
assert!(result.is_err());
assert!(result.err().unwrap().errors.iter().any(|m| *m == Error::Message("token".into())));