pub fn err<T, E>(err: E) -> Ready<Result<T, E>>Notable traits for Ready<T>impl<T> Future for Ready<T>    type Output = T;
Expand description

Create a future that is immediately ready with an error value.

Examples

use futures::future;

let a = future::err::<i32, i32>(1);
assert_eq!(a.await, Err(1));