Function or

pub fn or<T, F1, F2>(future1: F1, future2: F2) -> Or<F1, F2> 
where
    F1: Future<Output = T>,
    F2: Future<Output = T>,

Returns the result of the future that completes first, preferring future1 if both are ready.

If you need to treat the two futures fairly without a preference for either, use the race() function or the FutureExt::race() method.

Examples

use futures_lite::future::{self, pending, ready};

assert_eq!(future::or(ready(1), pending()).await, 1);
assert_eq!(future::or(pending(), ready(2)).await, 2);

// The first future wins.
assert_eq!(future::or(ready(1), ready(2)).await, 1);