Joins the result of two futures, waiting for them both to complete or for one to produce an error.

This function will return a new future which awaits both futures to complete. If successful, the returned future will finish with a tuple of both results. If unsuccessful, it will complete with the first error encountered.

Note that this function consumes the passed futures and returns a wrapped version of it.

Examples

When used on multiple futures that return Ok, try_join will return Ok of a tuple of the values:

# futures::executor::block_on(async {
use futures::future;

let a = future::ready(Ok::<i32, i32>(1));
let b = future::ready(Ok::<i32, i32>(2));
let pair = future::try_join(a, b);

assert_eq!(pair.await, Ok((1, 2)));
# });

If one of the futures resolves to an error, try_join will return that error:

# futures::executor::block_on(async {
use futures::future;

let a = future::ready(Ok::<i32, i32>(1));
let b = future::ready(Err::<i32, i32>(2));
let pair = future::try_join(a, b);

assert_eq!(pair.await, Err(2));
# });