Function futures_util::future::try_join [−][src]
pub fn try_join<Fut1, Fut2>(future1: Fut1, future2: Fut2) -> TryJoin<Fut1, Fut2>ⓘ where
Fut1: TryFuture,
Fut2: TryFuture<Error = Fut1::Error>,
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:
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:
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));