Function polkadot_node_subsystem::gen::futures::prelude::future::try_join_all
source · pub fn try_join_all<I>(iter: I) -> TryJoinAll<<I as IntoIterator>::Item> ⓘwhere
I: IntoIterator,
<I as IntoIterator>::Item: TryFuture,
Expand description
Creates a future which represents either a collection of the results of the futures given or an error.
The returned future will drive execution for all of its underlying futures,
collecting the results into a destination Vec<T>
in the same order as they
were provided.
If any future returns an error then all other futures will be canceled and
an error will be returned immediately. If all futures complete successfully,
however, then the returned future will succeed with a Vec
of all the
successful results.
This function is only available when the std
or alloc
feature of this
library is activated, and it is activated by default.
See Also
try_join_all
will switch to the more powerful FuturesOrdered
for performance
reasons if the number of futures is large. You may want to look into using it or
it’s counterpart FuturesUnordered
directly.
Some examples for additional functionality provided by these are:
-
Adding new futures to the set even after it has been started.
-
Only polling the specific futures that have been woken. In cases where you have a lot of futures this will result in much more efficient polling.
Examples
use futures::future::{self, try_join_all};
let futures = vec![
future::ok::<u32, u32>(1),
future::ok::<u32, u32>(2),
future::ok::<u32, u32>(3),
];
assert_eq!(try_join_all(futures).await, Ok(vec![1, 2, 3]));
let futures = vec![
future::ok::<u32, u32>(1),
future::err::<u32, u32>(2),
future::ok::<u32, u32>(3),
];
assert_eq!(try_join_all(futures).await, Err(2));