Trait SpawnExt

Provided Methods

fn spawn<Fut>(&self, future: Fut) -> Result<(), SpawnError>
where
    Fut: Future<Output = ()> + Send + 'static,

Spawns a task that polls the given future with output () to completion.

This method returns a Result that contains a SpawnError if spawning fails.

You can use spawn_with_handle if you want to spawn a future with output other than () or if you want to be able to await its completion.

Note this method will eventually be replaced with the upcoming Spawn::spawn method which will take a dyn Future as input. Technical limitations prevent Spawn::spawn from being implemented today. Feel free to use this method in the meantime.

# {
use futures::executor::ThreadPool;
use futures::task::SpawnExt;

let executor = ThreadPool::new().unwrap();

let future = async { /* ... */ };
executor.spawn(future).unwrap();
# }
# std::thread::sleep(std::time::Duration::from_millis(500)); // wait for background threads closed: https://github.com/rust-lang/miri/issues/1371

fn spawn_with_handle<Fut>(&self, future: Fut) -> Result<RemoteHandle<Fut::Output>, SpawnError>
where
    Fut: Future + Send + 'static,
    Fut::Output: Send,

Spawns a task that polls the given future to completion and returns a future that resolves to the spawned future's output.

This method returns a Result that contains a RemoteHandle, or, if spawning fails, a SpawnError. RemoteHandle is a future that resolves to the output of the spawned future.

# {
use futures::executor::{block_on, ThreadPool};
use futures::future;
use futures::task::SpawnExt;

let executor = ThreadPool::new().unwrap();

let future = future::ready(1);
let join_handle_fut = executor.spawn_with_handle(future).unwrap();
assert_eq!(block_on(join_handle_fut), 1);
# }
# std::thread::sleep(std::time::Duration::from_millis(500)); // wait for background threads closed: https://github.com/rust-lang/miri/issues/1371