Trait futures::task::LocalSpawnExt

[+] Show declaration

pub trait LocalSpawnExt: LocalSpawn {
    fn spawn_local<Fut>(&mut self, future: Fut) -> Result<(), SpawnError>
    where
        Fut: Future<Output = ()> + 'static,
    { ... }
    fn spawn_local_with_handle<Fut>(
        &mut self, 
        future: Fut
    ) -> Result<RemoteHandle<<Fut as Future>::Output>, SpawnError>
    where
        Fut: Future + 'static,
    { ... }
}

[−] Expand description

Extension trait for LocalSpawn.

Provided methods

fn spawn_local<Fut>(&mut self, future: Fut) -> Result<(), SpawnError> where
    Fut: Future<Output = ()> + '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.

#![feature(async_await, await_macro)]
use futures::executor::LocalPool;
use futures::task::LocalSpawnExt;

let executor = LocalPool::new();
let mut spawner = executor.spawner();

let future = async { /* ... */ };
spawner.spawn_local(future).unwrap();

fn spawn_local_with_handle<Fut>(
    &mut self,
    future: Fut
) -> Result<RemoteHandle<<Fut as Future>::Output>, SpawnError> where
    Fut: Future + 'static, [+]

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.

#![feature(async_await, await_macro)]
use futures::executor::LocalPool;
use futures::future;
use futures::task::LocalSpawnExt;

let mut executor = LocalPool::new();
let mut spawner = executor.spawner();

let future = future::ready(1);
let join_handle_fut = spawner.spawn_local_with_handle(future).unwrap();
assert_eq!(executor.run_until(join_handle_fut), 1);

Implementors

impl<Sp> LocalSpawnExt for Sp where
    Sp: LocalSpawn + ?Sized, [−]

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

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