Struct async_std::task::JoinHandle

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pub struct JoinHandle<T> { /* private fields */ }

Expand description

A handle that awaits the result of a task.

Dropping a JoinHandle will detach the task, meaning that there is no longer a handle to the task and no way to join on it.

Created when a task is spawned.

Implementations

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impl<T> JoinHandle<T>

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pub fn task(&self) -> &Task

Returns a handle to the underlying task.

Examples

use async_std::task;

let handle = task::spawn(async {
    1 + 2
});
println!("id = {}", handle.task().id());

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pub async fn cancel(self) -> Option<T>

Cancel this task.

Trait Implementations

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impl<T: Debug> Debug for JoinHandle<T>

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more

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impl<T> Drop for JoinHandle<T>

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fn drop(&mut self)

Executes the destructor for this type. Read more

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impl<T> Future for JoinHandle<T>

type Output = T

The type of value produced on completion.

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fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>

Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available. Read more

Auto Trait Implementations

impl<T> RefUnwindSafe for JoinHandle<T>

impl<T> Send for JoinHandle<T> where
T: Send,

impl<T> Sync for JoinHandle<T>

impl<T> Unpin for JoinHandle<T>

impl<T> UnwindSafe for JoinHandle<T>

Blanket Implementations

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impl<T> Any for T where
T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

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impl<T> Borrow<T> for T where
T: ?Sized,

const: unstable · source

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

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impl<T> BorrowMut<T> for T where
T: ?Sized,

const: unstable · source

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

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impl<T> From<T> for T

const: unstable · source

fn from(t: T) -> T

Returns the argument unchanged.

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impl<F> FutureExt for F where
F: Future + ?Sized,

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fn poll(&mut self, cx: &mut Context<'_>) -> Poll<Self::Output> where
Self: Unpin,

A convenience for calling Future::poll() on !Unpin types.

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fn or<F>(self, other: F) -> Or<Self, F>ⓘNotable traits for Or<F1, F2>`impl<T, F1, F2> Future for Or<F1, F2> where F1: Future<Output = T>, F2: Future<Output = T>, type Output = T;` where
F: Future<Output = Self::Output>,

Returns the result of self or other future, preferring self if both are ready. Read more

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fn race<F>(self, other: F) -> Race<Self, F>ⓘNotable traits for Race<F1, F2>`impl<T, F1, F2> Future for Race<F1, F2> where F1: Future<Output = T>, F2: Future<Output = T>, type Output = T;` where
F: Future<Output = Self::Output>,

Returns the result of self or other future, with no preference if both are ready. Read more

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fn catch_unwind(self) -> CatchUnwind<Self>ⓘNotable traits for CatchUnwind<F>`impl<F> Future for CatchUnwind<F> where F: Future + UnwindSafe, type Output = Result<<F as Future>::Output, Box<dyn Any + Send + 'static, Global>>;` where
Self: UnwindSafe,

Catches panics while polling the future. Read more

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fn boxed<'a>(
 self
) -> Pin<Box<dyn Future<Output = Self::Output> + Send + 'a, Global>>ⓘNotable traits for Pin`impl Future for Pin where P: DerefMut, ::Target: Future, type Output = <::Target as Future>::Output;` where
 Self: 'a + Send,

Boxes the future and changes its type to dyn Future + Send + 'a. Read more

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fn boxed_local<'a>(
 self
) -> Pin<Box<dyn Future<Output = Self::Output> + 'a, Global>>ⓘNotable traits for Pin`impl Future for Pin where P: DerefMut, ::Target: Future, type Output = <::Target as Future>::Output;` where
 Self: 'a,

Boxes the future and changes its type to dyn Future + 'a. Read more

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impl<T, U> Into for T where
U: From<T>,

const: unstable · source

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<F> IntoFuture for F where
F: Future,

type Output = <F as Future>::Output

🔬 This is a nightly-only experimental API. (into_future)

The output that the future will produce on completion.

type IntoFuture = F

🔬 This is a nightly-only experimental API. (into_future)

Which kind of future are we turning this into?

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fn into_future(self) -> <F as IntoFuture>::IntoFuture

🔬 This is a nightly-only experimental API. (into_future)

Creates a future from a value.

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impl<T, U> TryFrom for T where
U: Into<T>,

type Error = Infallible

The type returned in the event of a conversion error.

const: unstable · source

fn try_from(value: U) -> Result<T, <T as TryFrom>::Error>

Performs the conversion.

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impl<F, T, E> TryFuture for F where
F: Future<Output = Result<T, E>> + ?Sized,

type Ok = T

The type of successful values yielded by this future

type Error = E

The type of failures yielded by this future

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fn try_poll(
self: Pin<&mut F>,
cx: &mut Context<'_>
) -> Poll<<F as Future>::Output>

Poll this TryFuture as if it were a Future. Read more

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impl<T, U> TryInto for T where
U: TryFrom<T>,

type Error = >::Error

The type returned in the event of a conversion error.

const: unstable · source

fn try_into(self) -> Result<U, >::Error>

Performs the conversion.

Struct async_std::task::JoinHandle

Implementations

impl<T> JoinHandle<T>

pub fn task(&self) -> &Task

Examples

pub async fn cancel(self) -> Option<T>

Trait Implementations

impl<T: Debug> Debug for JoinHandle<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

impl<T> Drop for JoinHandle<T>

fn drop(&mut self)

impl<T> Future for JoinHandle<T>

type Output = T

fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>

Auto Trait Implementations

impl<T> RefUnwindSafe for JoinHandle<T>

impl<T> Send for JoinHandle<T> where T: Send,

impl<T> Sync for JoinHandle<T>

impl<T> Unpin for JoinHandle<T>

impl<T> UnwindSafe for JoinHandle<T>

Blanket Implementations

impl<T> Any for T where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<T> Borrow<T> for T where T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for T where T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

impl<T> From<T> for T

fn from(t: T) -> T

impl<F> FutureExt for F where F: Future + ?Sized,

fn poll(&mut self, cx: &mut Context<'_>) -> Poll<Self::Output> where Self: Unpin,

fn or<F>(self, other: F) -> Or<Self, F>ⓘNotable traits for Or<F1, F2>impl<T, F1, F2> Future for Or<F1, F2> where F1: Future<Output = T>, F2: Future<Output = T>, type Output = T; where F: Future<Output = Self::Output>,

fn race<F>(self, other: F) -> Race<Self, F>ⓘNotable traits for Race<F1, F2>impl<T, F1, F2> Future for Race<F1, F2> where F1: Future<Output = T>, F2: Future<Output = T>, type Output = T; where F: Future<Output = Self::Output>,

fn catch_unwind(self) -> CatchUnwind<Self>ⓘNotable traits for CatchUnwind<F>impl<F> Future for CatchUnwind<F> where F: Future + UnwindSafe, type Output = Result<<F as Future>::Output, Box<dyn Any + Send + 'static, Global>>; where Self: UnwindSafe,

fn boxed<'a>( self) -> Pin<Box<dyn Future<Output = Self::Output> + Send + 'a, Global>>ⓘNotable traits for Pin<P>impl<P> Future for Pin<P> where P: DerefMut, <P as Deref>::Target: Future, type Output = <<P as Deref>::Target as Future>::Output; where Self: 'a + Send,

fn boxed_local<'a>( self) -> Pin<Box<dyn Future<Output = Self::Output> + 'a, Global>>ⓘNotable traits for Pin<P>impl<P> Future for Pin<P> where P: DerefMut, <P as Deref>::Target: Future, type Output = <<P as Deref>::Target as Future>::Output; where Self: 'a,

impl<T, U> Into<U> for T where U: From<T>,

fn into(self) -> U

impl<F> IntoFuture for F where F: Future,

type Output = <F as Future>::Output

type IntoFuture = F

fn into_future(self) -> <F as IntoFuture>::IntoFuture

impl<T, U> TryFrom<U> for T where U: Into<T>,

type Error = Infallible

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

impl<F, T, E> TryFuture for F where F: Future<Output = Result<T, E>> + ?Sized,

type Ok = T

type Error = E

fn try_poll( self: Pin<&mut F>, cx: &mut Context<'_>) -> Poll<<F as Future>::Output>

impl<T, U> TryInto<U> for T where U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

impl<T> Send for JoinHandle<T> where
T: Send,

impl<T> Any for T where
T: 'static + ?Sized,

impl<T> Borrow<T> for T where
T: ?Sized,

impl<T> BorrowMut<T> for T where
T: ?Sized,

impl<F> FutureExt for F where
F: Future + ?Sized,

fn poll(&mut self, cx: &mut Context<'_>) -> Poll<Self::Output> where
Self: Unpin,

fn or<F>(self, other: F) -> Or<Self, F>ⓘNotable traits for Or<F1, F2>`impl<T, F1, F2> Future for Or<F1, F2> where F1: Future<Output = T>, F2: Future<Output = T>, type Output = T;` where
F: Future<Output = Self::Output>,

fn race<F>(self, other: F) -> Race<Self, F>ⓘNotable traits for Race<F1, F2>`impl<T, F1, F2> Future for Race<F1, F2> where F1: Future<Output = T>, F2: Future<Output = T>, type Output = T;` where
F: Future<Output = Self::Output>,

fn catch_unwind(self) -> CatchUnwind<Self>ⓘNotable traits for CatchUnwind<F>`impl<F> Future for CatchUnwind<F> where F: Future + UnwindSafe, type Output = Result<<F as Future>::Output, Box<dyn Any + Send + 'static, Global>>;` where
Self: UnwindSafe,

fn boxed<'a>(
self
) -> Pin<Box<dyn Future<Output = Self::Output> + Send + 'a, Global>>ⓘNotable traits for Pin<P>`impl<P> Future for Pin<P> where P: DerefMut, <P as Deref>::Target: Future, type Output = <<P as Deref>::Target as Future>::Output;` where
Self: 'a + Send,

fn boxed_local<'a>(
self
) -> Pin<Box<dyn Future<Output = Self::Output> + 'a, Global>>ⓘNotable traits for Pin<P>`impl<P> Future for Pin<P> where P: DerefMut, <P as Deref>::Target: Future, type Output = <<P as Deref>::Target as Future>::Output;` where
Self: 'a,

impl<T, U> Into<U> for T where
U: From<T>,

impl<F> IntoFuture for F where
F: Future,

impl<T, U> TryFrom<U> for T where
U: Into<T>,

impl<F, T, E> TryFuture for F where
F: Future<Output = Result<T, E>> + ?Sized,

fn try_poll(
self: Pin<&mut F>,
cx: &mut Context<'_>
) -> Poll<<F as Future>::Output>

impl<T, U> TryInto<U> for T where
U: TryFrom<T>,