Struct futures_core::future::FutureObj

[+] Show declaration

pub struct FutureObj<'a, T>(_);

[−] Expand description

A custom trait object for polling futures, roughly akin to Box<dyn Future<Output = T> + Send + 'a>.

This custom trait object was introduced for two reasons:

• Currently it is not possible to take dyn Trait by value and Box<dyn Trait> is not available in no_std contexts.
• The Future trait is currently not object safe: The Future::poll method makes uses the arbitrary self types feature and traits in which this feature is used are currently not object safe due to current compiler limitations. (See tracking issue for arbitrary self types for more information #44874)

Methods

impl<'a, T> FutureObj<'a, T>

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pub fn new<F: UnsafeFutureObj<'a, T> + Send>(f: F) -> FutureObj<'a, T>

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Create a FutureObj from a custom trait object representation.

Trait Implementations

impl<'a, T> From<FutureObj<'a, T>> for LocalFutureObj<'a, T>

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fn from(f: FutureObj<'a, T>) -> LocalFutureObj<'a, T>

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Performs the conversion.

impl<'a, F: Future<Output = ()> + Send + 'a> From<Pin<Box<F>>> for FutureObj<'a, ()>

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fn from(boxed: Pin<Box<F>>) -> Self

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Performs the conversion.

impl<'a, F: Future<Output = ()> + Send + 'a> From<Box<F>> for FutureObj<'a, ()>

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fn from(boxed: Box<F>) -> Self

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Performs the conversion.

impl<'a, T> Send for FutureObj<'a, T>

impl<'a, T> Debug for FutureObj<'a, T>

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

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Formats the value using the given formatter.

impl<'a, T> Unpin for FutureObj<'a, T>

impl<'a, T> Future for FutureObj<'a, T>

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type Output = T

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

futures in libcore are unstable

The result of the Future.

fn poll(self: Pin<&mut Self>, lw: &LocalWaker) -> Poll<T>

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

futures in libcore are unstable

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