Struct futures_core::future::FutureObj

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

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>

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

Create a FutureObj from a custom trait object representation.

Trait Implementations

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

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

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

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

Performs the conversion.

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

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

Performs the conversion.

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

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

Performs the conversion.

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

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

Formats the value using the given formatter.

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

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>

🔬 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.