Struct futures_util::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 as currently it is not possible to take dyn Trait by value and Box<dyn Trait> is not available in no_std contexts.

You should generally not need to use this type outside of no_std or when implementing Spawn, consider using BoxFuture instead.

Methods

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

Important traits for FutureObj<'_, T>

impl<'_, T> Future for FutureObj<'_, T> type Output = T;

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

Create a FutureObj from a custom trait object representation.

Trait Implementations

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

Important traits for FutureObj<'_, T>

impl<'_, T> Future for FutureObj<'_, T> type Output = T;

fn from(
    boxed: Pin<Box<dyn Future<Output = ()> + 'a + Send>>
) -> FutureObj<'a, ()>

Performs the conversion.

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

Important traits for FutureObj<'_, T>

impl<'_, T> Future for FutureObj<'_, T> type Output = T;

fn from(boxed: Box<dyn Future<Output = ()> + 'a + Send>) -> FutureObj<'a, ()>

Performs the conversion.

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

Important traits for FutureObj<'_, T>

impl<'_, T> Future for FutureObj<'_, T> type Output = T;

fn from(boxed: Pin<Box<F>>) -> FutureObj<'a, ()>

Performs the conversion.

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

Important traits for LocalFutureObj<'_, T>

impl<'_, T> Future for LocalFutureObj<'_, T> type Output = T;

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

Performs the conversion.

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

Important traits for FutureObj<'_, T>

impl<'_, T> Future for FutureObj<'_, T> type Output = T;

fn from(boxed: Box<F>) -> FutureObj<'a, ()>

Performs the conversion.

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

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

Formats the value using the given formatter.

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

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

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

type Output = T

The type of value produced on completion.

fn poll(self: Pin<&mut FutureObj<'_, T>>, cx: &mut Context) -> Poll<T>

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