Struct futures_util::future::FutureObj

source · [−]

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 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.

Implementations

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

pub fn new<F>(f: F) -> FutureObj<'a, T>ⓘNotable traits for FutureObj<'_, T>`impl<'_, T> Future for FutureObj<'_, T> type Output = T;` where
F: UnsafeFutureObj<'a, T> + Send,

Create a FutureObj from a custom trait object representation.

Trait Implementations

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

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

Formats the value using the given formatter. Read more

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

fn from(boxed: Box<F, Global>) -> FutureObj<'a, ()>ⓘNotable traits for FutureObj<'_, T>`impl<'_, T> Future for FutureObj<'_, T> type Output = T;`

Converts to this type from the input type.

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

fn from(
boxed: Box<dyn Future<Output = ()> + Send + 'a, Global>
) -> FutureObj<'a, ()>ⓘNotable traits for FutureObj<'_, T>`impl<'_, T> Future for FutureObj<'_, T> type Output = T;`

Converts to this type from the input type.

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

fn from(f: FutureObj<'a, T>) -> LocalFutureObj<'a, T>ⓘNotable traits for LocalFutureObj<'_, T>`impl<'_, T> Future for LocalFutureObj<'_, T> type Output = T;`

Converts to this type from the input type.

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

fn from(boxed: Pin<Box<F, Global>>) -> FutureObj<'a, ()>ⓘNotable traits for FutureObj<'_, T>`impl<'_, T> Future for FutureObj<'_, T> type Output = T;`

Converts to this type from the input type.

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

fn from(
boxed: Pin<Box<dyn Future<Output = ()> + Send + 'a, Global>>
) -> FutureObj<'a, ()>ⓘNotable traits for FutureObj<'_, T>`impl<'_, T> Future for FutureObj<'_, T> type Output = T;`

Converts to this type from the input type.

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. Read more

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

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

Auto Trait Implementations

impl<'a, T> !RefUnwindSafe for FutureObj<'a, T>

impl<'a, T> !Sync for FutureObj<'a, T>

impl<'a, T> !UnwindSafe for FutureObj<'a, T>

Blanket Implementations

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

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

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

const: unstable · source

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

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

impl<T> From<T> for T

const: unstable · source

fn from(t: T) -> T

Returns the argument unchanged.

impl<T, U> Into<U> 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.

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?

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

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

Creates a future from a value.

impl<T, U> TryFrom<U> 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<U>>::Error>

Performs the conversion.

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

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

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

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

The type returned in the event of a conversion error.

const: unstable · source

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

Performs the conversion.