Enum futures_util::future::MaybeDone

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pub enum MaybeDone<Fut: Future> {
    Future(Fut),
    Done(Fut::Output),
    Gone,
}

Expand description

A future that may have completed.

This is created by the maybe_done() function.

Variants

`Future(Fut)`

A not-yet-completed future

`Done(Fut::Output)`

The output of the completed future

`Gone`

The empty variant after the result of a MaybeDone has been taken using the take_output method.

Implementations

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impl<Fut: Future> MaybeDone<Fut>

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pub fn output_mut(self: Pin<&mut Self>) -> Option<&mut Fut::Output>

Returns an Option containing a mutable reference to the output of the future. The output of this method will be Some if and only if the inner future has been completed and take_output has not yet been called.

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pub fn take_output(self: Pin<&mut Self>) -> Option<Fut::Output>

Attempt to take the output of a MaybeDone without driving it towards completion.

Trait Implementations

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impl<Fut: Debug + Future> Debug for MaybeDone<Fut> where
Fut::Output: Debug,

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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<Fut: Future> FusedFuture for MaybeDone<Fut>

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fn is_terminated(&self) -> bool

Returns true if the underlying future should no longer be polled.

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impl<Fut: Future> Future for MaybeDone<Fut>

type Output = ()

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

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impl<Fut: Future + Unpin> Unpin for MaybeDone<Fut>

Auto Trait Implementations

impl<Fut> RefUnwindSafe for MaybeDone<Fut> where
Fut: RefUnwindSafe,
<Fut as Future>::Output: RefUnwindSafe,

impl<Fut> Send for MaybeDone<Fut> where
Fut: Send,
<Fut as Future>::Output: Send,

impl<Fut> Sync for MaybeDone<Fut> where
Fut: Sync,
<Fut as Future>::Output: Sync,

impl<Fut> UnwindSafe for MaybeDone<Fut> where
Fut: UnwindSafe,
<Fut as Future>::Output: UnwindSafe,

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<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<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.

Enum futures_util::future::MaybeDone

Variants

Future(Fut)

Done(Fut::Output)

Gone

Implementations

impl<Fut: Future> MaybeDone<Fut>

pub fn output_mut(self: Pin<&mut Self>) -> Option<&mut Fut::Output>

pub fn take_output(self: Pin<&mut Self>) -> Option<Fut::Output>

Trait Implementations

impl<Fut: Debug + Future> Debug for MaybeDone<Fut> where Fut::Output: Debug,

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

impl<Fut: Future> FusedFuture for MaybeDone<Fut>

fn is_terminated(&self) -> bool

impl<Fut: Future> Future for MaybeDone<Fut>

type Output = ()

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

impl<Fut: Future + Unpin> Unpin for MaybeDone<Fut>

Auto Trait Implementations

impl<Fut> RefUnwindSafe for MaybeDone<Fut> where Fut: RefUnwindSafe, <Fut as Future>::Output: RefUnwindSafe,

impl<Fut> Send for MaybeDone<Fut> where Fut: Send, <Fut as Future>::Output: Send,

impl<Fut> Sync for MaybeDone<Fut> where Fut: Sync, <Fut as Future>::Output: Sync,

impl<Fut> UnwindSafe for MaybeDone<Fut> where Fut: UnwindSafe, <Fut as Future>::Output: UnwindSafe,

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<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<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>

`Future(Fut)`

`Done(Fut::Output)`

`Gone`

impl<Fut: Debug + Future> Debug for MaybeDone<Fut> where
Fut::Output: Debug,

impl<Fut> RefUnwindSafe for MaybeDone<Fut> where
Fut: RefUnwindSafe,
<Fut as Future>::Output: RefUnwindSafe,

impl<Fut> Send for MaybeDone<Fut> where
Fut: Send,
<Fut as Future>::Output: Send,

impl<Fut> Sync for MaybeDone<Fut> where
Fut: Sync,
<Fut as Future>::Output: Sync,

impl<Fut> UnwindSafe for MaybeDone<Fut> where
Fut: UnwindSafe,
<Fut as Future>::Output: UnwindSafe,

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