Struct futures_util::stream::Once

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pub struct Once<Fut> { /* private fields */ }

Expand description

A stream which emits single element and then EOF.

Trait Implementations

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impl<Fut: Debug> Debug for Once<Fut>

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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> FusedStream for Once<Fut>

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fn is_terminated(&self) -> bool

Returns true if the stream should no longer be polled.

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impl<Fut: Future> Stream for Once<Fut>

type Item = <Fut as Future>::Output

Values yielded by the stream.

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fn poll_next(
self: Pin<&mut Self>,
cx: &mut Context<'_>
) -> Poll<Option<Self::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted. Read more

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fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream. Read more

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impl<'pin, Fut> Unpin for Once<Fut>where
Origin<'__pin, Fut>: Unpin,

Auto Trait Implementations

impl<Fut> RefUnwindSafe for Once<Fut>where
Fut: RefUnwindSafe,

impl<Fut> Send for Once<Fut>where
Fut: Send,

impl<Fut> Sync for Once<Fut>where
Fut: Sync,

impl<Fut> UnwindSafe for Once<Fut>where
Fut: UnwindSafe,

Blanket Implementations

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

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

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

const: unstable

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for Twhere
T: ?Sized,

const: unstable

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

impl<T> From<T> for T

const: unstable

fn from(t: T) -> T

Returns the argument unchanged.

impl<T, U> Into for Twhere
U: From<T>,

const: unstable

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<T, U> TryFrom for Twhere
U: Into<T>,

type Error = Infallible

The type returned in the event of a conversion error.

const: unstable

fn try_from(value: U) -> Result<T, <T as TryFrom>::Error>

Performs the conversion.

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

type Error = >::Error

The type returned in the event of a conversion error.

const: unstable

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

Performs the conversion.

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impl<S, T, E> TryStream for Swhere
S: Stream<Item = 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

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fn try_poll_next(
self: Pin<&mut S>,
cx: &mut Context<'_>
) -> Poll<Option<Result<<S as TryStream>::Ok, <S as TryStream>::Error>>>

Poll this TryStream as if it were a Stream. Read more

Struct futures_util::stream::Once

Trait Implementations

impl<Fut: Debug> Debug for Once<Fut>

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

impl<Fut: Future> FusedStream for Once<Fut>

fn is_terminated(&self) -> bool

impl<Fut: Future> Stream for Once<Fut>

type Item = <Fut as Future>::Output

fn poll_next(
self: Pin<&mut Self>,
cx: &mut Context<'_>
) -> Poll<Option<Self::Item>>

fn size_hint(&self) -> (usize, Option<usize>)

impl<'pin, Fut> Unpin for Once<Fut>where
Origin<'__pin, Fut>: Unpin,

Auto Trait Implementations

impl<Fut> RefUnwindSafe for Once<Fut>where
Fut: RefUnwindSafe,

impl<Fut> Send for Once<Fut>where
Fut: Send,

impl<Fut> Sync for Once<Fut>where
Fut: Sync,

impl<Fut> UnwindSafe for Once<Fut>where
Fut: UnwindSafe,

Blanket Implementations

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

fn type_id(&self) -> TypeId

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

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Twhere
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 Twhere
U: From<T>,

fn into(self) -> U

impl<T, U> TryFrom<U> for Twhere
U: Into<T>,

type Error = Infallible

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

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

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

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

impl<S, T, E> TryStream for Swhere
S: Stream<Item = Result<T, E>> + ?Sized,

type Ok = T

type Error = E

fn try_poll_next(
self: Pin<&mut S>,
cx: &mut Context<'_>
) -> Poll<Option<Result<<S as TryStream>::Ok, <S as TryStream>::Error>>>

Struct futures_util::stream::Once

Trait Implementations

impl<Fut: Debug> Debug for Once<Fut>

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

impl<Fut: Future> FusedStream for Once<Fut>

fn is_terminated(&self) -> bool

impl<Fut: Future> Stream for Once<Fut>

type Item = <Fut as Future>::Output

fn poll_next( self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>>

fn size_hint(&self) -> (usize, Option<usize>)

impl<'__pin, Fut> Unpin for Once<Fut>where __Origin<'__pin, Fut>: Unpin,

Auto Trait Implementations

impl<Fut> RefUnwindSafe for Once<Fut>where Fut: RefUnwindSafe,

impl<Fut> Send for Once<Fut>where Fut: Send,

impl<Fut> Sync for Once<Fut>where Fut: Sync,

impl<Fut> UnwindSafe for Once<Fut>where Fut: UnwindSafe,

Blanket Implementations

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

fn type_id(&self) -> TypeId

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

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Twhere 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 Twhere U: From<T>,

fn into(self) -> U

impl<T, U> TryFrom<U> for Twhere U: Into<T>,

type Error = Infallible

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

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

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

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

impl<S, T, E> TryStream for Swhere S: Stream<Item = Result<T, E>> + ?Sized,

type Ok = T

type Error = E

fn try_poll_next( self: Pin<&mut S>, cx: &mut Context<'_>) -> Poll<Option<Result<<S as TryStream>::Ok, <S as TryStream>::Error>>>

fn poll_next(
self: Pin<&mut Self>,
cx: &mut Context<'_>
) -> Poll<Option<Self::Item>>

impl<'pin, Fut> Unpin for Once<Fut>where
Origin<'__pin, Fut>: Unpin,

impl<Fut> RefUnwindSafe for Once<Fut>where
Fut: RefUnwindSafe,

impl<Fut> Send for Once<Fut>where
Fut: Send,

impl<Fut> Sync for Once<Fut>where
Fut: Sync,

impl<Fut> UnwindSafe for Once<Fut>where
Fut: UnwindSafe,

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

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

impl<T> BorrowMut<T> for Twhere
T: ?Sized,

impl<T, U> Into<U> for Twhere
U: From<T>,

impl<T, U> TryFrom<U> for Twhere
U: Into<T>,

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

impl<S, T, E> TryStream for Swhere
S: Stream<Item = Result<T, E>> + ?Sized,

fn try_poll_next(
self: Pin<&mut S>,
cx: &mut Context<'_>
) -> Poll<Option<Result<<S as TryStream>::Ok, <S as TryStream>::Error>>>