Struct futures_util::stream::Once

source · [−]

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

Expand description

A stream which emits single element and then EOF.

Trait Implementations

source

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

source

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

Formats the value using the given formatter. Read more

source

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

source

fn is_terminated(&self) -> bool

Returns true if the stream should no longer be polled.

source

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

type Item = <Fut as Future>::Output

Values yielded by the stream.

source

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

source

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

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

source

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

source

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

source

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

source

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

const: unstable · source

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

source

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

source

impl<T> From<T> for T

const: unstable · source

fn from(t: T) -> T

Returns the argument unchanged.

source

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.

source

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.

source

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.

source

impl<S, T, E> TryStream for S where
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

source

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 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<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>

impl<S, T, E> TryStream for S where
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 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<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>

impl<S, T, E> TryStream for S where 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 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<T, U> TryFrom<U> for T where
U: Into<T>,

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

impl<S, T, E> TryStream for S where
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>>>