[−][src]Struct futures::stream::Once
#[must_use = "streams do nothing unless polled"]pub struct Once<Fut> { /* fields omitted */ }
A stream which emits single element and then EOF.
This stream will never block and is always ready.
Trait Implementations
impl<Fut> Stream for Once<Fut> where
Fut: Future, [src]
impl<Fut> Stream for Once<Fut> where
Fut: Future, type Item = <Fut as Future>::Output
Values yielded by the stream.
fn poll_next(
self: PinMut<Once<Fut>>,
cx: &mut Context
) -> Poll<Option<<Fut as Future>::Output>>[src]
fn poll_next(
self: PinMut<Once<Fut>>,
cx: &mut Context
) -> Poll<Option<<Fut as Future>::Output>>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
impl<Fut> Debug for Once<Fut> where
Fut: Debug, [src]
impl<Fut> Debug for Once<Fut> where
Fut: Debug, fn fmt(&self, f: &mut Formatter) -> Result<(), Error>[src]
fn fmt(&self, f: &mut Formatter) -> Result<(), Error>Formats the value using the given formatter. Read more
impl<Fut> Unpin for Once<Fut> where
Fut: Unpin, [src]
impl<Fut> Unpin for Once<Fut> where
Fut: Unpin, Auto Trait Implementations
Blanket Implementations
impl<T> From for T[src]
impl<T> From for Timpl<T, U> TryFrom for T where
T: From<U>, [src]
impl<T, U> TryFrom for T where
T: From<U>, type Error = !
try_from)The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src]
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>try_from)Performs the conversion.
impl<T, U> TryInto for T where
U: TryFrom<T>, [src]
impl<T, U> TryInto for T where
U: TryFrom<T>, type Error = <U as TryFrom<T>>::Error
try_from)The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>[src]
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>try_from)Performs the conversion.
impl<T, U> Into for T where
U: From<T>, [src]
impl<T, U> Into for T where
U: From<T>, impl<T> Borrow for T where
T: ?Sized, [src]
impl<T> Borrow for T where
T: ?Sized, ⓘImportant traits for &'a mut Ifn borrow(&self) -> &T[src]
fn borrow(&self) -> &TImmutably borrows from an owned value. Read more
impl<T> BorrowMut for T where
T: ?Sized, [src]
impl<T> BorrowMut for T where
T: ?Sized, ⓘImportant traits for &'a mut Ifn borrow_mut(&mut self) -> &mut T[src]
fn borrow_mut(&mut self) -> &mut TMutably borrows from an owned value. Read more
impl<T> Any for T where
T: 'static + ?Sized, [src]
impl<T> Any for T where
T: 'static + ?Sized, fn get_type_id(&self) -> TypeId[src]
fn get_type_id(&self) -> TypeId🔬 This is a nightly-only experimental API. (get_type_id)
this method will likely be replaced by an associated static
Gets the TypeId of self. Read more
impl<T> StreamExt for T where
T: Stream + ?Sized, [src]
impl<T> StreamExt for T where
T: Stream + ?Sized, fn next(&mut self) -> Next<Self> where
Self: Unpin, [src]
fn next(&mut self) -> Next<Self> where
Self: Unpin, Creates a future that resolves to the next item in the stream. Read more
fn into_future(self) -> StreamFuture<Self> where
Self: Unpin, [src]
fn into_future(self) -> StreamFuture<Self> where
Self: Unpin, Converts this stream into a future of (next_item, tail_of_stream). If the stream terminates, then the next item is [None]. Read more
fn map<T, F>(self, f: F) -> Map<Self, F> where
F: FnMut(Self::Item) -> T, [src]
fn map<T, F>(self, f: F) -> Map<Self, F> where
F: FnMut(Self::Item) -> T, Maps this stream's items to a different type, returning a new stream of the resulting type. Read more
fn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>, [src]
fn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>, Filters the values produced by this stream according to the provided asynchronous predicate. Read more
fn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = Option<T>>, [src]
fn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = Option<T>>, Filters the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more
fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future, [src]
fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future, Computes from this stream's items new items of a different type using an asynchronous closure. Read more
fn collect<C>(self) -> Collect<Self, C> where
C: Default + Extend<Self::Item>, [src]
fn collect<C>(self) -> Collect<Self, C> where
C: Default + Extend<Self::Item>, Collect all of the values of this stream into a vector, returning a future representing the result of that computation. Read more
fn concat(self) -> Concat<Self> where
Self::Item: Extend<<Self::Item as IntoIterator>::Item>,
Self::Item: IntoIterator,
Self::Item: Default, [src]
fn concat(self) -> Concat<Self> where
Self::Item: Extend<<Self::Item as IntoIterator>::Item>,
Self::Item: IntoIterator,
Self::Item: Default, Concatenate all items of a stream into a single extendable destination, returning a future representing the end result. Read more
fn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F> where
F: FnMut(T, Self::Item) -> Fut,
Fut: Future<Output = T>, [src]
fn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F> where
F: FnMut(T, Self::Item) -> Fut,
Fut: Future<Output = T>, Execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more
fn flatten(self) -> Flatten<Self> where
Self::Item: Stream, [src]
fn flatten(self) -> Flatten<Self> where
Self::Item: Stream, Flattens a stream of streams into just one continuous stream. Read more
fn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>, [src]
fn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>, Skip elements on this stream while the provided asynchronous predicate resolves to true. Read more
fn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>, [src]
fn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>, Take elements from this stream while the provided asynchronous predicate resolves to true. Read more
fn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>, [src]
fn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>, Runs this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more
fn for_each_concurrent<Fut, F, impl Into>>(
self,
limit: impl Into>,
f: F
) -> ForEachConcurrent<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>,
impl Into>: Into<Option<usize>>, [src]
fn for_each_concurrent<Fut, F, impl Into>>(
self,
limit: impl Into>,
f: F
) -> ForEachConcurrent<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>,
impl Into>: Into<Option<usize>>, Runs this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available. Read more
fn take(self, n: u64) -> Take<Self>[src]
fn take(self, n: u64) -> Take<Self>Creates a new stream of at most n items of the underlying stream. Read more
fn skip(self, n: u64) -> Skip<Self>[src]
fn skip(self, n: u64) -> Skip<Self>Creates a new stream which skips n items of the underlying stream. Read more
fn fuse(self) -> Fuse<Self>[src]
fn fuse(self) -> Fuse<Self>Fuse a stream such that poll_next will never again be called once it has finished. Read more
ⓘImportant traits for &'a mut Ifn by_ref(&mut self) -> &mut Self[src]
fn by_ref(&mut self) -> &mut SelfBorrows a stream, rather than consuming it. Read more
fn catch_unwind(self) -> CatchUnwind<Self> where
Self: UnwindSafe, [src]
fn catch_unwind(self) -> CatchUnwind<Self> where
Self: UnwindSafe, Catches unwinding panics while polling the stream. Read more
fn buffered(self, n: usize) -> Buffered<Self> where
Self::Item: Future, [src]
fn buffered(self, n: usize) -> Buffered<Self> where
Self::Item: Future, An adaptor for creating a buffered list of pending futures. Read more
fn buffer_unordered(self, n: usize) -> BufferUnordered<Self> where
Self::Item: Future, [src]
fn buffer_unordered(self, n: usize) -> BufferUnordered<Self> where
Self::Item: Future, An adaptor for creating a buffered list of pending futures (unordered). Read more
fn zip<St>(self, other: St) -> Zip<Self, St> where
St: Stream, [src]
fn zip<St>(self, other: St) -> Zip<Self, St> where
St: Stream, An adapter for zipping two streams together. Read more
fn chain<St>(self, other: St) -> Chain<Self, St> where
St: Stream<Item = Self::Item>, [src]
fn chain<St>(self, other: St) -> Chain<Self, St> where
St: Stream<Item = Self::Item>, Adapter for chaining two stream. Read more
fn peekable(self) -> Peekable<Self>[src]
fn peekable(self) -> Peekable<Self>Creates a new stream which exposes a peek method. Read more
fn chunks(self, capacity: usize) -> Chunks<Self>[src]
fn chunks(self, capacity: usize) -> Chunks<Self>An adaptor for chunking up items of the stream inside a vector. Read more
fn select<St>(self, other: St) -> Select<Self, St> where
St: Stream<Item = Self::Item>, [src]
fn select<St>(self, other: St) -> Select<Self, St> where
St: Stream<Item = Self::Item>, This combinator will attempt to pull items from both streams. Each stream will be polled in a round-robin fashion, and whenever a stream is ready to yield an item that item is yielded. Read more
fn forward<S>(self, sink: S) -> Forward<Self, S> where
S: Sink + Unpin,
Self: Stream<Item = Result<<S as Sink>::SinkItem, <S as Sink>::SinkError>>, [src]
fn forward<S>(self, sink: S) -> Forward<Self, S> where
S: Sink + Unpin,
Self: Stream<Item = Result<<S as Sink>::SinkItem, <S as Sink>::SinkError>>, A future that completes after the given stream has been fully processed into the sink, including flushing. Read more
fn split(self) -> (SplitSink<Self>, SplitStream<Self>) where
Self: Sink, [src]
fn split(self) -> (SplitSink<Self>, SplitStream<Self>) where
Self: Sink, Splits this Stream + Sink object into separate Stream and Sink objects. Read more
fn inspect<F>(self, f: F) -> Inspect<Self, F> where
F: FnMut(&Self::Item), [src]
fn inspect<F>(self, f: F) -> Inspect<Self, F> where
F: FnMut(&Self::Item), Do something with each item of this stream, afterwards passing it on. Read more
ⓘImportant traits for Either<L, R>fn left_stream<B>(self) -> Either<Self, B> where
B: Stream<Item = Self::Item>, [src]
fn left_stream<B>(self) -> Either<Self, B> where
B: Stream<Item = Self::Item>, Wrap this stream in an Either stream, making it the left-hand variant of that Either. Read more
ⓘImportant traits for Either<L, R>fn right_stream<B>(self) -> Either<B, Self> where
B: Stream<Item = Self::Item>, [src]
fn right_stream<B>(self) -> Either<B, Self> where
B: Stream<Item = Self::Item>, Wrap this stream in an Either stream, making it the right-hand variant of that Either. Read more
fn poll_next_unpin(&mut self, cx: &mut Context) -> Poll<Option<Self::Item>> where
Self: Unpin, [src]
fn poll_next_unpin(&mut self, cx: &mut Context) -> Poll<Option<Self::Item>> where
Self: Unpin, A convenience method for calling [Stream::poll_next] on [Unpin] stream types. Read more
impl<S, T, E> TryStream for S where
S: Stream<Item = Result<T, E>>, [src]
impl<S, T, E> TryStream for S where
S: Stream<Item = Result<T, E>>, 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_next(
self: PinMut<S>,
cx: &mut Context
) -> Poll<Option<Result<<S as TryStream>::Ok, <S as TryStream>::Error>>>[src]
fn try_poll_next(
self: PinMut<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
impl<S> TryStreamExt for S where
S: TryStream, [src]
impl<S> TryStreamExt for S where
S: TryStream, fn err_into<E>(self) -> ErrInto<Self, E> where
Self::Error: Into<E>, [src]
fn err_into<E>(self) -> ErrInto<Self, E> where
Self::Error: Into<E>, Wraps the current stream in a new stream which converts the error type into the one provided. Read more
fn map_ok<T, F>(self, f: F) -> MapOk<Self, F> where
F: FnMut(Self::Ok) -> T, [src]
fn map_ok<T, F>(self, f: F) -> MapOk<Self, F> where
F: FnMut(Self::Ok) -> T, Wraps the current stream in a new stream which maps the success value using the provided closure. Read more
fn map_err<E, F>(self, f: F) -> MapErr<Self, F> where
F: FnMut(Self::Error) -> E, [src]
fn map_err<E, F>(self, f: F) -> MapErr<Self, F> where
F: FnMut(Self::Error) -> E, Wraps the current stream in a new stream which maps the error value using the provided closure. Read more
fn into_stream(self) -> IntoStream<Self>[src]
fn into_stream(self) -> IntoStream<Self>Wraps a [TryStream] into a type that implements Stream Read more
fn try_next(&mut self) -> TryNext<Self> where
Self: Unpin, [src]
fn try_next(&mut self) -> TryNext<Self> where
Self: Unpin, Creates a future that attempts to resolve the next item in the stream. If an error is encountered before the next item, the error is returned instead. Read more
fn try_for_each<Fut, F>(self, f: F) -> TryForEach<Self, Fut, F> where
F: FnMut(Self::Ok) -> Fut,
Fut: TryFuture<Ok = (), Error = Self::Error>, [src]
fn try_for_each<Fut, F>(self, f: F) -> TryForEach<Self, Fut, F> where
F: FnMut(Self::Ok) -> Fut,
Fut: TryFuture<Ok = (), Error = Self::Error>, Attempts to run this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more
fn try_skip_while<Fut, F>(self, f: F) -> TrySkipWhile<Self, Fut, F> where
F: FnMut(&Self::Ok) -> Fut,
Fut: TryFuture<Ok = bool, Error = Self::Error>, [src]
fn try_skip_while<Fut, F>(self, f: F) -> TrySkipWhile<Self, Fut, F> where
F: FnMut(&Self::Ok) -> Fut,
Fut: TryFuture<Ok = bool, Error = Self::Error>, Skip elements on this stream while the provided asynchronous predicate resolves to true. Read more
fn try_for_each_concurrent<Fut, F, impl Into>>(
self,
limit: impl Into>,
f: F
) -> TryForEachConcurrent<Self, Fut, F> where
F: FnMut(Self::Ok) -> Fut,
Fut: Future<Output = Result<(), Self::Error>>,
impl Into>: Into<Option<usize>>, [src]
fn try_for_each_concurrent<Fut, F, impl Into>>(
self,
limit: impl Into>,
f: F
) -> TryForEachConcurrent<Self, Fut, F> where
F: FnMut(Self::Ok) -> Fut,
Fut: Future<Output = Result<(), Self::Error>>,
impl Into>: Into<Option<usize>>, Attempts to run this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available, exiting as soon as an error occurs. Read more
fn try_collect<C>(self) -> TryCollect<Self, C> where
C: Default + Extend<Self::Ok>, [src]
fn try_collect<C>(self) -> TryCollect<Self, C> where
C: Default + Extend<Self::Ok>, Attempt to Collect all of the values of this stream into a vector, returning a future representing the result of that computation. Read more
fn try_filter_map<Fut, F, T>(self, f: F) -> TryFilterMap<Self, Fut, F> where
F: FnMut(Self::Ok) -> Fut,
Fut: TryFuture<Ok = Option<T>, Error = Self::Error>, [src]
fn try_filter_map<Fut, F, T>(self, f: F) -> TryFilterMap<Self, Fut, F> where
F: FnMut(Self::Ok) -> Fut,
Fut: TryFuture<Ok = Option<T>, Error = Self::Error>, Attempt to filter the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more
fn try_fold<T, Fut, F>(self, init: T, f: F) -> TryFold<Self, Fut, T, F> where
F: FnMut(T, Self::Ok) -> Fut,
Fut: TryFuture<Ok = T, Error = Self::Error>, [src]
fn try_fold<T, Fut, F>(self, init: T, f: F) -> TryFold<Self, Fut, T, F> where
F: FnMut(T, Self::Ok) -> Fut,
Fut: TryFuture<Ok = T, Error = Self::Error>, Attempt to execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more
fn try_buffer_unordered(self, n: usize) -> TryBufferUnordered<Self> where
Self::Ok: TryFuture,
<Self::Ok as TryFuture>::Error == Self::Error, [src]
fn try_buffer_unordered(self, n: usize) -> TryBufferUnordered<Self> where
Self::Ok: TryFuture,
<Self::Ok as TryFuture>::Error == Self::Error, Attempt to execute several futures from a stream concurrently. Read more