Enum futures::future::Either

pub enum Either<A, B> {
    A(A),
    B(B),
}

Combines two different futures yielding the same item and error types into a single type.

Variants

A(A)

First branch of the type

B(B)

Second branch of the type

Methods

impl<T, A, B> Either<(T, A), (T, B)>

pub fn split(self) -> (T, Either<A, B>)

Splits out the homogeneous type from an either of tuples.

This method is typically useful when combined with the Future::select2 combinator.

Trait Implementations

impl<A: Debug, B: Debug> Debug for Either<A, B>

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

Formats the value using the given formatter.

impl<A, B> Future for Either<A, B> where
    A: Future,
    B: Future<Item = A::Item, Error = A::Error>, 

type Item = A::Item

The type of value that this future will resolved with if it is successful.

type Error = A::Error

The type of error that this future will resolve with if it fails in a normal fashion.

fn poll(&mut self) -> Poll<A::Item, A::Error>

Query this future to see if its value has become available, registering interest if it is not.

fn wait(self) -> Result<Self::Item, Self::Error> where
    Self: Sized, 

Block the current thread until this future is resolved.

fn map<F, U>(self, f: F) -> Map<Self, F> where
    F: FnOnce(Self::Item) -> U,
    Self: Sized, 

Map this future's result to a different type, returning a new future of the resulting type.

fn map_err<F, E>(self, f: F) -> MapErr<Self, F> where
    F: FnOnce(Self::Error) -> E,
    Self: Sized, 

Map this future's error to a different error, returning a new future.

fn from_err<E: From<Self::Error>>(self) -> FromErr<Self, E> where
    Self: Sized, 

Map this future's error to any error implementing From for this future's Error, returning a new future.

fn then<F, B>(self, f: F) -> Then<Self, B, F> where
    F: FnOnce(Result<Self::Item, Self::Error>) -> B,
    B: IntoFuture,
    Self: Sized, 

Chain on a computation for when a future finished, passing the result of the future to the provided closure f.

fn and_then<F, B>(self, f: F) -> AndThen<Self, B, F> where
    F: FnOnce(Self::Item) -> B,
    B: IntoFuture<Error = Self::Error>,
    Self: Sized, 

Execute another future after this one has resolved successfully.

fn or_else<F, B>(self, f: F) -> OrElse<Self, B, F> where
    F: FnOnce(Self::Error) -> B,
    B: IntoFuture<Item = Self::Item>,
    Self: Sized, 

Execute another future if this one resolves with an error.

fn select<B>(self, other: B) -> Select<Self, B::Future> where
    B: IntoFuture<Item = Self::Item, Error = Self::Error>,
    Self: Sized, 

Waits for either one of two futures to complete.

fn select2<B>(self, other: B) -> Select2<Self, B::Future> where
    B: IntoFuture,
    Self: Sized, 

Waits for either one of two differently-typed futures to complete.

fn join<B>(self, other: B) -> Join<Self, B::Future> where
    B: IntoFuture<Error = Self::Error>,
    Self: Sized, 

Joins the result of two futures, waiting for them both to complete.

fn join3<B, C>(self, b: B, c: C) -> Join3<Self, B::Future, C::Future> where
    B: IntoFuture<Error = Self::Error>,
    C: IntoFuture<Error = Self::Error>,
    Self: Sized, 

Same as join, but with more futures.

fn join4<B, C, D>(
    self,
    b: B,
    c: C,
    d: D
) -> Join4<Self, B::Future, C::Future, D::Future> where
    B: IntoFuture<Error = Self::Error>,
    C: IntoFuture<Error = Self::Error>,
    D: IntoFuture<Error = Self::Error>,
    Self: Sized, 

Same as join, but with more futures.

fn join5<B, C, D, E>(
    self,
    b: B,
    c: C,
    d: D,
    e: E
) -> Join5<Self, B::Future, C::Future, D::Future, E::Future> where
    B: IntoFuture<Error = Self::Error>,
    C: IntoFuture<Error = Self::Error>,
    D: IntoFuture<Error = Self::Error>,
    E: IntoFuture<Error = Self::Error>,
    Self: Sized, 

Same as join, but with more futures.

fn into_stream(self) -> IntoStream<Self> where
    Self: Sized, 

Convert this future into a single element stream.

fn flatten(self) -> Flatten<Self> where
    Self::Item: IntoFuture,
    <Self::Item as IntoFuture>::Error: From<Self::Error>,
    Self: Sized, 

Flatten the execution of this future when the successful result of this future is itself another future.

fn flatten_stream(self) -> FlattenStream<Self> where
    Self::Item: Stream<Error = Self::Error>,
    Self: Sized, 

Flatten the execution of this future when the successful result of this future is a stream.

fn fuse(self) -> Fuse<Self> where
    Self: Sized, 

Fuse a future such that poll will never again be called once it has completed.

fn inspect<F>(self, f: F) -> Inspect<Self, F> where
    F: FnOnce(&Self::Item),
    Self: Sized, 

Do something with the item of a future, passing it on.

fn catch_unwind(self) -> CatchUnwind<Self> where
    Self: Sized + UnwindSafe, 

Catches unwinding panics while polling the future.

fn shared(self) -> Shared<Self> where
    Self: Sized, 

Create a cloneable handle to this future where all handles will resolve to the same result.

impl<A, B> Stream for Either<A, B> where
    A: Stream,
    B: Stream<Item = A::Item, Error = A::Error>, 

type Item = A::Item

The type of item this stream will yield on success.

type Error = A::Error

The type of error this stream may generate.

fn poll(&mut self) -> Poll<Option<A::Item>, A::Error>

Attempt to pull out the next value of this stream, returning None if the stream is finished.

Important traits for Wait<S>

impl<S: Stream> Iterator for Wait<S> type Item = Result<S::Item, S::Error>;

fn wait(self) -> Wait<Self> where
    Self: Sized, 

Creates an iterator which blocks the current thread until each item of this stream is resolved.

fn into_future(self) -> StreamFuture<Self> where
    Self: Sized, 

Converts this stream into a Future.

fn map<U, F>(self, f: F) -> Map<Self, F> where
    F: FnMut(Self::Item) -> U,
    Self: Sized, 

Converts a stream of type T to a stream of type U.

fn map_err<U, F>(self, f: F) -> MapErr<Self, F> where
    F: FnMut(Self::Error) -> U,
    Self: Sized, 

Converts a stream of error type T to a stream of error type U.

fn filter<F>(self, f: F) -> Filter<Self, F> where
    F: FnMut(&Self::Item) -> bool,
    Self: Sized, 

Filters the values produced by this stream according to the provided predicate.

fn filter_map<F, B>(self, f: F) -> FilterMap<Self, F> where
    F: FnMut(Self::Item) -> Option<B>,
    Self: Sized, 

Filters the values produced by this stream while simultaneously mapping them to a different type.

fn then<F, U>(self, f: F) -> Then<Self, F, U> where
    F: FnMut(Result<Self::Item, Self::Error>) -> U,
    U: IntoFuture,
    Self: Sized, 

Chain on a computation for when a value is ready, passing the resulting item to the provided closure f.

fn and_then<F, U>(self, f: F) -> AndThen<Self, F, U> where
    F: FnMut(Self::Item) -> U,
    U: IntoFuture<Error = Self::Error>,
    Self: Sized, 

Chain on a computation for when a value is ready, passing the successful results to the provided closure f.

fn or_else<F, U>(self, f: F) -> OrElse<Self, F, U> where
    F: FnMut(Self::Error) -> U,
    U: IntoFuture<Item = Self::Item>,
    Self: Sized, 

Chain on a computation for when an error happens, passing the erroneous result to the provided closure f.

fn collect(self) -> Collect<Self> where
    Self: Sized, 

Collect all of the values of this stream into a vector, returning a future representing the result of that computation.

fn concat2(self) -> Concat2<Self> where
    Self: Sized,
    Self::Item: Extend<<Self::Item as IntoIterator>::Item> + IntoIterator + Default, 

Concatenate all results of a stream into a single extendable destination, returning a future representing the end result.

fn concat(self) -> Concat<Self> where
    Self: Sized,
    Self::Item: Extend<<Self::Item as IntoIterator>::Item> + IntoIterator, 

Deprecated since 0.1.14:

please use Stream::concat2 instead

Concatenate all results of a stream into a single extendable destination, returning a future representing the end result.

fn fold<F, T, Fut>(self, init: T, f: F) -> Fold<Self, F, Fut, T> where
    F: FnMut(T, Self::Item) -> Fut,
    Fut: IntoFuture<Item = T>,
    Self::Error: From<Fut::Error>,
    Self: Sized, 

Execute an accumulating computation over a stream, collecting all the values into one final result.

fn flatten(self) -> Flatten<Self> where
    Self::Item: Stream,
    <Self::Item as Stream>::Error: From<Self::Error>,
    Self: Sized, 

Flattens a stream of streams into just one continuous stream.

fn skip_while<P, R>(self, pred: P) -> SkipWhile<Self, P, R> where
    P: FnMut(&Self::Item) -> R,
    R: IntoFuture<Item = bool, Error = Self::Error>,
    Self: Sized, 

Skip elements on this stream while the predicate provided resolves to true.

fn take_while<P, R>(self, pred: P) -> TakeWhile<Self, P, R> where
    P: FnMut(&Self::Item) -> R,
    R: IntoFuture<Item = bool, Error = Self::Error>,
    Self: Sized, 

Take elements from this stream while the predicate provided resolves to true.

fn for_each<F, U>(self, f: F) -> ForEach<Self, F, U> where
    F: FnMut(Self::Item) -> U,
    U: IntoFuture<Item = (), Error = Self::Error>,
    Self: Sized, 

Runs this stream to completion, executing the provided closure for each element on the stream.

fn from_err<E: From<Self::Error>>(self) -> FromErr<Self, E> where
    Self: Sized, 

Map this stream's error to any error implementing From for this stream's Error, returning a new stream.

fn take(self, amt: u64) -> Take<Self> where
    Self: Sized, 

Creates a new stream of at most amt items of the underlying stream.

fn skip(self, amt: u64) -> Skip<Self> where
    Self: Sized, 

Creates a new stream which skips amt items of the underlying stream.

fn fuse(self) -> Fuse<Self> where
    Self: Sized, 

Fuse a stream such that poll will never again be called once it has finished.

fn by_ref(&mut self) -> &mut Self where
    Self: Sized, 

Borrows a stream, rather than consuming it.

fn catch_unwind(self) -> CatchUnwind<Self> where
    Self: Sized + UnwindSafe, 

Catches unwinding panics while polling the stream.

fn buffered(self, amt: usize) -> Buffered<Self> where
    Self::Item: IntoFuture<Error = Self::Error>,
    Self: Sized, 

An adaptor for creating a buffered list of pending futures.

fn buffer_unordered(self, amt: usize) -> BufferUnordered<Self> where
    Self::Item: IntoFuture<Error = Self::Error>,
    Self: Sized, 

An adaptor for creating a buffered list of pending futures (unordered).

fn merge<S>(self, other: S) -> Merge<Self, S> where
    S: Stream<Error = Self::Error>,
    Self: Sized, 

Deprecated:

functionality provided by select now

An adapter for merging the output of two streams.

fn zip<S>(self, other: S) -> Zip<Self, S> where
    S: Stream<Error = Self::Error>,
    Self: Sized, 

An adapter for zipping two streams together.

fn chain<S>(self, other: S) -> Chain<Self, S> where
    S: Stream<Item = Self::Item, Error = Self::Error>,
    Self: Sized, 

Adapter for chaining two stream.

fn peekable(self) -> Peekable<Self> where
    Self: Sized, 

Creates a new stream which exposes a peek method.

fn chunks(self, capacity: usize) -> Chunks<Self> where
    Self: Sized, 

An adaptor for chunking up items of the stream inside a vector.

fn select<S>(self, other: S) -> Select<Self, S> where
    S: Stream<Item = Self::Item, Error = Self::Error>,
    Self: Sized, 

Creates a stream that selects the next element from either this stream or the provided one, whichever is ready first.

fn forward<S>(self, sink: S) -> Forward<Self, S> where
    S: Sink<SinkItem = Self::Item>,
    Self::Error: From<S::SinkError>,
    Self: Sized, 

A future that completes after the given stream has been fully processed into the sink, including flushing.

fn split(self) -> (SplitSink<Self>, SplitStream<Self>) where
    Self: Sink + Sized, 

Splits this Stream + Sink object into separate Stream and Sink objects.

fn inspect<F>(self, f: F) -> Inspect<Self, F> where
    F: FnMut(&Self::Item),
    Self: Sized, 

Do something with each item of this stream, afterwards passing it on.

fn inspect_err<F>(self, f: F) -> InspectErr<Self, F> where
    F: FnMut(&Self::Error),
    Self: Sized, 

Do something with the error of this stream, afterwards passing it on.