Struct futures_core::stream::StreamObj

pub struct StreamObj<'a, T>(_);

A custom trait object for polling streams, roughly akin to Box<dyn Stream<Item = T> + Send + 'a>.

This custom trait object was introduced for two reasons:

• Currently it is not possible to take dyn Trait by value and Box<dyn Trait> is not available in no_std contexts.
• The Stream trait is currently not object safe: The Stream::poll_next method makes uses the arbitrary self types feature and traits in which this feature is used are currently not object safe due to current compiler limitations. (See tracking issue for arbitray self types for more information #44874)

Methods

impl<'a, T> StreamObj<'a, T>

pub fn new<F: UnsafeStreamObj<'a, T> + Send>(f: F) -> StreamObj<'a, T>

Create a StreamObj from a custom trait object representation.

Trait Implementations

impl<'a, T> Stream for StreamObj<'a, T>

type Item = T

Values yielded by the stream.

fn poll_next(self: Pin<&mut Self>, lw: &LocalWaker) -> Poll<Option<T>>

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.

impl<'a, T> Send for StreamObj<'a, T>

impl<'a, T> From<StreamObj<'a, T>> for LocalStreamObj<'a, T>

fn from(f: StreamObj<'a, T>) -> LocalStreamObj<'a, T>

Performs the conversion.

impl<'a, F: Stream<Item = ()> + Send + 'a> From<Pin<Box<F>>> for StreamObj<'a, ()>

fn from(boxed: Pin<Box<F>>) -> Self

Performs the conversion.

impl<'a, F: Stream<Item = ()> + Send + 'a> From<Box<F>> for StreamObj<'a, ()>

fn from(boxed: Box<F>) -> Self

Performs the conversion.

impl<'a, T> Debug for StreamObj<'a, T>

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

Formats the value using the given formatter.

impl<'a, T> Unpin for StreamObj<'a, T>