Struct Pending 

pub struct Pending<'a, T> { /* private fields */ }

Pending is a decode result on its way.

It is a Future: .await it on any single-threaded executor, or wrap it so its waker also wakes an event loop. A host that runs a frame loop instead calls try_take once a frame. Dropping a Pending cancels the work if it has not started.

The lifetime is what a frame borrows from its Codec: opening an image answers a Pending<'static, _>, while a frame keeps the codec borrowed until it arrives, so one codec cannot be decoding two frames at once.

The type is !Send on purpose: the inline loader runs the decode inside poll, on the polling thread, and an opened codec belongs to that thread too.

Implementations

impl<'a, T> Pending<'a, T>

pub fn try_take(&mut self) -> Option<Result<T, DecodeError>>

try_take returns the result if it is ready, without blocking.

With an inline loader the first call does the decode. Returns None while a worker is still busy.

Panics

Panics if called again after it returned Some.

Trait Implementations

impl<T> Debug for Pending<'_, T>

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

Formats the value using the given formatter.

impl<T> Future for Pending<'_, T>

type Output = Result<T, DecodeError>

The type of value produced on completion.

fn poll(self: Pin<&mut Self>, context: &mut Context<'_>) -> Poll<Self::Output>

Attempts to resolve the future to a final value, registering the current task for wakeup if the value is not yet available.