Enum futures::prelude::future::TryMaybeDone

pub enum TryMaybeDone<Fut>where
    Fut: TryFuture,{
    Future(Fut),
    Done(<Fut as TryFuture>::Ok),
    Gone,
}

A future that may have completed with an error.

This is created by the try_maybe_done() function.

Variants

Future(Fut)

A not-yet-completed future

Done(<Fut as TryFuture>::Ok)

The output of the completed future

Gone

The empty variant after the result of a TryMaybeDone has been taken using the take_output method, or if the future returned an error.

Implementations

impl<Fut> TryMaybeDone<Fut>where Fut: TryFuture,

pub fn output_mut( self: Pin<&mut TryMaybeDone<Fut>> ) -> Option<&mut <Fut as TryFuture>::Ok>

Returns an Option containing a mutable reference to the output of the future. The output of this method will be Some if and only if the inner future has completed successfully and take_output has not yet been called.

pub fn take_output( self: Pin<&mut TryMaybeDone<Fut>> ) -> Option<<Fut as TryFuture>::Ok>

Attempt to take the output of a TryMaybeDone without driving it towards completion.

Trait Implementations

impl<Fut> Debug for TryMaybeDone<Fut>where Fut: Debug + TryFuture, <Fut as TryFuture>::Ok: Debug,

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

Formats the value using the given formatter.

impl<Fut> FusedFuture for TryMaybeDone<Fut>where Fut: TryFuture,

fn is_terminated(&self) -> bool

Returns true if the underlying future should no longer be polled.

impl<Fut> Future for TryMaybeDone<Fut>where Fut: TryFuture,

type Output = Result<(), <Fut as TryFuture>::Error>

The type of value produced on completion.

fn poll( self: Pin<&mut TryMaybeDone<Fut>>, cx: &mut Context<'_> ) -> Poll<<TryMaybeDone<Fut> as Future>::Output>

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

impl<Fut> Unpin for TryMaybeDone<Fut>where Fut: TryFuture + Unpin,