Enum MaybeDone

pub enum MaybeDone<Fut: Future> {
    Future(Fut),
    Done(Fut::Output),
    Gone,
}

A future that may have completed.

Variants

Future(Fut)

A not-yet-completed future

Done(Fut::Output)

The output of the completed future

Gone

The empty variant after the result of a MaybeDone has been taken using the take method.

Implementations

impl<Fut: Future> MaybeDone<Fut>

pub fn new(future: Fut) -> MaybeDone<Fut>

Create a new instance of MaybeDone.

pub fn output(self: Pin<&Self>) -> Option<&Fut::Output>

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

pub fn output_mut(self: Pin<&mut Self>) -> Option<&mut Fut::Output>

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 been completed and take has not yet been called.

pub fn take(self: Pin<&mut Self>) -> Option<Fut::Output>

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

Trait Implementations

impl<Fut: Debug + Future> Debug for MaybeDone<Fut>

where Fut::Output: Debug,

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

Formats the value using the given formatter.

impl<Fut: Future> Future for MaybeDone<Fut>

type Output = ()

The type of value produced on completion.

fn poll(self: Pin<&mut Self>, cx: &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.