Struct capnp::capability::Promise

#[must_use = "futures do nothing unless polled"]
pub struct Promise<T, E> { /* fields omitted */ }

A computation that might eventually resolve to a value of type T or to an error of type E. Dropping the promise cancels the computation.

Methods

impl<T, E> Promise<T, E>

Important traits for Promise<T, E>

impl<T, E> Future for Promise<T, E> type Output = Result<T, E>;

pub fn ok(value: T) -> Promise<T, E>

Important traits for Promise<T, E>

impl<T, E> Future for Promise<T, E> type Output = Result<T, E>;

pub fn err(error: E) -> Promise<T, E>

Important traits for Promise<T, E>

impl<T, E> Future for Promise<T, E> type Output = Result<T, E>;

pub fn from_future<F>(f: F) -> Promise<T, E> where
    F: Future<Output = Result<T, E>> + 'static, 

Trait Implementations

impl<T, E> Future for Promise<T, E>

type Output = Result<T, E>

The type of value produced on completion.

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

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