Struct core::task::ContextBuilder

pub struct ContextBuilder<'a> { /* private fields */ }

🔬This is a nightly-only experimental API. (local_waker #118959)

A Builder used to construct a Context instance with support for LocalWaker.

Examples

#![feature(local_waker)]
#![feature(noop_waker)]
use std::task::{ContextBuilder, LocalWaker, Waker, Poll};
use std::future::Future;

let local_waker = LocalWaker::noop();
let waker = Waker::noop();

let mut cx = ContextBuilder::from_waker(&waker)
    .local_waker(&local_waker)
    .build();

let mut future = std::pin::pin!(async { 20 });
let poll = future.as_mut().poll(&mut cx);
assert_eq!(poll, Poll::Ready(20));

Implementations

impl<'a> ContextBuilder<'a>

pub const fn from_waker(waker: &'a Waker) -> Self

🔬This is a nightly-only experimental API. (local_waker #118959)

Creates a ContextBuilder from a Waker.

pub const fn from(cx: &'a mut Context<'_>) -> Self

🔬This is a nightly-only experimental API. (context_ext #123392)

Creates a ContextBuilder from an existing Context.

pub const fn waker(self, waker: &'a Waker) -> Self

🔬This is a nightly-only experimental API. (context_ext #123392)

Sets the value for the waker on Context.

pub const fn local_waker(self, local_waker: &'a LocalWaker) -> Self

🔬This is a nightly-only experimental API. (local_waker #118959)

Sets the value for the local waker on Context.

pub const fn ext(self, data: &'a mut dyn Any) -> Self

🔬This is a nightly-only experimental API. (context_ext #123392)

Sets the value for the extension data on Context.

pub const fn build(self) -> Context<'a>

🔬This is a nightly-only experimental API. (local_waker #118959)

Builds the Context.

Trait Implementations

impl<'a> Debug for ContextBuilder<'a>

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

Formats the value using the given formatter.