W3cubDocs

/Rust

Struct 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)]
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

Source
impl<'a> ContextBuilder<'a>
Source
pub const fn from_waker(waker: &'a Waker) -> ContextBuilder<'a>
🔬This is a nightly-only experimental API. (local_waker #118959)

Creates a ContextBuilder from a Waker.

Source
pub const fn from(cx: &'a mut Context<'_>) -> ContextBuilder<'a>
🔬This is a nightly-only experimental API. (context_ext #123392)

Creates a ContextBuilder from an existing Context.

Source
pub const fn waker(self, waker: &'a Waker) -> ContextBuilder<'a>
🔬This is a nightly-only experimental API. (context_ext #123392)

Sets the value for the waker on Context.

Source
pub const fn local_waker(
    self,
    local_waker: &'a LocalWaker,
) -> ContextBuilder<'a>
🔬This is a nightly-only experimental API. (local_waker #118959)

Sets the value for the local waker on Context.

Source
pub const fn ext(self, data: &'a mut (dyn Any + 'static)) -> ContextBuilder<'a>
🔬This is a nightly-only experimental API. (context_ext #123392)

Sets the value for the extension data on Context.

Source
pub const fn build(self) -> Context<'a>
🔬This is a nightly-only experimental API. (local_waker #118959)

Builds the Context.

Trait Implementations

Source
impl<'a> Debug for ContextBuilder<'a>
Source
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
Formats the value using the given formatter. Read more

Auto Trait Implementations

impl<'a> Freeze for ContextBuilder<'a>
impl<'a> !RefUnwindSafe for ContextBuilder<'a>
impl<'a> !Send for ContextBuilder<'a>
impl<'a> !Sync for ContextBuilder<'a>
impl<'a> Unpin for ContextBuilder<'a>
impl<'a> !UnwindSafe for ContextBuilder<'a>

Blanket Implementations

Source
impl<T> Any for Twhere
    T: 'static + ?Sized,
Source
fn type_id(&self) -> TypeId
Gets the TypeId of self. Read more
Source
impl<T> Borrow<T> for Twhere
    T: ?Sized,
Source
fn borrow(&self) -> &T
Immutably borrows from an owned value. Read more
Source
impl<T> BorrowMut<T> for Twhere
    T: ?Sized,
Source
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
Source
impl<T> From<T> for T
Source
fn from(t: T) -> T

Returns the argument unchanged.

Source
impl<T, U> Into<U> for Twhere
    U: From<T>,
Source
fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Source
impl<T, U> TryFrom<U> for Twhere
    U: Into<T>,
Source
type Error = Infallible
The type returned in the event of a conversion error.
Source
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
Performs the conversion.
Source
impl<T, U> TryInto<U> for Twhere
    U: TryFrom<T>,
Source
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
Source
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
Performs the conversion.

© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/task/struct.ContextBuilder.html