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Struct std::sync::OnceState

pub struct OnceState { /* fields omitted */ }
🔬 This is a nightly-only experimental API. (once_poison #33577)

State yielded to call_once_force’s closure parameter. The state can be used to query the poison status of the Once.

Methods

impl OnceState[src]

pub fn poisoned(&self) -> bool[src]

🔬 This is a nightly-only experimental API. (once_poison #33577)

Returns true if the associated Once was poisoned prior to the invocation of the closure passed to call_once_force.

Examples

A poisoned Once:

#![feature(once_poison)]

use std::sync::Once;
use std::thread;

static INIT: Once = Once::new();

// poison the once
let handle = thread::spawn(|| {
    INIT.call_once(|| panic!());
});
assert!(handle.join().is_err());

INIT.call_once_force(|state| {
    assert!(state.poisoned());
});

An unpoisoned Once:

#![feature(once_poison)]

use std::sync::Once;

static INIT: Once = Once::new();

INIT.call_once_force(|state| {
    assert!(!state.poisoned());
});

Trait Implementations

impl Debug for OnceState[src]

Auto Trait Implementations

impl UnwindSafe for OnceState

impl RefUnwindSafe for OnceState

impl Unpin for OnceState

impl Send for OnceState

impl Sync for OnceState

Blanket Implementations

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T> From<T> for T[src]

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

ⓘImportant traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
    F: Unpin + Future + ?Sized, 
    type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
    I: Iterator + ?Sized, 
    type Item = <I as Iterator>::Item;
impl<'_, R: Read + ?Sized> Read for &'_ mut R
impl<'_, W: Write + ?Sized> Write for &'_ mut W

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

ⓘImportant traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
    F: Unpin + Future + ?Sized, 
    type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
    I: Iterator + ?Sized, 
    type Item = <I as Iterator>::Item;
impl<'_, R: Read + ?Sized> Read for &'_ mut R
impl<'_, W: Write + ?Sized> Write for &'_ mut W

impl<T> Any for T where
    T: 'static + ?Sized
[src]

© 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/sync/struct.OnceState.html