Enum Steal

#[must_use]
pub enum Steal<T>

Possible outcomes of a steal operation.

Examples

There are lots of ways to chain results of steal operations together:

use crossbeam_deque::Steal::{self, Empty, Retry, Success};

let collect = |v: Vec<Steal<i32>>| v.into_iter().collect::<Steal<i32>>();

assert_eq!(collect(vec![Empty, Empty, Empty]), Empty);
assert_eq!(collect(vec![Empty, Retry, Empty]), Retry);
assert_eq!(collect(vec![Retry, Success(1), Empty]), Success(1));

assert_eq!(collect(vec![Empty, Empty]).or_else(|| Retry), Retry);
assert_eq!(collect(vec![Retry, Empty]).or_else(|| Success(1)), Success(1));

Variants

Empty

The queue was empty at the time of stealing.

Success(T)

At least one task was successfully stolen.

Retry

The steal operation needs to be retried.

Implementations

impl<T> Steal<T>

fn is_empty(&self) -> bool

Returns true if the queue was empty at the time of stealing.

Examples

use crossbeam_deque::Steal::{Empty, Retry, Success};

assert!(!Success(7).is_empty());
assert!(!Retry::<i32>.is_empty());

assert!(Empty::<i32>.is_empty());

fn is_success(&self) -> bool

Returns true if at least one task was stolen.

Examples

use crossbeam_deque::Steal::{Empty, Retry, Success};

assert!(!Empty::<i32>.is_success());
assert!(!Retry::<i32>.is_success());

assert!(Success(7).is_success());

fn is_retry(&self) -> bool

Returns true if the steal operation needs to be retried.

Examples

use crossbeam_deque::Steal::{Empty, Retry, Success};

assert!(!Empty::<i32>.is_retry());
assert!(!Success(7).is_retry());

assert!(Retry::<i32>.is_retry());

fn success(self) -> Option<T>

Returns the result of the operation, if successful.

Examples

use crossbeam_deque::Steal::{Empty, Retry, Success};

assert_eq!(Empty::<i32>.success(), None);
assert_eq!(Retry::<i32>.success(), None);

assert_eq!(Success(7).success(), Some(7));

fn or_else<F>(self, f: F) -> Steal<T>
where
    F: FnOnce() -> Steal<T>,

If no task was stolen, attempts another steal operation.

Returns this steal result if it is Success. Otherwise, closure f is invoked and then:

  • If the second steal resulted in Success, it is returned.
  • If both steals were unsuccessful but any resulted in Retry, then Retry is returned.
  • If both resulted in None, then None is returned.

Examples

use crossbeam_deque::Steal::{Empty, Retry, Success};

assert_eq!(Success(1).or_else(|| Success(2)), Success(1));
assert_eq!(Retry.or_else(|| Success(2)), Success(2));

assert_eq!(Retry.or_else(|| Empty), Retry::<i32>);
assert_eq!(Empty.or_else(|| Retry), Retry::<i32>);

assert_eq!(Empty.or_else(|| Empty), Empty::<i32>);

Trait Implementations

impl<T> Debug for Steal<T>

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

impl<T> FromIterator<Steal<T>> for Steal<T>

fn from_iter<I>(iter: I) -> Steal<T>
where
    I: IntoIterator<Item = Steal<T>>,

Consumes items until a Success is found and returns it.

If no Success was found, but there was at least one Retry, then returns Retry. Otherwise, Empty is returned.

impl<T: Clone> Clone for Steal<T>

fn clone(&self) -> Self

impl<T: Copy> Copy for Steal<T>

impl<T: Eq> Eq for Steal<T>

impl<T: PartialEq> PartialEq for Steal<T>

fn eq(&self, other: &Self) -> bool

impl<T: PartialEq> StructuralPartialEq for Steal<T>

Auto Trait Implementations

impl<T> Freeze for Steal<T> where T: Freeze,

impl<T> RefUnwindSafe for Steal<T> where T: RefUnwindSafe,

impl<T> Send for Steal<T> where T: Send,

impl<T> Sync for Steal<T> where T: Sync,

impl<T> Unpin for Steal<T> where T: Unpin,

impl<T> UnsafeUnpin for Steal<T> where T: UnsafeUnpin,

impl<T> UnwindSafe for Steal<T> where T: UnwindSafe,

Blanket Implementations

impl<T> Any for Steal<T> where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<T> Borrow<T> for Steal<T> where T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Steal<T> where T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

impl<T> CloneToUninit for Steal<T> where T: Clone,

unsafe fn clone_to_uninit(&self, dest: *mut u8)

impl<T> From<T> for Steal<T>

fn from(t: T) -> T

Returns the argument unchanged.

impl<T> Pointable for Steal<T>

const ALIGN: usize = _;
type Init = T;
unsafe fn init(init: <T as Pointable>::Init) -> usize
unsafe fn deref<'a>(ptr: usize) -> &'a T
unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T
unsafe fn drop(ptr: usize)

impl<T> ToOwned for Steal<T> where T: Clone,

type Owned = T;
fn to_owned(&self) -> T
fn clone_into(&self, target: &mut T)

impl<T, U> Into<U> for Steal<T> where U: From<T>,

fn into(self) -> U

Calls U::from(self).

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

impl<T, U> TryFrom<U> for Steal<T> where U: Into<T>,

type Error = never;
fn try_from(value: U) -> Result<T, never>

impl<T, U> TryInto<U> for Steal<T> where U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error;
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>