Enum crossbeam::deque::Steal

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pub enum Steal<T> {
    Empty,
    Success(T),
    Retry,
}
Expand description

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§

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Empty

The queue was empty at the time of stealing.

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Success(T)

At least one task was successfully stolen.

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Retry

The steal operation needs to be retried.

Implementations§

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impl<T> Steal<T>

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pub 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());
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pub 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());
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pub 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());
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pub 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));
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pub 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§

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

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fn clone(&self) -> Steal<T>

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl<T> Debug for Steal<T>

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

Formats the value using the given formatter. Read more
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impl<T> FromIterator<Steal<T>> for Steal<T>

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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.

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

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fn eq(&self, other: &Steal<T>) -> bool

This method tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl<T> Copy for Steal<T>
where T: Copy,

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

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impl<T> StructuralPartialEq for Steal<T>

Auto Trait Implementations§

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

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

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

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

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

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

Blanket Implementations§

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

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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

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fn into(self) -> U

Calls U::from(self).

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

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impl<T> Pointable for T

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const ALIGN: usize = _

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.