core::task::LocalWaker - Rust
Description: API documentation for the Rust `LocalWaker` struct in crate `core`.
Keywords: rust, rustlang, rust-lang, LocalWaker

# [−][src]Struct core::task::LocalWaker

    #[repr(transparent)]
    pub struct LocalWaker(_);

🔬 This is a nightly-only experimental API. (`futures_api` #50547)

futures in libcore are unstable

A `LocalWaker` is a handle for waking up a task by notifying its executor that it is ready to be run.

This is similar to the `Waker` type, but cannot be sent across threads. Task executors can use this type to implement more optimized single-threaded wakeup behavior.

## Methods

### `impl LocalWaker`[src]

#### `pub unsafe fn new(inner: NonNull<dyn UnsafeWake>) -> Self`[src]

🔬 This is a nightly-only experimental API. (`futures_api` #50547)

futures in libcore are unstable

Constructs a new `LocalWaker` directly.

Note that most code will not need to call this. Implementers of the `UnsafeWake` trait will typically provide a wrapper that calls this but you otherwise shouldn't call it directly.

If you're working with the standard library then it's recommended to use the `local_waker_from_nonlocal` or `local_waker` to convert a `Waker` into a `LocalWaker`.

For this function to be used safely, it must be sound to call `inner.wake_local()` on the current thread.

#### `pub fn as_waker(&self) -> &Waker`[src]

🔬 This is a nightly-only experimental API. (`futures_api` #50547)

futures in libcore are unstable

Borrows this `LocalWaker` as a `Waker`.

`Waker` is nearly identical to `LocalWaker`, but is threadsafe (implements `Send` and `Sync`).

#### `pub fn into_waker(self) -> Waker`[src]

🔬 This is a nightly-only experimental API. (`futures_api` #50547)

futures in libcore are unstable

Converts this `LocalWaker` into a `Waker`.

`Waker` is nearly identical to `LocalWaker`, but is threadsafe (implements `Send` and `Sync`).

#### `pub fn wake(&self)`[src]

🔬 This is a nightly-only experimental API. (`futures_api` #50547)

futures in libcore are unstable

Wake up the task associated with this `LocalWaker`.

#### `pub fn will_wake(&self, other: &LocalWaker) -> bool`[src]

🔬 This is a nightly-only experimental API. (`futures_api` #50547)

futures in libcore are unstable

Returns whether or not this `LocalWaker` and `other` `LocalWaker` awaken the same task.

This function works on a best-effort basis, and may return false even when the `LocalWaker`s would awaken the same task. However, if this function returns true, it is guaranteed that the `LocalWaker`s will awaken the same task.

This function is primarily used for optimization purposes.

#### `pub fn will_wake_nonlocal(&self, other: &Waker) -> bool`[src]

🔬 This is a nightly-only experimental API. (`futures_api` #50547)

futures in libcore are unstable

Returns whether or not this `LocalWaker` and `other` `Waker` awaken the same task.

This function works on a best-effort basis, and may return false even when the `Waker`s would awaken the same task. However, if this function returns true, it is guaranteed that the `LocalWaker`s will awaken the same task.

This function is primarily used for optimization purposes.

## Trait Implementations

### `impl !Send for LocalWaker`[src]

### `impl !Sync for LocalWaker`[src]

### `impl Unpin for LocalWaker`[src]

### `impl Clone for LocalWaker`[src]

#### `fn clone(&self) -> LocalWaker`[src]

Returns a copy of the value. Read more

#### `fn clone_from(&mut self, source: &Self)`
1.0.0
[src]

Performs copy-assignment from `source`. Read more

### `impl From<LocalWaker> for Waker`[src]

#### `fn from(local_waker: LocalWaker) -> Self`[src]

Converts a `LocalWaker` into a `Waker`.

This conversion turns a `!Sync` `LocalWaker` into a `Sync` `Waker`, allowing a wakeup object to be sent to another thread, but giving up its ability to do specialized thread-local wakeup behavior.

### `impl Debug for LocalWaker`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result`[src]

Formats the value using the given formatter. Read more

## Blanket Implementations

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

#### `fn into(Self) -> U`[src]

Performs the conversion.

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

#### `fn from(T) -> T`[src]

Performs the conversion.

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

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

🔬 This is a nightly-only experimental API. (`try_from` #33417)

The type returned in the event of a conversion error.

#### `fn try_into(Self) -> Result<U, <U as TryFrom<T>>::Error>`[src]

🔬 This is a nightly-only experimental API. (`try_from` #33417)

Performs the conversion.

### `impl<T, U> TryFrom for T where
T: From<U>,` [src]

#### `type Error = !`

🔬 This is a nightly-only experimental API. (`try_from` #33417)

The type returned in the event of a conversion error.

#### `fn try_from(U) -> Result<T, <T as TryFrom<U>>::Error>`[src]

🔬 This is a nightly-only experimental API. (`try_from` #33417)

Performs the conversion.

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

#### `fn borrow(&Self) -> &T`[src]

Immutably borrows from an owned value. Read more

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

#### `fn borrow_mut(&mut Self) -> &mut T`[src]

Mutably borrows from an owned value. Read more

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

#### `fn get_type_id(&Self) -> TypeId`[src]

🔬 This is a nightly-only experimental API. (`get_type_id` #27745)

this method will likely be replaced by an associated static

Gets the `TypeId` of `self`. Read more

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