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

# [−][src]Struct core::task::Waker

    #[repr(transparent)]
    pub struct Waker { /* fields omitted */ }

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

futures in libcore are unstable

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

This handle contains a trait object pointing to an instance of the `UnsafeWake` trait, allowing notifications to get routed through it.

## Methods

### `impl Waker`[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 `Waker` 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 `Waker::from` function instead which works with the safe `Arc` type and the safe `Wake` trait.

#### `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 `Waker`.

#### `pub fn will_wake(&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 `Waker` and `other` 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 `Waker`s will awaken the same task.

This function is primarily used for optimization purposes.

#### `pub fn will_wake_local(&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 `Waker` and `other` `LocalWaker` 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 `Waker`s will awaken the same task.

This function is primarily used for optimization purposes.

## Trait Implementations

### `impl Send for Waker`[src]

### `impl Sync for Waker`[src]

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

### `impl Drop for Waker`[src]

#### `fn drop(&mut self)`[src]

Executes the destructor for this type. Read more

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

#### `fn clone(&self) -> Self`[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 Waker`[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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