# tokio_util::sync::ReusableBoxFuture - Rust
API documentation for the Rust `ReusableBoxFuture` struct in crate `tokio_util`.
Keywords: rust, rustlang, rust-lang, ReusableBoxFuture

# Struct tokio_util::sync::ReusableBoxFuture [−] [src]

    pub struct ReusableBoxFuture<T> { /* fields omitted */ }

A reusable `Pin<Box<dyn Future<Output = T> + Send>>`.

This type lets you replace the future stored in the box without reallocating when the size and alignment permits this.

## Implementations

### `impl<T> ReusableBoxFuture<T>` [src]

#### `pub fn new<F>(future: F) -> Self where
F: Future<Output = T> + Send + 'static,` [src]

Create a new `ReusableBoxFuture<T>` containing the provided future.

#### `pub fn set<F>(&mut self, future: F) where
F: Future<Output = T> + Send + 'static,` [src]

Replace the future currently stored in this box.

This reallocates if and only if the layout of the provided future is different from the layout of the currently stored future.

#### `pub fn try_set<F>(&mut self, future: F) -> Result<(), F> where
F: Future<Output = T> + Send + 'static,` [src]

Replace the future currently stored in this box.

This function never reallocates, but returns an error if the provided future has a different size or alignment from the currently stored future.

#### `pub fn get_pin(&mut self) -> Pin<&mut (dyn Future<Output = T> + Send)>` [src]

Get a pinned reference to the underlying future.

#### `pub fn poll(&mut self, cx: &mut Context<'_>) -> Poll<T>` [src]

Poll the future stored inside this box.

## Trait Implementations

### `impl<T> Debug for ReusableBoxFuture<T>` [src]

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

Formats the value using the given formatter. Read more

### `impl<T> Drop for ReusableBoxFuture<T>` [src]

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

Executes the destructor for this type. Read more

### `impl<T> Future for ReusableBoxFuture<T>` [src]

#### `type Output = T`

The type of value produced on completion.

#### `fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T>` [src]

Poll the future stored inside this box.

### `impl<T> Send for ReusableBoxFuture<T>` [src]

### `impl<T> Sync for ReusableBoxFuture<T>` [src]

### `impl<T> Unpin for ReusableBoxFuture<T>` [src]

## Auto Trait Implementations

### `impl<T> !RefUnwindSafe for ReusableBoxFuture<T>` [src]

### `impl<T> !UnwindSafe for ReusableBoxFuture<T>` [src]

## Blanket Implementations

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

#### `pub fn type_id(&self) -> TypeId` [src]

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

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

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

Immutably borrows from an owned value. Read more

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

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

Mutably borrows from an owned value. Read more

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

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

Performs the conversion.

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

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

Performs the conversion.

### `impl<F> IntoFuture for F where
F: Future,` [src]

#### `type Output = <F as Future>::Output`

🔬 This is a nightly-only experimental API. (`into_future`)

The output that the future will produce on completion.

#### `type Future = F`

🔬 This is a nightly-only experimental API. (`into_future`)

Which kind of future are we turning this into?

#### `pub fn into_future(self) -> <F as IntoFuture>::Future` [src]

🔬 This is a nightly-only experimental API. (`into_future`)

Creates a future from a value.

### `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.

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

Performs the conversion.

### `impl<F, T, E> TryFuture for F where
F: Future<Output = Result<T, E>> + ?Sized,` [src]

#### `type Ok = T`

The type of successful values yielded by this future

#### `type Error = E`

The type of failures yielded by this future

#### `pub fn try_poll(
self: Pin<&mut F>,
cx: &mut Context<'_>
) -> Poll<<F as Future>::Output>` [src]

Poll this `TryFuture` as if it were a `Future`. Read more

### `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.

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

Performs the conversion.