Struct ReusableBoxFuture 

pub(crate) struct ReusableBoxFuture<T> {
    boxed: NonNull<dyn Future<Output = T> + Send>,
}

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.

Fields

boxed: NonNull<dyn Future<Output = T> + Send>

Implementations

impl<T> ReusableBoxFuture<T>

pub(crate) fn new<F>(future: F) -> Self

where F: Future<Output = T> + Send + 'static,

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

pub(crate) fn set<F>(&mut self, future: F)

where F: Future<Output = T> + Send + 'static,

Replaces 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(crate) fn try_set<F>(&mut self, future: F) -> Result<(), F>

where F: Future<Output = T> + Send + 'static,

Replaces 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.

unsafe fn set_same_layout<F>(&mut self, future: F)

where F: Future<Output = T> + Send + 'static,

Sets the current future.

Safety

This function requires that the layout of the provided future is the same as self.layout.

pub(crate) fn get_pin(&mut self) -> Pin<&mut (dyn Future<Output = T> + Send)>

Gets a pinned reference to the underlying future.

pub(crate) fn poll(&mut self, cx: &mut Context<'_>) -> Poll<T>

Polls the future stored inside this box.

Trait Implementations

impl<T> Debug for ReusableBoxFuture<T>

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

Formats the value using the given formatter.

impl<T> Drop for ReusableBoxFuture<T>

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

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

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl<T> Future for ReusableBoxFuture<T>

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

Polls the future stored inside this box.

type Output = T

The type of value produced on completion.

impl<T> Send for ReusableBoxFuture<T>

impl<T> Sync for ReusableBoxFuture<T>

impl<T> Unpin for ReusableBoxFuture<T>