Struct futures_util::future::Shared

pub struct Shared<Fut: Future> {
    inner: Option<Arc<Inner<Fut>>>,
    waker_key: usize,
}

Future for the shared method.

Fields

inner: Option<Arc<Inner<Fut>>>

waker_key: usize

Implementations

impl<Fut: Future> Shared<Fut>

pub(super) fn new(future: Fut) -> Self

impl<Fut> Shared<Fut>

where Fut: Future,

pub fn peek(&self) -> Option<&Fut::Output>

Returns Some containing a reference to this Shared’s output if it has already been computed by a clone or None if it hasn’t been computed yet or this Shared already returned its output from poll.

pub fn downgrade(&self) -> Option<WeakShared<Fut>>

Creates a new WeakShared for this Shared.

Returns None if it has already been polled to completion.

pub fn strong_count(&self) -> Option<usize>

Gets the number of strong pointers to this allocation.

Returns None if it has already been polled to completion.

Safety

This method by itself is safe, but using it correctly requires extra care. Another thread can change the strong count at any time, including potentially between calling this method and acting on the result.

pub fn weak_count(&self) -> Option<usize>

Gets the number of weak pointers to this allocation.

Returns None if it has already been polled to completion.

Safety

This method by itself is safe, but using it correctly requires extra care. Another thread can change the weak count at any time, including potentially between calling this method and acting on the result.

pub fn ptr_hash<H: Hasher>(&self, state: &mut H)

Hashes the internal state of this Shared in a way that’s compatible with ptr_eq.

pub fn ptr_eq(&self, rhs: &Self) -> bool

Returns true if the two Shareds point to the same future (in a vein similar to Arc::ptr_eq).

Returns false if either Shared has terminated.

Trait Implementations

impl<Fut> Clone for Shared<Fut>

where Fut: Future,

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<Fut: Future> Debug for Shared<Fut>

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

Formats the value using the given formatter.

impl<Fut> Drop for Shared<Fut>

where Fut: Future,

fn drop(&mut self)

Executes the destructor for this type.

impl<Fut> FusedFuture for Shared<Fut>

where Fut: Future, Fut::Output: Clone,

fn is_terminated(&self) -> bool

Returns true if the underlying future should no longer be polled.

impl<Fut> Future for Shared<Fut>

where Fut: Future, Fut::Output: Clone,

type Output = <Fut as Future>::Output

The type of value produced on completion.

fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>

Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available.