[−][src]Struct futures::future::OptionFuture
#[must_use = "futures do nothing unless polled"]pub struct OptionFuture<F> { /* fields omitted */ }
A future representing a value which may or may not be present.
Created by the From implementation for Option.
Examples
#![feature(async_await, await_macro)] use futures::future::{self, OptionFuture}; let mut a: OptionFuture<_> = Some(future::ready(123)).into(); assert_eq!(await!(a), Some(123)); a = None.into(); assert_eq!(await!(a), None);
Trait Implementations
impl<F> Clone for OptionFuture<F> where
F: Clone, [src][+]
F: Clone,
ⓘImportant traits for OptionFuture<F>Important traits for OptionFuture<F>
impl<F> Future for OptionFuture<F> where
F: Future, type Output = Option<<F as Future>::Output>;fn clone(&self) -> OptionFuture<F>[src][+]
Important traits for OptionFuture<F>
impl<F> Future for OptionFuture<F> where
F: Future, type Output = Option<<F as Future>::Output>;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<F> Debug for OptionFuture<F> where
F: Debug, [src][+]
F: Debug,
fn fmt(&self, f: &mut Formatter) -> Result<(), Error>[src][+]
Formats the value using the given formatter. Read more
impl<F> Future for OptionFuture<F> where
F: Future, [src][+]
F: Future,
type Output = Option<<F as Future>::Output>
The type of value produced on completion.
fn poll(
self: Pin<&mut OptionFuture<F>>,
cx: &mut Context
) -> Poll<<OptionFuture<F> as Future>::Output>[src][+]
self: Pin<&mut OptionFuture<F>>,
cx: &mut Context
) -> Poll<<OptionFuture<F> as Future>::Output>
Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available. Read more
impl<T> From<Option<T>> for OptionFuture<T>[src][+]
ⓘImportant traits for OptionFuture<F>Important traits for OptionFuture<F>
impl<F> Future for OptionFuture<F> where
F: Future, type Output = Option<<F as Future>::Output>;fn from(option: Option<T>) -> OptionFuture<T>[src][+]
Important traits for OptionFuture<F>
impl<F> Future for OptionFuture<F> where
F: Future, type Output = Option<<F as Future>::Output>;Performs the conversion.
Auto Trait Implementations
impl<F> Send for OptionFuture<F> where
F: Send,
F: Send,
impl<F> Sync for OptionFuture<F> where
F: Sync,
F: Sync,
Blanket Implementations
impl<T> From for T[src][+]
impl<T, U> Into for T where
U: From<T>, [src][+]
U: From<T>,
impl<T> ToOwned for T where
T: Clone, [src][+]
T: Clone,
type Owned = T
The resulting type after obtaining ownership.
fn to_owned(&self) -> T[src][+]
Creates owned data from borrowed data, usually by cloning. Read more
fn clone_into(&self, target: &mut T)[src][+]
🔬 This is a nightly-only experimental API. (toowned_clone_into)
recently added
Uses borrowed data to replace owned data, usually by cloning. Read more
impl<T, U> TryFrom for T where
U: Into<T>, [src][+]
U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src][+]
Performs the conversion.
impl<T> Borrow for T where
T: ?Sized, [src][+]
T: ?Sized,
ⓘImportant traits for &'_ mut Ffn borrow(&self) -> &T[src][+]
Immutably borrows from an owned value. Read more
impl<T> Any for T where
T: 'static + ?Sized, [src][+]
T: 'static + ?Sized,
fn type_id(&self) -> TypeId[src][+]
Gets the TypeId of self. Read more
impl<T> BorrowMut for T where
T: ?Sized, [src][+]
T: ?Sized,
ⓘImportant traits for &'_ mut Ffn borrow_mut(&mut self) -> &mut T[src][+]
Mutably borrows from an owned value. Read more
impl<T, U> TryInto for T where
U: TryFrom<T>, [src][+]
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>[src][+]
Performs the conversion.
impl<T> FutureExt for T where
T: Future + ?Sized, [src][+]
T: Future + ?Sized,
ⓘImportant traits for Map<Fut, F>fn map<U, F>(self, f: F) -> Map<Self, F> where
F: FnOnce(Self::Output) -> U, [src][+]
F: FnOnce(Self::Output) -> U,
Map this future's output to a different type, returning a new future of the resulting type. Read more
ⓘImportant traits for Then<Fut1, Fut2, F>fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F> where
F: FnOnce(Self::Output) -> Fut,
Fut: Future, [src][+]
F: FnOnce(Self::Output) -> Fut,
Fut: Future,
Chain on a computation for when a future finished, passing the result of the future to the provided closure f. Read more
ⓘImportant traits for Either<A, B>fn left_future<B>(self) -> Either<Self, B> where
B: Future<Output = Self::Output>, [src][+]
B: Future<Output = Self::Output>,
Wrap this future in an Either future, making it the left-hand variant of that Either. Read more
ⓘImportant traits for Either<A, B>fn right_future<A>(self) -> Either<A, Self> where
A: Future<Output = Self::Output>, [src][+]
A: Future<Output = Self::Output>,
Wrap this future in an Either future, making it the right-hand variant of that Either. Read more
fn into_stream(self) -> IntoStream<Self>[src][+]
Convert this future into a single element stream. Read more
ⓘImportant traits for Flatten<Fut>fn flatten(self) -> Flatten<Self> where
Self::Output: Future, [src][+]
Self::Output: Future,
Flatten the execution of this future when the successful result of this future is itself another future. Read more
fn flatten_stream(self) -> FlattenStream<Self> where
Self::Output: Stream, [src][+]
Self::Output: Stream,
Flatten the execution of this future when the successful result of this future is a stream. Read more
ⓘImportant traits for Fuse<Fut>fn fuse(self) -> Fuse<Self>[src][+]
Fuse a future such that poll will never again be called once it has completed. This method can be used to turn any Future into a FusedFuture. Read more
ⓘImportant traits for Inspect<Fut, F>fn inspect<F>(self, f: F) -> Inspect<Self, F> where
F: FnOnce(&Self::Output), [src][+]
F: FnOnce(&Self::Output),
Do something with the output of a future before passing it on. Read more
ⓘImportant traits for CatchUnwind<Fut>Important traits for CatchUnwind<Fut>
impl<Fut> Future for CatchUnwind<Fut> where
Fut: Future + UnwindSafe, type Output = Result<<Fut as Future>::Output, Box<dyn Any + 'static + Send>>;fn catch_unwind(self) -> CatchUnwind<Self> where
Self: UnwindSafe, [src][+]
Important traits for CatchUnwind<Fut>
impl<Fut> Future for CatchUnwind<Fut> where
Fut: Future + UnwindSafe, type Output = Result<<Fut as Future>::Output, Box<dyn Any + 'static + Send>>;Self: UnwindSafe,
Catches unwinding panics while polling the future. Read more
ⓘImportant traits for Shared<Fut>fn shared(self) -> Shared<Self> where
Self::Output: Clone, [src][+]
Self::Output: Clone,
Create a cloneable handle to this future where all handles will resolve to the same result. Read more
fn remote_handle(self) -> (Remote<Self>, RemoteHandle<Self::Output>)[src][+]
Turn this future into a future that yields () on completion and sends its output to another future on a separate task. Read more
ⓘImportant traits for Pin<P>fn boxed<'a>(self) -> Pin<Box<dyn Future<Output = Self::Output> + 'a + Send>> where
Self: Send + 'a, [src][+]
Self: Send + 'a,
Wrap the future in a Box, pinning it.
ⓘImportant traits for UnitError<Fut>fn unit_error(self) -> UnitError<Self>[src][+]
Turns a Future<Output = T> into a TryFuture<Ok = T, Error = ()>. Read more
ⓘImportant traits for NeverError<Fut>Important traits for NeverError<Fut>
impl<Fut, T> Future for NeverError<Fut> where
Fut: Future<Output = T>, type Output = Result<T, !>;fn never_error(self) -> NeverError<Self>[src][+]
Important traits for NeverError<Fut>
impl<Fut, T> Future for NeverError<Fut> where
Fut: Future<Output = T>, type Output = Result<T, !>;Turns a Future<Output = T> into a TryFuture<Ok = T, Error = !>. Read more
fn poll_unpin(&mut self, cx: &mut Context) -> Poll<Self::Output> where
Self: Unpin, [src][+]
Self: Unpin,
A convenience for calling Future::poll on Unpin future types.