Module futures_util::future

Asynchronous values.

This module contains:

• The Future trait.
• The FutureExt and TryFutureExt trait, which provides adapters for chaining and composing futures.
• Top-level future combinators like lazy which creates a future from a closure that defines its return value, and ready, which constructs a future with an immediate defined value.

Re-exports

• pub use core::future::Future;

Structs

• AbortHandle
  A handle to an Abortable task.
• AbortRegistration
  A registration handle for an Abortable task. Values of this type can be acquired from AbortHandle::new and are used in calls to Abortable::new.
• Abortable
  A future/stream which can be remotely short-circuited using an AbortHandle.
• Aborted
  Indicator that the Abortable task was aborted.
• AlwaysReady
  Future for the always_ready function.
• AndThen
  Future for the and_then method.
• CatchUnwind
  Future for the catch_unwind method.
• ErrInto
  Future for the err_into method.
• Flatten
  Future for the flatten method.
• FlattenStream
  Stream for the flatten_stream method.
• Fuse
  Future for the fuse method.
• FutureObj
  A custom trait object for polling futures, roughly akin to Box<dyn Future<Output = T> + Send + 'a>.
• Inspect
  Future for the inspect method.
• InspectErr
  Future for the inspect_err method.
• InspectOk
  Future for the inspect_ok method.
• IntoFuture
  Future for the into_future method.
• IntoStream
  Stream for the into_stream method.
• Join
  Future for the join function.
• Join3
  Future for the join3 function.
• Join4
  Future for the join4 function.
• Join5
  Future for the join5 function.
• JoinAll
  Future for the join_all function.
• Lazy
  Future for the lazy function.
• LocalFutureObj
  A custom trait object for polling futures, roughly akin to Box<dyn Future<Output = T> + 'a>.
• Map
  Future for the map method.
• MapErr
  Future for the map_err method.
• MapInto
  Future for the map_into combinator.
• MapOk
  Future for the map_ok method.
• MapOkOrElse
  Future for the map_ok_or_else method.
• NeverError
  Future for the never_error combinator.
• OkInto
  Future for the ok_into method.
• OptionFuture
  A future representing a value which may or may not be present.
• OrElse
  Future for the or_else method.
• Pending
  Future for the pending() function.
• PollFn
  Future for the poll_fn function.
• PollImmediate
  Future for the poll_immediate function.
• Ready
  Future for the ready function.
• Select
  Future for the select() function.
• SelectAll
  Future for the select_all function.
• SelectOk
  Future for the select_ok function.
• Shared
  Future for the shared method.
• Then
  Future for the then method.
• TryFlatten
  Future for the try_flatten method.
• TryFlattenStream
  Future for the try_flatten_stream method.
• TryJoin
  Future for the try_join function.
• TryJoin3
  Future for the try_join3 function.
• TryJoin4
  Future for the try_join4 function.
• TryJoin5
  Future for the try_join5 function.
• TryJoinAll
  Future for the try_join_all function.
• TrySelect
  Future for the try_select() function.
• UnitError
  Future for the unit_error combinator.
• UnwrapOrElse
  Future for the unwrap_or_else method.
• WeakShared
  A weak reference to a Shared that can be upgraded much like an Arc.

Enums

• Either
  Combines two different futures, streams, or sinks having the same associated types into a single type.
• MaybeDone
  A future that may have completed.
• TryMaybeDone
  A future that may have completed with an error.

Traits

• FusedFuture
  A future which tracks whether or not the underlying future should no longer be polled.
• FutureExt
  An extension trait for Futures that provides a variety of convenient adapters.
• TryFuture
  A convenience for futures that return Result values that includes a variety of adapters tailored to such futures.
• TryFutureExt
  Adapters specific to Result-returning futures
• UnsafeFutureObj
  A custom implementation of a future trait object for FutureObj, providing a vtable with drop support.

Functions

• abortable
  Creates a new Abortable future and an AbortHandle which can be used to stop it.
• always_ready
  Creates a future that is always immediately ready with a value.
• err
  Create a future that is immediately ready with an error value.
• join
  Joins the result of two futures, waiting for them both to complete.
• join3
  Same as join, but with more futures.
• join4
  Same as join, but with more futures.
• join5
  Same as join, but with more futures.
• join_all
  Creates a future which represents a collection of the outputs of the futures given.
• lazy
  Creates a new future that allows delayed execution of a closure.
• maybe_done
  Wraps a future into a MaybeDone
• ok
  Create a future that is immediately ready with a success value.
• pending
  Creates a future which never resolves, representing a computation that never finishes.
• poll_fn
  Creates a new future wrapping around a function returning Poll.
• poll_immediate
  Creates a future that is immediately ready with an Option of a value. Specifically this means that poll always returns Poll::Ready.
• ready
  Creates a future that is immediately ready with a value.
• select
  Waits for either one of two differently-typed futures to complete.
• select_all
  Creates a new future which will select over a list of futures.
• select_ok
  Creates a new future which will select the first successful future over a list of futures.
• try_join
  Joins the result of two futures, waiting for them both to complete or for one to produce an error.
• try_join3
  Same as try_join, but with more futures.
• try_join4
  Same as try_join, but with more futures.
• try_join5
  Same as try_join, but with more futures.
• try_join_all
  Creates a future which represents either a collection of the results of the futures given or an error.
• try_maybe_done
  Wraps a future into a TryMaybeDone
• try_select
  Waits for either one of two differently-typed futures to complete.

Type Aliases

• BoxFuture
  An owned dynamically typed Future for use in cases where you can’t statically type your result or need to add some indirection.
• LocalBoxFuture
  BoxFuture, but without the Send requirement.