CHANGELOG.md

0.3.25 - 2022-10-20

• Fix soundness issue in join! and try_join! macros (#2649)
• Implement Clone for sink::Drain (#2650)

0.3.24 - 2022-08-29

• Fix incorrect termination of select_with_strategy streams (#2635)

0.3.23 - 2022-08-14

• Work around MSRV increase due to a cargo bug.

0.3.22 - 2022-08-14

• Fix Sync impl of BiLockGuard (#2570)
• Fix partial iteration in FuturesUnordered (#2574)
• Fix false detection of inner panics in Shared (#2576)
• Add Mutex::lock_owned and Mutex::try_lock_owned (#2571)
• Add io::copy_buf_abortable (#2507)
• Remove Unpin bound from TryStreamExt::into_async_read (#2599)
• Make run_until_stalled handle self-waking futures (#2593)
• Use FuturesOrdered in try_join_all (#2556)
• Fix orderings in LocalPool waker (#2608)
• Fix stream::Chunk adapters size hints (#2611)
• Add push_front and push_back to FuturesOrdered (#2591)
• Deprecate FuturesOrdered::push in favor of FuturesOrdered::push_back (#2591)
• Performance improvements (#2583, #2626)
• Documentation improvements (#2579, #2604, #2613)

0.3.21 - 2022-02-06

• Fix potential data race in FlattenUnordered that introduced in 0.3.20 (#2566)

0.3.20 - 2022-02-06

NOTE: This release has been yanked due to a bug fixed in 0.3.21.

• Fix stacked borrows violations when -Zmiri-tag-raw-pointers is enabled. This raises MSRV of futures-task to 1.45. (#2548, #2550)
• Change FuturesUnordered to respect yielding from future (#2551)
• Add StreamExt::{flatten_unordered, flat_map_unordered} (#2083)

0.3.19 - 2021-12-18

• Remove unstable read-initializer feature (#2534)
• Fix panic in FuturesUnordered (#2535)
• Fix compatibility issue with FuturesUnordered and tokio's cooperative scheduling (#2527)
• Add StreamExt::count (#2495)

0.3.18 - 2021-11-23

NOTE: This release has been yanked. See #2529 for details.

• Fix unusable Sink implementation on stream::Scan (#2499)
• Make task::noop_waker_ref available without std feature (#2505)
• Add async LineWriter (#2477)
• Remove dependency on proc-macro-hack. This raises MSRV of utility crates to 1.45. (#2520)

0.3.17 - 2021-08-30

• Use FuturesOrdered in join_all (#2412)
• Add {future, stream}::poll_immediate (#2452)
• Add stream_select! macro (#2262)
• Implement Default for OptionFuture (#2471)
• Add Peekable::{peek_mut, poll_peek_mut} (#2488)
• Add BufReader::seek_relative (#2489)

0.3.16 - 2021-07-23

• Add TryStreamExt::try_chunks (#2438)
• Add StreamExt::{all, any} (#2460)
• Add stream::select_with_strategy (#2450)
• Update to new io_slice_advance interface (#2454)

0.3.15 - 2021-05-11

• Use #[proc_macro] at Rust 1.45+ to fix an issue where proc macros don't work with rust-analyzer (#2407)
• Support targets that do not have atomic CAS on stable Rust (#2400)
• futures-test: Add async #[test] function attribute (#2409)
• Add stream::abortable (#2410)
• Add FuturesUnordered::clear (#2415)
• Implement IntoIterator for FuturesUnordered (#2423)
• Implement Send and Sync for FuturesUnordered iterators (#2416)
• Make FuturesUnordered::iter_pin_ref public (#2423)
• Add SelectAll::clear (#2430)
• Add SelectAll::{iter, iter_mut} (#2428)
• Implement IntoIterator for SelectAll (#2428)
• Implement Clone for WeakShared (#2396)

0.3.14 - 2021-04-10

• Add future::SelectAll::into_inner (#2363)
• Allow calling UnboundedReceiver::try_next after None (#2369)
• Reexport non-Ext traits from the root of futures_util (#2377)
• Add AsyncSeekExt::stream_position (#2380)
• Add stream::Peekable::{next_if, next_if_eq} (#2379)

0.3.13 - 2021-02-23

• Mitigated starvation issues in FuturesUnordered (#2333)
• Fixed race with dropping mpsc::Receiver (#2304)
• Added Shared::{strong_count, weak_count} (#2346)
• Added no_std support for task::noop_waker_ref (#2332)
• Implemented Stream::size_hint for Either (#2325)

0.3.12 - 2021-01-15

• Fixed Unpin impl of future::{MaybeDone, TryMaybeDone} where trait bounds were accidentally added in 0.3.9. (#2317)

0.3.11 - 2021-01-14

• Fixed heap buffer overflow in AsyncReadExt::{read_to_end, read_to_string} (#2314)

0.3.10 - 2021-01-13

NOTE: This release has been yanked. See #2310 for details.

• Fixed type-inference in sink::unfold by specifying more of its types (breaking change -- see #2311)

0.3.9 - 2021-01-08

NOTE: This release has been yanked. See #2310 for details.

• Significantly improved compile time when async-await crate feature is disabled (#2273)
• Added stream::repeat_with (#2279)
• Added StreamExt::unzip (#2263)
• Added sink::unfold (#2268)
• Added SinkExt::feed (#2155)
• Implemented FusedFuture for oneshot::Receiver (#2300)
• Implemented Clone for sink::With (#2290)
• Re-exported MapOkOrElse, MapInto, OkInto, TryFlatten, WriteAllVectored (#2275)

0.3.8 - 2020-11-04

NOTE: This release has been yanked. See #2310 for details.

• Switched proc-macros to use native #[proc_macro] at Rust 1.45+ (#2243)
• Added WeakShared (#2169)
• Added TryStreamExt::try_buffered (#2245)
• Added StreamExt::cycle (#2252)
• Implemented Clone for stream::{Empty, Pending, Repeat, Iter} (#2248, #2252)
• Fixed panic in some TryStreamExt combinators (#2250)

0.3.7 - 2020-10-23

NOTE: This release has been yanked. See #2310 for details.

• Fixed unsoundness in MappedMutexGuard (#2240)
• Re-exported TakeUntil (#2235)
• futures-test: Prevent double panic in panic_waker (#2236)

0.3.6 - 2020-10-06

NOTE: This release has been yanked. See #2310 for details.

• Fixed UB due to missing 'static on task::waker (#2206)
• Added AsyncBufReadExt::fill_buf (#2225)
• Added TryStreamExt::try_take_while (#2212)
• Added is_connected_to method to mpsc::{Sender, UnboundedSender} (#2179)
• Added is_connected_to method to oneshot::Sender (#2158)
• Implement FusedStream for FuturesOrdered (#2205)
• Fixed documentation links
• Improved documentation
• futures-test: Added track_closed method to AsyncWriteTestExt and SinkTestExt (#2159)
• futures-test: Implemented more traits for InterleavePending (#2208)
• futures-test: Implemented more traits for AssertUnmoved (#2208)

0.3.5 - 2020-05-08

NOTE: This release has been yanked. See #2310 for details.

• Added StreamExt::flat_map.
• Added StreamExt::ready_chunks.
• Added *_unpin methods to SinkExt.
• Added a cancellation() future to oneshot::Sender.
• Added reunite method to ReadHalf and WriteHalf.
• Added Extend implementations for Futures(Un)Ordered and SelectAll.
• Added support for reexporting the join! and select! macros.
• Added no_std support for the pending! and poll! macros.
• Added Send and Sync support for AssertUnmoved.
• Fixed a bug where Shared wasn't relinquishing control to the executor.
• Removed the Send bound on the output of RemoteHandle.
• Relaxed bounds on FuturesUnordered.
• Reorganized internal tests to work under different --features.
• Reorganized the bounds on StreamExt::forward.
• Removed and replaced a large amount of internal unsafe.

0.3.4 - 2020-02-06

NOTE: This release has been yanked. See #2310 for details.

• Fixed missing Drop for UnboundedReceiver (#2064)

0.3.3 - 2020-02-04

NOTE: This release has been yanked. See #2310 for details.

• Fixed compatibility issue with pinned facade (#2062)

0.3.2 - 2020-02-03

NOTE: This release has been yanked. See #2310 for details.

• Improved buffering performance of SplitSink (#1969)
• Added select_biased! macro (#1976)
• Added hash_receiver method to mpsc channel (#1962)
• Added stream::try_unfold (#1977)
• Fixed bug with zero-size buffers in vectored IO (#1998)
• AtomicWaker::new() is now const fn (#2007)
• Fixed bug between threadpool and user park/unparking (#2010)
• Added stream::Peekable::peek (#2021)
• Added StreamExt::scan (#2044)
• Added impl of AsyncRead/Write for BufReader/Writer (#2033)
• Added impl of Spawn and LocalSpawn for Arc<impl Spawn and Rc<impl Spawn> (#2039)
• Fixed Sync issues with FuturesUnordered (#2054)
• Added into_inner method for future::Ready (#2055)
• Added MappedMutexGuard API (#2056)
• Mitigated starvation issues in FuturesUnordered (#2049)
• Added TryFutureExt::map_ok_or_else (#2058)

0.3.1 - 2019-11-07

NOTE: This release has been yanked. See #2310 for details.

• Fix signature of SpawnExt and LocalSpawnExt trait (breaking change -- see #1959)

0.3.0 - 2019-11-05

NOTE: This release has been yanked. See #2310 for details.

• Stable release along with stable async/await!
• Added async/await to default features (#1953)
• Changed Spawn trait and FuturesUnordered::push to take &self (#1950)
• Moved Spawn and FutureObj out of futures-core and into futures-task (#1925)
• Changed case convention for feature names (#1937)
• Added executor feature (#1949)
• Moved copy_into/copy_buf_into (#1948)
• Changed SinkExt::send_all to accept a TryStream (#1946)
• Removed ThreadPool::run (#1944)
• Changed to use our own definition of io::Cursor (#1943)
• Removed BufReader::poll_seek_relative (#1938)
• Changed skip to take a usize rather than u64 (#1931)
• Removed Stream impl for VecDeque (#1930)
• Renamed Peekable::peek to poll_peek (#1928)
• Added immutable iterators for FuturesUnordered (#1922)
• Made ThreadPool optional (#1910)
• Renamed oneshot::Sender::poll_cancel to poll_canceled (#1908)
• Added some missing Clone implementations
• Documentation fixes

0.3.0-alpha.19 - 2019-09-25

• Stabilized the async-await feature (#1816)
• Made async-await feature no longer require std feature (#1815)
• Updated proc-macro2, syn, and quote to 1.0 (#1798)
• Exposed unstable BiLock (#1827)
• Renamed "nightly" feature to "unstable" (#1823)
• Moved to our own io::{Empty, Repeat, Sink} (#1829)
• Made AsyncRead::initializer API unstable (#1845)
• Moved the Never type from futures-core to futures-util (#1836)
• Fixed use-after-free on panic in ArcWake::wake_by_ref (#1797)
• Added AsyncReadExt::chain (#1810)
• Added Stream::size_hint (#1853)
• Added some missing FusedFuture (#1868) and FusedStream implementations (#1831)
• Added a From impl for Mutex (#1839)
• Added Mutex::{get_mut, into_inner} (#1839)
• Re-exported TryConcat and TryFilter (#1814)
• Lifted Unpin bound and implemented AsyncBufRead for io::Take (#1821)
• Lifted Unpin bounds on get_pin_mut (#1820)
• Changed SendAll to flush the Sink when the source Stream is pending (#1877)
• Set default threadpool size to one if num_cpus::get() returns zero (#1835)
• Removed dependency on rand by using our own PRNG (#1837)
• Removed futures-core dependency from futures-sink (#1832)

0.3.0-alpha.18 - 2019-08-09

• Rewrote join! and try_join! as procedural macros to allow passing expressions (#1783)
• Banned manual implementation of TryFuture and TryStream for forward compatibility. See #1776 for more details. (#1777)
• Changed AsyncReadExt::read_to_end to return the total number of bytes read (#1721)
• Changed ArcWake::into_waker to a free function waker (#1676)
• Supported trailing commas in macros (#1733)
• Removed futures-channel dependency from futures-executor (#1735)
• Supported channel::oneshot in no_std environment (#1749)
• Added Future bounds to FusedFuture (#1779)
• Added Stream bounds to FusedStream (#1779)
• Changed StreamExt::boxed to return BoxStream (#1780)
• Added StreamExt::boxed_local (#1780)
• Added AsyncReadExt::read_to_string (#1721)
• Implemented AsyncWrite for IntoAsyncRead (#1734)
• Added get_ref, get_mut and into_inner methods to Compat01As03 and Compat01As03Sink (#1705)
• Added ThreadPool::{spawn_ok, spawn_obj_ok} (#1750)
• Added TryStreamExt::try_flatten (#1731)
• Added FutureExt::now_or_never (#1747)

0.3.0-alpha.17 - 2019-07-03

• Removed try_ready! macro in favor of ready!(..)?. (#1602)
• Removed io::Window::{set_start, set_end} in favor of io::Window::set. (#1667)
• Re-exported pin_utils::pin_mut! macro. (#1686)
• Made all extension traits unnamed in the prelude. (#1662)
• Allowed ?Sized types in some methods and structs. (#1647)
• Added Send + Sync bounds to ArcWake trait to fix unsoundness. (#1654)
• Changed AsyncReadExt::copy_into to consume self. (#1674)
• Renamed future::empty to pending. (#1689)
• Added #[must_use] to some combinators. (#1600)
• Added AsyncWriteExt::{write, write_vectored}. (#1612)
• Added AsyncReadExt::read_vectored. (#1612)
• Added TryFutureExt::try_poll_unpin. (#1613)
• Added TryFutureExt::try_flatten_stream. (#1618)
• Added io::BufWriter. (#1608)
• Added Sender::same_receiver and UnboundedSender::same_receiver. (#1617)
• Added future::try_select. (#1622)
• Added TryFutureExt::{inspect_ok, inspect_err}. (#1630)
• Added Compat::get_ref. (#1648)
• Added io::Window::set. (#1667)
• Added AsyncWriteExt::into_sink. (#1675)
• Added AsyncBufReadExt::copy_buf_into. (#1674)
• Added stream::pending. (#1689)
• Implemented std::error::Error for SpawnError. (#1604)
• Implemented Stream for FlattenSink. (#1651)
• Implemented Sink for TryFlattenStream. (#1651)
• Implemented AsyncRead, AsyncWrite, AsyncSeek, AsyncBufRead, FusedFuture and FusedStream for Either. (#1695)
• Replaced empty enums with Never type, an alias for core::convert::Infallible.
• Removed the futures-channel dependency from futures-sink and make futures-sink an optional dependency of futures-channel.
• Renamed Sink::SinkError to Sink::Error.
• Made a number of dependencies of futures-util optional.

0.3.0-alpha.16 - 2019-05-10

• Updated to new nightly async_await.
• Changed AsyncRead::poll_vectored_read and AsyncWrite::poll_vectored_write to use stabilized std::io::{IoSlice, IoSliceMut} instead of iovec::IoVec, and renamed to AsyncRead::poll_read_vectored and AsyncWrite::poll_write_vectored.
• Added LocalBoxFuture and FutureExt::boxed_local.
• Added TryStreamExt::{try_filter, inspect_ok, inspect_err}.
• Added try_future::select_ok.
• Added AsyncBufReadExt::{read_line, lines}.
• Added io::BufReader.

0.3.0-alpha.15 - 2019-04-26

• Updated to stabilized futures_api.
• Removed StreamObj, cautioned against usage of FutureObj.
• Changed StreamExt::select to a function.
• Added AsyncBufRead and AsyncSeek traits.
• Expanded trait impls to include more pinned pointers and ?Sized types.
• Added future::Fuse::terminated constructor.
• Added never_error combinator.
• Added StreamExt::enumerate.
• Re-added TryStreamExt::{and_then, or_else}.
• Added functions to partially progress a local pool.
• Changed to use our own Either type rather than the one from the either crate.

0.3.0-alpha.14 - 2019-04-15

• Updated to new nightly futures_api.
• Changed Forward combinator to drop sink after completion, and allow !Unpin Sinks.
• Added 0.1 <-> 0.3 compatibility shim for Sinks.
• Changed Sink::Item to a generic parameter Sink<Item>, allowing Sinks to accept multiple different types, including types containing references.
• Changed AsyncRead and AsyncWrite to take Pin<&mut Self> rather than &mut self.
• Added support for no_std + alloc use.
• Changed join and try_join combinators to functions.
• Fixed propagation of cfg-target-has-atomic feature.

0.3.0-alpha.13 - 2019-02-20

• Updated to new nightly with stabilization candidate API.
• Removed LocalWaker.
• Added #[must_use] to Stream and Sink traits.
• Enabled using !Unpin futures in JoinAll.
• Added the try_join_all combinator.
• Stopped closing a whole channel upon closing of one sender.
• Removed TokioDefaultSpawner and tokio-compat.
• Moved intra-crate dependencies to exact versions.

0.3.0-alpha.12 - 2019-01-14

• Updated to new nightly with a modification to Pin::set.
• Expose AssertUnmoved and PendingOnce.
• Prevent double-panic in AssertUnmoved.
• Support nested invocations of the select! macro.
• Implement Default for Mutex and SelectAll.

0.3.0-alpha.11 - 2018-12-27

• Updated to newly stabilized versions of the pin and arbitrary_self_types features.
• Re-added select_all for streams.
• Added TryStream::into_async_read for converting from a stream of bytes into an AsyncRead.
• Added try_poll_next_unpin.
• Rewrote select! as a procedural macro for better error messages
• Exposed join_all from the facade

0.3.0-alpha.10 - 2018-11-27

• Revamped select! macro
• Added select_next_some method for getting only the Some elements of a stream from select!
• Added futures::lock::Mutex for async-aware synchronization.
• Fixed bug converting Pin<Box<_>> to StreamObj
• Improved performance of futures::channel
• Improved performance and documentation of Shared
• Add new method and more derives to the Compat type
• Enabled spawning on a borrowed threadpool
• Re-added join_all
• Added try_concat

0.3.0-alpha.9 - 2018-10-18

• Fixed in response to new nightly handling of 2018 edition + #![no_std]

0.3.0-alpha.8 - 2018-10-16

• Fixed stack overflow in 0.1 compatibility layer
• Added AsyncRead / AsyncWrite compatibility layer
• Added Spawn -> 0.1 Executor compatibility
• Made 0.1 futures usable on 0.3 executors without an additional global Task, accomplished by wrapping 0.1 futures in an 0.1 Spawn when using them as 0.3 futures.
• Cleanups and improvements to the AtomicWaker implementation.

0.3.0-alpha.7 - 2018-10-01

• Update to new nightly which removes Spawn from task::Context and replaces Context with LocalWaker.
• Add Spawn and LocalSpawn traits and FutureObj and LocalFutureObj types to futures-core.

0.3.0-alpha.6 - 2018-09-10

• Replace usage of crate visibility with pub(crate) now that crate visibility is no longer included in the 2018 edition
• Remove newly-stabilized "edition" feature in Cargo.toml files

0.3.0-alpha.5 - 2018-09-03

• Revert usage of cargo crate renaming feature

0.3.0-alpha.4 - 2018-09-02

Note: This release does not work, use 0.3.0-alpha.5 instead

• future::ok and future:err to create result wrapping futures (similar to future::ready)
• futures-test crate with testing utilities
• StreamExt::boxed combinator
• Unsoundness fix for FuturesUnordered
• StreamObj (similar to FutureObj)
• Code examples for compatibility layer functions
• Use cargo create renaming feature to import futures@0.1 for compatibility layer
• Import pinning APIs from core::pin
• Run Clippy in CI only when it is available

0.3.0-alpha.3 - 2018-08-15

• Compatibility with newest nightly
• Futures 0.1 compatibility layer including Tokio compatibility
• Added spawn! and spawn_with_handle! macros
• Added SpawnExt methods spawn and spawn_with_handle
• Extracted pin macros into pin_utils crate
• Added FutureExt combinators boxed and unit_error
• Remove prelude from all doc examples (The prelude is still recommended for usage in playground examples. However, for doc examples we determined that fully expanded imports are more helpful)
• Improvements to select! and join! macros
• Added try_join! macro
• Added StreamExt combinator methods try_join and for_each_concurrent
• Added TryStreamExt combinator methods into_stream, try_filter_map, try_skip_while, try_for_each_concurrent and try_buffer_unordered
• Fix stream termination bug in StreamExt::buffered and StreamExt::buffer_unordered
• Added docs for StreamExt::buffered, StreamExt::buffer_unordered
• Added task::local_waker_ref_from_nonlocal and task::local_waker_ref functions
• CI improvements
• Doc improvements to StreamExt::select

0.3.0-alpha.2 - 2018-07-30

• The changelog is back!
• Compatibility with futures API in latest nightly
• Code examples and doc improvements
  • IO: Methods of traits AsyncReadExt, AsyncWriteExt
  • Future:
    • Methods of trait TryFutureExt
    • Free functions empty, lazy, maybe_done, poll_fn and ready
    • Type FutureOption
    • Macros join!, select! and pending!
  • Stream: Methods of trait TryStreamExt
• Added TryStreamExt combinators map_ok, map_err, err_into, try_next and try_for_each
• Added Drain, a sink that will discard all items given to it. Can be created using the drain function
• Bugfix for the write_all combinator
• AsyncWrite impl for Cursor<T: AsMut<[u8]>>
• FuturesUnordered optimization: Since the context stores a &LocalWaker reference, it was possible to avoid cloning the Arc of the waker
• Futures-rs now uses Clippy
• We now use in-band lifetimes
• The join! and select! macros are now exposed by the futures crate
• The project logo was added to the README.md
• sink::MapErr::get_pinned_mut is now called get_pin_mut
• We now use the unstable use_extern_macros feature for macro reexports
• CI improvements: Named CI jobs, tests are now run on macOS and Linux, the docs are generated and Clippy needs to pass
• #[deny(warnings)] was removed from all crates and is now only enforced in the CI
• We now have a naming convention for type parameters: Fut future, F function, St stream, Si sink, S sink & stream, R reader, W writer, T value, E error
• "Task" is now defined as our term for "lightweight thread". The code of the executors and FuturesUnordered was refactored to align with this definition.

0.3.0-alpha.1 - 2018-07-19

• Major changes: See the announcement on our new blog for details. The changes are too numerous to be covered in this changelog because nearly every line of code was modified.

0.1.17 - 2017-10-31

• Add a close method on sink::Wait
• Undeprecate stream::iter as stream::iter_result
• Improve performance of wait-related methods
• Tweak buffered sinks with a 0 capacity to forward directly to the underlying sink.
• Add FromIterator implementation for FuturesOrdered and FuturesUnordered.

0.1.16 - 2017-09-15

• A prelude module has been added to glob import from and pick up a whole bunch of useful types
• sync::mpsc::Sender::poll_ready has been added as an API
• sync::mpsc::Sender::try_send has been added as an API

0.1.15 - 2017-08-24

• Improve performance of BiLock methods
• Implement Clone for FutureResult
• Forward Stream trait through SinkMapErr
• Add stream::futures_ordered next to futures_unordered
• Reimplement Stream::buffered on top of stream::futures_ordered (much more efficient at scale).
• Add a with_notify function for abstractions which previously required UnparkEvent.
• Add get_ref/get_mut/into_inner functions for stream take/skip methods
• Add a Clone implementation for SharedItem and SharedError
• Add a mpsc::spawn function to spawn a Stream into an Executor
• Add a reunite function for BiLock and the split stream/sink types to rejoin two halves and reclaim the original item.
• Add stream::poll_fn to behave similarly to future::poll_fn
• Add Sink::with_flat_map like Iterator::flat_map
• Bump the minimum Rust version to 1.13.0
• Expose AtomicTask in the public API for managing synchronization around task notifications.
• Unify the Canceled type of the sync and unsync modules.
• Deprecate the boxed methods. These methods have caused more confusion than they've solved historically, so it's recommended to use a local extension trait or a local helper instead of the trait-based methods.
• Deprecate the Stream::merge method as it's less ergonomic than select.
• Add oneshot::Sender::is_canceled to test if a oneshot is canceled off a task.
• Deprecates UnboundedSender::send in favor of a method named unbounded_send to avoid a conflict with Sink::send.
• Deprecate the stream::iter function in favor of an stream::iter_ok adaptor to avoid the need to deal with Result manually.
• Add an inspect function to the Future and Stream traits along the lines of Iterator::inspect

0.1.14 - 2017-05-30

This is a relatively large release of the futures crate, although much of it is from reworking internals rather than new APIs. The banner feature of this release is that the futures::{task, executor} modules are now available in no_std contexts! A large refactoring of the task system was performed in PR #436 to accommodate custom memory allocation schemes and otherwise remove all dependencies on std for the task module. More details about this change can be found on the PR itself.

Other API additions in this release are:

• A FuturesUnordered::push method was added and the FuturesUnordered type itself was completely rewritten to efficiently track a large number of futures.
• A Task::will_notify_current method was added with a slightly different implementation than Task::is_current but with stronger guarantees and documentation wording about its purpose.
• Many combinators now have get_ref, get_mut, and into_inner methods for accessing internal futures and state.
• A Stream::concat2 method was added which should be considered the "fixed" version of concat, this one doesn't panic on empty streams.
• An Executor trait has been added to represent abstracting over the concept of spawning a new task. Crates which only need the ability to spawn a future can now be generic over Executor rather than requiring a tokio_core::reactor::Handle.

As with all 0.1.x releases this PR is intended to be 100% backwards compatible. All code that previously compiled should continue to do so with these changes. As with other changes, though, there are also some updates to be aware of:

• The task::park function has been renamed to task::current.
• The Task::unpark function has been renamed to Task::notify, and in general terminology around "unpark" has shifted to terminology around "notify"
• The Unpark trait has been deprecated in favor of the Notify trait mentioned above.
• The UnparkEvent structure has been deprecated. It currently should perform the same as it used to, but it's planned that in a future 0.1.x release the performance will regress for crates that have not transitioned away. The primary primitive to replace this is the addition of a push function on the FuturesUnordered type. If this does not help implement your use case though, please let us know!
• The Task::is_current method is now deprecated, and you likely want to use Task::will_notify_current instead, but let us know if this doesn't suffice!

0.1.13 - 2017-04-05

• Add forwarding sink/stream impls for stream::FromErr and sink::SinkFromErr
• Add PartialEq and Eq to mpsc::SendError
• Reimplement Shared with spawn instead of UnparkEvent

0.1.12 - 2017-04-03

• Add Stream::from_err and Sink::from_err
• Allow SendError to be Clone when possible

0.1.11 - 2017-03-13

The major highlight of this release is the addition of a new "default" method on the Sink trait, Sink::close. This method is used to indicate to a sink that no new values will ever need to get pushed into it. This can be used to implement graceful shutdown of protocols and otherwise simply indicates to a sink that it can start freeing up resources.

Currently this method is not a default method to preserve backwards compatibility, but it's intended to become a default method in the 0.2 series of the futures crate. It's highly recommended to audit implementations of Sink to implement the close method as is fit.

Other changes in this release are:

• A new select combinator, Future::select2 was added for a heterogeneous select.
• A Shared::peek method was added to check to see if it's done.
• Sink::map_err was implemented
• The log dependency was removed
• Implementations of the Debug trait are now generally available.
• The stream::IterStream type was renamed to stream::Iter (with a reexport for the old name).
• Add a Sink::wait method which returns an adapter to use an arbitrary Sink synchronously.
• A Stream::concat method was added to concatenate a sequence of lists.
• The oneshot::Sender::complete method was renamed to send and now returns a Result indicating successful transmission of a message or not. Note that the complete method still exists, it's just deprecated.

0.1.10 - 2017-01-30

• Add a new unsync module which mirrors sync to the extent that it can but is intended to not perform cross-thread synchronization (only usable within one thread).
• Tweak Shared to work when handles may not get poll'd again.

0.1.9 - 2017-01-18

• Fix Send/Sync of a few types
• Add future::tail_fn for more easily writing loops
• Export SharedItem/SharedError
• Remove an unused type parameter in from_err

0.1.8 - 2017-01-11

• Fix some race conditions in the Shared implementation
• Add Stream::take_while
• Fix an unwrap in stream::futures_unordered
• Generalize Stream::for_each
• Add Stream::chain
• Add stream::repeat
• Relax &mut self to &self in UnboundedSender::send

0.1.7 - 2016-12-18

• Add a Future::shared method for creating a future that can be shared amongst threads by cloning the future itself. All derivative futures will resolve to the same value once the original future has been resolved.
• Add a FutureFrom trait for future-based conversion
• Fix a wakeup bug in Receiver::close
• Add future::poll_fn for quickly adapting a Poll-based function to a future.
• Add an Either enum with two branches to easily create one future type based on two different futures created on two branches of control flow.
• Remove the 'static bound on Unpark
• Optimize send_all and forward to send as many items as possible before calling poll_complete.
• Unify the return types of the ok, err, and result future to assist returning different varieties in different branches of a function.
• Add CpuFuture::forget to allow the computation to continue running after a drop.
• Add a stream::futures_unordered combinator to turn a list of futures into a stream representing their order of completion.

0.1.6 - 2016-11-22

• Fix Clone bound on the type parameter on UnboundedSender

0.1.5 - 2016-11-22

• Fix #![no_std] support

0.1.4 - 2016-11-22

This is quite a large release relative to the previous point releases! As with all 0.1 releases, this release should be fully compatible with the 0.1.3 release. If any incompatibilities are discovered please file an issue!

The largest changes in 0.1.4 are the addition of a Sink trait coupled with a reorganization of this crate. Note that all old locations for types/traits still exist, they're just deprecated and tagged with #[doc(hidden)].

The new Sink trait is used to represent types which can periodically over time accept items, but may take some time to fully process the item before another can be accepted. Essentially, a sink is the opposite of a stream. This trait will then be used in the tokio-core crate to implement simple framing by modeling I/O streams as both a stream and a sink of frames.

The organization of this crate is to now have three primary submodules, future, stream, and sink. The traits as well as all combinator types are defined in these submodules. The traits and types like Async and Poll are then reexported at the top of the crate for convenient usage. It should be a relatively rare occasion that the modules themselves are reached into.

Finally, the 0.1.4 release comes with a new module, sync, in the futures crate. This is intended to be the home of a suite of futures-aware synchronization primitives. Currently this is inhabited with a oneshot module (the old oneshot function), a mpsc module for a new multi-producer single-consumer channel, and a BiLock type which represents sharing ownership of one value between two consumers. This module may expand over time with more types like a mutex, rwlock, spsc channel, etc.

Notable deprecations in the 0.1.4 release that will be deleted in an eventual 0.2 release:

• The TaskRc type is now deprecated in favor of BiLock or otherwise Arc sharing.
• All future combinators should be accessed through the future module, not the top-level of the crate.
• The Oneshot and Complete types are now replaced with the sync::oneshot module.
• Some old names like collect are deprecated in favor of more appropriately named versions like join_all
• The finished constructor is now ok.
• The failed constructor is now err.
• The done constructor is now result.

As always, please report bugs to https://github.com/rust-lang-nursery/futures-rs and we always love feedback! If you've got situations we don't cover, combinators you'd like to see, or slow code, please let us know!

Full changelog:

• Improve scalability of buffer_unordered combinator
• Fix a memory ordering bug in oneshot
• Add a new trait, Sink
• Reorganize the crate into three primary modules
• Add a new sync module for synchronization primitives
• Add a BiLock sync primitive for two-way sharing
• Deprecate TaskRc
• Rename collect to join_all
• Use a small vec in Events for improved clone performance
• Add Stream::select for selecting items from two streams like merge but requiring the same types.
• Add stream::unfold constructor
• Add a sync::mpsc module with a futures-aware multi-producer single-consumer queue. Both bounded (with backpressure) and unbounded (no backpressure) variants are provided.
• Renamed failed, finished, and done combinators to err, ok, and result.
• Add Stream::forward to send all items to a sink, like Sink::send_all
• Add Stream::split for streams which are both sinks and streams to have separate ownership of the stream/sink halves
• Improve join_all with concurrency

0.1.3 - 2016-10-24

• Rewrite oneshot for efficiency and removing allocations on send/recv
• Errors are passed through in Stream::take and Stream::skip
• Add a select_ok combinator to pick the first of a list that succeeds
• Remove the unnecessary SelectAllNext typedef
• Add Stream::chunks for receiving chunks of data
• Rewrite stream::channel for efficiency, correctness, and removing allocations
• Remove Send + 'static bounds on the stream::Empty type

0.1.2 - 2016-10-04

• Fixed a bug in drop of FutureSender
• Expose the channel SendError type
• Add Future::into_stream to convert to a single-element stream
• Add Future::flatten_to_stream to convert a future of a stream to a stream
• impl Debug for SendError
• Add stream::once for a one element stream
• Accept IntoIterator in stream::iter
• Add Stream::catch_unwind

0.1.1 - 2016-09-09

Initial release!