Are we async yet?
The long-awaited async/await syntax
has been stabilized in Rust 1.39.
You can use it with the active ecosystem of asynchronous I/O around
futures ,
mio ,
tokio , and
async-std .
async syntax and blockers
`async`/`await` syntax
stabilized in 1.39
[in stable]
/
RFC 2394
/
#50547
Related issues under A-async-await
#70905 - ICE on generators + arrays
#70818 - note_obligation_cause reporting for non-async/await not optimal
#70098 - no_mangle causes compilation errors with async-await on armv7-linux-androideabi and aarch64-linux-android targets
#69938 - incorrect error message for duplicate Send impl
#69912 - Tracking Issue for the Wake trait
#69826 - Tracking Issue for Generator Memory Usage
#69785 - ICE in collect_and_partition_mono_items
#69781 - It is hard to see the return types of async functions
#69663 - More precise generator captures
#69446 - Which `captured variable cannot escape `FnMut` closure body`?
#69431 - Tracking Issue for async blocks in const fn
#69307 - ICE: src/librustc/middle/region.rs:1037: Encountered greater count 28
#69276 - Improve error message for "return type cannot contain a projection or `Self`..."
#69083 - Detect cases where `Box::pin` was likely intended
#68604 - E0700 does not point to where the captured lifetime is
#68543 - Unsized locals and async ICE
#68523 - Bad error message with async main
#68521 - "expected bound lifetime parameter, found concrete lifetime" when passing a 'static reference to a closure that returns a future
#68430 - Rustc doesn't report line numbers for type errors within proc macro async fn within macro_rules macro
#68119 - Error message for closure with async block needs improvement
#68112 - Explanation for why future is not Send is wrong
#68109 - rustc panics when compiling code that uses tokio's LocalSet
#67982 - Re-land "add IntoFuture trait and support for await"
#67893 - rustc compiler crashed when using async in loop
#67765 - Unhelpful error messages from borrow checker with async/await
#67644 - Tracking issue for `IntoFuture`
#67204 - Explain editions when trying to use async block in 2015 edition
#67087 - ICE while compiling async/await code
#67025 - Reduce type errors in async fns
#66731 - More friendly error msg when await on NONE ASYNC fn/block or return a obj that implements deprecated Future
#66709 - std::future: Document that each Future (Stream, etc) must only be used by one task at a time
#66634 - Error in `async` function/block produces errors for valid unrelated expressions
#66481 - Context and Waker might be accidentally `Sync`
#66445 - Too many `type inside `async` object must be known in this context` errors
#66444 - Show the location of a type usage for trait bound failures
#66281 - Waker::will_wake() gets mostly defeated by executor optimizations
#66168 - async fn unmet lifetime constraints produce confusing diagnostics
#66107 - async-block diagnostics do not suggest async move when it may be needed
#65978 - Symbols in optimized async programs are often not useful
#65677 - Doucment auto traits for `async fn`
#65442 - impl Trait that does not capture generic argument
#65409 - Suggest as_mut to reborrow Pin when calling method
#64692 - No error for private type in public async fn
#64650 - Unhelpful error "one type is more general than the other" in async code
#64552 - Lifetime bounds in auto trait impls prevent trait from being implemented on generators
#64286 - EXPERIMENT: Make `async fn`, `.await`, `async move? {` legal on 2015
#63818 - Resolve unsound interaction between self-referential generators (incl. async fn) and noalias
#63768 - An async fn which isn't Send but which should be?
#63647 - inline attribute on async fn doesn't work properly
#63616 - Handle partial initialization correctly in generators
#63526 - Include type parameters on string representation of `impl Trait`
#63514 - Provide map_ok and map_err method for Poll<Option<Result<T, E>>>
#63502 - Error "cannot infer type" when using '?' in async block + bad diagnostic
#63033 - Async fn does not compile if lifetime does not appear in bounds (sometimes)
#63032 - Lifetime is unnecessarily captured in nested functions returning impl trait via async
#62958 - Async fn doubles argument size
#62572 - Pretty-printing support for Rust generators
#62391 - Pin docs should mention pitfalls of generic code
#62386 - Invalid suggestion when attempting to call async closure
#62290 - Tracking issue for `#!feature(async_closure)]` (RFC 2394)
#62284 - Mutually recursive `async fn`s are hard to make `Send`
#61949 - Inherent async fn returning `Self` treats type's lifetime parameters as `'static`
#61482 - A `rustc`-internal compile error on future and task API
#61335 - ICE when combining unsized locals and async
#61076 - suggest `await` for future-related type errors
#60658 - Wrong Send constraint when using a trait with lifetime + associated type in async
#59971 - async/await: cannot move out of captured variable in an `Fn` closure
#59337 - async closures have concrete argument lifetimes
#59245 - Inconsistency in Send/Sync requirements for async/await
#59087 - Generator size: borrowed variables are assumed live across following yield points
#57478 - Dropped variables still included in generator type
#57017 - async/await: awaiting inside a match block captures borrow too eagerly
#51932 - Weird async/await error message around mutablility
#70736 - internal compiler error: local_def_id: no entry for HirId { owner ...
#70594 - internal compiler error: no type for local variable
#70488 - Async performance regression
#69672 - `x = yield;` makes generators larger than they need to be
#69632 - Overlapping `From` impls produce confusing errors in async code
#69355 - Unexpected panic in rustc with async_stream
#69298 - Move keyword page makes no mention of async blocks
#68950 - Strange borrowing issue in inherent async method.
#68864 - 25% compile time increase on beta when building async-std
#68759 - Async await mulitple lifetimes issue with `Box`
#68477 - ICE cause by tokio::spawn a async function return future opaque type
#68197 - Confusing error message when expecting BoxFuture
#67832 - ICE in nightly when using trying to preserve rand::rngs::ThreadRng across awaits
#67778 - async fn ICEs in macro on stable
#67757 - Nightly 2019-12-29 causes `reached the type-length limit` error in previously working code
#67706 - Major async/await compiler performance regression
#67651 - Confusing/incorrect error message with incoherent implementations and async blocks
#67611 - not Send due to await retainment
#67376 - improve diagnostics for non-send Futures that might be solved by introducing temporary variables
#67200 - rustc panic from unwrapping None
#67158 - ICE on beta and nightly as result of use of `yield` in combination with macro call in `async` block
#67036 - Unexpected interactions with async blocks, auto traits, and trait objects
#66958 - ICE on rustc 1.41.0-nightly (25d8a9494 2019-11-29) running on x86_64-apple-darwin
#66910 - Slightly incorrect help message with mismatched typs in async code
#66909 - async-await keywords are not documented in the libstd docs
#66814 - Incremental compilation breaks trait objects in async fns
#66695 - Broken MIR after compiler update when indexing statics with async values
#66618 - ICE on 1.39.0 stable with combination of `async` and `..`
#66440 - Confusing error message on variables created on the fly and passed to an async fn
#66387 - Compiler crash on "if" without "else" in async fn
#66312 - async fn presence affects an unrelated error message
#66198 - Borrowing from arguments with higher order async functions
#66100 - [codegen] Unnecessary panicking branches in resumption of infinite generator (stored in static variable)
#65923 - Unhelpful error message when awaiting an async closure while forgetting the brackets
#65899 - Add more context when trying to write async trait function
#65667 - Async/Await: Confusing error message when using non-Send type in async fn
#65436 - async/await regression regarding borrows across yields
#65419 - Attempting to run an async fn after completion mentions generators
#65180 - Async-related type error messages defy expectations (in span location)
#65159 - Nightly async fn ICE
#65147 - check_mod_item_types query times regressed bigly
#64960 - Cannot await in scope that contains call to format!
#64853 - Should async/await be strict keywords?
#64636 - async functions with `unimplemented!()` are marked as unreachable
#64630 - Async struct method, <_'> lifetime shadowing
#64512 - async fn drop order for temporaries in return expression does not match sync
#64493 - Spurious "unused lifetime parameter" warning with async function
#64477 - Spurious new Send requirement in async block
#64433 - Lifetime errors on nightly-2019-09-11 but not nightly-2019-09-10
#64392 - Async function return type inference fails without an ending return
#64391 - async functions fail to move values into generated futures in the latest nightly
#64382 - Consider async blocks on lifetime errors
#64176 - Lifetime error when Send is enforced on async function return type
#64130 - non-send futures error at point of use, but could cite point of definition in some cases
#64004 - async-await: mutually recursive functions compile sometimes
#63832 - temporary lifetime around await is (maybe) unexpectedly short
#63778 - Temporary values do not outlive a direct await
#63716 - [bug] async specialization is not parsed
#63710 - rustdoc renders re-exported `async fn`s incorrectly
#63533 - Improve error message for `.await` in 2015 edition
#63500 - async fn methods and impl `'_` elision do not interact correctly
#63398 - Wrong block referenced when emitting E0728
#63391 - Improve diagnostic for `break` in `async { ... }` block
#63388 - `&self` lifetime elision with two parameters does not work with `async fn`
#63385 - Unhelpful error message with async usage of Iterator
#63277 - Different error messages between async and regular functions
#63225 - Error with nested async fn and anonymous lifetimes
#63167 - Confusing error message with type unification of impl Traits
#63100 - "Try invoking the function" hint
#62918 - Remove TLS dependency from async/await
#62658 - ICE: assertion failed: `(left == right)` in type_of.rs
#62570 - Async blocks are leaky about wording wrt. `?` in diagnostics
#62566 - include material on async fn in the Rust reference
#62539 - diagnostic for naive recursive async functions is really unfriendly
#62517 - async fn with elided lifetime causes rustc panic
#62506 - ICE on generator type check with a must_use type
#62501 - Tracking issue for `#!feature(async_unsafe)]` (RFC 2394)
#62500 - move async unsafe fn to distinct feature gate
#62382 - Unhelpful span in async type inference error
#62312 - Future compat warning with `.await`ing a `BoxFuture`
#62236 - Move tests in `src/test/run-pass/async-await` -> `src/test/ui/async-await`
#62232 - Inconsistent syntax between `unsafe async fn` and `async fn unsafe`
#62214 - Split the `async_await` feature gate for the subset we want to stabilize
#62149 - [Stabilization] async/await MVP
#62121 - increase test coverage for async-await
#62097 - rustc suggests invalid syntax to fix lifetime inferring error
#62087 - Async/Await rustc assertion panic
#62028 - thread 'rustc' panicked at 'assertion failed: target_offset >= offset'
#62025 - Broken MIR: generator contains type std::vec::Vec<()>
#62009 - ICE when playing with async/await.
#61991 - Can't infer type after collecting an iterator of futures
#61986 - ICE compiling with futures compat
#61950 - Async function using non-across-yield non-Send value is Send only if the usage is inside curly brackets
#61920 - E0373 help suggests `move async` but the correct syntax is `async move`
#61910 - error: internal compiler error: broken MIR in DefId ...
#61906 - Since rust is not going in CPS style coroutine, where is the context carrier for async?
#61834 - Broken MIR: generator contains type impl std::future::Future in MIR, but typeck only knows about {impl std::future::Future, ()}
#61798 - `unreachable_code` warning when invoke `.await` on async diverging function
#61793 - Codegen ICE/regression with 2019-06-12 nightly when using async fn<T: Fn()>(&self, T)
#61770 - Broken MIR: generator contains type
#61731 - "Broken MIR" ICE when using runtime crate
#61685 - Rustc paniced when apply `.await` on a closure in a non-async function
#61664 - compiler panicked at 'Box<Any>'
#61579 - ICE: Broken MIR in generators
#61452 - [ICE] async fn vs lint order
#61442 - Broken MIR in futures generator (async/await)
#61211 - async/await borrows more around await points than necessary
#61187 - Internal compiler error in nightly when reversing a vector inside a async fn
#61115 - unused-lifetimes lint false-positives with async functions
#61072 - async fn + rustfmt don't "just work" inside of RLS
#60889 - Don't ignore generator fields in miri
#60797 - improve the "must use" lint for `Future` to suggest await
#60709 - future miscompiling to ud2
#60674 - Async fn loses mut pattern when passed to attribute macro
#60661 - HIR printing of `async fn` is broken
#60660 - std::r#await! macro cannot be used even if #![feature(await_macro)] is enabled
#60655 - `existential type` complains about `'_` in concrete type of self-borrowing generators
#60653 - Make the parser aware of await where macro calls are expected
#60645 - Are blanket Future impls necessary?
#60615 - async/await unresolved type parameter in generator error shouldn't refer to `yield`
#60613 - Provide appropriate suggestions for some of the discussed await syntaxes
#60610 - Remove await! macro-like syntax support
#60589 - Is async/await compatible with io_uring (Linux async io)?
#60566 - async fn raises unused_mut on parameter that is used mutably
#60518 - ICE with the newest nightly in `lower_ty_direct`
#60509 - Extend `async fn` test suite to account for `ref mut?` patterns
#60498 - async fn forgets the mutability of the arguments
#60438 - __arg variables from async fn desugaring are accessible to the user
#60424 - type inference doesn't work in async fn that return Box<dyn SomeTrait>
#60418 - Move async/await UI tests into a folder
#60414 - Using associated types in async fn type break typing
#60236 - Drop order of async fn arguments doesn't exactly match the equivalent regular fn.
#60203 - Async fns that take structs with elided lifetime parameters are broken.
#60069 - Can define and use async fn without feature gate on nightly
#60016 - Implement `await` syntax
#59972 - Futures involving uninhabited variables are incorrectly considered uninhabited.
#59313 - `async move` breaks doc tests
#59123 - Generator size: unwinding and drops force extra generator state allocation
#59113 - Tracking issue for RFC 2592, futures_api
#59001 - async: hidden type for `impl Trait` captures lifetime that does not appear in bounds
#58945 - internal compiler error: Trying to create type name for unexpected type [debuginfo]
#58930 - async/await produces unspecific "type inside generator must be known in this context" error messages
#58888 - ICE unexpected type in type_metadata: impl core::future::future::Future
#58885 - async/await: Usage of trait objects reports multiple different lifetimes when only one is used
#58884 - async/await: Potentially incorrect lifetime handling when structs with lifetimes are referenced
#58814 - Playing with async triggers compiler bug "TLS Waker not set"
#58652 - async fn should be disallowed entirely on 2015 edition
#58639 - expected signature of `for<'r, 's> fn(&'r mut std::task::Context<'s>)
#58027 - Rustdoc renders async fn incorrectly
#57640 - Resolve `await` syntax
#57084 - ICE(async_await,futures_api,await_macro,generators): cannot relate bound region: ReLateBound(DebruijnIndex(1), BrAnon(2)) <= '_#1r
#57036 - async/await: Sending Waker seems to invalidate it
#56974 - Cannot define async fn with no_std
#56767 - await macro is not in libcore.
#56651 - Obscure compiler panic with async/await
#56238 - async fn should support multiple lifetimes
#55809 - Mixing async functions and &mut leads to overflow evaluating requirement
#55324 - `async fn` doesn't capture lifetimes of type parameters if other lifetimes are present
#54974 - async fn: 'static lifetime not inferred for Arc trait object
#54716 - Unused arguments to async fn are dropped too early
#54326 - Mismatched types diagnostic for async fn return type trusts random returns over function signature
#54289 - ICE with async_await + extern crate + invalid import
#54239 - Using await on an internal future makes private type trigger missing_debug_implementations lint
#53989 - compile async await function error
#53714 - `async fn` inside inherent impl produces generic parse error on 2015 edition
#53548 - async/await: “the requirement `for<'r> 'r : 'static` is not satisfied” with `'static` across await point
#53447 - ICE with --pretty=expanded and async/await
#53259 - Missing detection of Send for async fn
#53249 - async/await assertion failed: unbounded recursion
#52924 - Generators are too big
#51995 - ICE in generator MIR generated by async/await
#51933 - async fn inside fn fails to parse
#51751 - async/await errors should not discuss "yield statements"
#51353 - 'assertion failed: current_depth > ty::DebruijnIndex::INNERMOST' when using generators
#50659 - Suggestion for E0627's message
#50547 - Tracking issue for async/await (RFC 2394)
#50458 - Implement DerefAsync and DerefMutAsync as Deref and DerefMut in async context
`std::task` and `std::future`
stabilized in 1.36
[in stable]
/
RFC 2592
/
#59113
Pin APIs
stabilized in 1.33
[in stable]
/
RFC 2349
/
#49150
`Pin` as a method receiver
stabilized in 1.33
[in stable]
/
RFC 2362
/
#55786
2018 edition
stabilized in 1.31
[in stable]
`async` as a keyword in 2018 edition
stabilized in 1.28
[in stable]
`impl Trait` in return position
stabilized in 1.26
[in stable]
/
RFC 1522
/
#34511
Related issues under A-impl-trait
Future extensions
`async fn` in trait method
not stabilized yet
Workaround is available as an attribute macro:
`async-trait`
Generic associated types (GAT)
not stabilized yet
/
RFC 1598
/
#44265
Named existentials and impl Trait variable declarations
not stabilized yet
/
RFC 2071
/
#63066
Async iterators or stream
unresolved
Async closures
not stabilized yet
/
RFC 2394
async ecosystem
tokio -
An event-driven, non-blocking I/O platform for writing asynchronous applications.
It has async/await support starting from 0.2.0-alpha.1
#1201
async-std -
Async version of the Rust standard library. It provides all the interfaces
you are used to, but in an async version and designed for Rust's
async/await syntax.
thin_main_loop -
An experimental, cross platform, main loop and futures executor/reactor,
that binds to the OS APIs suitable for making native GUI applications.
It supports callbacks as well as the async/await syntax.
async-task -
Task abstraction for building executors.
Posts about async
Generated at Wed, 08 Apr 2020 17:52:56 +0000
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