Tracking Issue for async_fn_in_trait, return_position_impl_trait_in_trait #91611

nikomatsakis · 2021-12-06T23:34:04Z

This is a tracking issue for the RFC "static async fn in traits" (Static async fn in traits rfcs#3185) and "Return position impl Trait in traits" (Return position impl Trait in traits rfcs#3425).
The feature gate for async fn in traits is #![feature(async_fn_in_trait)].
The feature gate for return position impl Trait in traits is #![feature(return_position_impl_trait_in_trait)].
This feature is developed as part of the async fundamentals initiative -- see that website for more information!

About tracking issues

Tracking issues are used to record the overall progress of implementation.
They are also used as hubs connecting to other relevant issues, e.g., bugs or open design questions.
A tracking issue is however not meant for large scale discussion, questions, or bug reports about a feature.
Instead, open a dedicated issue for the specific matter and add the relevant feature gate label.

Steps

Implement the RFC
Adjust documentation (see instructions on rustc-dev-guide)
Stabilization PR: Stabilize async fn and return-position impl Trait in trait #115822

Unresolved Questions

Async fn in trait

Do we need Send bounds to stabilize async_fn_in_trait? #103854

Return position impl Trait in trait

Should we stabilize this feature together with async fn to mitigate hazards of writing a trait that is not forwards-compatible with its desugaring?
Resolution of RPITIT is allowed to name any in-scope lifetime parameter, unlike inherent RPIT methods #112194
- Note that this might impact the desugaring, as described in this comment.
Should we limit the legal positions for impl Trait to positions that are nameable using upcoming features like return-type notation (RTN)? (See this comment for an example.)

Implementation history

Async fn in trait

F-async_fn_in_trait Static async fn in traits

Return position impl Trait in trait

F-return_position_impl_trait_in_trait `#![feature(return_position_impl_trait_in_trait)]`

Several of these include code specific to async fn in trait.

The text was updated successfully, but these errors were encountered:

HTGAzureX1212 · 2022-02-05T00:54:38Z

May I take a go at this?

LeSeulArtichaut · 2022-03-23T21:23:53Z

Currently trying to take a stab at this. @rustbot claim

nikomatsakis · 2022-03-24T16:28:07Z

@LeSeulArtichaut actually, @spastorino has been looking into doing various refactorings to make this easier, you should probably synchronize with him, I'm not sure what state we are in.

spastorino · 2022-03-24T19:26:44Z

Ohh, unsure why I've never assigned this to myself. I've been working on this since a while, and I've implemented RPITIT and async fns in traits support partially. At some point, we've realized that we wanted to change the design of the solution and started doing some refactors on RPITs.
Anyway, I've already talked with @LeSeulArtichaut, and I'd be happy to share some work with them about this feature or about any other feature ❤️

fakedrake · 2022-09-12T23:38:01Z

It seems this has been asleep for a while, is it blocked? is it dead? Does it need more love?

spastorino · 2022-09-13T12:49:13Z

@fakedrake we are working on this thing, there's some support work being done by my RPIT Refactor and by RPITIT PR that just landed. You can see discussions on https://rust-lang.zulipchat.com/#narrow/stream/330606-wg-async.2Fasync-fn-in-trait-impl

=== stdout === === stderr === warning: the feature `return_position_impl_trait_in_trait` is incomplete and may not be safe to use and/or cause compiler crashes --> /home/runner/work/glacier/glacier/ices/102140.rs:1:12 | 1 | #![feature(return_position_impl_trait_in_trait)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: see issue #91611 <rust-lang/rust#91611> for more information = note: `#[warn(incomplete_features)]` on by default error[E0601]: `main` function not found in crate `102140` --> /home/runner/work/glacier/glacier/ices/102140.rs:23:2 | 23 | } | ^ consider adding a `main` function to `/home/runner/work/glacier/glacier/ices/102140.rs` error[E0277]: the trait bound `&dyn MyTrait: MyTrait` is not satisfied --> /home/runner/work/glacier/glacier/ices/102140.rs:21:22 | 21 | MyTrait::foo(&self) | ------------ -^^^^ | | | | | the trait `MyTrait` is not implemented for `&dyn MyTrait` | | help: consider removing the leading `&`-reference | required by a bound introduced by this call error[E0277]: the trait bound `&dyn MyTrait: MyTrait` is not satisfied --> /home/runner/work/glacier/glacier/ices/102140.rs:21:9 | 21 | MyTrait::foo(&self) | ^^^^^^^^^^^^^^^^^^^ the trait `MyTrait` is not implemented for `&dyn MyTrait` | = help: the trait `MyTrait` is implemented for `Outer` error[E0277]: the trait bound `&dyn MyTrait: MyTrait` is not satisfied --> /home/runner/work/glacier/glacier/ices/102140.rs:21:9 | 21 | MyTrait::foo(&self) | ^^^^^^^^^^^^ the trait `MyTrait` is not implemented for `&dyn MyTrait` | = help: the trait `MyTrait` is implemented for `Outer` error: aborting due to 4 previous errors; 1 warning emitted Some errors have detailed explanations: E0277, E0601. For more information about an error, try `rustc --explain E0277`. ==============

=== stdout === === stderr === warning: the feature `async_fn_in_trait` is incomplete and may not be safe to use and/or cause compiler crashes --> /home/runner/work/glacier/glacier/ices/102219.rs:2:12 | 2 | #![feature(async_fn_in_trait)] | ^^^^^^^^^^^^^^^^^ | = note: see issue #91611 <rust-lang/rust#91611> for more information = note: `#[warn(incomplete_features)]` on by default warning: 1 warning emitted ==============

=== stdout === === stderr === error[E0706]: functions in traits cannot be declared `async` --> /home/runner/work/glacier/glacier/ices/101665.rs:7:5 | 7 | async fn baz()-> impl Debug{} | -----^^^^^^^^^^^^^^^^^^^^^^ | | | `async` because of this | = note: `async` trait functions are not currently supported = note: consider using the `async-trait` crate: https://crates.io/crates/async-trait = note: see issue #91611 <rust-lang/rust#91611> for more information = help: add `#![feature(async_fn_in_trait)]` to the crate attributes to enable error[E0308]: mismatched types --> /home/runner/work/glacier/glacier/ices/101665.rs:7:32 | 7 | async fn baz()-> impl Debug{} | ^^ expected associated type, found `()` | = note: expected associated type `impl Debug` found unit type `()` error[E0308]: mismatched types --> /home/runner/work/glacier/glacier/ices/101665.rs:7:32 | 7 | async fn baz()-> impl Debug{} | ^^ expected associated type, found opaque type | = note: expected associated type `impl Future<Output = impl Debug>` (trait associated opaque type at </home/runner/work/glacier/glacier/ices/101665.rs:7:22>) found opaque type `impl Future<Output = impl Debug>` (opaque type at </rustc/f83e0266cf7aaa4b41505c49a5fd9c2363166522/library/core/src/future/mod.rs:72:43>) error: aborting due to 3 previous errors Some errors have detailed explanations: E0308, E0706. For more information about an error, try `rustc --explain E0308`. ==============

[![Mend Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com) This PR contains the following updates: | Package | Type | Update | Change | |---|---|---|---| | [Swatinem/rust-cache](https://togithub.com/Swatinem/rust-cache) | action | patch | `v2.0.0` -> `v2.0.2` | | [clap](https://togithub.com/clap-rs/clap) | dependencies | patch | `3.2.17` -> `3.2.23` | | [const_format](https://togithub.com/rodrimati1992/const_format_crates) | dependencies | patch | `0.2.26` -> `0.2.30` | | [darling](https://togithub.com/TedDriggs/darling) | dependencies | patch | `0.14.1` -> `0.14.2` | | [futures](https://rust-lang.github.io/futures-rs) ([source](https://togithub.com/rust-lang/futures-rs)) | dependencies | patch | `0.3.23` -> `0.3.25` | | [proc-macro2](https://togithub.com/dtolnay/proc-macro2) | dependencies | patch | `1.0.43` -> `1.0.47` | | [serde](https://serde.rs) ([source](https://togithub.com/serde-rs/serde)) | dependencies | patch | `1.0.144` -> `1.0.147` | | [serde_json](https://togithub.com/serde-rs/json) | dependencies | patch | `1.0.85` -> `1.0.87` | | [serde_yaml](https://togithub.com/dtolnay/serde-yaml) | dependencies | patch | `0.9.10` -> `0.9.14` | | [snafu](https://togithub.com/shepmaster/snafu) | dependencies | patch | `0.7.1` -> `0.7.3` | | [syn](https://togithub.com/dtolnay/syn) | dependencies | patch | `1.0.99` -> `1.0.103` | | [thiserror](https://togithub.com/dtolnay/thiserror) | dependencies | patch | `1.0.32` -> `1.0.37` | | [tokio](https://tokio.rs) ([source](https://togithub.com/tokio-rs/tokio)) | dependencies | patch | `1.21.1` -> `1.21.2` | | [tracing](https://tokio.rs) ([source](https://togithub.com/tokio-rs/tracing)) | dependencies | patch | `0.1.36` -> `0.1.37` | | [tracing-subscriber](https://tokio.rs) ([source](https://togithub.com/tokio-rs/tracing)) | dependencies | patch | `0.3.15` -> `0.3.16` | --- ### Release Notes <details> <summary>Swatinem/rust-cache</summary> ### [`v2.0.2`](https://togithub.com/Swatinem/rust-cache/releases/tag/v2.0.2) [Compare Source](https://togithub.com/Swatinem/rust-cache/compare/v2.0.1...v2.0.2) - Avoid calling cargo metadata on pre-cleanup. ### [`v2.0.1`](https://togithub.com/Swatinem/rust-cache/releases/tag/v2.0.1) [Compare Source](https://togithub.com/Swatinem/rust-cache/compare/v2.0.0...v2.0.1) - Primarily just updating dependencies to fix GitHub deprecation notices. </details> <details> <summary>clap-rs/clap</summary> ### [`v3.2.23`](https://togithub.com/clap-rs/clap/releases/tag/v3.2.23) [Compare Source](https://togithub.com/clap-rs/clap/compare/v3.2.22...v3.2.23) #### \[3.2.23] - 2022-10-24 ##### Fixes - Upgrade to `textwrap` 0.16 ### [`v3.2.22`](https://togithub.com/clap-rs/clap/releases/tag/v3.2.22) [Compare Source](https://togithub.com/clap-rs/clap/compare/v3.2.21...v3.2.22) ##### \[3.2.22] - 2022-09-16 ##### Fixes - Unify dependencies on `terminal_size` to the 0.2 release ### [`v3.2.21`](https://togithub.com/clap-rs/clap/releases/tag/v3.2.21) [Compare Source](https://togithub.com/clap-rs/clap/compare/v3.2.20...v3.2.21) #### \[3.2.21] - 2022-09-12 ##### Features - `TypedValueParser::map` to allow reusing existing value parsers for other purposes ### [`v3.2.20`](https://togithub.com/clap-rs/clap/releases/tag/v3.2.20) [Compare Source](https://togithub.com/clap-rs/clap/compare/v3.2.19...v3.2.20) #### \[3.2.20] - 2022-09-02 ##### Features - `ArgMatches::get_count` help for `ArgAction::Count` - `ArgMatches::get_flag` help for `ArgAction::SetTrue` / `ArgAction::SetFalse` ### [`v3.2.19`](https://togithub.com/clap-rs/clap/releases/tag/v3.2.19) [Compare Source](https://togithub.com/clap-rs/clap/compare/v3.2.18...v3.2.19) #### \[3.2.19] - 2022-08-30 ##### Fixes - *(help)* Ensure required arguments for parent commands aren't shown in their subcommands when using `args_conflicts_with_subcommand` ### [`v3.2.18`](https://togithub.com/clap-rs/clap/blob/HEAD/CHANGELOG.md#3218---2022-08-29) [Compare Source](https://togithub.com/clap-rs/clap/compare/v3.2.17...v3.2.18) ##### Fixes - *(help)* `Command::print_help` now respects `Command::colored_help` - *(derive)* Improved error messages </details> <details> <summary>rodrimati1992/const_format_crates</summary> ### [`v0.2.29`](https://togithub.com/rodrimati1992/const_format_crates/blob/HEAD/Changelog.md#0229) Added lowercase hexadecimal formatting support. Breaking: to add lowercase hexadecimal formatting, this crate changed the uppercase hexadecimal formatter from `{:x}` to `{:X}` ### [`v0.2.27`](https://togithub.com/rodrimati1992/const_format_crates/blob/HEAD/Changelog.md#0227) Replacing existing features with these: - `"rust_1_64"`: superceeding the soft-deprecated `"more_str_macros"` feature. - `"rust_1_51"`: superceeding the soft-deprecated `"const_generics"` feature. The new features are enabled by the feature they superceede. Now the `"fmt"` feature enables the `"rust_1_64"` feature. </details> <details> <summary>TedDriggs/darling</summary> ### [`v0.14.2`](https://togithub.com/TedDriggs/darling/blob/HEAD/CHANGELOG.md#v0142-October-26-2022) [Compare Source](https://togithub.com/TedDriggs/darling/compare/v0.14.1...v0.14.2) - Derived impls of `FromMeta` will now error on literals, rather than silently ignoring them. [#193](https://togithub.com/TedDriggs/darling/pull/193) - Don't include property paths in compile errors when spans are available. [#203](https://togithub.com/TedDriggs/darling/pull/203) </details> <details> <summary>rust-lang/futures-rs</summary> ### [`v0.3.25`](https://togithub.com/rust-lang/futures-rs/blob/HEAD/CHANGELOG.md#0325---2022-10-20) [Compare Source](https://togithub.com/rust-lang/futures-rs/compare/0.3.24...0.3.25) - Fix soundness issue in `join!` and `try_join!` macros ([#2649](https://togithub.com/rust-lang/futures-rs/issues/2649)) - Implement `Clone` for `sink::Drain` ([#2650](https://togithub.com/rust-lang/futures-rs/issues/2650)) ### [`v0.3.24`](https://togithub.com/rust-lang/futures-rs/blob/HEAD/CHANGELOG.md#0324---2022-08-29) [Compare Source](https://togithub.com/rust-lang/futures-rs/compare/0.3.23...0.3.24) - Fix incorrect termination of `select_with_strategy` streams ([#2635](https://togithub.com/rust-lang/futures-rs/issues/2635)) </details> <details> <summary>dtolnay/proc-macro2</summary> ### [`v1.0.47`](https://togithub.com/dtolnay/proc-macro2/releases/tag/1.0.47) [Compare Source](https://togithub.com/dtolnay/proc-macro2/compare/1.0.46...1.0.47) - Fix integer overflow when nesting depth of nested comments exceeds 4 billion ([#357](https://togithub.com/dtolnay/proc-macro2/issues/357)) ### [`v1.0.46`](https://togithub.com/dtolnay/proc-macro2/releases/tag/1.0.46) [Compare Source](https://togithub.com/dtolnay/proc-macro2/compare/1.0.45...1.0.46) - Make proc_macro2::TokenStream's `FromStr` impl consistent with proc_macro::TokenStream's on strings that begin with a byte order mark `\u{feff}` ([#353](https://togithub.com/dtolnay/proc-macro2/issues/353)) ### [`v1.0.45`](https://togithub.com/dtolnay/proc-macro2/releases/tag/1.0.45) [Compare Source](https://togithub.com/dtolnay/proc-macro2/compare/1.0.44...1.0.45) - Fix panic on parsing disallowed raw identifiers such as `r#self` ([#351](https://togithub.com/dtolnay/proc-macro2/issues/351)) ### [`v1.0.44`](https://togithub.com/dtolnay/proc-macro2/releases/tag/1.0.44) [Compare Source](https://togithub.com/dtolnay/proc-macro2/compare/1.0.43...1.0.44) - Expose `span.before()` and `span.after()` to access an empty `Span` located immediately before or after the input span ([#348](https://togithub.com/dtolnay/proc-macro2/issues/348), upstream tracking issue: [https://github.com/rust-lang/rust/issues/87552](https://togithub.com/rust-lang/rust/issues/87552)) </details> <details> <summary>serde-rs/serde</summary> ### [`v1.0.147`](https://togithub.com/serde-rs/serde/releases/tag/v1.0.147) [Compare Source](https://togithub.com/serde-rs/serde/compare/v1.0.146...v1.0.147) - Add `serde::de::value::EnumAccessDeserializer` which transforms an `EnumAccess` into a `Deserializer` ([#2305](https://togithub.com/serde-rs/serde/issues/2305)) ### [`v1.0.146`](https://togithub.com/serde-rs/serde/releases/tag/v1.0.146) [Compare Source](https://togithub.com/serde-rs/serde/compare/v1.0.145...v1.0.146) - Allow internally tagged newtype variant to contain unit ([#2303](https://togithub.com/serde-rs/serde/issues/2303), thanks [@tage64](https://togithub.com/tage64)) ### [`v1.0.145`](https://togithub.com/serde-rs/serde/releases/tag/v1.0.145) [Compare Source](https://togithub.com/serde-rs/serde/compare/v1.0.144...v1.0.145) - Allow RefCell\<T>, Mutex\<T>, and RwLock\<T> to be serialized regardless of whether T is `Sized` ([#2282](https://togithub.com/serde-rs/serde/issues/2282), thanks [@ChayimFriedman2](https://togithub.com/ChayimFriedman2)) </details> <details> <summary>serde-rs/json</summary> ### [`v1.0.87`](https://togithub.com/serde-rs/json/releases/tag/v1.0.87) [Compare Source](https://togithub.com/serde-rs/json/compare/v1.0.86...v1.0.87) - Add `write_i128` and `write_u128` methods to `serde_json::Formatter` to control the formatting of 128-bit integers ([#940](https://togithub.com/serde-rs/json/issues/940), thanks [@Lucretiel](https://togithub.com/Lucretiel)) ### [`v1.0.86`](https://togithub.com/serde-rs/json/releases/tag/v1.0.86) [Compare Source](https://togithub.com/serde-rs/json/compare/v1.0.85...v1.0.86) - Support `arbitrary_precision` feature even in no-std mode ([#928](https://togithub.com/serde-rs/json/issues/928), thanks [@kvinwang](https://togithub.com/kvinwang)) </details> <details> <summary>dtolnay/serde-yaml</summary> ### [`v0.9.14`](https://togithub.com/dtolnay/serde-yaml/releases/tag/0.9.14) [Compare Source](https://togithub.com/dtolnay/serde-yaml/compare/0.9.13...0.9.14) - Implement `Deserializer` for `TaggedValue` and `&TaggedValue` ([#339](https://togithub.com/dtolnay/serde-yaml/issues/339)) ### [`v0.9.13`](https://togithub.com/dtolnay/serde-yaml/releases/tag/0.9.13) [Compare Source](https://togithub.com/dtolnay/serde-yaml/compare/0.9.12...0.9.13) - Recognize `True`, `TRUE`, `False`, `FALSE` as booleans, `Null`, `NULL` as null ([#330](https://togithub.com/dtolnay/serde-yaml/issues/330)) ### [`v0.9.12`](https://togithub.com/dtolnay/serde-yaml/releases/tag/0.9.12) [Compare Source](https://togithub.com/dtolnay/serde-yaml/compare/0.9.11...0.9.12) - Support deserializing tagged literal scalar into primitive ([#327](https://togithub.com/dtolnay/serde-yaml/issues/327)) ```yaml "foo": !!int |- 7200 ``` ### [`v0.9.11`](https://togithub.com/dtolnay/serde-yaml/releases/tag/0.9.11) [Compare Source](https://togithub.com/dtolnay/serde-yaml/compare/0.9.10...0.9.11) - Serialize strings on a single line when they do not already contain a newline character, regardless of string length ([#321](https://togithub.com/dtolnay/serde-yaml/issues/321), [#322](https://togithub.com/dtolnay/serde-yaml/issues/322)) </details> <details> <summary>shepmaster/snafu</summary> ### [`v0.7.3`](https://togithub.com/shepmaster/snafu/blob/HEAD/CHANGELOG.md#073---2022-10-20) [Compare Source](https://togithub.com/shepmaster/snafu/compare/0.7.2...0.7.3) ##### Fixed - The macro no longer generates invalid code when implicitly-generated types (such as backtraces) were used in conjunction with `#[snafu(source(from))]` and the type before transformation does not implement `std::error::Error`. [0.7.3]: https://togithub.com/shepmaster/snafu/releases/tag/0.7.3 ### [`v0.7.2`](https://togithub.com/shepmaster/snafu/blob/HEAD/CHANGELOG.md#072---2022-10-09) [Compare Source](https://togithub.com/shepmaster/snafu/compare/0.7.1...0.7.2) ##### Added - `Report` can be returned from `main` or test functions to provide a user-friendly display of errors. - A cheat sheet for the most common `#[snafu(...)]` attribute usages has been added to the `Snafu` macro's documentation. - Optional support for using the standard library's `std::backtrace::Backtrace` type via the `backtraces-impl-std` feature flag. - Optional support for implementing the Provider API using the `std::error::Error::provide` method via the `unstable-provider-api` feature flag. - Optional support for implementing the `core::error::Error` trait instead of `std::error::Error` via the `unstable-core-error` feature flag. - `GenerateImplicitData` has a new method `generate_with_source`. ##### Changed - `ErrorCompat::iter_chain` and `ChainCompat` are now available in no_std environments. - `ChainCompat` now implements `Clone`. - The `Debug` implementation for `Location` no longer shows some irrelevant internal details. [0.7.2]: https://togithub.com/shepmaster/snafu/releases/tag/0.7.2 </details> <details> <summary>dtolnay/syn</summary> ### [`v1.0.103`](https://togithub.com/dtolnay/syn/releases/tag/1.0.103) [Compare Source](https://togithub.com/dtolnay/syn/compare/1.0.102...1.0.103) - Implement `PartialOrd` for `Cursor` ([#1236](https://togithub.com/dtolnay/syn/issues/1236), [#1237](https://togithub.com/dtolnay/syn/issues/1237), thanks [@CAD97](https://togithub.com/CAD97)) ### [`v1.0.102`](https://togithub.com/dtolnay/syn/releases/tag/1.0.102) [Compare Source](https://togithub.com/dtolnay/syn/compare/1.0.101...1.0.102) - More efficient internal representation for `TokenBuffer` ([#1223](https://togithub.com/dtolnay/syn/issues/1223), thanks [@CAD97](https://togithub.com/CAD97)) - Fix parsing of a left shift after macro metavariable in type position ([#1229](https://togithub.com/dtolnay/syn/issues/1229)) ### [`v1.0.101`](https://togithub.com/dtolnay/syn/releases/tag/1.0.101) [Compare Source](https://togithub.com/dtolnay/syn/compare/1.0.100...1.0.101) - Eliminate a bunch of redundant work done by LitStr::parse ([#1221](https://togithub.com/dtolnay/syn/issues/1221)) ### [`v1.0.100`](https://togithub.com/dtolnay/syn/releases/tag/1.0.100) [Compare Source](https://togithub.com/dtolnay/syn/compare/1.0.99...1.0.100) - Parse closures with explicit empty lifetime parameter list `for<> || -> T {…}` ([#1212](https://togithub.com/dtolnay/syn/issues/1212), [https://github.com/rust-lang/rust/issues/97362](https://togithub.com/rust-lang/rust/issues/97362)) - Parse `dyn*` provisional syntax ([#1213](https://togithub.com/dtolnay/syn/issues/1213), [https://github.com/rust-lang/rust/issues/91611](https://togithub.com/rust-lang/rust/issues/91611)) - Parse attributes on the "rest" pattern of a struct in pattern position, `Struct { #[attr] .. }` ([#1214](https://togithub.com/dtolnay/syn/issues/1214)) - Parse `static async` and `static async move` closures ([#1215](https://togithub.com/dtolnay/syn/issues/1215), [https://github.com/rust-lang/rust/issues/62290](https://togithub.com/rust-lang/rust/issues/62290)) </details> <details> <summary>dtolnay/thiserror</summary> ### [`v1.0.37`](https://togithub.com/dtolnay/thiserror/releases/tag/1.0.37) [Compare Source](https://togithub.com/dtolnay/thiserror/compare/1.0.36...1.0.37) - Documentation improvements ### [`v1.0.36`](https://togithub.com/dtolnay/thiserror/releases/tag/1.0.36) [Compare Source](https://togithub.com/dtolnay/thiserror/compare/1.0.35...1.0.36) - Documentation improvements ([#195](https://togithub.com/dtolnay/thiserror/issues/195), thanks [@matklad](https://togithub.com/matklad)) ### [`v1.0.35`](https://togithub.com/dtolnay/thiserror/releases/tag/1.0.35) [Compare Source](https://togithub.com/dtolnay/thiserror/compare/1.0.34...1.0.35) - More work on integrating [std::any::Provider](https://doc.rust-lang.org/std/any/trait.Provider.html) for backtrace support - Fix *"Multiple applicable `provide` methods in scope"* error when the caller has both std::error::Error and std::any::Provide traits in scope ([#185](https://togithub.com/dtolnay/thiserror/issues/185)) ### [`v1.0.34`](https://togithub.com/dtolnay/thiserror/releases/tag/1.0.34) [Compare Source](https://togithub.com/dtolnay/thiserror/compare/1.0.33...1.0.34) - Tweak "generic member access" based Backtrace implementation ([#184](https://togithub.com/dtolnay/thiserror/issues/184)) ### [`v1.0.33`](https://togithub.com/dtolnay/thiserror/releases/tag/1.0.33) [Compare Source](https://togithub.com/dtolnay/thiserror/compare/1.0.32...1.0.33) - Expose backtraces via the new "generic member access" API on the Error trait ([https://github.com/rust-lang/rust/issues/99301](https://togithub.com/rust-lang/rust/issues/99301), [https://github.com/rust-lang/rust/issues/96024](https://togithub.com/rust-lang/rust/issues/96024)) </details> <details> <summary>tokio-rs/tokio</summary> ### [`v1.21.2`](https://togithub.com/tokio-rs/tokio/releases/tag/tokio-1.21.2) [Compare Source](https://togithub.com/tokio-rs/tokio/compare/tokio-1.21.1...tokio-1.21.2) ### 1.21.2 (September 27, 2022) This release removes the dependency on the `once_cell` crate to restore the MSRV of 1.21.x, which is the latest minor version at the time of release. ([#5048]) [#5048]: https://togithub.com/tokio-rs/tokio/pull/5048 </details> <details> <summary>tokio-rs/tracing</summary> ### [`v0.1.37`](https://togithub.com/tokio-rs/tracing/releases/tag/tracing-0.1.37) [Compare Source](https://togithub.com/tokio-rs/tracing/compare/tracing-0.1.36...tracing-0.1.37) This release of `tracing` incorporates changes from `tracing-core` [v0.1.30][core-0.1.30] and `tracing-attributes` [v0.1.23][attrs-0.1.23], including the new `Subscriber::on_register_dispatch` method for performing late initialization after a `Subscriber` is registered as a `Dispatch`, and bugfixes for the `#[instrument]` attribute. Additionally, it fixes instances of the `bare_trait_objects` lint, which is now a warning on `tracing`'s MSRV and will become an error in the next edition. ##### Fixed - **attributes**: Incorrect handling of inner attributes in `#[instrument]`ed functions ([#2307]) - **attributes**: Incorrect location of compiler diagnostic spans generated for type errors in `#[instrument]`ed `async fn`s ([#2270]) - **attributes**: Updated `syn` dependency to fix compilation with `-Z minimal-versions` ([#2246]) - `bare_trait_objects` warning in `valueset!` macro expansion ([#2308]) ##### Added - **core**: `Subscriber::on_register_dispatch` method ([#2269]) - **core**: `WeakDispatch` type and `Dispatch::downgrade()` function ([#2293]) ##### Changed - `tracing-core`: updated to [0.1.30][core-0.1.30] - `tracing-attributes`: updated to [0.1.23][attrs-0.1.23] ##### Documented - Added [`tracing-web`][tracing-web] and [`reqwest-tracing`][reqwest-tracing] to related crates ([#2283], [#2331]) Thanks to new contributors [@compiler-errors](https://togithub.com/compiler-errors), [@e-nomem](https://togithub.com/e-nomem), [@WorldSEnder](https://togithub.com/WorldSEnder), [@Xiami2012](https://togithub.com/Xiami2012), and [@tl-rodrigo-gryzinski](https://togithub.com/tl-rodrigo-gryzinski), as well as [@jswrenn](https://togithub.com/jswrenn) and [@CAD97](https://togithub.com/CAD97), for contributing to this release! [core-0.1.30]: https://togithub.com/tokio-rs/tracing/releases/tag/tracing-core-0.1.30 [attrs-0.1.23]: https://togithub.com/tokio-rs/tracing/releases/tag/tracing-attributes-0.1.23 [`tracing-web`]: https://crates.io/crates/tracing-web/ [`reqwest-tracing`]: https://crates.io/crates/reqwest-tracing/ [#2246]: https://togithub.com/tokio-rs/tracing/pull/2246 [#2269]: https://togithub.com/tokio-rs/tracing/pull/2269 [#2283]: https://togithub.com/tokio-rs/tracing/pull/2283 [#2270]: https://togithub.com/tokio-rs/tracing/pull/2270 [#2293]: https://togithub.com/tokio-rs/tracing/pull/2293 [#2307]: https://togithub.com/tokio-rs/tracing/pull/2307 [#2308]: https://togithub.com/tokio-rs/tracing/pull/2308 [#2331]: https://togithub.com/tokio-rs/tracing/pull/2331 </details> --- ### Configuration 📅 **Schedule**: Branch creation - "after 5:00 and before 6:00 every weekday" in timezone Europe/Berlin, Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. 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compiler-errors · 2023-09-14T09:44:43Z

For the record, a stabilization PR has been opened over at: #115822.

#91611 (comment): @zachs18: Yeah, I think the async book should be adjusted to mention something along the lines of "future isn't, in general, gonna to be run to completion unless it is awaited" -- the point, afaict, is more to make sure folks know .await needs to be called on the future unlike other langs which spawn tasks and kick them off immediately as a part of their async desugaring or something.

- This currently requires using either beta or nightly channel. - Due to rust-lang/rust#91611

## Summary Salsa requires rust-lang/rust#91611 which stabalized with [1.75](https://blog.rust-lang.org/2023/12/28/Rust-1.75.0.html) 1.75 doesn't change the supported platforms. So I think this upgrade is fine in a minor. ## Test Plan `cargo build`

rust-lang/rust#91611

this is required because of return_position_impl_trait_in_trait being used in `pigeons` rust-lang/rust#91611

nikomatsakis added T-lang Relevant to the language team, which will review and decide on the PR/issue. C-tracking-issue Category: An issue tracking the progress of sth. like the implementation of an RFC labels Dec 6, 2021

nikomatsakis mentioned this issue Dec 7, 2021

Static async fn in traits rust-lang/rfcs#3185

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uselessgoddess mentioned this issue Jan 18, 2022

Implement fast async API with asynchronous traits linksplatform/Data.Doublets#290

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crlf0710 added B-RFC-approved Blocker: Approved by a merged RFC but not yet implemented. F-async_fn_in_trait Static async fn in traits labels Feb 5, 2022

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Asynchronous embedded-hal traits roadmap rust-embedded/embedded-hal#356

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Add async support xgroleau/mx25r-rs#1

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Stabilize generic associated types #96709

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joshtriplett added the S-tracking-impl-incomplete Status: The implementation is incomplete. label Jul 27, 2022

crlf0710 added F-return_position_impl_trait_in_trait `#![feature(return_position_impl_trait_in_trait)]` F-dyn_star `#![feature(dyn_star)]` labels Sep 17, 2022

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Parse dyn* syntax dtolnay/syn#1213

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nikomatsakis mentioned this issue Oct 4, 2022

Async fns in traits rust-lang/lang-team#150

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Kani does not yet support dyn* model-checking/kani#1784

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crlf0710 removed the F-dyn_star `#![feature(dyn_star)]` label Oct 22, 2022

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Stabilize async fn and return-position impl Trait in trait #115822

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est31 mentioned this issue Sep 25, 2023

Support async fn in trait methods (async/await follow-up) rust-lang/rfcs#2739

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kevinaboos mentioned this issue Oct 3, 2023

Add Scheduler trait theseus-os/Theseus#1035

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nazar-pc mentioned this issue Oct 16, 2023

Update Rust to latest nightly autonomys/subspace#2127

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Stable Rust now that GATs are stable? bytedance/monoio#129

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Support for Async Fn in Trait? google/tarpc#409

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zanieb added a commit to astral-sh/uv that referenced this issue Nov 8, 2023

Switch to nightly rust for rust-lang/rust#91611

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add async func in trait support ihciah/service-async#2

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Upgrade PubGrub to 02a19f72d636119fb3f826a922122e21da69cfa5 astral-sh/uv#370

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Get rid of the boxed iterator returned from query in favor of impl Iterator tgecho/canrun_rs#24

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randombtree added a commit to randombtree/rpcudp-rs that referenced this issue Dec 9, 2023

Set minimum Rust version.

89c9f55

- This currently requires using either beta or nightly channel. - Due to rust-lang/rust#91611

sffc mentioned this issue Dec 22, 2023

Add explicit ZeroVec and VarZeroVec iterator types unicode-org/icu4x#4487

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thejoven mentioned this issue Jan 9, 2024

Attempting cargo build encountered a question hack-ink/atomicalsir#28

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Compilation error on Alpine Linux crunchy-labs/crunchy-cli#306

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Hello, I have encountered a question: functions in traits cannot be declared async rbatis/rbatis#481

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cargo run dev -> error MatthiasGrandl/Loungy#2

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Build wstunnel 9.2.2 erebe/wstunnel#232

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Unable to write blanket impl for subtrait on RPITIT trait #124729

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tiran mentioned this issue Jun 5, 2024

Lower MSRV to 1.75 pydantic/pydantic-core#1315

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Set 1.75 as minimal Rust version astral-sh/ruff#11821

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MSRV googlefonts/fontations#1019

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Specialize Prefix/Suffix Match for Like/ILike between Array and Scalar for StringViewArray apache/arrow-rs#6231

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tsionyx added a commit to tsionyx/prop-logic that referenced this issue Jan 21, 2025

bump MSRV to 1.75 for RPITIT

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rust-lang/rust#91611

tsionyx added a commit to tsionyx/prop-logic that referenced this issue Feb 1, 2025

bump MSRV to 1.75 for RPITIT

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rust-lang/rust#91611

chrjabs added a commit to chrjabs/rustsat that referenced this issue Apr 2, 2025

chore: bump MSRV to 1.75.0

39da5e6

this is required because of return_position_impl_trait_in_trait being used in `pigeons` rust-lang/rust#91611

chrjabs added a commit to chrjabs/rustsat that referenced this issue Apr 2, 2025

chore: bump MSRV to 1.75.0

f21e6b9

this is required because of return_position_impl_trait_in_trait being used in `pigeons` rust-lang/rust#91611

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Tracking Issue for async_fn_in_trait, return_position_impl_trait_in_trait #91611

Tracking Issue for async_fn_in_trait, return_position_impl_trait_in_trait #91611

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Tracking Issue for async_fn_in_trait, return_position_impl_trait_in_trait #91611

Tracking Issue for async_fn_in_trait, return_position_impl_trait_in_trait #91611

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