Make it so that async-fn-in-trait is compatible with a concrete future in implementation #120103

compiler-errors · 2024-01-18T17:29:16Z

There's no technical reason why an AFIT like async fn foo() cannot be satisfied with an implementation signature like fn foo() -> Pin<Box<dyn Future<Output = ()> + 'static>>.

We rejected this previously because we were uncertain about how AFITs worked with refinement, but I don't believe this needs to be a restriction any longer.

r? oli-obk

compiler-errors · 2024-01-18T17:29:31Z

I'm gonna lang nominate this.

@rustbot label: I-lang-nominated

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

tmandry · 2024-01-24T16:56:38Z

We discussed this in the lang team meeting; everyone present was in favor, but agreed that this was a form of refinement and should be treated like any other kind of refinement.

@rfcbot merge

rfcbot · 2024-01-24T16:56:40Z

Team member @tmandry has proposed to merge this. The next step is review by the rest of the tagged team members:

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
See this document for info about what commands tagged team members can give me.

rfcbot · 2024-01-24T16:57:13Z

🔔 This is now entering its final comment period, as per the review above. 🔔

traviscross · 2024-01-25T05:06:37Z

@rustbot labels -I-lang-nominated

As tmandry noted, we discussed this in T-lang triage and were in favor of doing this. It's now entering FCP, so let's unnominate.

bors · 2024-01-29T02:22:21Z

☔ The latest upstream changes (presumably #119972) made this pull request unmergeable. Please resolve the merge conflicts.

rfcbot · 2024-02-03T16:59:44Z

The final comment period, with a disposition to merge, as per the review above, is now complete.

As the automated representative of the governance process, I would like to thank the author for their work and everyone else who contributed.

This will be merged soon.

compiler-errors · 2024-02-03T17:44:28Z

@rustbot ready

compiler-errors · 2024-02-07T00:00:31Z

oops forgot to re-approve

@bors r=oli-obk

bors · 2024-02-07T00:00:34Z

📌 Commit 1a3214b has been approved by oli-obk

It is now in the queue for this repository.

…oli-obk Make it so that async-fn-in-trait is compatible with a concrete future in implementation There's no technical reason why an AFIT like `async fn foo()` cannot be satisfied with an implementation signature like `fn foo() -> Pin<Box<dyn Future<Output = ()> + 'static>>`. We rejected this previously because we were uncertain about how AFITs worked with refinement, but I don't believe this needs to be a restriction any longer. r? oli-obk

…iaskrgr Rollup of 8 pull requests Successful merges: - rust-lang#119162 (Add unstable `-Z direct-access-external-data` cmdline flag for `rustc`) - rust-lang#119592 (resolve: Unload speculatively resolved crates before freezing cstore) - rust-lang#120103 (Make it so that async-fn-in-trait is compatible with a concrete future in implementation) - rust-lang#120455 ( Add FileCheck annotations to MIR-opt SROA tests) - rust-lang#120470 (Mark "unused binding" suggestion as maybe incorrect) - rust-lang#120619 (Assert that params with the same *index* have the same *name*) - rust-lang#120633 (pattern_analysis: gather up place-relevant info) - rust-lang#120726 (Don't use bashism in checktools.sh) r? `@ghost` `@rustbot` modify labels: rollup

…oli-obk Make it so that async-fn-in-trait is compatible with a concrete future in implementation There's no technical reason why an AFIT like `async fn foo()` cannot be satisfied with an implementation signature like `fn foo() -> Pin<Box<dyn Future<Output = ()> + 'static>>`. We rejected this previously because we were uncertain about how AFITs worked with refinement, but I don't believe this needs to be a restriction any longer. r? oli-obk

…iaskrgr Rollup of 8 pull requests Successful merges: - rust-lang#119592 (resolve: Unload speculatively resolved crates before freezing cstore) - rust-lang#120103 (Make it so that async-fn-in-trait is compatible with a concrete future in implementation) - rust-lang#120206 (hir: Make sure all `HirId`s have corresponding HIR `Node`s) - rust-lang#120214 (match lowering: consistently lower bindings deepest-first) - rust-lang#120596 ([rustdoc] Correctly generate path for non-local items in source code pages) - rust-lang#120688 (GVN: also turn moves into copies with projections) - rust-lang#120702 (docs: also check the inline stmt during redundant link check) - rust-lang#120739 (improve pretty printing for associated items in trait objects) r? `@ghost` `@rustbot` modify labels: rollup

…oli-obk Make it so that async-fn-in-trait is compatible with a concrete future in implementation There's no technical reason why an AFIT like `async fn foo()` cannot be satisfied with an implementation signature like `fn foo() -> Pin<Box<dyn Future<Output = ()> + 'static>>`. We rejected this previously because we were uncertain about how AFITs worked with refinement, but I don't believe this needs to be a restriction any longer. r? oli-obk

…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#119592 (resolve: Unload speculatively resolved crates before freezing cstore) - rust-lang#120103 (Make it so that async-fn-in-trait is compatible with a concrete future in implementation) - rust-lang#120206 (hir: Make sure all `HirId`s have corresponding HIR `Node`s) - rust-lang#120214 (match lowering: consistently lower bindings deepest-first) - rust-lang#120596 ([rustdoc] Correctly generate path for non-local items in source code pages) - rust-lang#120688 (GVN: also turn moves into copies with projections) - rust-lang#120727 (exhaustiveness: Prefer "`0..MAX` not covered" to "`_` not covered") - rust-lang#120734 (Add `SubdiagnosticMessageOp` as a trait alias.) - rust-lang#120739 (improve pretty printing for associated items in trait objects) r? `@ghost` `@rustbot` modify labels: rollup

…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#119592 (resolve: Unload speculatively resolved crates before freezing cstore) - rust-lang#120103 (Make it so that async-fn-in-trait is compatible with a concrete future in implementation) - rust-lang#120206 (hir: Make sure all `HirId`s have corresponding HIR `Node`s) - rust-lang#120214 (match lowering: consistently lower bindings deepest-first) - rust-lang#120688 (GVN: also turn moves into copies with projections) - rust-lang#120702 (docs: also check the inline stmt during redundant link check) - rust-lang#120727 (exhaustiveness: Prefer "`0..MAX` not covered" to "`_` not covered") - rust-lang#120734 (Add `SubdiagnosticMessageOp` as a trait alias.) - rust-lang#120739 (improve pretty printing for associated items in trait objects) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of rust-lang#120103 - compiler-errors:concrete-afits, r=oli-obk Make it so that async-fn-in-trait is compatible with a concrete future in implementation There's no technical reason why an AFIT like `async fn foo()` cannot be satisfied with an implementation signature like `fn foo() -> Pin<Box<dyn Future<Output = ()> + 'static>>`. We rejected this previously because we were uncertain about how AFITs worked with refinement, but I don't believe this needs to be a restriction any longer. r? oli-obk

…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#119592 (resolve: Unload speculatively resolved crates before freezing cstore) - rust-lang#120103 (Make it so that async-fn-in-trait is compatible with a concrete future in implementation) - rust-lang#120206 (hir: Make sure all `HirId`s have corresponding HIR `Node`s) - rust-lang#120214 (match lowering: consistently lower bindings deepest-first) - rust-lang#120688 (GVN: also turn moves into copies with projections) - rust-lang#120702 (docs: also check the inline stmt during redundant link check) - rust-lang#120727 (exhaustiveness: Prefer "`0..MAX` not covered" to "`_` not covered") - rust-lang#120734 (Add `SubdiagnosticMessageOp` as a trait alias.) - rust-lang#120739 (improve pretty printing for associated items in trait objects) r? `@ghost` `@rustbot` modify labels: rollup

Cheban1996 · 2024-05-02T14:06:57Z

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -695,8 +664,13 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
    // RPITs.
    let errors = ocx.select_all_or_error();
    if !errors.is_empty() {
-        let reported = infcx.err_ctxt().report_fulfillment_errors(errors);
-        return Err(reported);
+        if let Err(guar) = try_report_async_mismatch(tcx, infcx, &errors, trait_m, impl_m, impl_sig)


I think this line better try_report_async_mismatch(tcx, infcx, &errors, trait_m, impl_m, impl_sig)?; than now

Pkgsrc changes: * Adapt checksums and patches, some have beene intregrated upstream. Upstream chnages: Version 1.78.0 (2024-05-02) =========================== Language -------- - [Stabilize `#[cfg(target_abi = ...)]`] (rust-lang/rust#119590) - [Stabilize the `#[diagnostic]` namespace and `#[diagnostic::on_unimplemented]` attribute] (rust-lang/rust#119888) - [Make async-fn-in-trait implementable with concrete signatures] (rust-lang/rust#120103) - [Make matching on NaN a hard error, and remove the rest of `illegal_floating_point_literal_pattern`] (rust-lang/rust#116284) - [static mut: allow mutable reference to arbitrary types, not just slices and arrays] (rust-lang/rust#117614) - [Extend `invalid_reference_casting` to include references casting to bigger memory layout] (rust-lang/rust#118983) - [Add `non_contiguous_range_endpoints` lint for singleton gaps after exclusive ranges] (rust-lang/rust#118879) - [Add `wasm_c_abi` lint for use of older wasm-bindgen versions] (rust-lang/rust#117918) This lint currently only works when using Cargo. - [Update `indirect_structural_match` and `pointer_structural_match` lints to match RFC] (rust-lang/rust#120423) - [Make non-`PartialEq`-typed consts as patterns a hard error] (rust-lang/rust#120805) - [Split `refining_impl_trait` lint into `_reachable`, `_internal` variants] (rust-lang/rust#121720) - [Remove unnecessary type inference when using associated types inside of higher ranked `where`-bounds] (rust-lang/rust#119849) - [Weaken eager detection of cyclic types during type inference] (rust-lang/rust#119989) - [`trait Trait: Auto {}`: allow upcasting from `dyn Trait` to `dyn Auto`] (rust-lang/rust#119338) Compiler -------- - [Made `INVALID_DOC_ATTRIBUTES` lint deny by default] (rust-lang/rust#111505) - [Increase accuracy of redundant `use` checking] (rust-lang/rust#117772) - [Suggest moving definition if non-found macro_rules! is defined later] (rust-lang/rust#121130) - [Lower transmutes from int to pointer type as gep on null] (rust-lang/rust#121282) Target changes: - [Windows tier 1 targets now require at least Windows 10] (rust-lang/rust#115141) - [Enable CMPXCHG16B, SSE3, SAHF/LAHF and 128-bit Atomics in tier 1 Windows] (rust-lang/rust#120820) - [Add `wasm32-wasip1` tier 2 (without host tools) target] (rust-lang/rust#120468) - [Add `wasm32-wasip2` tier 3 target] (rust-lang/rust#119616) - [Rename `wasm32-wasi-preview1-threads` to `wasm32-wasip1-threads`] (rust-lang/rust#122170) - [Add `arm64ec-pc-windows-msvc` tier 3 target] (rust-lang/rust#119199) - [Add `armv8r-none-eabihf` tier 3 target for the Cortex-R52] (rust-lang/rust#110482) - [Add `loongarch64-unknown-linux-musl` tier 3 target] (rust-lang/rust#121832) Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [Bump Unicode to version 15.1.0, regenerate tables] (rust-lang/rust#120777) - [Make align_offset, align_to well-behaved in all cases] (rust-lang/rust#121201) - [PartialEq, PartialOrd: document expectations for transitive chains] (rust-lang/rust#115386) - [Optimize away poison guards when std is built with panic=abort] (rust-lang/rust#100603) - [Replace pthread `RwLock` with custom implementation] (rust-lang/rust#110211) - [Implement unwind safety for Condvar on all platforms] (rust-lang/rust#121768) - [Add ASCII fast-path for `char::is_grapheme_extended`] (rust-lang/rust#121138) Stabilized APIs --------------- - [`impl Read for &Stdin`] (https://doc.rust-lang.org/stable/std/io/struct.Stdin.html#impl-Read-for-%26Stdin) - [Accept non `'static` lifetimes for several `std::error::Error` related implementations] (rust-lang/rust#113833) - [Make `impl<Fd: AsFd>` impl take `?Sized`] (rust-lang/rust#114655) - [`impl From<TryReserveError> for io::Error`] (https://doc.rust-lang.org/stable/std/io/struct.Error.html#impl-From%3CTryReserveError%3E-for-Error) These APIs are now stable in const contexts: - [`Barrier::new()`] (https://doc.rust-lang.org/stable/std/sync/struct.Barrier.html#method.new) Cargo ----- - [Stabilize lockfile v4](rust-lang/cargo#12852) - [Respect `rust-version` when generating lockfile] (rust-lang/cargo#12861) - [Control `--charset` via auto-detecting config value] (rust-lang/cargo#13337) - [Support `target.<triple>.rustdocflags` officially] (rust-lang/cargo#13197) - [Stabilize global cache data tracking] (rust-lang/cargo#13492) Misc ---- - [rustdoc: add `--test-builder-wrapper` arg to support wrappers such as RUSTC_WRAPPER when building doctests] (rust-lang/rust#114651) Compatibility Notes ------------------- - [Many unsafe precondition checks now run for user code with debug assertions enabled] (rust-lang/rust#120594) This change helps users catch undefined behavior in their code, though the details of how much is checked are generally not stable. - [riscv only supports split_debuginfo=off for now] (rust-lang/rust#120518) - [Consistently check bounds on hidden types of `impl Trait`] (rust-lang/rust#121679) - [Change equality of higher ranked types to not rely on subtyping] (rust-lang/rust#118247) - [When called, additionally check bounds on normalized function return type] (rust-lang/rust#118882) - [Expand coverage for `arithmetic_overflow` lint] (rust-lang/rust#119432) Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Update to LLVM 18](rust-lang/rust#120055) - [Build `rustc` with 1CGU on `x86_64-pc-windows-msvc`] (rust-lang/rust#112267) - [Build `rustc` with 1CGU on `x86_64-apple-darwin`] (rust-lang/rust#112268) - [Introduce `run-make` V2 infrastructure, a `run_make_support` library and port over 2 tests as example] (rust-lang/rust#113026) - [Windows: Implement condvar, mutex and rwlock using futex] (rust-lang/rust#121956)

Features from Rust 1.78 can be used now. Notable features from [Rust 1.78](https://releases.rs/docs/1.78.0/): - Concrete signature for AFIT (rust-lang/rust#120103) - `impl Read for &Stdin`

rustbot assigned oli-obk Jan 18, 2024

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Jan 18, 2024

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rust-cloud-vms bot force-pushed the concrete-afits branch from 0f86b22 to 7db77e1 Compare January 18, 2024 17:30

shepmaster mentioned this pull request Jan 18, 2024

Allow expectation on async trait function to return a future asomers/mockall#189

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traviscross added the T-lang Relevant to the language team, which will review and decide on the PR/issue. label Jan 19, 2024

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compiler/rustc_hir_analysis/src/check/compare_impl_item.rs Outdated Show resolved Hide resolved

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compiler-errors added 3 commits February 5, 2024 20:33

Allow desugaring async fn in trait to compatible, concrete future types

16cbdd0

Make the error message better

e65abc0

Make sure refinement still works

1a3214b

rust-cloud-vms bot force-pushed the concrete-afits branch from ad392ff to 1a3214b Compare February 5, 2024 21:09

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matthiaskrgr mentioned this pull request Feb 7, 2024

Rollup of 8 pull requests #120731

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matthiaskrgr mentioned this pull request Feb 7, 2024

Rollup of 8 pull requests #120755

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Rollup of 9 pull requests #120766

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Rollup of 9 pull requests #120767

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Make it so that async-fn-in-trait is compatible with a concrete future in implementation #120103

Make it so that async-fn-in-trait is compatible with a concrete future in implementation #120103

compiler-errors commented Jan 18, 2024

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Cheban1996 May 2, 2024

Make it so that async-fn-in-trait is compatible with a concrete future in implementation #120103

Make it so that async-fn-in-trait is compatible with a concrete future in implementation #120103

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