From 88669aed22aeeef5fb7ecdb7f43ed33e674f8fcb Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Sat, 7 Dec 2024 23:54:10 +0000 Subject: [PATCH] Don't use AsyncFnOnce::CallOnceFuture bounds for signature deduction --- compiler/rustc_hir_typeck/src/closure.rs | 12 ++++-------- .../async-closures/call-once-deduction.rs | 14 ++++++++++++++ 2 files changed, 18 insertions(+), 8 deletions(-) create mode 100644 tests/ui/async-await/async-closures/call-once-deduction.rs diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs index e715a7f7e1588..9037caf0066fe 100644 --- a/compiler/rustc_hir_typeck/src/closure.rs +++ b/compiler/rustc_hir_typeck/src/closure.rs @@ -454,20 +454,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { closure_kind: hir::ClosureKind, projection: ty::PolyProjectionPredicate<'tcx>, ) -> Option> { - let tcx = self.tcx; - - let trait_def_id = projection.trait_def_id(tcx); + let def_id = projection.projection_def_id(); // For now, we only do signature deduction based off of the `Fn` and `AsyncFn` traits, // for closures and async closures, respectively. match closure_kind { - hir::ClosureKind::Closure - if self.tcx.fn_trait_kind_from_def_id(trait_def_id).is_some() => - { + hir::ClosureKind::Closure if self.tcx.is_lang_item(def_id, LangItem::FnOnceOutput) => { self.extract_sig_from_projection(cause_span, projection) } hir::ClosureKind::CoroutineClosure(hir::CoroutineDesugaring::Async) - if self.tcx.async_fn_trait_kind_from_def_id(trait_def_id).is_some() => + if self.tcx.is_lang_item(def_id, LangItem::AsyncFnOnceOutput) => { self.extract_sig_from_projection(cause_span, projection) } @@ -475,7 +471,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // `F: FnOnce() -> Fut, Fut: Future` style bound. Let's still // guide inference here, since it's beneficial for the user. hir::ClosureKind::CoroutineClosure(hir::CoroutineDesugaring::Async) - if self.tcx.fn_trait_kind_from_def_id(trait_def_id).is_some() => + if self.tcx.is_lang_item(def_id, LangItem::FnOnceOutput) => { self.extract_sig_from_projection_and_future_bound(cause_span, projection) } diff --git a/tests/ui/async-await/async-closures/call-once-deduction.rs b/tests/ui/async-await/async-closures/call-once-deduction.rs new file mode 100644 index 0000000000000..41d92bc3d786c --- /dev/null +++ b/tests/ui/async-await/async-closures/call-once-deduction.rs @@ -0,0 +1,14 @@ +//@ edition: 2021 +//@ check-pass + +#![feature(async_closure, async_fn_traits, unboxed_closures)] + +fn bar(_: F) +where + F: AsyncFnOnce<(), CallOnceFuture = O>, +{ +} + +fn main() { + bar(async move || {}); +}