diff options
3 files changed, 6 insertions, 0 deletions
diff --git a/compiler/rustc_typeck/src/check/check.rs b/compiler/rustc_typeck/src/check/check.rs index ab3c26fac83..f0bc31641b4 100644 --- a/compiler/rustc_typeck/src/check/check.rs +++ b/compiler/rustc_typeck/src/check/check.rs @@ -1446,6 +1446,9 @@ fn async_opaque_type_cycle_error(tcx: TyCtxt<'tcx>, span: Span) { struct_span_err!(tcx.sess, span, E0733, "recursion in an `async fn` requires boxing") .span_label(span, "recursive `async fn`") .note("a recursive `async fn` must be rewritten to return a boxed `dyn Future`") + .note( + "consider using the `async_recursion` crate: https://crates.io/crates/async_recursion", + ) .emit(); } diff --git a/src/test/ui/async-await/mutually-recursive-async-impl-trait-type.stderr b/src/test/ui/async-await/mutually-recursive-async-impl-trait-type.stderr index f6e4c8be292..f789ad2a05c 100644 --- a/src/test/ui/async-await/mutually-recursive-async-impl-trait-type.stderr +++ b/src/test/ui/async-await/mutually-recursive-async-impl-trait-type.stderr @@ -5,6 +5,7 @@ LL | async fn rec_1() { | ^ recursive `async fn` | = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future` + = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion error[E0733]: recursion in an `async fn` requires boxing --> $DIR/mutually-recursive-async-impl-trait-type.rs:9:18 @@ -13,6 +14,7 @@ LL | async fn rec_2() { | ^ recursive `async fn` | = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future` + = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion error: aborting due to 2 previous errors diff --git a/src/test/ui/async-await/recursive-async-impl-trait-type.stderr b/src/test/ui/async-await/recursive-async-impl-trait-type.stderr index 892d91e3a49..63f64f44557 100644 --- a/src/test/ui/async-await/recursive-async-impl-trait-type.stderr +++ b/src/test/ui/async-await/recursive-async-impl-trait-type.stderr @@ -5,6 +5,7 @@ LL | async fn recursive_async_function() -> () { | ^^ recursive `async fn` | = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future` + = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion error: aborting due to previous error |