| error[E0658]: async closures are unstable |
| --> $DIR/trait-bounds-in-macro.rs:8:28 |
| | |
| LL | async fn foo() -> impl async Fn() { } |
| | ^^^^^ |
| | |
| = note: see issue #62290 <https://github.com/rust-lang/rust/issues/62290> for more information |
| = help: add `#![feature(async_closure)]` to the crate attributes to enable |
| = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date |
| = help: to use an async block, remove the `||`: `async {` |
| |
| error: aborting due to 1 previous error |
| |
| For more information about this error, try `rustc --explain E0658`. |
