1 error[E0271]: expected `[async block@$DIR/async.rs:12:17: 12:25]` to be a future that resolves to `i32`, but it resolves to `()`
2 --> $DIR/async.rs:12:17
4 LL | needs_async(async {});
5 | ----------- ^^^^^^^^ expected `i32`, found `()`
7 | required by a bound introduced by this call
9 note: required by a bound in `needs_async`
10 --> $DIR/async.rs:8:31
12 LL | fn needs_async(_: impl Future<Output = i32>) {}
13 | ^^^^^^^^^^^^ required by this bound in `needs_async`
15 error: aborting due to previous error
17 For more information about this error, try `rustc --explain E0271`.