|  | error[E0277]: the `?` operator can only be applied to values that implement `Try` | 
|  | --> $DIR/issue-84841.rs:9:5 | 
|  | | | 
|  | LL |     test()?; | 
|  | |     ^^^^^^^ the `?` operator cannot be applied to type `impl Future<Output = ()>` | 
|  | | | 
|  | = help: the trait `Try` is not implemented for `impl Future<Output = ()>` | 
|  |  | 
|  | error[E0277]: the `?` operator can only be used in an async function that returns `Result` or `Option` (or another type that implements `FromResidual`) | 
|  | --> $DIR/issue-84841.rs:9:11 | 
|  | | | 
|  | LL |   async fn foo() { | 
|  | |  ________________- | 
|  | LL | |     // Adding an .await here avoids the ICE | 
|  | LL | |     test()?; | 
|  | | |           ^ cannot use the `?` operator in an async function that returns `()` | 
|  | ...  | | 
|  | LL | | } | 
|  | | |_- this function should return `Result` or `Option` to accept `?` | 
|  |  | 
|  | error: aborting due to 2 previous errors | 
|  |  | 
|  | For more information about this error, try `rustc --explain E0277`. |