error[E0277]: the `?` operator can only be used in an async block that returns `Result` or `Option` (or another type that implements `FromResidual`) --> $DIR/try-on-option-in-async.rs:8:10 | LL | / async { LL | | let x: Option = None; LL | | x?; | | ^ cannot use the `?` operator in an async block that returns `{integer}` LL | | 22 LL | | } | |_____- this function should return `Result` or `Option` to accept `?` | = help: the trait `FromResidual>` is not implemented for `{integer}` error[E0277]: the `?` operator can only be used in an async closure that returns `Result` or `Option` (or another type that implements `FromResidual`) --> $DIR/try-on-option-in-async.rs:17:10 | LL | let async_closure = async || { | __________________________________- LL | | let x: Option = None; LL | | x?; | | ^ cannot use the `?` operator in an async closure that returns `u32` LL | | 22_u32 LL | | }; | |_____- this function should return `Result` or `Option` to accept `?` | = help: the trait `FromResidual>` is not implemented for `u32` error[E0277]: the `?` operator can only be used in an async function that returns `Result` or `Option` (or another type that implements `FromResidual`) --> $DIR/try-on-option-in-async.rs:26:6 | LL | async fn an_async_function() -> u32 { | _____________________________________- LL | | let x: Option = None; LL | | x?; | | ^ cannot use the `?` operator in an async function that returns `u32` LL | | 22 LL | | } | |_- this function should return `Result` or `Option` to accept `?` | = help: the trait `FromResidual>` is not implemented for `u32` error: aborting due to 3 previous errors For more information about this error, try `rustc --explain E0277`.