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 {
   |     ----- this function should return `Result` or `Option` to accept `?`
LL |         let x: Option<u32> = None;
LL |         x?;
   |          ^ cannot use the `?` operator in an async block that returns `{integer}`
   |
   = help: the trait `FromResidual<Option<Infallible>>` 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<u32> = 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<Option<Infallible>>` 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<u32> = 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<Option<Infallible>>` is not implemented for `u32`

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0277`.