src/test/ui/try-trait/try-on-option.stderr

   1 error[E0277]: the `?` operator can only be used on `Result`s, not `Option`s, in a function that returns `Result`
   2   --> $DIR/try-on-option.rs:5:6
   3    |
   4 LL | / fn foo() -> Result<u32, ()> {
   5 LL | |     let x: Option<u32> = None;
   6 LL | |     x?;
   7    | |      ^ use `.ok_or(...)?` to provide an error compatible with `Result<u32, ()>`
   8 LL | |     Ok(22)
   9 LL | | }
  10    | |_- this function returns a `Result`
  11    |
  12    = help: the trait `FromResidual<Option<Infallible>>` is not implemented for `Result<u32, ()>`
  13
  14 error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
  15   --> $DIR/try-on-option.rs:11:6
  16    |
  17 LL | / fn bar() -> u32 {
  18 LL | |     let x: Option<u32> = None;
  19 LL | |     x?;
  20    | |      ^ cannot use the `?` operator in a function that returns `u32`
  21 LL | |     22
  22 LL | | }
  23    | |_- this function should return `Result` or `Option` to accept `?`
  24    |
  25    = help: the trait `FromResidual<Option<Infallible>>` is not implemented for `u32`
  26
  27 error: aborting due to 2 previous errors
  28
  29 For more information about this error, try `rustc --explain E0277`.