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    = help: the following other types implement trait `FromResidual<R>`:
  14              <Result<T, F> as FromResidual<Result<Infallible, E>>>
  15              <Result<T, F> as FromResidual<Yeet<E>>>
  16
  17 error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
  18   --> $DIR/try-on-option.rs:11:6
  19    |
  20 LL | / fn bar() -> u32 {
  21 LL | |     let x: Option<u32> = None;
  22 LL | |     x?;
  23    | |      ^ cannot use the `?` operator in a function that returns `u32`
  24 LL | |     22
  25 LL | | }
  26    | |_- this function should return `Result` or `Option` to accept `?`
  27    |
  28    = help: the trait `FromResidual<Option<Infallible>>` is not implemented for `u32`
  29
  30 error: aborting due to 2 previous errors
  31
  32 For more information about this error, try `rustc --explain E0277`.