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

   1 error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `std::ops::Try`)
   2   --> $DIR/try-on-option-diagnostics.rs:7:5
   3    |
   4 LL | / fn a_function() -> u32 {
   5 LL | |     let x: Option<u32> = None;
   6 LL | |     x?;
   7    | |     ^^ cannot use the `?` operator in a function that returns `u32`
   8 LL | |     22
   9 LL | | }
  10    | |_- this function should return `Result` or `Option` to accept `?`
  11    |
  12    = help: the trait `std::ops::Try` is not implemented for `u32`
  13    = note: required by `std::ops::Try::from_error`
  14
  15 error[E0277]: the `?` operator can only be used in a closure that returns `Result` or `Option` (or another type that implements `std::ops::Try`)
  16   --> $DIR/try-on-option-diagnostics.rs:14:9
  17    |
  18 LL |       let a_closure = || {
  19    |  _____________________-
  20 LL | |         let x: Option<u32> = None;
  21 LL | |         x?;
  22    | |         ^^ cannot use the `?` operator in a closure that returns `{integer}`
  23 LL | |         22
  24 LL | |     };
  25    | |_____- this function should return `Result` or `Option` to accept `?`
  26    |
  27    = help: the trait `std::ops::Try` is not implemented for `{integer}`
  28    = note: required by `std::ops::Try::from_error`
  29
  30 error: aborting due to 2 previous errors
  31
  32 For more information about this error, try `rustc --explain E0277`.