src/test/ui/option-to-result.stderr

   1 error[E0277]: `?` couldn't convert the error to `()`
   2   --> $DIR/option-to-result.rs:5:6
   3    |
   4 LL | fn test_result() -> Result<(),()> {
   5    |                     ------------- expected `()` because of this
   6 LL |     let a:Option<()> = Some(());
   7 LL |     a?;
   8    |      ^ the trait `From<NoneError>` is not implemented for `()`
   9    |
  10    = note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
  11    = note: required by `from`
  12 help: consider converting the `Option<T>` into a `Result<T, _>` using `Option::ok_or` or `Option::ok_or_else`
  13    |
  14 LL |     a.ok_or_else(|| /* error value */)?;
  15    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  16
  17 error[E0277]: `?` couldn't convert the error to `NoneError`
  18   --> $DIR/option-to-result.rs:11:6
  19    |
  20 LL | fn test_option() -> Option<i32>{
  21    |                     ----------- expected `NoneError` because of this
  22 LL |     let a:Result<i32, i32> = Ok(5);
  23 LL |     a?;
  24    |      ^ the trait `From<i32>` is not implemented for `NoneError`
  25    |
  26    = note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
  27    = note: required by `from`
  28 help: consider converting the `Result<T, _>` into an `Option<T>` using `Result::ok`
  29    |
  30 LL |     a.ok()?;
  31    |      ^^^^^
  32
  33 error: aborting due to 2 previous errors
  34
  35 For more information about this error, try `rustc --explain E0277`.