src/test/ui/issues/issue-32709.stderr

   1 error[E0277]: `?` couldn't convert the error to `()`
   2   --> $DIR/issue-32709.rs:4:11
   3    |
   4 LL | fn a() -> Result<i32, ()> {
   5    |           --------------- expected `()` because of this
   6 LL |     Err(5)?;
   7    |           ^ the trait `From<{integer}>` is not implemented for `()`
   8    |
   9    = note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
  10    = note: required because of the requirements on the impl of `FromResidual<Result<Infallible, {integer}>>` for `Result<i32, ()>`
  11    = note: required by `from_residual`
  12
  13 error: aborting due to previous error
  14
  15 For more information about this error, try `rustc --explain E0277`.