1 error[E0277]: the `?` operator can only be used on `Result`s, not `Option`s, in a function that returns `Result`
2 --> $DIR/option-to-result.rs:5:6
4 LL | fn test_result() -> Result<(),()> {
5 | --------------------------------- this function returns a `Result`
6 LL | let a:Option<()> = Some(());
8 | ^ use `.ok_or(...)?` to provide an error compatible with `Result<(), ()>`
10 = help: the trait `FromResidual<Option<Infallible>>` is not implemented for `Result<(), ()>`
11 = help: the following other types implement trait `FromResidual<R>`:
12 <Result<T, F> as FromResidual<Result<Infallible, E>>>
13 <Result<T, F> as FromResidual<Yeet<E>>>
15 error[E0277]: the `?` operator can only be used on `Option`s, not `Result`s, in a function that returns `Option`
16 --> $DIR/option-to-result.rs:11:6
18 LL | fn test_option() -> Option<i32>{
19 | ------------------------------- this function returns an `Option`
20 LL | let a:Result<i32, i32> = Ok(5);
22 | ^ use `.ok()?` if you want to discard the `Result<Infallible, i32>` error information
24 = help: the trait `FromResidual<Result<Infallible, i32>>` is not implemented for `Option<i32>`
25 = help: the following other types implement trait `FromResidual<R>`:
26 <Option<T> as FromResidual<Yeet<()>>>
27 <Option<T> as FromResidual>
29 error: aborting due to 2 previous errors
31 For more information about this error, try `rustc --explain E0277`.