mirror of https://github.com/rust-lang/rust
32 lines
1.5 KiB
Plaintext
32 lines
1.5 KiB
Plaintext
error[E0277]: the `?` operator can only be used on `Result`s, not `Option`s, in a function that returns `Result`
|
|
--> $DIR/option-to-result.rs:5:6
|
|
|
|
|
LL | fn test_result() -> Result<(),()> {
|
|
| --------------------------------- this function returns a `Result`
|
|
LL | let a:Option<()> = Some(());
|
|
LL | a?;
|
|
| ^ use `.ok_or(...)?` to provide an error compatible with `Result<(), ()>`
|
|
|
|
|
= help: the trait `FromResidual<Option<Infallible>>` is not implemented for `Result<(), ()>`
|
|
= help: the following other types implement trait `FromResidual<R>`:
|
|
<Result<T, F> as FromResidual<Result<Infallible, E>>>
|
|
<Result<T, F> as FromResidual<Yeet<E>>>
|
|
|
|
error[E0277]: the `?` operator can only be used on `Option`s, not `Result`s, in a function that returns `Option`
|
|
--> $DIR/option-to-result.rs:11:6
|
|
|
|
|
LL | fn test_option() -> Option<i32>{
|
|
| ------------------------------- this function returns an `Option`
|
|
LL | let a:Result<i32, i32> = Ok(5);
|
|
LL | a?;
|
|
| ^ use `.ok()?` if you want to discard the `Result<Infallible, i32>` error information
|
|
|
|
|
= help: the trait `FromResidual<Result<Infallible, i32>>` is not implemented for `Option<i32>`
|
|
= help: the following other types implement trait `FromResidual<R>`:
|
|
<Option<T> as FromResidual<Yeet<()>>>
|
|
<Option<T> as FromResidual>
|
|
|
|
error: aborting due to 2 previous errors
|
|
|
|
For more information about this error, try `rustc --explain E0277`.
|