| error[E0277]: `?` couldn't convert the error to `()` |
| --> $DIR/try-on-option.rs:7:6 |
| | |
| LL | fn foo() -> Result<u32, ()> { |
| | --------------- expected `()` because of this |
| LL | let x: Option<u32> = None; |
| LL | x?; |
| | ^ the trait `std::convert::From<std::option::NoneError>` is not implemented for `()` |
| | |
| = note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait |
| = note: required by `std::convert::From::from` |
| help: consider converting the `Option<T>` into a `Result<T, _>` using `Option::ok_or` or `Option::ok_or_else` |
| | |
| LL | x.ok_or_else(|| /* error value */)?; |
| | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
| |
| error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `std::ops::Try`) |
| --> $DIR/try-on-option.rs:13:5 |
| | |
| LL | / fn bar() -> u32 { |
| LL | | let x: Option<u32> = None; |
| LL | | x?; |
| | | ^^ cannot use the `?` operator in a function that returns `u32` |
| LL | | 22 |
| LL | | } |
| | |_- this function should return `Result` or `Option` to accept `?` |
| | |
| = help: the trait `std::ops::Try` is not implemented for `u32` |
| = note: required by `std::ops::Try::from_error` |
| |
| error: aborting due to 2 previous errors |
| |
| For more information about this error, try `rustc --explain E0277`. |