mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-28 09:44:08 +00:00
48 lines
2.3 KiB
Plaintext
48 lines
2.3 KiB
Plaintext
error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
|
|
--> $DIR/try-on-option-diagnostics.rs:7:6
|
|
|
|
|
LL | fn a_function() -> u32 {
|
|
| ---------------------- this function should return `Result` or `Option` to accept `?`
|
|
LL | let x: Option<u32> = None;
|
|
LL | x?;
|
|
| ^ cannot use the `?` operator in a function that returns `u32`
|
|
|
|
|
= help: the trait `FromResidual<Option<Infallible>>` is not implemented for `u32`
|
|
|
|
error[E0277]: the `?` operator can only be used in a closure that returns `Result` or `Option` (or another type that implements `FromResidual`)
|
|
--> $DIR/try-on-option-diagnostics.rs:14:10
|
|
|
|
|
LL | let a_closure = || {
|
|
| -- this function should return `Result` or `Option` to accept `?`
|
|
LL | let x: Option<u32> = None;
|
|
LL | x?;
|
|
| ^ cannot use the `?` operator in a closure that returns `{integer}`
|
|
|
|
|
= help: the trait `FromResidual<Option<Infallible>>` is not implemented for `{integer}`
|
|
|
|
error[E0277]: the `?` operator can only be used in a method that returns `Result` or `Option` (or another type that implements `FromResidual`)
|
|
--> $DIR/try-on-option-diagnostics.rs:26:14
|
|
|
|
|
LL | fn a_method() {
|
|
| ------------- this function should return `Result` or `Option` to accept `?`
|
|
LL | let x: Option<u32> = None;
|
|
LL | x?;
|
|
| ^ cannot use the `?` operator in a method that returns `()`
|
|
|
|
|
= help: the trait `FromResidual<Option<Infallible>>` is not implemented for `()`
|
|
|
|
error[E0277]: the `?` operator can only be used in a trait method that returns `Result` or `Option` (or another type that implements `FromResidual`)
|
|
--> $DIR/try-on-option-diagnostics.rs:39:14
|
|
|
|
|
LL | fn a_trait_method() {
|
|
| ------------------- this function should return `Result` or `Option` to accept `?`
|
|
LL | let x: Option<u32> = None;
|
|
LL | x?;
|
|
| ^ cannot use the `?` operator in a trait method that returns `()`
|
|
|
|
|
= help: the trait `FromResidual<Option<Infallible>>` is not implemented for `()`
|
|
|
|
error: aborting due to 4 previous errors
|
|
|
|
For more information about this error, try `rustc --explain E0277`.
|