mirror of https://github.com/rust-lang/rust
29 lines
1.3 KiB
Plaintext
29 lines
1.3 KiB
Plaintext
error[E0277]: the `?` operator can only be used on `Result`s, not `Option`s, in a function that returns `Result`
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--> $DIR/try-on-option.rs:5:6
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LL | fn foo() -> Result<u32, ()> {
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| --------------------------- this function returns a `Result`
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LL | let x: Option<u32> = None;
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LL | x?;
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| ^ use `.ok_or(...)?` to provide an error compatible with `Result<u32, ()>`
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= help: the trait `FromResidual<Option<Infallible>>` is not implemented for `Result<u32, ()>`
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= help: the following other types implement trait `FromResidual<R>`:
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<Result<T, F> as FromResidual<Result<Infallible, E>>>
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<Result<T, F> as FromResidual<Yeet<E>>>
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error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
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--> $DIR/try-on-option.rs:11:6
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LL | fn bar() -> u32 {
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| --------------- this function should return `Result` or `Option` to accept `?`
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LL | let x: Option<u32> = None;
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LL | x?;
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| ^ cannot use the `?` operator in a function that returns `u32`
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= help: the trait `FromResidual<Option<Infallible>>` is not implemented for `u32`
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error: aborting due to 2 previous errors
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For more information about this error, try `rustc --explain E0277`.
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