07e7823c01
If a symbol name can only be imported from one place for a type, and as long as it was not glob-imported anywhere in the current crate, we can trim its printed path and print only the name. This has wide implications on error messages with types, for example, shortening `std::vec::Vec` to just `Vec`, as long as there is no other `Vec` importable anywhere. This adds a new '-Z trim-diagnostic-paths=false' option to control this feature. On the good path, with no diagnosis printed, we should try to avoid issuing this query, so we need to prevent trimmed_def_paths query on several cases. This change also relies on a previous commit that differentiates between `Debug` and `Display` on various rustc types, where the latter is trimmed and presented to the user and the former is not.
34 lines
1.3 KiB
Plaintext
34 lines
1.3 KiB
Plaintext
error[E0277]: `?` couldn't convert the error to `()`
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--> $DIR/try-on-option.rs:7:6
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LL | fn foo() -> Result<u32, ()> {
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| --------------- expected `()` because of this
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LL | let x: Option<u32> = None;
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LL | x?;
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| ^ the trait `From<NoneError>` is not implemented for `()`
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= note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
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= note: required by `from`
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help: consider converting the `Option<T>` into a `Result<T, _>` using `Option::ok_or` or `Option::ok_or_else`
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LL | x.ok_or_else(|| /* error value */)?;
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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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 `Try`)
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--> $DIR/try-on-option.rs:13:5
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LL | / fn bar() -> u32 {
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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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LL | | 22
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LL | | }
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| |_- this function should return `Result` or `Option` to accept `?`
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= help: the trait `Try` is not implemented for `u32`
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= note: required by `from_error`
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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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