rust/src/test/ui/issues/issue-37534.stderr
Dan Aloni 07e7823c01 pretty: trim paths of unique symbols
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.
2020-09-02 22:26:37 +03:00

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error[E0404]: expected trait, found derive macro `Hash`
--> $DIR/issue-37534.rs:1:16
|
LL | struct Foo<T: ?Hash> { }
| ^^^^ not a trait
|
help: consider importing this trait instead
|
LL | use std::hash::Hash;
|
warning: default bound relaxed for a type parameter, but this does nothing because the given bound is not a default; only `?Sized` is supported
--> $DIR/issue-37534.rs:1:12
|
LL | struct Foo<T: ?Hash> { }
| ^
error[E0392]: parameter `T` is never used
--> $DIR/issue-37534.rs:1:12
|
LL | struct Foo<T: ?Hash> { }
| ^ unused parameter
|
= help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`
error: aborting due to 2 previous errors; 1 warning emitted
Some errors have detailed explanations: E0392, E0404.
For more information about an error, try `rustc --explain E0392`.