rust/tests/ui/consts/const_in_pattern/issue-65466.stderr

error: constant of non-structural type `&[O<B>]` in a pattern
  --> $DIR/issue-65466.rs:14:9
   |
LL | struct B;
   | -------- must be annotated with `#[derive(PartialEq)]` to be usable in patterns
LL |
LL | const C: &[O<B>] = &[O::None];
   | ---------------- constant defined here
...
LL |         C => (),
   |         ^ constant of non-structural type
   |
   = note: see https://doc.rust-lang.org/stable/std/marker/trait.StructuralPartialEq.html for details

error: aborting due to 1 previous error
Reword message for non-structural type constant in pattern 2024-11-20 04:15:37 +00:00			error: constant of non-structural type `&[O<B>]` in a pattern
make non-PartialEq-typed consts as patterns a hard error 2024-02-08 20:08:19 +01:00			`--> $DIR/issue-65466.rs:14:9`
work towards rejecting consts in patterns that do not implement PartialEq 2023-09-16 14:15:48 +02:00			`\|`
Add more context to fall-through "const pattern of non-structural type" error Point at types that need to be marked with `#[derive(PartialEq)]`. We use a visitor to look at a type that isn't structural, looking for all ADTs that don't derive `PartialEq`. These can either be manual `impl PartialEq`s or no `impl` at all, so we differentiate between those two cases to provide more context to the user. We also only point at types and impls from the local crate, otherwise show only a note. ``` error: constant of non-structural type `&[B]` in a pattern --> $DIR/issue-61188-match-slice-forbidden-without-eq.rs:15:9 \| LL \| struct B(i32); \| -------- must be annotated with `#[derive(PartialEq)]` to be usable in patterns LL \| LL \| const A: &[B] = &[]; \| ------------- constant defined here ... LL \| A => (), \| ^ constant of non-structural type \| = note: see https://doc.rust-lang.org/stable/std/marker/trait.StructuralPartialEq.html for details ``` 2024-11-20 23:10:39 +00:00			`LL \| struct B;`
			\| -------- must be annotated with `#[derive(PartialEq)]` to be usable in patterns
			`LL \|`
On `const` pattern errors, point at the `const` item definition Centralize emitting an error in `const_to_pat` so that all errors from that evaluating a `const` in a pattern can add addditional information. With this, now point at the `const` item's definition: ``` error[E0158]: constant pattern depends on a generic parameter --> $DIR/associated-const-type-parameter-pattern.rs:20:9 \| LL \| pub trait Foo { \| ------------- LL \| const X: EFoo; \| ------------- constant defined here ... LL \| A::X => println!("A::X"), \| ^^^^ ``` 2024-11-20 02:15:21 +00:00			`LL \| const C: &[O<B>] = &[O::None];`
			`\| ---------------- constant defined here`
			`...`
work towards rejecting consts in patterns that do not implement PartialEq 2023-09-16 14:15:48 +02:00			`LL \| C => (),`
Tweak output of some const pattern errors - Add primary span labels. - Point at const generic parameter used as pattern. - Point at statics used as pattern. - Point at let bindings used in const pattern. 2024-11-20 03:57:30 +00:00			`\| ^ constant of non-structural type`
Add context to fall-through "const pattern of non-structural type" error Unify wording with the regular non-structural type error. 2024-11-20 06:49:13 +00:00			`\|`
			`= note: see https://doc.rust-lang.org/stable/std/marker/trait.StructuralPartialEq.html for details`
work towards rejecting consts in patterns that do not implement PartialEq 2023-09-16 14:15:48 +02:00
make non-PartialEq-typed consts as patterns a hard error 2024-02-08 20:08:19 +01:00			`error: aborting due to 1 previous error`
work towards rejecting consts in patterns that do not implement PartialEq 2023-09-16 14:15:48 +02:00