rust/tests/ui/rfcs/rfc-1445-restrict-constants-in-patterns/cant-hide-behind-indirect-struct-embedded.stderr
Esteban Küber 335d05aee5 Add additional context for non-sructural type constant used in pattern
- Point at type that should derive `PartialEq` to be structural.
- Point at manual `impl PartialEq`, explaining that it is not sufficient to be structural.

```
error: constant of non-structural type `MyType` in a pattern
  --> $DIR/const-partial_eq-fallback-ice.rs:14:12
   |
LL | struct MyType;
   | ------------- `MyType` must be annotated with `#[derive(PartialEq)]` to be usable in patterns
...
LL | const CONSTANT: &&MyType = &&MyType;
   | ------------------------ constant defined here
...
LL |     if let CONSTANT = &&MyType {
   |            ^^^^^^^^ constant of non-structural type
   |
note: the `PartialEq` trait must be derived, manual `impl`s are not sufficient; see https://doc.rust-lang.org/stable/std/marker/trait.StructuralPartialEq.html for details
  --> $DIR/const-partial_eq-fallback-ice.rs:5:1
   |
LL | impl PartialEq<usize> for MyType {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
2024-12-04 20:29:36 +00:00

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Plaintext

error: constant of non-structural type `NoDerive` in a pattern
--> $DIR/cant-hide-behind-indirect-struct-embedded.rs:22:9
|
LL | struct NoDerive(#[allow(dead_code)] i32);
| --------------- `NoDerive` must be annotated with `#[derive(PartialEq)]` to be usable in patterns
...
LL | const WRAP_INDIRECT_INLINE: & &WrapInline = & &WrapInline(NoDerive(0));
| ----------------------------------------- constant defined here
...
LL | WRAP_INDIRECT_INLINE => { panic!("WRAP_INDIRECT_INLINE matched itself"); }
| ^^^^^^^^^^^^^^^^^^^^ constant of non-structural type
|
note: the `PartialEq` trait must be derived, manual `impl`s are not sufficient; see https://doc.rust-lang.org/stable/std/marker/trait.StructuralPartialEq.html for details
--> $DIR/cant-hide-behind-indirect-struct-embedded.rs:11:1
|
LL | impl PartialEq for NoDerive { fn eq(&self, _: &Self) -> bool { false } }
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to 1 previous error