335d05aee5
- 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 {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
24 lines
429 B
Rust
24 lines
429 B
Rust
// Note: It is no longer true that both `Eq` and `PartialEq` must the derived, only the later.
|
|
|
|
#[derive(Eq)]
|
|
struct Foo {
|
|
x: u32
|
|
}
|
|
|
|
impl PartialEq for Foo {
|
|
fn eq(&self, _: &Foo) -> bool {
|
|
false // ha ha!
|
|
}
|
|
}
|
|
|
|
const FOO: Foo = Foo { x: 0 };
|
|
|
|
fn main() {
|
|
let y = Foo { x: 1 };
|
|
match y {
|
|
FOO => { }
|
|
//~^ ERROR constant of non-structural type `Foo` in a pattern
|
|
_ => { }
|
|
}
|
|
}
|