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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
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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
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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
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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.
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#[derive(Eq)]
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struct Foo {
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x: u32
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}
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impl PartialEq for Foo {
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fn eq(&self, _: &Foo) -> bool {
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false // ha ha!
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}
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}
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const FOO: Foo = Foo { x: 0 };
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fn main() {
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let y = Foo { x: 1 };
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match y {
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FOO => { }
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//~^ ERROR constant of non-structural type `Foo` in a pattern
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_ => { }
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}
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}
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