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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 {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
27 lines
861 B
Rust
27 lines
861 B
Rust
// This is part of a set of tests exploring the different ways a
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// structural-match ADT might try to hold a
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// non-structural-match in hidden manner that lets matches
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// through that we had intended to reject.
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//
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// See discussion on rust-lang/rust#62307 and rust-lang/rust#62339
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struct NoDerive(#[allow(dead_code)] i32);
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// This impl makes NoDerive irreflexive.
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impl PartialEq for NoDerive { fn eq(&self, _: &Self) -> bool { false } }
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impl Eq for NoDerive { }
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#[derive(PartialEq, Eq)]
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struct WrapInline(NoDerive);
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const WRAP_DIRECT_INLINE: WrapInline = WrapInline(NoDerive(0));
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fn main() {
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match WRAP_DIRECT_INLINE {
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WRAP_DIRECT_INLINE => { panic!("WRAP_DIRECT_INLINE matched itself"); }
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//~^ ERROR constant of non-structural type `NoDerive` in a pattern
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_ => { println!("WRAP_DIRECT_INLINE did not match itself"); }
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}
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}
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