mirror of
https://github.com/rust-lang/rust.git
synced 2025-05-02 21:17:39 +00:00
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 {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
27 lines
938 B
Rust
27 lines
938 B
Rust
// This is part of a set of tests exploring the different ways a
|
|
// structural-match ADT might try to hold a
|
|
// non-structural-match in hidden manner that lets matches
|
|
// through that we had intended to reject.
|
|
//
|
|
// See discussion on rust-lang/rust#62307 and rust-lang/rust#62339
|
|
|
|
struct NoDerive(#[allow(dead_code)] i32);
|
|
|
|
// This impl makes NoDerive irreflexive.
|
|
impl PartialEq for NoDerive { fn eq(&self, _: &Self) -> bool { false } }
|
|
|
|
impl Eq for NoDerive { }
|
|
|
|
#[derive(PartialEq, Eq)]
|
|
struct WrapInline<'a>(&'a &'a NoDerive);
|
|
|
|
const WRAP_DOUBLY_INDIRECT_INLINE: & &WrapInline = & &WrapInline(& & NoDerive(0));
|
|
|
|
fn main() {
|
|
match WRAP_DOUBLY_INDIRECT_INLINE {
|
|
WRAP_DOUBLY_INDIRECT_INLINE => { panic!("WRAP_DOUBLY_INDIRECT_INLINE matched itself"); }
|
|
//~^ ERROR constant of non-structural type `NoDerive` in a pattern
|
|
_ => { println!("WRAP_DOUBLY_INDIRECT_INLINE correctly did not match itself"); }
|
|
}
|
|
}
|