#[derive(PartialEq)] on a packed struct suggests nonsensical clone #153126
Description
Code
#[repr(packed, C)]
#[derive(PartialEq)]
struct Thing(u8, String);Current output
error[E0507]: cannot move out of a shared reference
--> src/lib.rs:3:18
|
2 | #[derive(PartialEq)]
| --------- in this derive macro expansion
3 | struct Thing(u8, String);
| ^^^^^^ move occurs because value has type `String`, which does not implement the `Copy` trait
|
= note: `#[derive(PartialEq)]` triggers a move because taking references to the fields of a packed struct is undefined behaviour
help: consider cloning the value if the performance cost is acceptable
|
3 | struct Thing(u8, String.clone());
| ++++++++
For more information about this error, try `rustc --explain E0507`.Desired output
Don't suggest the cloneRationale and extra context
No response
Other cases
Rust Version
Reproducible on the playground with version 1.95.0-nightly (2026-02-24 859951e3c7c9d0322c39)Anything else?
No response