Suggestion for "error[E0507]: cannot move out of a shared reference" suggests removing the wrong borrow

[unflxw]

I tried this code (playground):

use std::collections::HashMap;

fn main() {
    HashMap::<String, i32>::new().iter().filter( |&(&k, &v)| { true });
}

I expected to see this happen:

error[E0507]: cannot move out of a shared reference
[...]
help: consider removing the borrow
  |
4 -     HashMap::<String, i32>::new().iter().filter( |&(&k, &v)| { true });
4 +     HashMap::<String, i32>::new().iter().filter( |&(k, &v)| { true });
  |

Instead, this happened:

error[E0507]: cannot move out of a shared reference
[...]
help: consider removing the borrow
  |
4 -     HashMap::<String, i32>::new().iter().filter( |&(&k, &v)| { true });
4 +     HashMap::<String, i32>::new().iter().filter( |(&k, &v)| { true });
  |

Diff between the two (red is actual, green is expected):

- 4 +     HashMap::<String, i32>::new().iter().filter( |(&k, &v)| { true });
+ 4 +     HashMap::<String, i32>::new().iter().filter( |&(k, &v)| { true });

That is, it is suggesting removing the borrow on the tuple, which is not the correct borrow to remove; instead, it should suggest removing the borrow on k, the element that isn't Copy.

Happens in playground nightly: 1.8.0-nightly (2024-11-08 59cec72)

[dianne]

@rustbot claim

[unflxw]

Thank you for fixing this @dianne! 🙇