Possible suggestion improvements on match_ref_pats

[llogiq]

Another example from Carboxyl:

        match &mut *current.borrow_mut() {
            &mut Some(ref mut trans) => action(trans),
            _ => panic!("there is no active transaction to register a callback"),
        }

Our lint suggests using match *&mut *current.borrow_mut() { .. } while actually match *current.borrow_mut() { .. } (and removing &mut in the arm) will suffice.

[oli-obk]

Orthogonal issue:

shouldn't it actually be current.borrow_mut().expect("there is no active transaction to register a callback") ?

[llogiq]

I'm not going to judge... 😄

One could lint match some_option { None => panic!(..), .. }, but unless this is the only non-empty arm, it'd look very opinionated.

[mrchilliballs]

I'm not able to reproduce this using Rust Playground's Clippy (version 0.1.88 at the time of this comment).
https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=96b2449e8f026412f199293f8245e052

EDIT: I wasn't able to reproduce this in Carboxyl either. I ran git checkout 29e1ecdacd95227cead9a83e7d1fc1b34168604b, taking me to the commit before src/transaction.rs was fixed, and then ran Clippy version 0.1.90. There was no output by the match_ref_pats lint. Should this issue be closed?

[samueltardieu]

Yes, it should. Thanks for triaging.