rustfmt doesn't understand if let chains

[SUPERCILEX]

See rust-lang/rust#53667, they might be stabilized soon. Currently, rustfmt refuses to make any changes to an if let statement and its contents, silently letting code go unformatted.

[ytmimi]

Thanks for the report.

This is related to #5177, and the PR that adds this support (#5203) is intentionally on hold. I don't know if I can articulate it any better than rust-lang/rust#95262 (comment) and #5203 (comment).

To summarize, there are still some unanswered questions around let-chain formatting being discussed on rust-lang/style-team#169. It's important that the formatting RFC be resolved so we know what rules to implement in rustfmt because there's a strong desire not to continually introduce breaking formatting changes.

The best way to move things forward is to bring broader awareness to rust-lang/style-team#169 and to share your thoughts on the proposal 😁

[SUPERCILEX]

Thanks for the explanation!