rust-lang / rust-lang/rust-clippy

explicit_auto_deref suggests code that does not compile

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C-bug I-false-positive I-suggestion-causes-error
Dominant language
Rust
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Description

Summary

Reproducer attached. Clippy suggests to remove the dereference operator but without it the code doesn't compile.

Lint Name

explicit_auto_deref

Reproducer

I tried this code:

fn takes_array_ref<T, const N: usize>(array: &&[T; N]) {
    takes_slice(*array) // clippy suggests to remove dereference
}

fn takes_slice<T>(slice: &[T]) {
    todo!()
}

I saw this happen:

 --> src/lib.rs:2:17
  |
2 |     takes_slice(*array)
  |                 ^^^^^^ help: try this: `array`
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_auto_deref
  = note: `#[warn(clippy::explicit_auto_deref)]` on by default

I expected to see this happen:
No lint, or a suggestion that builds

Version
rustc 1.67.0-nightly (6284998a2 2022-11-12)
binary: rustc
commit-hash: 6284998a2677d7e3e8420db783f3aa4fd80d7423
commit-date: 2022-11-12
host: aarch64-apple-darwin
release: 1.67.0-nightly
LLVM version: 15.0.4
Additional Labels

@rustbot label +I-suggestion-causes-error

Contributor guide

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First steps

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  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by compiling the Rust reproducer and confirming the explicit_auto_deref diagnostic and replacement suggestion. Then inspect the explicit_auto_deref lint implementation and its suggestion logic; done means the lint is suppressed for this case or emits a replacement that compiles.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
tooling
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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