dangerous_implicit_autorefs lint suggestion triggers clippy::needless_borrow #14743
Description
Description
(transfered from rust-lang/rust#140720)
Let's take the following example:
unsafe fn slice_ptr_len_because_of_msrv<T>(slice: *[T]) -> usize { unsafe { (*slice).len() } }on current nightly, it triggers:
warning: implicit autoref creates a reference to the dereference of a raw pointer --> src/main.rs:2:14 | 3 | unsafe { (*slice).len() } | ^^^^^^^^^^^^^^ | = note: creating a reference requires the pointer target to be valid and imposes aliasing requirements = note: `#[warn(dangerous_implicit_autorefs)]` on by default help: try using a raw pointer method instead; or if this reference is intentional, make it explicit | 3 | unsafe { (&(*slice)).len() } | ++ + If the suggestion is applied, then clippy complains:
warning: this expression borrows a value the compiler would automatically borrow --> src/main.rs:2:14 | 2 | unsafe { (&(*slice)).len() } | ^^^^^^^^^^^ help: change this to: `(*slice)` | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow = note: `#[warn(clippy::needless_borrow)]` on by default Curiously enough, (*slice)[..].len() also triggers dangerous_implicit_autorefs, but the suggested (&(*slice))[..].len() doesn't trigger clippy::needless_borrow.
Version
rustc 1.88.0-nightly (2e6882ac5 2025-05-05) binary: rustc commit-hash: 2e6882ac5be27a73293d6f7ae56397fdf32848de commit-date: 2025-05-05 host: aarch64-apple-darwin release: 1.88.0-nightly LLVM version: 20.1.4 Additional Labels
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