Lint overcapturing in impl Trait on 2024 edition

[GoldsteinE]

Code

pub fn check(x: &[u8]) -> impl std::fmt::Display {
    x[0]
}

Current output

(empty)

Desired output

A warning, like one produced by impl_trait_overcaptures.

Rationale and extra context

Currently, impl_trait_overcaptures lints code that would be overcapturing in edition = 2024 on editions < 2024. I think it would be valuable to add a (maybe allow-by-default) lint to detect overcapturing in new, edition 2024 code. Code like this is probably not meant to capture lifetime of x, so linting against this may help to avoid too-strict signatures. If the function was meant to be stricter than necessary (e.g. for future-compat reasons), you can always just #[allow] the lint.

Rust Version

$ rustc --version --verbose
rustc 1.83.0-nightly (eb4e23467 2024-10-09)
binary: rustc
commit-hash: eb4e2346748e1760f74fcaa27b42431e0b95f8f3
commit-date: 2024-10-09
host: x86_64-unknown-linux-gnu
release: 1.83.0-nightly
LLVM version: 19.1.1

Anything else?

Alternatively, this could be a Clippy lint. Having it in rustc could probably allow code reuse with the edition lint though.

[compiler-errors]

Yeah, makes sense. I could implement such a lint.

@rustbot claim