Suggest usage of `array.as_slice()` (instead of `&array[..]`) and `array.as_mut_slice()`

What it does

Lints for example this code:

let array: [u8; 4] = [1, 2, 3, 4];
let slice: &[u8] = &array[..];

and suggests array::as_slice:

let array: [u8; 4] = [1, 2, 3, 4];
let slice: &[u8] = array.as_slice();

(same should be suggested for &mut array[..], which can be replaced with array.as_mut_slice())

Categories (optional)

• Kind: clippy::pedantic or clippy::style

What is the advantage of the recommended code over the original code?

For example:

• easier to read for people new to rust (not very obvious what [..] does)
• there must be a reason why array::as_slice exists? (see rust-lang/rust#76120)

Drawbacks

• might have a lot of false positives or not much benefit in using the function

Possibly related issues:

• #728
• #5598

Stabilization

At the time of writing this issue, the function is still unstable, but with the merging of rust-lang/rust#88353, this feature will be stabilized. (final-comment-period, so will be merged in the next few days)