Tracking Issue for `array_methods`

[LukasKalbertodt]

This is a tracking issue for a couple of basic methods on arrays. The feature gate for the issue is #![feature(array_methods)]. Currently, this includes the following methods:

• as_slice, as_mut_slice Add [T; N]::as_[mut_]slice #76120
• each_ref, each_mut Add [T; N]::each_ref and [T; N]::each_mut #75490

Note: these methods were all collected under the same array_methods feature name as I suspect many (often small) methods to be added to array in the near future. Creating a new feature and tracking issue for each seems overkill. We can still split off some methods into dedicated features later, if required.

About tracking issues

Tracking issues are used to record the overall progress of implementation.
They are also uses as hubs connecting to other relevant issues, e.g., bugs or open design questions.
A tracking issue is however not meant for large scale discussion, questions, or bug reports about a feature.
Instead, open a dedicated issue for the specific matter and add the relevant feature gate label.

Steps

• Decide what set of methods to stabilize in the first round
• Change feature names of all methods that are not yet stabilized to something specific
• Adjust documentation (see instructions on rustc-dev-guide)
• Stabilization PR (see instructions on rustc-dev-guide)

Unresolved Questions

• Use the names each_ref and each_mut or change it to something else? Alternatives: each_as_ref/each_as_mut, as_refs/as_mut_refs. See PR Add [T; N]::each_ref and [T; N]::each_mut #75490 for the name discussion.

[LukasKalbertodt]

Just for the protocol, I plan to add the following methods in the near future:

• cloned, copied and unzip: blocked by figuring out how we best add additional impl blocks for arrays (e.g. [&T; N] where T: Clone)
• zip: waiting for add array::FillError similar to array::IntoIter #75717 or Add 'core::array::from_fn' and 'core::array::try_from_fn' #75644 to get merged; otherwise this method would add duplicate code already added in Added [T; N]::zip() #79451

(discussions about the usefulness of those method should be had in the dedicated PR threads and not here)

[usbalbin]

@LukasKalbertodt I have opened PR #79451 for zip, saw your comment just now.