ACP: change `as_{mut,const}` on pointers to `cast_{mut,const}`

[Kixunil]

Proposal

Problem statement

The as_mut method on *const T may be confused with *mut T.

Motivation, use-cases

This confusion already broke the doc once. Also I believe cast_ is more clear, especially since a similar cast() method exists.

Solution sketches

Rename the method to use cast_ prefix

Links and related work

#92675
#98174

What happens now?

This issue is part of the libs-api team API change proposal process. Once this issue is filed the libs-api team will review open proposals in its weekly meeting. You should receive feedback within a week or two.

[yaahc]

This confusion already broke the doc once. Also I believe cast_ is more clear, especially since a similar cast() method exists.

can you link to the example you're referring to?

[cuviper]

I'm not sure what broke, but to be more explicit about the confusion, we have one that casts and one that forms a reference, which is an unresolved question on rust-lang/rust#92675.

• <*const T>::as_mut(self) -> *mut T (unstable)
• <*mut T>::as_mut<'a>(self) -> Option<&'a mut T> (stable 1.9)

[yaahc]

I'm not sure what broke, but to be more explicit about the confusion, we have one that casts and one that forms a reference, which is an unresolved question on rust-lang/rust#92675.

* `<*const T>::as_mut(self) -> *mut T` (unstable)

* `<*mut T>::as_mut<'a>(self) -> Option<&'a mut T>` (stable 1.9)

that seems to support the renaming being proposed here

[scottmcm]

👍 from me. Having the common prefix sounds good.

[yaahc]

Seconded

@rustbot label +initial-comment-period

[rustbot]

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[yaahc]

gosh dangit

[yaahc]

trying to fix it but, uuuh, github is having a moment... #52

just gonna add the label manually for now

[Kixunil]

There was also an interesting point that to_mut/to_const may be better: rust-lang/rust#98174 (comment)

Regarding breaking the docs, I meant this: rust-lang/rust#96327

[yaahc]

There was also an interesting point that to_mut/to_const may be better: rust-lang/rust#98174 (comment)

According to https://rust-lang.github.io/api-guidelines/naming.html#ad-hoc-conversions-follow-as_-to_-into_-conventions-c-conv that wouldn't be consistent with the ways we normally use as_ vs to_. Best alternative I can think up with that is consistent with the naming guidelines would be as_mut_ptr