Implement AsRef<ByteStr> for [u8]

[thaliaarchi]

This impl was omitted from #135073 due to inference failures. Add it separately to judge its impact.

Tracked in #139429.

r? libs-api

cc @joshtriplett

[rustbot]

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

[thaliaarchi]

The failure is now from inference failures in external crates.

[dtolnay]

Add it separately to judge its impact.

If you are looking for a crater run on this PR, we'll need a green build first before that can be kicked off. Please try updating jiff from 0.2.5 to 0.2.6 to pull in BurntSushi/jiff@f41d586.

error[E0283]: type annotations needed
   --> /cargo/registry/src/index.crates.io-1949cf8c6b5b557f/jiff-0.2.5/src/shared/posix.rs:26:42
    |
26  |             Parser { ianav3plus: true, ..Parser::new(bytes.as_ref()) };
    |                                          ^^^^^^^^^^^ -------------- type must be known at this point
    |                                          |
    |                                          cannot infer type of the type parameter `B` declared on the associated function `new`
    |
    = note: multiple `impl`s satisfying `_: AsRef<[u8]>` found in the following crates: `alloc`, `core`:
            - impl AsRef<[u8]> for ByteStr;
            - impl AsRef<[u8]> for ByteString;
            - impl AsRef<[u8]> for String;
            - impl AsRef<[u8]> for str;
note: required by a bound in `shared::posix::Parser::<'s>::new`
   --> /cargo/registry/src/index.crates.io-1949cf8c6b5b557f/jiff-0.2.5/src/shared/posix.rs:602:24
    |
602 |     fn new<B: ?Sized + AsRef<[u8]>>(tz: &'s B) -> Parser<'s> {
    |                        ^^^^^^^^^^^ required by this bound in `Parser::<'s>::new`
help: consider specifying the generic argument
    |
26  |             Parser { ianav3plus: true, ..Parser::new::<B>(bytes.as_ref()) };
    |                                                     +++++
help: consider removing this method call, as the receiver has type `&[u8]` and `&[u8]: AsRef<[u8]>` trivially holds
    |
26  -             Parser { ianav3plus: true, ..Parser::new(bytes.as_ref()) };
26  +             Parser { ianav3plus: true, ..Parser::new(bytes) };
    |

[alex-semenyuk]

@thaliaarchi
Thanks for your contribution.
Form wg-triage. Any updates on this PR?

[rustbot]

⚠️ Warning ⚠️

• There are issue links (such as #123) in the commit messages of the following commits.
  Please move them to the PR description, to avoid spamming the issues with references to the commit, and so this bot can automatically canonicalize them to avoid issues with subtree.
  • da39b9f

[rust-log-analyzer]

The job aarch64-gnu-llvm-19-1 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

   Compiling gix-index v0.41.0
error[E0282]: type annotations needed
   --> /cargo/registry/src/index.crates.io-1949cf8c6b5b557f/sec1-0.7.3/src/point.rs:532:14
    |
532 |         if y.as_ref().last().expect("empty y-coordinate") & 1 == 1 {
    |              ^^^^^^   ---- type must be known at this point
    |
help: try using a fully qualified path to specify the expected types
    |
532 -         if y.as_ref().last().expect("empty y-coordinate") & 1 == 1 {
532 +         if <[u8] as AsRef<T>>::as_ref(y).last().expect("empty y-coordinate") & 1 == 1 {
    |

For more information about this error, try `rustc --explain E0282`.
[RUSTC-TIMING] sec1 test:false 0.347
error: could not compile `sec1` (lib) due to 1 previous error

[thaliaarchi]

I rebased to incorporate the jiff version bump on master. The failure is now with the sec1 crate.

error[E0282]: type annotations needed
   --> /cargo/registry/src/index.crates.io-1949cf8c6b5b557f/sec1-0.7.3/src/point.rs:532:14
    |
532 |         if y.as_ref().last().expect("empty y-coordinate") & 1 == 1 {
    |              ^^^^^^   ---- type must be known at this point
    |
help: try using a fully qualified path to specify the expected types
    |
532 -         if y.as_ref().last().expect("empty y-coordinate") & 1 == 1 {
532 +         if <[u8] as AsRef<T>>::as_ref(y).last().expect("empty y-coordinate") & 1 == 1 {
    |

Is the path forward for this PR then to upstream fixes in each crate that r-l/r depends on, then run crater, then to consider it?