impl<'a> From<&'a BString> for Cow<'a, BStr>

[wbenny]

This commit simplifies code in situations like:

let mut v = Vec::<Cow<'a, BStr>>::new();
let s = BString::new(...);

// Before this commit, we would have to do:
// v.push(s.as_bstr().into());
v.push(s.into());

[BurntSushi]

Makes sense to me, and lines up with the corresponding impl in std.

[BurntSushi]

This PR is on crates.io in bstr 1.9.2.

[wbenny]

Makes sense to me, and lines up with the corresponding impl in std.

Yes, exactly, forgot to mention that.

Huge thank you for releasing the crate so fast!

Cheers

[epage]

I upgraded cargo to bstr 1.9.2 and it broke the build of gix

cargo on  deps is 📦 v0.83.0
❯ cargo check
    Checking gix-date v0.8.6
    Checking gix-credentials v0.24.2
error[E0283]: type annotations needed
  --> /home/epage/.cargo/registry/src/index.crates.io-6f17d22bba15001f/gix-credentials-0.24.2/src/program/mod.rs:83:63
   |
83 |                 gix_command::prepare(gix_path::from_bstr(args.as_ref()).into_owned())
   |                                                               ^^^^^^
   |
   = note: multiple `impl`s satisfying `BString: AsRef<_>` found in the `bstr` crate:
           - impl AsRef<BStr> for BString;
           - impl AsRef<[u8]> for BString;
help: try using a fully qualified path to specify the expected types
   |
83 |                 gix_command::prepare(gix_path::from_bstr(<BString as AsRef<T>>::as_ref(&args)).into_owned())
   |                                                          +++++++++++++++++++++++++++++++    ~

error[E0283]: type annotations needed
   --> /home/epage/.cargo/registry/src/index.crates.io-6f17d22bba15001f/gix-credentials-0.24.2/src/program/mod.rs:83:3
8
    |
83  |                 gix_command::prepare(gix_path::from_bstr(args.as_ref()).into_owned())
    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type for reference `&_`
    |
    = note: multiple `impl`s satisfying `Cow<'_, BStr>: From<&_>` found in the `bstr` crate:
            - impl<'a> From<&'a BStr> for Cow<'a, BStr>;
            - impl<'a> From<&'a BString> for Cow<'a, BStr>;
    = note: required for `&_` to implement `Into<Cow<'_, BStr>>`
note: required by a bound in `from_bstr`
   --> /home/epage/.cargo/registry/src/index.crates.io-6f17d22bba15001f/gix-path-0.10.7/src/convert.rs:135:34
    |
135 | pub fn from_bstr<'a>(input: impl Into<Cow<'a, BStr>>) -> Cow<'a, Path> {
    |                                  ^^^^^^^^^^^^^^^^^^^ required by this bound in `from_bstr`

    Checking gix-actor v0.31.2
For more information about this error, try `rustc --explain E0283`.
error: could not compile `gix-credentials` (lib) due to 2 previous errors
warning: build failed, waiting for other jobs to finish...

Would this be considered

• A major incompatibility (breaking change)
• A minor incompatibility
• An issue within gix

[BurntSushi]

Uuuuuuuuuuggggggg. That's "incorrect" as_ref() usage.

I'll yank bstr 1.9.2 for now, but I don't think this can be a permanent thing. Otherwise I can basically never add any new trait impls. People should only be using as_ref() when the target type is constrained.

[BurntSushi]

OK, it has been yanked. But yes, I generally consider this an issue in gix.

[BurntSushi]

I filed an issue with gix: Byron/gitoxide#1466

[BurntSushi]

Sorry @wbenny. Hopefully we can get this trait impl published soon, but given this was caught early and yanking in this specific case doesn't really have too much downside, I want to avoid creating an emergency for gitoxide. The quickest way is probably landing a PR fixing the specific error @epage ran into and getting them to do a release. Then I can publish a new release of bstr. That way, there will at least be a release of gitoxide that is compatible with bstr.

[BurntSushi]

OK, let's try this again. This PR is on crates.io in bstr 1.10.0.