remove the into_vec method from &[T]

[thestinger]

The corresponding method is deprecated on Vec<T> and always does the same thing as to_vec on slices. There's no reason to keep this around.

[JIghtuse]

Looks like to_vec is deprecated and needs to be removed, not into_vec. Am I right?

priority_queue.rs:

#[deprecated="renamed to `into_vec`"]
fn to_vec(self) -> Vec<T> { self.into_vec() }

I'll try to do this.

[aturon]

@JIghtuse I think you're looking at the wrong method (into_owned).

The into_vec method should be deprecated on CloneableVector, and Vec should just not implement CloneableVector.

[JIghtuse]

Ah, I see. Thanks for the explanation, @aturon!

So, simply saying, I need to remove into_vec in CloneableVector and impl<T: Clone> CloneableVector<T> for Vec<T> in vec and then fix code to make sure all builds fine?

[aturon]

@JIghtuse Please leave into_vec in CloneableVector for now, but mark it with #[deprecated = "use to_vec instead"] (and a similar change in its doc comment). That way people have a chance to migrate their code.

(We can remove the impl in Vec because it's already been deprecated for a while.)

You'll need to write [breaking-change] on your commit message, which is how we track changes that break code (and currently, deprecation is included here as a courtesy.)

[JIghtuse]

@aturon, ah, yep. I already see problems with removing into_vec now. At least libgraphviz will be broken. Thanks again!

[aturon]

@JIghtuse No problem! Once you mark it deprecated, you should go ahead and update uses within the rust distribution to use to_vec instead. The deprecation warnings should help you with that.

[JIghtuse]

make check failed, but not because of my changes:

make[1]: Leaving directory '/home/jightuse/code/projects/rust/src/test/run-make/interdependent-c-libraries'

------ stderr ---------------------------------------------
bar.rs:13:1: 13:18 error: found staticlib `foo` instead of rlib `foo` , please compile using --crate-type rlib instead.
bar.rs:13 extern crate foo;
          ^~~~~~~~~~~~~~~~~
          error: aborting due to previous error

I don't know if change in librustc/middle/traits/select.rs was needed and if I've done it correctly, but without it rust didn't built.

[JIghtuse]

Ah, it was my change to fix #14416. My fault. Rerun check now.

[BurntSushi]

Using CloneableVector was useful to express input as, "I want a Vec of things. If you give me a Vec, I'll use that, otherwise, I'll clone your slice into a Vec." Strings have this with the StrAllocating trait.

Is there anything in the standard lib that replaces this for Vec<T>, or should I define my own trait?

[aturon]

@BurntSushi The Cow (clone-on-write) pointer in rust-lang/rfcs#235 will likely cover these use cases, but it hasn't been added to std yet. Please have a look and let me know whether you think that would work for you. (One advantage of the Cow approach is that it's generic across all types, including vectors and strings.)

For now, probably best to define your own trait.

Thanks for the heads-up about the use case!

[BurntSushi]

@aturon I had read your collections reform RFC and I largely think it to be beautiful. :-) I believe you're right that Cow would help me. But yeah, I'll just go with my own trait for now. Thank you!