Rename .cap() methods to .capacity()

[mgeier]

As mentioned in #60316, there are a few .cap() methods, which seem out-of-place because such methods are called .capacity() in the rest of the code.

This PR renames them to .capacity() but leaves RawVec::cap() in there for backwards compatibility.

I didn't try to mark the old version as "deprecated", because I guess this would cause too much noise.

[rust-highfive]

r? @joshtriplett

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[rust-highfive]

The job x86_64-gnu-llvm-6.0 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

travis_time:end:027a071e:start=1556396909133286972,finish=1556396909921163385,duration=787876413
$ git checkout -qf FETCH_HEAD
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Encrypted environment variables have been removed for security reasons.
See https://docs.travis-ci.com/user/pull-requests/#pull-requests-and-security-restrictions
$ export SCCACHE_BUCKET=rust-lang-ci-sccache2
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$ export GCP_CACHE_BUCKET=rust-lang-ci-cache
$ export AWS_ACCESS_KEY_ID=AKIA46X5W6CZEJZ6XT55
---
[00:04:23] Compiling hashbrown v0.3.0
[00:04:30] error: method is never used: `cap`
[00:04:30] --> src/libstd/sync/mpsc/sync.rs:479:5
[00:04:30] |
[00:04:30] 479 | fn cap(&self) -> usize { self.capacity() } // For backwards compatibility
[00:04:30] |
[00:04:30] = note: `-D dead-code` implied by `-D warnings`
[00:04:30] [00:04:30] error: aborting due to previous error
---
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cat: ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers: No such file or directory
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I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[mgeier]

Turns out that VecDeque<T> has both methods at the same time: a (public) .capacity() and a (private) .cap() (latter always returns 1 more than former). This is a bit confusing, and probably a potential source for bugs within the implementation.

[Mark-Simulacrum]

r? @alexcrichton

We don't need to keep the cap method on RawVec around; RawVec is a private internal type so there's no need to preserve compatibility.

I'm uncertain what to do about the VecDeque double-method (i.e., capacity and cap); I suspect better naming for the internal method might be in order, but it's hard to say exactly what the right approach there is.

[alexcrichton]

Instead of #[inline(always)] could this be #[doc(hidden)] and #[rustc_deprecated]?

[mgeier]

In case you are asking me: I'm a total Rust newbie, and I don't know what should be used here.

Just tell me, and I can change the PR. Or feel free to make any changes yourself.

@Mark-Simulacrum mentioned that RawVec is a private internal type and we don't need to keep compatibility?

[alexcrichton]

Seems reasonable to me! Just one nit otherwise r=me

[mgeier]

Thanks @alexcrichton for the review!

What about the private method VecDeque::cap()?
Shall we rename it to something less ambiguous?

[alexcrichton]

I don't personally have a preference one way or another.

[Dylan-DPC-zz]

ping from triage @mgeier any updates on this?

[jonas-schievink]

Visiting for triage, @mgeier can you address the review comment?

[mgeier]

Sorry for the long delay!

I've removed RawVec::cap() in abe3bdf, as suggested in #60340 (comment).

I couldn't come up with a better name for the internal function VecDeque::cap(), so I've left that unchanged.

[alexcrichton]

@bors: r+

[Centril]

@bors rollup=never

[joelpalmer]

Hi @mgeier - ping from Triage. Closing due to inactivity. Please re-open before pushing changes. Thanks for the PR.

@rustbot modify labels to +S-inactive-closed, -S-waiting-on-author

[Dylan-DPC-zz]

@joelpalmerthis failed because of another PR in the rollup (check #60340 (comment)) so let's keep it open

oops we can close it due to inactivity

[mgeier]

@joelpalmer

I have made the requested changes and reported the latest status in #60340 (comment).

What is there left to do for me?

[Dylan-DPC-zz]

@mgeier you need to address the failing tests

[mgeier]

Thanks @Dylan-DPC, can you please point me to the failing tests?

[Dylan-DPC-zz]

@mgeier looks to have been due to a spurious issue.

@alexcrichton can you review this?

[alexcrichton]

@bors: r+

[bors]

📌 Commit abe3bdf has been approved by alexcrichton

[bors]

⌛ Testing commit abe3bdf with merge 890881f...

[bors]

☀️ Test successful - checks-azure
Approved by: alexcrichton
Pushing 890881f to master...

[rust-highfive]

📣 Toolstate changed by #60340!

Tested on commit 890881f.
Direct link to PR: #60340

💔 rustfmt on windows: test-pass → build-fail (cc @topecongiro, @rust-lang/infra).
💔 rustfmt on linux: test-pass → build-fail (cc @topecongiro, @rust-lang/infra).