Skip to content

make slice::{split_at,split_at_unchecked} const functions - #100076

Merged
bors merged 2 commits into
rust-lang:masterfrom
tspiteri:const_slice_split_at
Aug 26, 2022
Merged

make slice::{split_at,split_at_unchecked} const functions#100076
bors merged 2 commits into
rust-lang:masterfrom
tspiteri:const_slice_split_at

Conversation

@tspiteri

@tspiteritspiteri commented Aug 2, 2022

Copy link
Copy Markdown
Contributor

Now that slice::from_raw_parts is const in stable 1.64, it makes sense to have split_at const as well, otherwise unsafe code is required to achieve a const equivalent.

@rustbot

rustbot commented Aug 2, 2022

Copy link
Copy Markdown
Collaborator

Hey! It looks like you've submitted a new PR for the library teams!

If this PR contains changes to any rust-lang/rust public library APIs then please comment with @rustbot label +T-libs-api -T-libs to tag it appropriately. If this PR contains changes to any unstable APIs please edit the PR description to add a link to the relevant API Change Proposal or create one if you haven't already. If you're unsure where your change falls no worries, just leave it as is and the reviewer will take a look and make a decision to forward on if necessary.

Examples of T-libs-api changes:

  • Stabilizing library features
  • Introducing insta-stable changes such as new implementations of existing stable traits on existing stable types
  • Introducing new or changing existing unstable library APIs (excluding permanently unstable features / features without a tracking issue)
  • Changing public documentation in ways that create new stability guarantees
  • Changing observable runtime behavior of library APIs

@rustbotrustbot added the T-libs Relevant to the library team, which will review and decide on the PR/issue. label Aug 2, 2022
@rust-highfive

rust-highfive commented Aug 2, 2022

Copy link
Copy Markdown
Contributor

r? @thomcc

(rust-highfive has picked a reviewer for you, use r? to override)

@rust-highfiverust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Aug 2, 2022
@tspiteri

tspiteri commented Aug 2, 2022

Copy link
Copy Markdown
ContributorAuthor

The logic in split_at_unchecked was copied from split_at_mut_unchecked, replacing from_raw_parts_mut with from_raw_parts. So it should be sound.

@tspiteri

tspiteri commented Aug 2, 2022

Copy link
Copy Markdown
ContributorAuthor

Makes public stable method slice::split_at unstably const, so

@rustbot label +T-libs-api -T-libs

@rustbotrustbot added T-libs-api [DEPRECATED; DO NOT USE] and removed T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Aug 2, 2022
@tspiteri
tspiteriforce-pushed the const_slice_split_at branch from 6183707 to 4b90601CompareAugust 2, 2022 20:15
@tspiteri
tspiteriforce-pushed the const_slice_split_at branch from 4b90601 to 97c963dCompareAugust 2, 2022 20:22
@thomcc

thomcc commented Aug 22, 2022

Copy link
Copy Markdown
Member

Sorry for the delay. It took some discussion as to the process here for making these unstably const. It seems like the process for unstably constifying something is to get some signoff from @rust-lang/wg-const-eval that this is reasonable to have as an (unstable) const fn, and then I can review it.

Hopefully the @ above works to ping someone.

@oli-obk

oli-obk commented Aug 22, 2022

Copy link
Copy Markdown
Contributor

r? @oli-obk yea, wg-const-eval can do unstable constifications

@rust-highfiverust-highfive assigned oli-obk and unassigned thomccAug 22, 2022
oli-obk
oli-obk reviewed Aug 22, 2022
View reviewed changes
Comment threadlibrary/core/src/slice/mod.rs Outdated
oli-obk
oli-obk reviewed Aug 22, 2022
View reviewed changes
Comment threadlibrary/core/src/slice/mod.rs
fee1-dead
fee1-dead approved these changes Aug 22, 2022
View reviewed changes

@fee1-deadfee1-dead left a comment

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

LGTM with reviews by oli addressed.

@oli-obk

oli-obk commented Aug 25, 2022

Copy link
Copy Markdown
Contributor

@bors r+ rollup

@bors

bors commented Aug 25, 2022

Copy link
Copy Markdown
Collaborator

📌 Commit bc3d719 has been approved by oli-obk

It is now in the queue for this repository.

@borsbors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Aug 25, 2022
@tspiteritspiteri mentioned this pull request Aug 25, 2022
Closed
3 tasks
@tspiteri

tspiteri commented Aug 25, 2022

Copy link
Copy Markdown
ContributorAuthor

Should I create a tracking issue for const_slice_split_at_not_mut once this is merged?

JohnTitor added a commit to JohnTitor/rust that referenced this pull request Aug 25, 2022
@JohnTitor
Rollup merge ofrust-lang#100076- tspiteri:const_slice_split_at, r=o…
5759a97
…li-obk
make slice::{split_at,split_at_unchecked} const functions
Now that `slice::from_raw_parts` is const in stable 1.64, it makes sense to have `split_at` const as well, otherwise unsafe code is required to achieve a const equivalent.
@JohnTitorJohnTitor mentioned this pull request Aug 25, 2022
Closed
@JohnTitorJohnTitor mentioned this pull request Aug 26, 2022
Merged
bors added a commit to rust-lang-ci/rust that referenced this pull request Aug 26, 2022
@bors
Auto merge ofrust-lang#101017- JohnTitor:rollup-73f2fhb, r=JohnTitor
13a6aaf
Rollup of 8 pull requests
Successful merges:
- rust-lang#99064 (distinguish the method and associated function diagnostic information)
- rust-lang#99920 (Custom allocator support in `rustc_serialize`)
- rust-lang#100034 ( Elaborate all box dereferences in `ElaborateBoxDerefs`)
- rust-lang#100076 (make slice::{split_at,split_at_unchecked} const functions)
- rust-lang#100604 (Remove unstable Result::into_ok_or_err)
- rust-lang#100933 (Reduce code size of `assert_matches_failed`)
- rust-lang#100978 (Handle `Err` in `ast::LitKind::to_token_lit`.)
- rust-lang#101010 (rustdoc: remove unused CSS for `.multi-column`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
@bors
bors merged commit e193f46 into rust-lang:masterAug 26, 2022
@rustbotrustbot added this to the 1.65.0 milestone Aug 26, 2022
@tspiteri
tspiteri deleted the const_slice_split_at branch August 26, 2022 10:45
@tspiteritspiteri mentioned this pull request Aug 29, 2022
Closed
3 tasks
Sign up for freeto join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@oli-obkoli-obkoli-obk left review comments
@fee1-deadfee1-deadfee1-dead approved these changes

Assignees

@oli-obkoli-obk

Labels

S-waiting-on-borsStatus: Waiting on bors to run and complete tests. Bors will change the label on completion.T-libs-api[DEPRECATED; DO NOT USE]

Projects

None yet

Milestone

1.65.0

Development

Successfully merging this pull request may close these issues.

7 participants

@tspiteri@rustbot@rust-highfive@thomcc@oli-obk@bors@fee1-dead