rust-lang / rust-lang/rust

Tracking Issue for const_index

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#143,775 2 comments 15 reactions 0 assignees View on GitHub

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C-tracking-issue F-const_trait_impl S-tracking-impl-incomplete T-libs
Dominant language
Rust
Stars
119k
Forks
16.1k
PR merge metrics
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Description

Feature gate: #![feature(const_index)]

This is a tracking issue for the constness of the Index, IndexMut, and SliceIndex traits and const functions using them

Public API
const {
    let x: &[u32] = ...;
    let y = &x[5..];
}
Steps / History

(Remember to update the S-tracking-* label when checking boxes.)

Unresolved Questions
  • None yet.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with implementation PR #143921 and the const_index feature gate. Review the proposed constness for Index, IndexMut, and SliceIndex, including the example using &x[5..]. Done requires completing the implementation, final comment period, and stabilization PR checklist items.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
compilers
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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