Tracking Issue for `likely_unlikely`
Nobody has claimed this yet.
- Dominant language
- Rust
- Stars
- 119k
- Forks
- 16.2k
- PR merge metrics
- PR metrics pending
Description
Feature gate: #![feature(likely_unlikely)]
This is a tracking issue for core::hint::{likely, unlikely}.
This tracking issue was split from https://github.com/rust-lang/rust/issues/136873. Please also see the meta discussion at https://github.com/rust-lang/rust/issues/26179.
Public API
// core::hint
pub const fn likely(b: bool) -> bool;
pub const fn unlikely(b: bool) -> bool;
Steps / History
(Remember to update the S-tracking-* label when checking boxes.)
- Intrinsic implementation: https://github.com/rust-lang/rust/pull/120370
- Reexport in
std::hint: https://github.com/rust-lang/rust/pull/133695 - Behavior improvements: https://github.com/rust-lang/rust/pull/133852
- Final comment period (FCP)^1
- Stabilization PR
Unresolved Questions
- None yet.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the core::hint::{likely, unlikely} public API and the listed feature-gate history, especially the completed intrinsic, reexport, and behavior-improvement PRs. Review the linked feature-lifecycle stabilization guidance and the unresolved-questions section; done requires the remaining FCP and stabilization PR steps.
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
- Quiet
- Clarity
- Needs clarification
- Newbie friendliness
- 30/100