rust-lang / rust-lang/rustc-hash

Document determinism guarantee of FxHasher

Open
#59 1 comment 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
Rust
Stars
596
Forks
62
PR merge metrics
No merged PRs in 30d

Description

Currently, FxHasher is deterministic (accross multiple instances within one run, accross runs, accross machines with the same target_pointer_width). I am wondering if this crate is committed to upholding this rule or if this cannot relied upon with future changes?

I am asking because I think determinism is an important part for many applications (think about when you want you iterate over a FxHashMap and want your runs to be reproducible). So if the crate is committed to uphold this rule it would be great if this could be documented somewhere.

Contributor guide

No contributing guide indexed for this repository

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 by reviewing the existing FxHasher and crate documentation to determine where its determinism behavior is described. Confirm with maintainers whether the guarantee covers instances, runs, machines, and target_pointer_width; done means documenting the agreed scope and any limits.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
documentation
Issue type
Documentation
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
30/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.