Tracking Issue for RFC 3955: Named Fn trait parameters
@JonathanBrouwer is already working on this.
Since Jun 27, 2026.
- Dominant language
- Rust
- Stars
- 119k
- Forks
- 16.1k
- PR merge metrics
- PR metrics pending
Description
This is a tracking issue for the RFC 3955: Named Fn trait parameters
The feature gate for the issue is #![feature(named_fn_trait_parameters)].
About tracking issues
Tracking issues are used to record the overall progress of implementation.
They are also used as hubs connecting to other relevant issues, e.g., bugs or open design questions.
A tracking issue is however not meant for large scale discussion, questions, or bug reports about a feature.
Instead, open a dedicated issue for the specific matter and add the relevant feature gate label.
Discussion comments will get marked as off-topic or deleted.
Repeated discussions on the tracking issue may lead to the tracking issue getting locked.
Steps
- Implement the RFC (claimed by @JonathanBrouwer)
- Adjust documentation (see instructions on rustc-dev-guide)
- Style updates for any new syntax (nightly-style-procedure)
- Style team decision on new formatting
- Formatting for new syntax has been added to the Style Guide
- (non-blocking) Formatting has been implemented in
rustfmt
- Stabilization PR (see instructions on rustc-dev-guide)
Unresolved Questions
- list all the "unresolved questions" found in the RFC to ensure they are
not forgotten.
Implementation history
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.
Assessment
This issue has not been assessed yet.