rust-lang / rust-lang/rust-analyzer

Render auto traits in RPIT

Open
#23,237 3 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

A-hover A-inlay-hints C-feature E-medium
Dominant language
Rust
Stars
16.9k
Forks
2.2k
Avg merge
1d 12h
Merged PRs (30d)
72

Description

Similar #14055

trait Trait {}
impl Trait for T {}
fn foo() -> impl Trait {
    &raw const ()
}

Hover on impl outputs:

impl Trait + Unpin + UnwindSafe + RefUnwindSafe
impl Trait = *const ()
---
impl
---
keyword docs...

Maybe we can use inlayHints, but there are too many auto traits

Complex cases that should be implemented:

async foo() -> Result<(impl ToString, impl Fn()), impl Error> { /*...*/ }

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 by tracing how hover output for impl Trait is produced and evaluate the issue's suggestion to use inlay hints. Compare the simple RPIT example with the async nested impl case, and consider how the result should represent auto traits without excessive output.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
devtools
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Active
Clarity
Mostly clear
Newbie friendliness
45/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.