rust-lang / rust-lang/rust-analyzer
Unknown placeholder inlayHints in path segment
Open
Nobody has claimed this yet.
C-bug
- Dominant language
- Rust
- Stars
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- 2.2k
- Avg merge
- 1d 12h
- Merged PRs (30d)
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Description
rust-analyzer version: rust-analyzer 0.4.2710-standalone
rustc version: rustc 1.91.0-nightly (040a98af7 2025-08-20)
editor or extension: Vim
code snippet to reproduce:
fn main() {
Foo::<_>::convert(2);
}
struct Foo<T>(T);
impl<T> Convert<T> for Foo<T> {
fn convert(_: T) -> Self {
loop { }
}
}
trait Convert<T> {
fn convert(value: T) -> Self;
}
Output:
Foo::<_ = {unknown}>::convert(2);
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
Reproduce the report in Vim with the Rust snippet and inspect rust-analyzer's inlay-hint handling for the generic path segment. Done means the expression no longer renders the unknown placeholder and displays the correct inlay hint behavior for this example.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- compilers, devtools
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100