rust-lang / rust-lang/rust-clippy
Warn when using a variable named the same as a type
Nobody has claimed this yet.
- Dominant language
- Rust
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Description
Some examples from Rust 1.20:
🙅 — compiler generates an error (can't shadow unit structs)
struct Dog;
fn x(Dog: Dog) {}
⚠️ — compiler generates a warning (non-snake case variable)
struct Dog {}
fn x(Dog: Dog) {}
😖 — compiler doesn't generate a warning (and indeed the variable str is valid to use)
struct Dog {}
fn x(str: Dog) {}
I propose that Clippy warn when a variable name matches an in-scope type. I'm not even sure if it's possible to know all the types, but using the built-in lowercase primitive types (e.g. bool, str, i32) would be a great start.
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 by reviewing Clippy's existing lint architecture and Rust's name-resolution capabilities. Use the issue's examples as the initial behavior cases, especially variables matching primitive or in-scope type names. Done means Clippy warns for the proposed name collision without rejecting valid variable usage.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- tooling
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100