rust-lang / rust-lang/rust-clippy

lint missing trait impls for Cow

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Dominant language
Rust
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Description

Cow is often very useful to avoid allocations in cases where things could be both borrowed or owned. However, its ergonomics is impeded by missing trait impls.

We can look up if there is an impl for trait T for a type I that has a ToOwned impl whose Owned also has a T impl and where Cow<I> does not implement T.

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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

The issue names Cow, ToOwned, and the missing trait implementations but no repository files or tests. Start by locating Clippy's lint infrastructure and the Rust definitions for Cow and ToOwned. Done means a lint identifies cases where the described trait implementations exist for the borrowed and owned types but not for Cow itself.

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
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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