rust-lang / rust-lang/rust-clippy

Detect useless PhantomData

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#2,464 2 comments 0 reactions 0 assignees View on GitHub

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L-unnecessary T-middle
Dominant language
Rust
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Description

Twice in a few days, after refactoring code, I've ended up with unnecessary PhantomData. And while the compiler complains when PhantomData is necessary (although not directly speaking of PhantomData), there is currently nothing that detects when they are (still) used but the code doesn't require them anymore.

OTOH, there are a few cases where they are used but where the compiler would not require them, in libstd or libcore.

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Research direction

No files, tests, or entry points are named. Start by tracing how Clippy currently handles PhantomData and compare cases where the compiler requires it with the libstd and libcore cases where it remains intentional; done means detecting unnecessary uses without flagging those exceptions.

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
Needs clarification
Newbie friendliness
25/100

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