rust-lang/rust-clippy

lint String::as_str()

Open

#874 opened on Apr 23, 2016

View on GitHub
 (9 comments) (0 reactions) (0 assignees)Rust (10,406 stars) (1,391 forks)batch import
A-lintT-middlegood first issue

Description

Using my_string.as_str() is noisy and adds no value in comparison to &my_string. This lint should not apply to using it in a .map(_) or some other higher-order stuff, just calling the function directly.

Contributor guide

Tech stack
rust
Domain
toolingdeveloper experience
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Basic RustClippy internals overview
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45
Research direction
Examine existing clippy lints in `clippy lints/src/` for patterns like unnecessary method calls. Study how to register a new lint via `declare clippy lint!` and implement LintPass. Note the issue's exception for higher order functions; ensure lint is skipped inside closures and .map(). Re read comments on issue #874 for additional nuance. Implement a lint that flags direct calls to `String::as str()` and suggests `&my string`.