False positive for inherent_to_string_shadow_display? · rust-lang/rust-clippy#4396

(16 评论) (0 反应) (0 负责人)Rust (10,406 star) (1,391 fork)batch import

C-bugC-enhancementI-false-positiveL-suggestiongood first issue

描述

I think I found a false positive or at least questionable case of inherent_to_string_shadow_display rule triggering.

The place this rule is (or rather "was", since I disabled it) triggered: https://github.com/huxi/rusty_ulid/blob/72ac82736311981d12c339b78756049f48406179/src/lib.rs#L557

The place where the method in question is used to actually implement Display: https://github.com/huxi/rusty_ulid/blob/72ac82736311981d12c339b78756049f48406179/src/lib.rs#L571

This boils down to a situation where a type has an efficient implementation of fn to_string(&self) -> String that is used to implement fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> of fmt::Display.

I think this case (method is used to implement trait) shouldn't trigger the rule.

贡献者指南

技术栈: rust
领域: toolingdeveloper experience
议题类型: bug
难度: 3
预计时间: 1-2 days
活动状态: needs maintainer response
清晰度: mostly clear
前置要求: Rust programmingclippy internals
新手友好度: 40
研究方向: Examine the clippy lint implementation for `inherent to string shadow display` in the clippy source. The issue points to a case where an inherent `to string` is used to implement `Display`, so the lint should not trigger. Investigate the lint's logic to see if there is an existing exception for this pattern. The fix would likely involve modifying the lint to check whether the inherent method is used to satisfy the `Display` trait. Consult relevant comments and the Rust documentation on trait implementation.