`never_loop`: Note why the loop will never loop.

Description

loop {
    do_something();
    // No need to point this out.
    panic!();
}

// Imagine something less obvious.
let x = || Some(panic!());

loop {
    // Why doesn't this loop?
    x().unwrap();
}

Contributor guide

Tech stack

rust

Domain

developer 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.

active

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

clear

Prerequisites

Rustclippy developmentlint implementation

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

45

Research direction

The issue requests a note in the `never loop` lint to explain why a loop never iterates for non obvious cases. Implementation involves detecting control flow patterns that guarantee no iteration, such as after a `panic!` or a function that never returns. The maintainers should review existing lint logic in `clippy lints/src/never loop.rs` and avoid adding notes for obvious cases. The assignee and comments provide additional context for the expected behavior.