rust-lang / rust-lang/rust-clippy

Lint suggesting from_fn instead of while let Some(x)

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#3,940 8 comments 0 reactions 1 assignee View on GitHub

@jtjlehi is already working on this.

Since Aug 26, 2026.

A-lint good first issue L-style L-suggestion
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Rust
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Description

With the release of 1.34 with the from_fn function, I'd like to propose a new lint that matches: while let Some(x) = expr and suggests replacing it with for x in from_fn(|| expr). (With a special-case for while let Some(x) = fn() that suggests for x in from_fn(fn) if possible.)

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