How to disable unused variable warning in Rust?

Question

According to this answer, #[allow(dead_code)] should work, but it doesn't

fn main() {
    #[allow(dead_code)]
    let x = 0;
}

The best way would be to remove the unused code. Maybe you'd be better off explaining why that approach is one you're avoiding, someone might be able to give you a better solution. — loganfsmyth, Jun 22 '21 at 01:18
For machine disabling you can look to my answer at below link. https://stackoverflow.com/a/71119013/10943567 — Kargat TTT, Feb 14 '22 at 22:30

score 16 · Answer 1 · answered Jun 22 '21 at 00:02

16

These are different lints. dead_code refers to unused code at the item level, e.g. imports, functions and types. unused_variables refers to variables that are never accessed.

You can also cover both cases with #[allow(unused)].

answered Jun 22 '21 at 00:02

Peter Hall

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Also, prefixing the variable name with an underscore suppresses the warning: `let _x = 0;` – Jmb Jun 22 '21 at 07:03

score 9 · Accepted Answer · edited May 27 '22 at 00:03

9

The correct is

fn main() {
    #[allow(unused_variables)]
    let x = 0;
}

edited May 27 '22 at 00:03

Ryan M

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answered Jun 21 '21 at 23:43

Guerlando OCs

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score 8 · Answer 3 · answered Jan 14 '23 at 21:45

8

Put #![allow(unused)] at the top of the file (note the !).

answered Jan 14 '23 at 21:45

phocks

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Thanks for specifying that it has to be at the top of the file. – Austin Heller Jul 02 '23 at 19:15

How to disable unused variable warning in Rust?

3 Answers3