Clippy lint · Complexity · checked with Clippy 0.1.99

clippy::manual_checked_ops: Detects manual zero checks before dividing integers, such as if x != 0 { y / x }

What it meansDetects manual zero checks before dividing integers, such as if x != 0 { y / x }. It is in the complexity group and warns by default.

Does it matter?

checked_div already handles the zero case and makes the intent clearer while avoiding a panic from a manual division.

Code that does something simple in a complicated way. Warns by default.

How to fix it

Clippy does not fix this one automatically. Change the code by hand:

Flagged

if b != 0 {
    let result = a / b;
    println!("{result}");
}

Write this instead

if let Some(result) = a.checked_div(b) {
    println!("{result}");
}

Turn it off, or on

Allow it where it does not fit your code, as narrowly as you can:

On one item

#[allow(clippy::manual_checked_ops)]
fn my_function() { /* ... */ }

Whole crate (Cargo.toml)

[lints.clippy]
manual_checked_ops = "allow"

One run

cargo clippy -- -A clippy::manual-checked-ops

The [lints] table needs Rust 1.74 or newer. In a workspace, put it under [workspace.lints.clippy] and add [lints] workspace = true to each member.

Complexitygroup

warndefault level

nofixed by cargo clippy --fix

1.95.0added in Rust

Clippy's own documentation

What it does

Detects manual zero checks before dividing integers, such as if x != 0 { y / x }.

Why is this bad?

checked_div already handles the zero case and makes the intent clearer while avoiding a panic from a manual division.

Example

if b != 0 {
    let result = a / b;
    println!("{result}");
}

Use instead:

if let Some(result) = a.checked_div(b) {
    println!("{result}");
}

From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.

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