Clippy lint · Complexity · checked with Clippy 0.1.99

clippy::wildcard_in_or_patterns: Checks for wildcard pattern used with others patterns in same match arm

What it meansChecks for wildcard pattern used with others patterns in same match arm. It is in the complexity group and warns by default.

Does it matter?

Wildcard pattern already covers any other pattern as it will match anyway. It makes the code less readable, especially to spot wildcard pattern use in match arm.

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

match s {
    "a" => {},
    "bar" | _ => {},
}

Write this instead

match s {
    "a" => {},
    _ => {},
}

Turn it off, or on

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

On one item

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

Whole crate (Cargo.toml)

[lints.clippy]
wildcard_in_or_patterns = "allow"

One run

cargo clippy -- -A clippy::wildcard-in-or-patterns

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

1.42.0added in Rust

Clippy's own documentation

What it does

Checks for wildcard pattern used with others patterns in same match arm.

Why is this bad?

Wildcard pattern already covers any other pattern as it will match anyway. It makes the code less readable, especially to spot wildcard pattern use in match arm.

Example

match s {
    "a" => {},
    "bar" | _ => {},
}

Use instead:

match s {
    "a" => {},
    _ => {},
}

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

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