Clippy lint · Complexity · checked with Clippy 0.1.99

clippy::manual_range_patterns: this OR pattern can be rewritten using a range

What it meansLooks for combined OR patterns that are all contained in a specific range, e.g. 6 | 4 | 5 | 9 | 7 | 8 can be rewritten as 4..=9. It is in the complexity group and warns by default.

What you see

warning: this OR pattern can be rewritten using a range
 --> main.rs:4:23
  |
4 | let foo = matches!(x, 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10);
  |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `1..=10`
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#manual_range_patterns
  = note: `#[warn(clippy::manual_range_patterns)]` on by default

Real output of Clippy 0.1.99 (Rust 1.99) on the example below. Names and line numbers in yours will differ.

Does it matter?

Using an explicit range is more concise and easier to read.

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

How to fix it

Clippy can fix this one for you: run cargo clippy --fix (add --allow-dirty if you have uncommitted changes). Review the diff before you commit.

Flagged

let x = 6;
let foo = matches!(x, 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10);

Write this instead

let x = 6;
let foo = matches!(x, 1..=10);

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_range_patterns)]
fn my_function() { /* ... */ }

Whole crate (Cargo.toml)

[lints.clippy]
manual_range_patterns = "allow"

One run

cargo clippy -- -A clippy::manual-range-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

yesfixed by cargo clippy --fix

1.72.0added in Rust

Clippy's own documentation

What it does

Looks for combined OR patterns that are all contained in a specific range, e.g. 6 | 4 | 5 | 9 | 7 | 8 can be rewritten as 4..=9.

Why is this bad?

Using an explicit range is more concise and easier to read.

Known issues

This lint intentionally does not handle numbers greater than i128::MAX for u128 literals in order to support negative numbers.

Example

let x = 6;
let foo = matches!(x, 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10);

Use instead:

let x = 6;
let foo = matches!(x, 1..=10);

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

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