Clippy lints / Pedantic
Clippy lint · Pedantic · checked with Clippy 0.1.99
clippy::unreadable_literal: long literal lacking separators
What it meansWarns if a long integral or floating-point constant does not contain underscores. It is in the pedantic group and off by default.
What you see
warning: long literal lacking separators --> main.rs:3:1 | 3 | 61864918973511 | ^^^^^^^^^^^^^^ help: consider: `61_864_918_973_511` | = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#unreadable_literal = note: `-W clippy::unreadable-literal` implied by `-W clippy::pedantic`
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?
Reading long numbers is difficult without separators.
Stricter lints with some false positives. Off by default; opt in with clippy::pedantic.
How to fix it
Clippy does not fix this one automatically (its suggestion may change behaviour, so it only shows it). Change the code by hand:
Flagged
61864918973511
Write this instead
61_864_918_973_511
Turn it off, or on
It is off by default. To use it, set it to warn or deny:
Whole crate (Cargo.toml)
[lints.clippy]
unreadable_literal = "warn"In code
#![warn(clippy::unreadable_literal)]One run
cargo clippy -- -W clippy::unreadable-literalThe [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.
Settings in clippy.toml
unreadable-literal-lint-fractions: Should the fraction of a decimal be linted to include separators.
Clippy's own documentation
What it does
Warns if a long integral or floating-point constant does not contain underscores.
Why is this bad?
Reading long numbers is difficult without separators.
Example
61864918973511
Use instead:
61_864_918_973_511
Configuration
-
unreadable-literal-lint-fractions: Should the fraction of a decimal be linted to include separators.(default:
true)
From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.
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- unnecessary_wrapsthis function's return value is unnecessarily wrapped by `Option`
- unnested_or_patternsunnested or-patterns
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All 847 Clippy lints · Rust compiler errors · Cargo.toml checker
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