clippy::just_underscores_and_digits: consider choosing a more descriptive name

What you see

warning: consider choosing a more descriptive name
 --> main.rs:3:5
  |
3 | let _1 = 1;
  |     ^^
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#just_underscores_and_digits
  = note: `#[warn(clippy::just_underscores_and_digits)]` 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?

It’s hard to memorize what a variable means without a descriptive name.

Code that works but is not idiomatic Rust. Warns by default.

How to fix it

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

Flagged

let _1 = 1;
let ___1 = 1;
let __1___2 = 11;

Turn it off, or on

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

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

[lints.clippy]
just_underscores_and_digits = "allow"

cargo clippy -- -A clippy::just-underscores-and-digits

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.