Clippy lint · Style · checked with Clippy 0.1.99

clippy::needless_else: this `else` branch is empty

What it meansChecks for empty else branches. It is in the style group and warns by default.

What you see

warning: this `else` branch is empty
 --> main.rs:5:3
  |
5 |   } else {
  |  ___^
6 | | }
  | |_^ help: you can remove it
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#needless_else
  = note: `#[warn(clippy::needless_else)]` 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?

An empty else branch does nothing and can be removed.

Code that works but is not idiomatic Rust. 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

if check() {
    println!("Check successful!");
} else {
}

Write this instead

if check() {
    println!("Check successful!");
}

Turn it off, or on

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

On one item

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

Whole crate (Cargo.toml)

[lints.clippy]
needless_else = "allow"

One run

cargo clippy -- -A clippy::needless-else

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.

Stylegroup

warndefault level

yesfixed by cargo clippy --fix

1.72.0added in Rust

Clippy's own documentation

What it does

Checks for empty else branches.

Why is this bad?

An empty else branch does nothing and can be removed.

Example

if check() {
    println!("Check successful!");
} else {
}

Use instead:

if check() {
    println!("Check successful!");
}

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

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