Clippy lint · Suspicious · checked with Clippy 0.1.99

clippy::empty_line_after_outer_attr: empty line after outer attribute

What it meansChecks for empty lines after outer attributes It is in the suspicious group and warns by default.

What you see

warning: empty line after outer attribute
 --> main.rs:3:1
  |
3 | / #[allow(dead_code)]
4 | |
  | |_^
5 |   fn not_quite_good_code() {}
  |   ---------------------- the attribute applies to this function
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#empty_line_after_outer_attr
  = note: `#[warn(clippy::empty_line_after_outer_attr)]` on by default
  = help: if the empty line is unintentional, remove it

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?

The attribute may have meant to be an inner attribute (#![attr]). If it was meant to be an outer attribute (#[attr]) then the empty line should be removed

Code that is most likely wrong or useless. Warns by default.

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

#[allow(dead_code)]

fn not_quite_good_code() {}

Write this instead

// Good (as inner attribute)
#![allow(dead_code)]

fn this_is_fine() {}

// or

// Good (as outer attribute)
#[allow(dead_code)]
fn this_is_fine_too() {}

Turn it off, or on

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

On one item

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

Whole crate (Cargo.toml)

[lints.clippy]
empty_line_after_outer_attr = "allow"

One run

cargo clippy -- -A clippy::empty-line-after-outer-attr

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.

Suspiciousgroup

warndefault level

nofixed by cargo clippy --fix

pre 1.29.0added in Rust

Clippy's own documentation

What it does

Checks for empty lines after outer attributes

Why is this bad?

The attribute may have meant to be an inner attribute (#![attr]). If it was meant to be an outer attribute (#[attr]) then the empty line should be removed

Example

#[allow(dead_code)]

fn not_quite_good_code() {}

Use instead:

// Good (as inner attribute)
#![allow(dead_code)]

fn this_is_fine() {}

// or

// Good (as outer attribute)
#[allow(dead_code)]
fn this_is_fine_too() {}

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

Up next

Also worth your time

Did this answer your question?