Clippy lint · Style · checked with Clippy 0.1.99

clippy::tabs_in_doc_comments: using tabs in doc comments is not recommended

What it meansChecks doc comments for usage of tab characters. It is in the style group and warns by default.

What you see

warning: using tabs in doc comments is not recommended
 --> main.rs:5:5
  |
5 | ///     - first        one
  |     ^^^^ help: consider using four spaces per tab
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#tabs_in_doc_comments
  = note: `#[warn(clippy::tabs_in_doc_comments)]` 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?

The rust style-guide promotes spaces instead of tabs for indentation. To keep a consistent view on the source, also doc comments should not have tabs. Also, explaining ascii-diagrams containing tabs can get displayed incorrectly when the display settings of the author and reader differ.

Code that works but is not idiomatic Rust. 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

///
/// Struct to hold two strings:
/// 	- first		one
/// 	- second	one
pub struct DoubleString {
   ///
   /// 	- First String:
   /// 		- needs to be inside here
   first_string: String,
   ///
   /// 	- Second String:
   /// 		- needs to be inside here
   second_string: String,
}

Write this instead

///
/// Struct to hold two strings:
///     - first        one
///     - second    one
pub struct DoubleString {
   ///
   ///     - First String:
   ///         - needs to be inside here
   first_string: String,
   ///
   ///     - Second String:
   ///         - needs to be inside here
   second_string: String,
}

Turn it off, or on

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

On one item

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

Whole crate (Cargo.toml)

[lints.clippy]
tabs_in_doc_comments = "allow"

One run

cargo clippy -- -A clippy::tabs-in-doc-comments

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

nofixed by cargo clippy --fix

1.41.0added in Rust

Clippy's own documentation

What it does

Checks doc comments for usage of tab characters.

Why is this bad?

Example

///
/// Struct to hold two strings:
/// 	- first		one
/// 	- second	one
pub struct DoubleString {
   ///
   /// 	- First String:
   /// 		- needs to be inside here
   first_string: String,
   ///
   /// 	- Second String:
   /// 		- needs to be inside here
   second_string: String,
}

Will be converted to:

///
/// Struct to hold two strings:
///     - first        one
///     - second    one
pub struct DoubleString {
   ///
   ///     - First String:
   ///         - needs to be inside here
   first_string: String,
   ///
   ///     - Second String:
   ///         - needs to be inside here
   second_string: String,
}

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

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