Clippy lint · Restriction · checked with Clippy 0.1.99

clippy::unnecessary_self_imports: import ending with `::{self}`

What it meansChecks for imports ending in ::{self}. It is in the restriction group and off by default.

What you see

warning: import ending with `::{self}`
 --> main.rs:3:1
  |
3 | use std::io::{self};
  | ^^^^^^^^^-----------
  |          |
  |          help: consider omitting `::{self}`: `io;`
  |
  = note: this will slightly change semantics; any non-module items at the same path will also be imported
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#unnecessary_self_imports
  = note: requested on the command line with `-W clippy::unnecessary-self-imports`

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?

In most cases, this can be written much more cleanly by omitting ::{self}.

Lints that forbid language features for specific codebases (no unwrap, no indexing...). Off by default; pick them one by one, never the whole group.

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

use std::io::{self};

Write this instead

use std::io;

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]
unnecessary_self_imports = "warn"

In code

#![warn(clippy::unnecessary_self_imports)]

One run

cargo clippy -- -W clippy::unnecessary-self-imports

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.

Restrictiongroup

allowdefault level

nofixed by cargo clippy --fix

1.53.0added in Rust

Clippy's own documentation

What it does

Checks for imports ending in ::{self}.

Why restrict this?

In most cases, this can be written much more cleanly by omitting ::{self}.

Known problems

Removing ::{self} will cause any non-module items at the same path to also be imported. This might cause a naming conflict (https://github.com/rust-lang/rustfmt/issues/3568). This lint makes no attempt to detect this scenario and that is why it is a restriction lint.

Example

use std::io::{self};

Use instead:

use std::io;

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

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