use - Rust
Description: API documentation for the Rust `use` keyword in crate `std`.
Keywords: rust, rustlang, rust-lang, use

# [−]Keyword use

Import or rename items from other crates or modules.

Usually a `use` keyword is used to shorten the path required to refer to a module item. The keyword may appear in modules, blocks and even functions, usually at the top.

The most basic usage of the keyword is `use path::to::item;`, though a number of convenient shortcuts are supported:

- Simultaneously binding a list of paths with a common prefix, using the glob-like brace syntax `use a::b::{c, d, e::f, g::h::i};`
- Simultaneously binding a list of paths with a common prefix and their common parent module, using the `self` keyword, such as `use a::b::{self, c, d::e};`
- Rebinding the target name as a new local name, using the syntax `use p::q::r as x;`. This can also be used with the last two features: `use a::b::{self as ab, c as abc}`.
- Binding all paths matching a given prefix, using the asterisk wildcard syntax `use a::b::*;`.
- Nesting groups of the previous features multiple times, such as `use a::b::{self as ab, c, d::{*, e::f}};`
- Reexporting with visibility modifiers such as `pub use a::b;`
- Importing with `_` to only import the methods of a trait without binding it to a name (to avoid conflict for example): `use ::std::io::Read as _;`.

Using path qualifiers like `crate`, `super` or `self` is supported: `use crate::a::b;`.

Note that when the wildcard `*` is used on a type, it does not import its methods (though for `enum`s it imports the variants, as shown in the example below).

ⓘThis example deliberately fails to compile

    enum ExampleEnum {
        VariantA,
        VariantB,
    }

    impl ExampleEnum {
        fn new() -> Self {
            Self::VariantA
        }
    }

    use ExampleEnum::*;

    // Compiles.
    let _ = VariantA;

    // Does not compile !
    let n = new();

Run

For more information on `use` and paths in general, see the Reference.

The differences about paths and the `use` keyword between the 2015 and 2018 editions can also be found in the Reference.