Rust 1.81.0
eeb90cda1

Attributes

There is a new edition of the book and this is an old link.

Any item declaration may have an attribute applied to it.

// A function marked as a unit test
#[test]
fn test_foo() {
    /* ... */
}

Here are the relevant sections in the new and old books:

• In the Rust Reference: Ch 6.5 — Attributes
• In the first edition: Ch 3.27 — Attributes