文檔注釋在大項目非常有用。當運行 Rustdoc, 這些都是編譯到文檔的注釋。 它們被表示為 ///, 並由 Markdown 支持.

/// A human being is represented here
pub struct Person {
    /// A person must have a name, no matter how much Juliet may hate it
    name: String,
}

impl Person {
    /// Returns a person with the name given them
    ///
    /// # Arguments
    ///
    /// * `name` - A string slice that holds the name of the person
    ///
    /// # Example
    ///
    /// ```
    /// // You can have rust code between fences inside the comments
    /// // If you pass --test to Rustdoc, it will even test it for you!
    /// let person = Person::new("name");
    /// ```
    pub fn new(name: &str) -> Person {
        Person {
            name: name.to_string(),
        }
    }

    /// Gives a friendly hello!
    ///
    /// Says "Hello, [name]" to the `Person` it is called on.
    pub fn hello(& self) {
        println!("Hello, {}!", self.name);
    }
}

fn main() {
    let john = Person::new("John");

    john.hello();
}