Derive

The derive attribute can be used to auto-implement certain Traits for you.

Some traits you can most likely derive:

std::default::Default
serde’s Serialize & Deserialize (Requires derive feature on serde)
std::clone::Clone
std::fmt::Debug

To use derive in a simple example:

// We'll use std::fmt::Debug and std::default::Default traits
#[derive(Debug, Default)]
struct Point (u32, u32); // Simple Point structure

fn main() {
    // We call the default method (Provided for us by Default)
    let p: Point = Point::default(); // This is equal to 'let p: Point = Point(0, 0);'
    // We can debug print out the structure (Provided by Debug)
    // Note: Using '{}' will fail as we don't implement std::fmt::Display
    //       Debug uses '{:?}' and will print the structure (structure name, and fields + values)
    //           This also means any values we use must also implement Debug and Default!
    println!("p = {:?}", p);
    // p = Point(0, 0)
}