Prototype

Prototype in Rust

Prototype is a creational design pattern that allows cloning objects, even complex ones, without coupling to their specific classes.

All prototype classes should have a common interface that makes it possible to copy objects even if their concrete classes are unknown. Prototype objects can produce full copies since objects of the same class can access each other’s private fields.

Learn more about Prototype

Built-in Clone trait

Rust has a built-in std::clone::Clone trait with many implementations for various types (via #[derive(Clone)]). Thus, the Prototype pattern is ready to use out of the box.

main.rs

#[derive(Clone)]
struct Circle {
    pub x: u32,
    pub y: u32,
    pub radius: u32,
}

fn main() {
    let circle1 = Circle {
        x: 10,
        y: 15,
        radius: 10,
    };

    // Prototype in action.
    let mut circle2 = circle1.clone();
    circle2.radius = 77;

    println!("Circle 1: {}, {}, {}", circle1.x, circle1.y, circle1.radius);
    println!("Circle 2: {}, {}, {}", circle2.x, circle2.y, circle2.radius);
}

Output

Circle 1: 10, 15, 10
Circle 2: 10, 15, 77

Prototype in Other Languages