Struct with vector of structs - Polygon

• We can create a struct that has a single attribute which is a vector of Point instances.
• We can then use impl to implement a function.

struct Point {
    x: i32,
    y: i32,
}

struct Polygon {
    points: Vec<Point>,
}

impl Polygon {
    fn length(&self) -> i32 {
        42
    }
}

fn main() {
    let poly = Polygon {
        points: vec![
            Point { x: 3, y: 7 },
            Point { x: 10, y: 6 },
            Point { x: 23, y: 12 },
            Point { x: -2, y: -2 },
        ],
    };

    for point in &poly.points {
        println!("x: {} y: {}", point.x, point.y)
    }

    println!("Length: {}", poly.length());
}

x: 3 y: 7
x: 10 y: 6
x: 23 y: 12
x: -2 y: -2
Length: 42