Implement a method for a struct

• impl

• self

• &self

• We can add methods to a struct using the impl keyword (we implement the method).

• The first parameter of every method must be the variable name self that will represent the current instance.

• We can have either self or &self. The latter will borrow the instance and it will allow us to call two methods (or the same method twice as in our example).

• If we used only self the instance would be moved on the first method call. Rarely used.

struct Point {
    x: f64,
    y: f64,
}

impl Point {
    fn distance(&self) -> f64 {
        (self.x * self.x + self.y * self.y).sqrt()
    }
}

fn main() {
    let pnt = Point { x: 2.0, y: 3.0 };
    println!("x: {}", pnt.x);
    println!("y: {}", pnt.y);

    println!("Distance from origo: {}", pnt.distance());
    println!("Distance from origo: {}", pnt.distance());
}

x: 2
y: 3
Distance from origo: 3.605551275463989
Distance from origo: 3.605551275463989