How do I fix “wrong number of type arguments” while trying to implement a method?

Question

I\'m trying to implement a method:

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

struct Line {
    start: Point,
    end: Point,
}

i         


        

Answer 1

You need to add a type parameter to the impl:

impl Line<f64> {
    fn length(&self) -> f64 {
        let dx: f64 = self.start.x - self.end.x;
        let dy: f64 = self.start.y - self.end.y;
        (dx * dx + dy * dy).sqrt()
    }
}