#[derive(Debug, Clone)]
struct Point {
    x: f64,
    y: f64,
}
 
#[derive(Debug)]
struct Line {
    start: Point,
    end: Point,
}
 
impl Default for Line {
    fn default() -> Self {
        Self {
            start: Point { x: 0.0, y: 0.0 },
            end: Point { x: 1.0, y: 1.0 },
        }
    }
}
 
impl From<(f64, f64)> for Point {
    fn from(coords: (f64, f64)) -> Self {
        Point { x: coords.0, y: coords.1 }
    }
}
 
impl From<Point> for (f64, f64) {
    fn from(point: Point) -> Self {
        (point.x, point.y)
    }
}
 
impl Line {
    fn new(start: Point, end: Point) -> Self {
        Self { start, end }
    }
 
    fn length(&self) -> f64 {
        let dx = self.end.x - self.start.x;
        let dy = self.end.y - self.start.y;
        (dx * dx + dy * dy).sqrt()
    }
}
 
fn main() {
    let default_line = Line::default();
    println!("Default line: {:?}", default_line);
 
    let point_from_tuple: Point = (3.0, 4.0).into();
    println!("Point from tuple: {:?}", point_from_tuple);
 
    let tuple_from_point: (f64, f64) = point_from_tuple.into();
    println!("Tuple from point: {:?}", tuple_from_point);
 
    let line = Line::new((0.0, 0.0).into(), (3.0, 4.0).into());
    println!("Line length: {:.2}", line.length());
}