// A data-carrying enum becomes a Nim object variant, and a pattern that binds
// becomes an if/elif chain, because Nim's `case` cannot destructure.
#[derive(Debug)]
enum Shape {
    Empty,
    Square(i32),
    Rect { w: i32, h: i32 },
}

fn area(s: Shape) -> i32 {
    match s {
        Shape::Empty => 0,
        Shape::Square(a) => a * a,
        Shape::Rect { w, h } => w * h,
    }
}

fn main() {
    println!("{}", area(Shape::Empty));
    println!("{}", area(Shape::Square(4)));
    println!("{}", area(Shape::Rect { w: 3, h: 5 }));
    println!("{:?}", Shape::Square(4));
    println!("{:?}", Shape::Empty);
}