// EXIT:0
// OUTPUT:some 7
// OUTPUT:none
// OUTPUT:point 3 4
// OUTPUT:empty
unit patterns;

enum Shape {
    Empty,
    Point(i32),
    Pair { x: i32, y: i32 },
}

fn pick(flag: bool) -> ?i32 {
    if flag { return 7; }
    return null;
}

fn describe(s: Shape) -> void {
    match s {
        Empty => { @print("empty\n"); }
        Point(v) => { @print("point {}\n", v); }
        Pair { x, y } => { @print("point {} {}\n", x, y); }
    }
}

fn main() -> i32 {
    if let Some(v) = pick(true) { @print("some {}\n", v); }
    else { @print("unexpected\n"); }
    if let None = pick(false) { @print("none\n"); }
    else { @print("unexpected\n"); }
    describe(Shape.Pair{ x: 3, y: 4 });
    describe(Shape.Empty);
    return 0;
}