discriminated union in csharp

main.cs
public class UnionExample
{
    public enum ShapeType { Square, Circle, Rectangle };

    public class Shape
    {
        public ShapeType Type { get; }
        public Shape(ShapeType type) => Type = type;
    }
    public class Square : Shape
    {
        public int SideLength { get; }
        public Square(int sideLength) : base(ShapeType.Square) => SideLength = sideLength;
    }

    public class Circle : Shape
    {
        public int Radius { get; }
        public Circle(int radius) : base(ShapeType.Circle) => Radius = radius;
    }

    public class Rectangle : Shape
    {
        public int Width { get; }
        public int Height { get; }
        public Rectangle(int width, int height) : base(ShapeType.Rectangle)
        {
            Width = width;
            Height = height;
        }
    }

    public static void Main()
    {
        Shape[] shapes = new Shape[] { new Square(5), new Circle(3), new Rectangle(4, 6) };

        foreach(var shape in shapes) {
            switch(shape) {
                case Square square:
                    Console.WriteLine($"Square with side length {square.SideLength}");
                    break;
                case Circle circle:
                    Console.WriteLine($"Circle with radius {circle.Radius}");
                    break;
                case Rectangle rectangle:
                    Console.WriteLine($"Rectangle with width {rectangle.Width} and height {rectangle.Height}");
                    break;
            }
        }
    }
}
1516 chars
52 lines