如何在.NET中创建自己的原始数据类型？

public struct Point
{
    public int X;
    public int Y;

    public Point(int x, int y)
    {
        X = x;
        Y = y;
    }

    public override string ToString()
    {
        return $"({X}, {Y})";
    }
}

Point p = new Point(3, 4);
Console.WriteLine(p); // 输出：(3, 4)

public enum Color
{
    Red,
    Green,
    Blue
}

Color c = Color.Red;
Console.WriteLine(c); // 输出：Red