What's the best C# pattern for implementing a hierarchy with an enum?

Question

I\'m implementing value types which represents a distance (or length). There\'s an enum that represents the different units of measure, eg:

public enum Distance         


        

Answer 1

Do you really need an enum here? Maybe, a simple value object will do?

public class Distance
{
    private readonly decimal millimeters;

    public decimal Meters
    { 
        get { return millimeters * 0.001m; } 
    }

    private Distance(decimal millimeters)
    {
        this.millimeters = millimeters;
    }

    public static Distance Yards(decimal yards)
    {
        return new Distance(yards * 914.4m);
    }
}

With extension methods you and properly defined operators can get very Ruby-like syntax:

var theWholeNineYards = 9.Yards() + 34.Inches();