Enum with methods for functionality (Combine Class / Enum)

Question

I may miss some sort of point here, if that\'s the case - please include that discussion as a part of my question :).

This is a shortened down and renamed sample of a wo

Answer 1

C# enums don't work well like this. However, you can implement your own "fixed set of values" fairly easily:

public sealed class Foo
{
    public static readonly Foo FirstValue = new Foo(...);
    public static readonly Foo SecondValue = new Foo(...);

    private Foo(...)
    {
    }

    // Add methods here
}

As it happens, one example I've got of this is remarkably similar to yours - DateTimeFieldType in Noda Time. Sometimes you might even want to make the class unsealed, but keep the private constructor - which allows you to create subclasses only as nested classes. Very handy for restricting inheritance.

The downside is that you can't use switch :(

Answer 2

If you don't mind a little more writing you can make extension methods to expand the interface of the enum.

e.g.

public enum TimeUnit
{
   Second,
   Minute,
   Hour,
   Day,
   Year,
   /* etc */
}
public static class TimeUnitExtensions
{
    public static long InTicks(this TimeUnit myUnit)
    {
         switch(myUnit)
         {
           case TimeUnit.Second:
               return TimeSpan.TicksPerSecond;
           case TimeUnit.Minute:
               return TimeSpan.TicksPerMinute;
            /* etc */
         }
    }
}

This can add "instance" methods to your enums. It's a bit more verbose than mostly liked, though.

Remember though that an enum should be treated mostly as a named value.