Question

I found a goodlooking example about implementation enums in a different way. That is called type-safe enum pattern i think. I started using it but i realized that i can not use it in a switch statement.
My implementation looks like the following:

public sealed class MyState
{
    private readonly string m_Name;
    private readonly int m_Value;

    public static readonly MyState PASSED= new MyState(1, "OK");
    public static readonly MyState FAILED= new MyState(2, "ERROR");

    private MyState(int value, string name)
    {
        m_Name = name;
        m_Value = value;
    }

    public override string ToString()
    {
        return m_Name;
    }

    public int GetIntValue()
    {
        return m_Value;
    }
}

What can i add to my class in order to be able to use this pattern in switch statements in C#?
Thanks.

Answer 1

You can try something like this:

class Program
{
    static void Main(string[] args)
    {
        Gender gender = Gender.Unknown;

        switch (gender)
        {
            case Gender.Enum.Male:
                break;
            case Gender.Enum.Female:
                break;
            case Gender.Enum.Unknown:
                break;
        }
    }
}

public class Gender : NameValue
{
    private Gender(int value, string name)
        : base(value, name)
    {
    }

    public static readonly Gender Unknown = new Gender(Enum.Unknown, "Unknown");
    public static readonly Gender Male = new Gender(Enum.Male, "Male");
    public static readonly Gender Female = new Gender(Enum.Female, "Female");
    public class Enum
    {
        public const int Unknown = -1;
        public const int Male = 1;
        public const int Female = 2;
    }

}

public abstract class NameValue
{
    private readonly int _value;
    private readonly string _name;

    protected NameValue(int value, string name)
    {
        _value = value;
        _name = name;
    }

    public int Value
    {
        get { return _value; }
    }

    public string Name
    {
        get { return _name; }
    }

    public override string ToString()
    {
        return Name;
    }
    public override int GetHashCode()
    {
        return Value.GetHashCode();
    }

    public override bool Equals(object obj)
    {
        NameValue other = obj as NameValue;
        if (ReferenceEquals(other, null)) return false;
        return this.Value == other.Value;
    }

    public static implicit operator int(NameValue nameValue)
    {
        return nameValue.Value;
    }
}