using System;
using System.Collections.Generic;

public class MyClass
{

    [Flags]
    public enum ErrorTypes : int {
        None = 0,
        MissingPassword = 1,
        MissingUsername = 2,
        PasswordIncorrect = 4
    }

    public static void RunSnippet()
    {

        //used like the following...

        ErrorTypes error = ErrorTypes.None;
        error = error.Append(ErrorTypes.MissingUsername);
        error = error.Append(ErrorTypes.MissingPassword);
        error = error.Remove(ErrorTypes.MissingUsername);
        error = error.Append(ErrorTypes.PasswordIncorrect);

        Console.WriteLine("MissingUsername:\t" + error.Has(ErrorTypes.MissingUsername));
        Console.WriteLine("MissingPassword:\t" + error.Has(ErrorTypes.MissingPassword));
        Console.WriteLine("PasswordIncorrect:\t" + error.Has(ErrorTypes.PasswordIncorrect));

        //then you can check using other methods
        if (error.Has(ErrorTypes.MissingUsername)) {

        }

    }


    #region Helper methods

    public static void Main()
    {
        try
        {
            RunSnippet();
        }
        catch (Exception e)
        {
            string error = string.Format("---\nThe following error occurred while executing the snippet:\n{0}\n---", e.ToString());
            Console.WriteLine(error);
        }
        finally
        {
            Console.Write("Press any key to continue...");
            Console.ReadKey();
        }
    }

    private static void WL(object text, params object[] args)
    {
        Console.WriteLine(text.ToString(), args);
    }

    private static void RL()
    {
        Console.ReadLine();
    }

    private static void Break()
    {
        System.Diagnostics.Debugger.Break();
    }

    #endregion
}
public static class EnumExtensions {

    public static T Append<T>(this System.Enum type, T value) {
        return (T)(object)(((int)(object)type | (int)(object)value));
    }

    public static T Remove<T>(this System.Enum type, T value) {
        return (T)(object)(((int)(object)type & ~(int)(object)value));
    }

    public static bool Has<T>(this System.Enum type, T value) {
        return (((int)(object)type & (int)(object)value) == (int)(object)value);
    }

}