Enumeration Extensions 2.0

A while back I had posted some code about making it easier to work with enumerated types — Especially with the Flags attribute. An experienced programmer won’t have a hard time understanding all the voodoo magic behind the the bitwise operators but for the rest of us then something a little easier to read is always welcome.

The problem with the previous code is that it was created to work with the project I was currently working on so I didn’t put a lot of effort into making it work with multiple types. That said, below is the official version 2.0 of the EnumerationExtensions class.

using System;

namespace Extensions {

    /// <summary>
    /// Extension methods to make working with Enum values easier
    /// </summary>
    public static class EnumerationExtensions {

        #region Extension Methods

        /// <summary>
        /// Includes an enumerated type and returns the new value
        /// </summary>
        public static T Include<T>(this Enum value, T append) {
            Type type = value.GetType();

            //determine the values
            object result = value;
            _Value parsed = new _Value(append, type);
            if (parsed.Signed is long) {
                result = Convert.ToInt64(value) | (long)parsed.Signed;
            }
            else if (parsed.Unsigned is ulong) {
                result = Convert.ToUInt64(value) | (ulong)parsed.Unsigned;
            }

            //return the final value
            return (T)Enum.Parse(type, result.ToString());
        }

        /// <summary>
        /// Removes an enumerated type and returns the new value
        /// </summary>
        public static T Remove<T>(this Enum value, T remove) {
            Type type = value.GetType();

            //determine the values
            object result = value;
            _Value parsed = new _Value(remove, type);
            if (parsed.Signed is long) {
                result = Convert.ToInt64(value) & ~(long)parsed.Signed;
            }
            else if (parsed.Unsigned is ulong) {
                result = Convert.ToUInt64(value) & ~(ulong)parsed.Unsigned;
            }

            //return the final value
            return (T)Enum.Parse(type, result.ToString());
        }

        /// <summary>
        /// Checks if an enumerated type contains a value
        /// </summary>
        public static bool Has<T>(this Enum value, T check) {
            Type type = value.GetType();

            //determine the values
            object result = value;
            _Value parsed = new _Value(check, type);
            if (parsed.Signed is long) {
                return (Convert.ToInt64(value)& (long)parsed.Signed) == (long)parsed.Signed;
            }
            else if (parsed.Unsigned is ulong) {
                return (Convert.ToUInt64(value) & (ulong)parsed.Unsigned) == (ulong)parsed.Unsigned;
            }
            else {
                return false;
            }
        }

        /// <summary>
        /// Checks if an enumerated type is missing a value
        /// </summary>
        public static bool Missing<T>(this Enum obj, T value) {
            return !EnumerationExtensions.Has<T>(obj, value);
        }

        #endregion

        #region Helper Classes

        //class to simplfy narrowing values between 
        //a ulong and long since either value should
        //cover any lesser value
        private class _Value {

            //cached comparisons for tye to use
            private static Type _UInt64 = typeof(ulong);
            private static Type _UInt32 = typeof(long);

            public long? Signed;
            public ulong? Unsigned;

            public _Value(object value, Type type) {

                //make sure it is even an enum to work with
                if (!type.IsEnum) {
                    throw new ArgumentException("Value provided is not an enumerated type!");
                }

                //then check for the enumerated value
                Type compare = Enum.GetUnderlyingType(type);

                //if this is an unsigned long then the only
                //value that can hold it would be a ulong
                if (compare.Equals(_Value._UInt32) || compare.Equals(_Value._UInt64)) {
                    this.Unsigned = Convert.ToUInt64(value);
                }
                //otherwise, a long should cover anything else
                else {
                    this.Signed = Convert.ToInt64(value);
                }

            }

        }

        #endregion

    }

}

This code results in a much easier to read syntax and is mildly better at avoiding type casting issues. Instead of defaulting to int as the other version did, this version attempts to decide between Int64 or UInt64 since either could meet the requirements for any of their lesser counterparts.

Now we can use syntax similar like you see below…

//create the typical object
RegexOptions options = RegexOptions.None;

//Assign a value
options = options.Include(RegexOptions.IgnoreCase); //IgnoreCase

//Or assign multiple values
options = options.Include(RegexOptions.Multiline | RegexOptions.Singleline); //IgnoreCase, Multiline, Singleline

//Remove values from the list
options = options.Remove(RegexOptions.IgnoreCase); //Multiline, Singleline

//Check if a value even exists
bool multiline = options.Has(RegexOptions.Multiline); //true
bool ignoreCase = options.Missing(RegexOptions.IgnoreCase); //true

Anyways, a whole lot easier to read in my opinion. Enjoy!