Maybe.cs

 public class Maybe<T> : IEnumerable<T>
    {
        private readonly IEnumerable<T> _values;

        public Maybe()
        {
            _values = new T[0];
        }

        public Maybe(T value)
        {
            _values = new[] {value};
        }

        public IEnumerator<T> GetEnumerator()
        {
            return _values.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }

    public static class Maybe
    {
        public static Maybe<T> ToMaybe<T>(this T value)
        {
            return new Maybe<T>(value);
        }

        public static Maybe<T> Empty<T>()
        {
            return new Maybe<T>();
        }
    }