C# Big Array Class One Dimensional Array Greater than 2Gb.

gistfile1.txt

 [Serializable]
    public class BigArray<T> : IEnumerable<T>
    {
        private readonly T[][] _arrays;
        public ulong Length { get; private set;}

        public T this[ulong index]
        {
            get
            {
                if (index > Length - 1)
                    throw new Exception("Getter: Index out of bound "+index+" must be less than or equal to "+(Length - 1));
                return _arrays[index >> 19][index & 524287UL];
            }
            set
            {
                if (index > Length - 1)
                    throw new Exception("Setter: Index out of bound "+index+" must be less than or equal to "+(Length - 1));
                _arrays[index >> 19][index & 524287UL] = value;
            }
        }

        public BigArray(ulong size)
        {
            var NumberOfArrays = size / 524288UL;
            while (NumberOfArrays * 524288UL < size)
                ++NumberOfArrays;
            Length = NumberOfArrays * 524288UL;
            _arrays = new T[NumberOfArrays][];
            for (ulong i = 0; i < NumberOfArrays; ++i)
                _arrays[i] = new T[524288];
        }

        IEnumerator<T> IEnumerable<T>.GetEnumerator()
        {
            return new Enumerator(this);
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return new Enumerator(this);
        }

        [Serializable]
        public struct Enumerator : IEnumerator<T>
        {
            private readonly BigArray<T> biga;
            private ulong index;

            public T Current { get; private set; }

            object IEnumerator.Current
            {
                get
                {
                    if (index == biga.Length + 1)
                        throw new InvalidOperationException("Enumerator out of range: " + index);
                    return Current;
                }
            }

            internal Enumerator(BigArray<T> biga)
            {
                this.biga = biga;
                index = 0;
                Current = default(T);
            }

            public void Dispose()
            {
            }

            public bool MoveNext()
            {
                if (index < biga.Length)
                {
                    Current = biga[index];
                    index++;
                    return true;
                }
                index = biga.Length + 1;
                Current = default(T);
                return false;
            }

            void IEnumerator.Reset()
            {
                index = 0;
                Current = default(T);
            }
        }
    }