C# quickest way to shift array

Question

How can I quickly shift all the items in an array one to the left, padding the end with null?

For example, [0,1,2,3,4,5,6] would become [1,2,3,4,5,6,null]

Ed

Answer 1

Here is my solution, similar to Task's in that it is a simple Array wrapper and that it takes O(1) time to shift the array to the left.

public class ShiftyArray
{
    private readonly T[] array;
    private int front;

    public ShiftyArray(T[] array)
    {
        this.array = array;
        front = 0;
    }

    public void ShiftLeft()
    {
        array[front++] = default(T);
        if(front > array.Length - 1)
        {
            front = 0;
        }
    }

    public void ShiftLeft(int count)
    {
        for(int i = 0; i < count; i++)
        {
            ShiftLeft();
        }
    }

    public T this[int index]
    {
        get
        {
            if(index > array.Length - 1)
            {
                throw new IndexOutOfRangeException();
            }

            return array[(front + index) % array.Length];
        }
    }

    public int Length { get { return array.Length; } }
}

Running it through Jason Punyon's test code...

int?[] intData = Enumerable.Range(1, 100).Cast().ToArray();
ShiftyArray array = new ShiftyArray(intData);

Stopwatch watch = new Stopwatch();
watch.Start();

for(int i = 0; i < 1000000; i++)
{
    array.ShiftLeft();
}

watch.Stop();

Console.WriteLine(watch.ElapsedMilliseconds);

Takes ~29ms, regardless of the array size.