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

If it absolutely has to be in an array, then I would recommend the most obvious code possible.

for (int index = startIndex; index + 1 < values.Length; index++)
     values[index] = values[index + 1];
values[values.Length - 1] = null;

This gives the optimizer the most opportunities to find the best way on whatever target platform the program is installed on.

EDIT:

I just borrowed Jason Punyon's test code, and I'm afraid he's right. Array.Copy wins!

    var source = Enumerable.Range(1, 100).Cast().ToArray();
    int indexToRemove = 4;

    var s = new Stopwatch();
    s.Start();
    for (int i = 0; i < 1000000; i++)
    {
        Array.Copy(source, indexToRemove + 1, source, indexToRemove, source.Length - indexToRemove - 1);
        //for (int index = indexToRemove; index + 1 < source.Length; index++)
        //    source[index] = source[index + 1]; 
    }
    s.Stop();
    Console.WriteLine(s.Elapsed);

Array.Copy takes between 103 and 150 ms on my machine.

for loop takes between 269 and 338 ms on my machine.