title: C memcpy in reverse
body: <p>I am working with audio data. I'd like to play the sample file in reverse. The data is stored as unsigned ints and packed nice and tight. Is there a way to call <code>memcpy</code> that will copy in reverse order. i.e. if I had 1,2,3,4 stored in an array, could I call <code>memcpy</code> and <em>magically</em> reverse them so I get 4,3,2,1.</p>