iOS: Convert a string from little endiand to big endian
<p>I got a string in <strong>little</strong> endian that I would like to convert in <strong>big</strong> endian.</p>

<p>This "647b" should become "7b64". How can I do this in <strong>iOS</strong> (C++ code welcome)?</p>

<p><strong>PS: I am deriving the string from a NSData object.</strong></p>