Playing a "Meta-Puzzle"

From "Fred" (not his real name):

"I don't much care for their puzzle-based interview culture, so I did as J Allard suggests, and played a 'meta-puzzle:' I tried to answer at least one question, correctly, in a way that my interviewer had not heard before, and would not (immediately) understand! And I think I succeeded, with the good 'ol triple-xor-register-swap trick:

"Q: Write a C++ function to reverse the characters in a string. Optimize.

"A: [ed: clever answer using XOR]

"After explaining the funky exclusive-or logic, and how this allows an optimizer to 'save' a cpu register, my interviewer immediately left, and returned with his manager in tow... Hmm.. does this mean I get the job? ;-)"