> checks if the values are equal Not the values (the values being equal doesn't break the trick), but the pointers. That is, if you use the XOR trick to swap a

> checks if the values are equal Not the values (the values being equal doesn't break the trick), but the pointers. That is, if you use the XOR trick to swap a value with itself, then it will be set to zero, instead. As if you had written: x ^= x x ^= x x ^= x Yeah, now x would be zero, not itself.