Analyzing ReactOS's code

I will only cite the following piece of code for dessert:

    #define SWAP(a,b,c)  c = a;\
                         a = b;\
                         a = c

http://www.viva64.com/en/a/0076/

>>1
What's wrong with:

inline void Swap(int *a, int *b)
{
    a ^= b;
    b ^= a;
    a ^= b;
}

>>7

xor swap fails if you happen to call it with two pointers to the same address, so it might be good to have


inline void swap(int *a, int *b) {
  if(a != b) {
    *a ^= *b;
    *b ^= *a;
    *a ^= *b;
  }
}

although the check will have a certain amount of cost, and a smart program shouldn't try to swap the contents of a single memory address.