#include <iostream>
 
#define myswap(a, b) do { (a) ^= (b); (b) ^= (a); (a) ^= (b); } while(0)
 
template<typename T> void myswap2(T &a, T &b) {
  a = a ^ b;
  b = a ^ b;
  a = a ^ b;
}
 
int main() {
  int a = 3, b = 5;
  std::cout << "a = " << a << ", b = " << b << std::endl;
  myswap(a, b);
  std::cout << "a = " << a << ", b = " << b << std::endl;
  a = 4;
  std::cout << "a = " << a << std::endl;
  myswap(a, a);
  std::cout << "a = " << a << std::endl;
  return 0;
}
/* end */
 

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