Example for WordPress Post https://congdanhqx.wordpress.com/2016/07/07/hey-guys-dont-try-to-be-smart-with-swap/

swap.cpp

#include <memory>

int a;
int b;
void swap1(void) 
{
  int t = a;
  a = b;
  b = t;
}

// Don't try to be smart guy
void swap2(void) 
{
  a ^= b;
  b ^= a;
  a ^= b;
}

// Don't try to be smart guy
void swap3(void)
{
  b += a;
  a = b - a;
  b -= a;
}

// Obviously, this can be done only in C++
void swap4(void)
{
  std::swap(a, b);
}