Algorithm to swap two values of the same data type.


#include <algorithm>

#include <cassert>



int main()

{

  int a = 3;

  int b = 7;

  std::swap(a,b);

  assert(a == 7);

  assert(b == 3);

}

Consider specializing std::swap for your own classes when you know a more efficient way to exhange their values by calling operator= three times [1].

Example definition


template <class T>

inline void swap(T& a, T& b)

{

  const T tmp = a;

  a = b;

  b = tmp;

}

XOR swap

The XOR swap is another way to swap two values. Prefer using std::swap [2].


void XorSwap (int *x, int *y) 

{

  if (x != y) 

  {

    *x ^= *y;

    *y ^= *x;

    *x ^= *y;

  }

}

Herb Sutter. Exceptional C++ style. 2005. ISBN: 0-201-76042-8. Item 6 guideline: 'consider specializing std::swap for your own types when objects of your type have a way to exhange their values more efficiently than via brute-force assignment'.
big_bad_al: How to swap two integers in C++: 'If you use the xor trick to swap integers, STOP IT!'