Use iterators to swap elements at locations 0 and 1 of an array : iter_swap « STL Algorithms Modifying sequence operations « C++ Tutorial

1. C++ Tutorial
2. STL Algorithms Modifying sequence operations
3. iter_swap

#include <iostream>
using std::cout;
using std::endl;

#include <algorithm>
#include <iterator>

int main()
{
   int a[ 10 ] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
   std::ostream_iterator< int > output( cout, " " );

   cout << "Array a contains:\n   ";
   std::copy( a, a + 10, output );


   std::iter_swap( &a[ 0 ], &a[ 1 ] ); // swap with iterators
   cout << "\nArray a after swapping a[0] and a[1] using iter_swap:\n   ";
   std::copy( a, a + 10, output );

   cout << endl;
   return 0;
}

Array a contains:
   1 2 3 4 5 6 7 8 9 10
Array a after swapping a[0] and a[1] using iter_swap:
   2 1 3 4 5 6 7 8 9 10