function template

std::iter_swap

<algorithm>
template <class ForwardIterator1, class ForwardIterator2>
  void iter_swap ( ForwardIterator1 a, ForwardIterator2 b );
Exchange values of objects pointed by two iterators
Assigns the content of *a to *b and the content of *b to *a.

The behavior of this function template is equivalent to:
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template <class ForwardIterator1, class ForwardIterator2>
  void iter_swap ( ForwardIterator1 a, ForwardIterator2 b )
{
  swap (*a, *b);
}


Parameters

a, b
Forward iterators to the objects whose contents are swapped.

Return value

none

Example

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// iter_swap example
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

int main () {

  int myints[]={10,20,30,40,50 };          //   myints:  10  20  30  40  50
  vector<int> myvector (4,99);             // myvector:  99  99  99  99

  iter_swap(myints,myvector.begin());      //   myints: [99] 20  30  40  50
                                           // myvector: [10] 99  99  99

  iter_swap(myints+3,myvector.begin()+2);  //   myints:  99  20  30 [99]
                                           // myvector:  10  99 [40] 99

  cout << "myvector contains:";
  for (vector<int>::iterator it=myvector.begin(); it!=myvector.end(); ++it)
    cout << " " << *it;

  cout << endl;

  return 0;
}


Output:
myvector contains: 10 99 40 99

Complexity

Constant: Performs exactly one copy construction and two assignments (although notice that each of these operations works on its own complexity).

See also