swap_ranges

Algorithm

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• Data Type and Member Function Indexes
• Synopsis
• Description
• Example
• Warning
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Exchange a range of values in one location with those in another

None

#include <algorithm>

template <class ForwardIterator1, class ForwardIterator2>
ForwardIterator2 swap_ranges (ForwardIterator1 first1,
                              ForwardIterator1 last1,
                              ForwardIterator2 first2);

The swap_ranges algorithm exchanges corresponding values in two ranges, in the following manner:

For each non-negative integer n < (last - first) the function exchanges *(first1 + n) with *(first2 + n)). After completing all exchanges, swap_ranges returns an iterator that points to the end of the second container, i.e., first2 + (last1 -first1). The result of swap_ranges is undefined if the two ranges [first, last) and [first2, first2 + (last1 - first1)) overlap.

//
// swap.cpp
//
 #include <vector>
 #include <algorithm>

 int main()
 {
   int d1[] = {6, 7, 8, 9, 10, 1, 2, 3, 4, 5};

   // Set up a vector
   vector<int> v(d1,d1 + 10);

   // Output original vector
   cout << "For the vector: ";
   copy(v.begin(),v.end(),ostream_iterator<int,char>(cout," "));

   // Swap the first five elements with the last five elements
   swap_ranges(v.begin(),v.begin()+5, v.begin()+5);

   // Output result
   cout << endl << endl
        << "Swapping the first five elements "
        << "with the last five gives: "
        << endl << "     ";
   copy(v.begin(),v.end(),ostream_iterator<int,char>(cout," "));

   return 0;
 }

Output :
For the vector: 6 7 8 9 10 1 2 3 4 5
Swapping the first five elements with the last five gives:
     1 2 3 4 5 6 7 8 9 10
Swapping the first and last elements gives:
     10 2 3 4 5 6 7 8 9 1

If your compiler does not support default template parameters, you need to always supply the Allocator template argument. For instance, you will need to write :

vector<int, allocator<int> >

instead of :

vector<int>

iter_swap, swap

©Copyright 1996, Rogue Wave Software, Inc.