swap_ranges(3C++)

Standard C++ Library
Copyright 1998, Rogue Wave Software, Inc.

NAME

swap_ranges

- Exchanges a range of values in one location with those in another.

SYNOPSIS

#include <algorithm>
template <class ForwardIterator1, class ForwardIterator2>

ForwardIterator2

swap_ranges (ForwardIterator1 first1,

ForwardIterator1 last1,
ForwardIterator2 first2);

DESCRIPTION

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 (in other words, first2 + (last1 -first1)). The result of swap_ranges is undefined if the two ranges [first, last) and [first2, first2 + (last1 - first1)) overlap.

EXAMPLE

//
// swap.cpp
//
#include <vector>
#include <algorithm>
#include <iostream>
using namespace std;

int main()
{
int d1[] = {6, 7, 8, 9, 10, 1, 2, 3, 4, 5};
// Set up a vector
vector<int> v(d1+0,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;
}

Program 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

WARNINGS

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

vector<int, allocator<int> >

instead of:

vector<int>

If your compiler does not support namespaces, then you do not need the using declaration for std.