< cpp‎ | algorithm
Defined in header <algorithm>
template< class ForwardIt1, class ForwardIt2 >
ForwardIt2 swap_ranges( ForwardIt1 first1, ForwardIt1 last1, ForwardIt2 first2 );

Exchanges elements between range [first1, last1) and another range starting at first2.


[edit] Parameters

first1, last1 - the first range of elements to swap
first2 - beginning of the second range of elements to swap
Type requirements
ForwardIt1, ForwardIt2 must meet the requirements of ForwardIterator.
The types of dereferenced ForwardIt1 and ForwardIt2 must meet the requirements of Swappable

[edit] Return value

Iterator to the element past the last element exchanged in the range beginning with first2.

[edit] Possible implementation

template<class ForwardIt1, class ForwardIt2>
ForwardIt2 swap_ranges(ForwardIt1 first1, 
                             ForwardIt1 last1, 
                             ForwardIt2 first2)
    while (first1 != last1) {
        std::iter_swap(first1++, first2++);
    return first2;

[edit] Example

Demonstrates swapping of subranges from different containers

#include <algorithm>
#include <list>
#include <vector>
#include <iostream>
int main()
    std::vector<int> v = {1, 2, 3, 4, 5};
    std::list<int> l = {-1, -2, -3, -4, -5};
    std::swap_ranges(v.begin(), v.begin()+3, l.begin());
    for(int n : v)
       std::cout << n << ' ';
    std::cout << '\n';
    for(int n : l)
       std::cout << n << ' ';
    std::cout << '\n';


-1 -2 -3 4 5
1 2 3 -4 -5

[edit] Complexity

linear in the distance between first and last

[edit] See also

swaps the elements pointed to by two iterators
(function template) [edit]
swaps the values of two objects
(function template) [edit]
parallelized version of std::swap_ranges
(function template) [edit]