swap_ranges


Category: algorithms	Component type: function

Prototype

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

Description

Swap_ranges swaps each of the elements in the range [first1, last1) with the corresponding element in the range [first2, first2 + (last1 - first1)). That is, for each integer n such that 0 <= n < (last1 - first1), it swaps *(first1 + n) and *(first2 + n). The return value is first2 + (last1 - first1).

Definition

Defined in algo.h.

Requirements on types

ForwardIterator1 and ForwardIterator2 must both be models of Forward Iterator. The value types of ForwardIterator1 and ForwardIterator2 must be convertible to each other.

Preconditions

[first1, last1) is a valid range.
[first2, first2 + (last1 - first1)) is a valid range.
The two ranges [first1, last1) and [first2, first2 + (last1 - first1)) do not overlap.

Complexity

Linear. Exactly last1 - first1 swaps are performed.

Example

vector<int> V1, V2;
V1.push_back(1);
V1.push_back(2);
V2.push_back(3);
V2.push_back(4);

assert(V1[0] == 1 && V1[1] == 2 && V2[0] == 3 && V2[1] == 4);
swap_ranges(V1.begin(), V1.end(), V2.begin());
assert(V1[0] == 3 && V1[1] == 4 && V2[0] == 1 && V2[1] == 2);