template<class ForwardIterator1, class ForwardIterator2>
ForwardIterator2
swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
ForwardIterator2
swap_ranges(ExecutionPolicy&& exec,
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2);
Requires: The two ranges [first1, last1) and [first2, first2 + (last1 - first1)) shall not overlap. *(first1 + n) shall be swappable with ([swappable.requirements]) *(first2 + n).
Effects: For each non-negative integer n < (last1 - first1) performs: swap(*(first1 + n), *(first2 + n)).
Returns: first2 + (last1 - first1).
Complexity: Exactly last1 - first1 swaps.
template<class ForwardIterator1, class ForwardIterator2>
void iter_swap(ForwardIterator1 a, ForwardIterator2 b);
Requires: a and b shall be dereferenceable. *a shall be swappable with ([swappable.requirements]) *b.
Effects: As if by swap(*a, *b).