25 Algorithms library [algorithms]

25.7 Sorting and related operations [alg.sorting]

25.7.6 Set operations on sorted structures [alg.set.operations]

25.7.6.5 set_­symmetric_­difference [set.symmetric.difference]

template<class InputIterator1, class InputIterator2, class OutputIterator> constexpr OutputIterator set_symmetric_difference(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result); template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2, class ForwardIterator> ForwardIterator set_symmetric_difference(ExecutionPolicy&& exec, ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2, ForwardIterator result); template<class InputIterator1, class InputIterator2, class OutputIterator, class Compare> constexpr OutputIterator set_symmetric_difference(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp); template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2, class ForwardIterator, class Compare> ForwardIterator set_symmetric_difference(ExecutionPolicy&& exec, ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2, ForwardIterator result, Compare comp); template<InputIterator I1, Sentinel<I1> S1, InputIterator I2, Sentinel<I2> S2, WeaklyIncrementable O, class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity> requires Mergeable<I1, I2, O, Comp, Proj1, Proj2> constexpr ranges::set_symmetric_difference_result<I1, I2, O> ranges::set_symmetric_difference(I1 first1, S1 last1, I2 first2, S2 last2, O result, Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}); template<InputRange R1, InputRange R2, WeaklyIncrementable O, class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity> requires Mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2> constexpr ranges::set_symmetric_difference_result<safe_iterator_t<R1>, safe_iterator_t<R2>, O> ranges::set_symmetric_difference(R1&& r1, R2&& r2, O result, Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
Let comp be less{}, and proj1 and proj2 be identity{} for the overloads with no parameters by those names.
Requires: The resulting range shall not overlap with either of the original ranges.
The ranges [first1, last1) and [first2, last2) shall be sorted with respect to comp and proj1 or proj2, respectively.
The resulting range shall not overlap with either of the original ranges.
Effects: Copies the elements of the range [first1, last1) that are not present in the range [first2, last2), and the elements of the range [first2, last2) that are not present in the range [first1, last1) to the range beginning at result.
The elements in the constructed range are sorted.
Returns: Let result_­last be the end of the constructed range.
Returns
  • result_­last for the overloads in namespace std, or
  • {last1, last2, result_­last} for the overloads in namespace ranges.
Complexity: At most 2 * ((last1 - first1) + (last2 - first2)) - 1 comparisons and applications of each projection.
Remarks: Stable ([algorithm.stable]).
If [first1, last1) contains m elements that are equivalent to each other and [first2, last2) contains n elements that are equivalent to them, then of those elements shall be copied to the output range: the last of these elements from [first1, last1) if , and the last of these elements from [first2, last2) if .
In either case, the elements are copied in order.