cppreference.com > C++ Algorithms > set_symmetric_difference set_symmetric_difference Syntax:
      #include <algorithm>
      iterator set_symmetric_difference( iterator start1, iterator end1, iterator start2, iterator end2, iterator result );
      iterator set_symmetric_difference( iterator start1, iterator end1, iterator start2, iterator end2, iterator result, StrictWeakOrdering cmp );
The set_symmetric_difference() algorithm computes the symmetric difference of the two sets defined by [start1,end1) and [start2,end2) and stores the difference starting at result. Both of the sets, given as ranges, must be sorted in ascending order. The return value of set_symmetric_difference() is an iterator to the end of the result range. If the strict weak ordering comparison function object cmp is not specified, set_symmetric_difference() will use the < operator to compare elements. Related topics: includes set_difference set_intersection set_union