Standard C++ Library Copyright 1998, Rogue Wave Software, Inc.

set_symmetric_difference- A basic set operation for constructing a sorted symmetric difference.

#include <algorithm> template <class InputIterator1, class InputIterator2, class OutputIterator> OutputIterator set_symmetric_difference (InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result); template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare> OutputIterator set_symmetric_difference (InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);

set_symmetric_difference constructs a sorted symmetric difference of the elements from the two ranges. This means that the constructed range includes copies of the elements that are present in the range [first1,last1) (but not present in the range [first2,last2)) and copies of the ele- ments that are present in the range [first2,last2) (but not in the range [first1,last1)). It returns the end of the constructed range. For example, suppose we have two sets:12345and34567The set_symmetric_difference of these two sets is:1267The result of set_symmetric_difference is undefined if the result range overlaps with either of the original ranges. set_symmetric_difference assumes that the ranges are sorted using the default comparison operator less than (<), unless an alternative comparison operator (comp) is provided. Use the set_symmetric_difference algorithm to return a result that includes elements that are present in the first set and not in the second.

At most ((last1-first1) + (last2-first2)) *2-1com- parisons are performed.

// // set_s_di.cpp // #include<algorithm> #include<set> #include <istream.h> using namespace std; int main() { //Initialize some sets int a1[] = {1,3,5,7,9,11}; int a3[] = {3,5,7,8}; set<int, less<int> > odd(a1+0,a1+6), result, small(a3+0,a3+4); //Create an insert_iterator for result insert_iterator<set<int, less<int> > > res_ins(result, result.begin()); //Demonstrate set_symmetric_difference cout << "The symmetric difference of:" << endl << "{"; copy(small.begin(),small.end(), ostream_iterator<int,char>(cout," ")); cout << "} with {"; copy(odd.begin(),odd.end(), ostream_iterator<int,char>(cout," ")); cout << "} =" << endl << "{"; set_symmetric_difference(small.begin(), small.end(), odd.begin(), odd.end(), res_ins); copy(result.begin(),result.end(), ostream_iterator<int,char>(cout," ")); cout << "}" << endl << endl; return 0; } Program Output The symmetric difference of: {3 5 7 8 } with {1 3 5 7 9 11 } = {1 8 9 11 }

If your compiler does not support default template parame- ters, then you always need to supply theComparetemplate argument and theAllocatortemplate argument. For instance, you need to write:set<int,less<int>,allocator<int> > instead of:set<int> If your compiler does not support namespaces, then you do not need the using declaration forstd.

includes, set, set_union, set_intersection, set_difference