(C++) std::set_symmetric_difference

 

std::set_symmetric_difference is an STL algorithm to obtain the elements from two containers which are in only one of these containers.

 

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#include <algorithm> #include <cassert> #include <vector> int main() {   std::vector<int> evens;   evens.push_back(2);   evens.push_back(4);   std::vector<int> primes;   primes.push_back(2);   primes.push_back(3);   std::vector<int> result;   std::set_symmetric_difference(     evens.begin(),evens.end(),     primes.begin(), primes.end(),     std::back_inserter(result));   //Assume that the result consists of   //- a '3' (a non-even prime)   //- a '4' (a non-prime even)   assert(result.size() == 2);   assert(result[0] == 3 || result[0] == 4);   assert(result[1] == 3 || result[1] == 4);   assert(result[0] != result[1]); }