foo.cc: In member function ‘SeqList SeqList::intersection(const SeqList&) const’:
foo.cc:21:18: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   21 |         while (i < sortedA.size() && j < sortedB.size()) {
      |                ~~^~~~~~~~~~~~~~~~
foo.cc:21:40: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   21 |         while (i < sortedA.size() && j < sortedB.size()) {
      |                                      ~~^~~~~~~~~~~~~~~~