foo.cc: In member function ‘polylist polylist::operator+(polylist&)’:
foo.cc:30:26: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<polylistnode>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   30 |                 while (i < v1.size() && j < v2.size())
      |                        ~~^~~~~~~~~~~
foo.cc:30:43: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<polylistnode>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   30 |                 while (i < v1.size() && j < v2.size())
      |                                         ~~^~~~~~~~~~~
foo.cc:42:26: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<polylistnode>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   42 |                 while (i < v1.size())
      |                        ~~^~~~~~~~~~~
foo.cc:44:26: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<polylistnode>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   44 |                 while (j < v2.size())
      |                        ~~^~~~~~~~~~~