/in/foo.cc: In function 'std::vector<int> operator+(std::vector<int>&, std::vector<int>&)':
/in/foo.cc:12:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |     for (int i = 0; i < a.size(); i++)
      |                     ~~^~~~~~~~~~
/in/foo.cc:15:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |         if (i < b.size()) t += b[i];
      |             ~~^~~~~~~~~~
/in/foo.cc: In function 'std::vector<int> operator*(std::vector<int>&, std::vector<int>&)':
/in/foo.cc:26:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |     for (int i = 0; i < a.size(); i++)
      |                     ~~^~~~~~~~~~
/in/foo.cc:28:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |         for (int j = 0; j < b.size(); j++)
      |                         ~~^~~~~~~~~~
/in/foo.cc:33:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |     for (int i = 0; i < c.size()-1; i++)
      |                     ~~^~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:62:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |     for (int i = 0; i < s.size(); i++)
      |                     ~~^~~~~~~~~~