/in/foo.cc: In function 'std::__cxx11::string sDiv(std::__cxx11::string, std::__cxx11::string)':
/in/foo.cc:89:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 while (nAi <= sA.size())
        ~~~~^~~~~~~~~~~~
/in/foo.cc:100:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 if (nAi != sA.size())
     ~~~~^~~~~~~~~~~~
/in/foo.cc: In function 'std::__cxx11::string sSub(std::__cxx11::string, std::__cxx11::string)':
/in/foo.cc:123:22: warning: unused variable 'j' [-Wunused-variable]
 int nLenA, nLenB, i, j, nSub = 0, nA, nB;
                      ^
/in/foo.cc: In function 'std::__cxx11::string sAtimesB(std::__cxx11::string, std::__cxx11::string)':
/in/foo.cc:61:5: warning: 'nC' may be used uninitialized in this function [-Wmaybe-uninitialized]
 nC--;
     ^