/in/foo.cc: In function 'int main()':
/in/foo.cc:44:58: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     pair<int, pair<string, string> > cat = make_pair(pos == string::npos ? 1 : 0, make_pair(name, prefix));
                                                      ~~~~^~~~~~~~~
/in/foo.cc:48:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    } while (pos != string::npos);
             ~~~~^~~~~~~~~