/in/foo.cc: In function 'std::vector<int> mult(std::vector<int>, int)':
/in/foo.cc:8:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i1 = 0; i1 < m.size(); i1++)
                  ~~~^~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:32:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(i4 = 0; i4 < m.size(); ++i4)
               ~~~^~~~~~~~~~
/in/foo.cc:39:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i4 != m.size())
      ~~~^~~~~~~~~~~
/in/foo.cc:42:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(i4 = 0; i4 < m.size(); ++i4)
               ~~~^~~~~~~~~~
/in/foo.cc:49:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i4 != m.size())
      ~~~^~~~~~~~~~~
/in/foo.cc:55:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(i4 = 0; i4 < m.size(); ++i4)
               ~~~^~~~~~~~~~
/in/foo.cc:62:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i4 != m.size())
      ~~~^~~~~~~~~~~
/in/foo.cc:64:7: warning: unused variable 'num' [-Wunused-variable]
   int num = i1 * 100 + i2 * 10 + i3;
       ^~~