/in/foo.cc: In function 'std::__cxx11::string gettime(std::__cxx11::string)':
/in/foo.cc:14:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int j = tmp; j < s.size(); j++)
                    ~~^~~~~~~~~~
/in/foo.cc:28:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int change(std::__cxx11::string, make*, int)':
/in/foo.cc:104:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^