/in/foo.cc:12:7: error: extra qualification 'Complex::' on member 'operator<' [-fpermissive]
  bool Complex::operator<(Complex &c)
       ^~~~~~~
/in/foo.cc:16:7: error: extra qualification 'Complex::' on member 'operator>' [-fpermissive]
  bool Complex::operator>(Complex &c)
       ^~~~~~~
/in/foo.cc: In member function 'void Complex::Output()':
/in/foo.cc:27:26: warning: format '%d' expects a matching 'int' argument [-Wformat=]
    printf("%d+%di\n",real);
                          ^