/in/foo.cc: In function 'int main()':
/in/foo.cc:21:24: warning: 'y0' may be used uninitialized in this function [-Wmaybe-uninitialized]
   cout << x0 << " " << y0 << endl;
                        ^~
/in/foo.cc:21:17: warning: 'x0' may be used uninitialized in this function [-Wmaybe-uninitialized]
   cout << x0 << " " << y0 << endl;
                 ^~~