/in/foo.cc: In function 'int main()':
/in/foo.cc:22:17: warning: 'd' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<c<<" "<<d;
                 ^
/in/foo.cc:22:11: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<c<<" "<<d;
           ^~~