/in/foo.cc: In function 'int main()':
/in/foo.cc:40:16: warning: 'd' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<c<<" "<<d<<endl;
                ^
/in/foo.cc:40:11: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<c<<" "<<d<<endl;
           ^~~