/in/foo.cc: In function 'int main()':
/in/foo.cc:8:9: warning: unused variable 'b' [-Wunused-variable]
  int a, b;
         ^
/in/foo.cc:9:10: warning: 'a' is used uninitialized in this function [-Wuninitialized]
  cout << a << endl;
          ^