/in/foo.cc: In function 'int main()':
/in/foo.cc:6:3: warning: 'a' is used uninitialized in this function [-Wuninitialized]
  c=a;
  ~^~
/in/foo.cc:7:5: warning: 'b' is used uninitialized in this function [-Wuninitialized]
  a=b;
     ^