/in/foo.cc: In function 'int main()':
/in/foo.cc:7:2: warning: 'r' is used uninitialized in this function [-Wuninitialized]
  if(r==A)
  ^~
/in/foo.cc:7:2: warning: 'A' is used uninitialized in this function [-Wuninitialized]
/in/foo.cc:9:2: warning: 'P' is used uninitialized in this function [-Wuninitialized]
  if(r==P)
  ^~