anchor.diff:    1
     2)
   
  -(defcstruct (struct-pair+double :class pair+double)
  +(defcstruct (struct-pair+double)
     (pr (:struct struct-pair-default-translate))
     (dbl :double))
   
  
positive.code:     (pair-plus-one-pointer-sum '((1 . 2) . 3))
    6)
  
  #+#:unimplemented
  (defcfun "make_pair_plus_one" (:struct pair+1)
    (a :int)
    (b :int)
    (c :int))
  
  (defcfun "alloc_pair_plus_one" struct-pair+1
    (a :int)
    (b :int)
    (c :int))
  
negative.code: (defcfun "pair_plus_one_sum" :int
    (p (:struct pair+1)))
  
  #+#:unused
  (defcfun "pair_plus_one_pointer_sum" :int
    (p (:pointer (:struct struct-pair+1))))
  
  