(declare (foreign-declare "C_extern void registerfunc(C_word,C_word,C_word) C_noret;"))
(define reg (##core#primitive "registerfunc"))
(reg)

(define a (create-foo 2))
(define b (create-foo 4))
(set! a #f)
;;(gc #t)
(set! b #f)
(gc #t)
(exit)