(library (r7b-util metadata)
         (export metadata-set!
                 metadata-ref)
         (import (rnrs) (r7b-util weak-eq-hashtable))
(define store (make-weak-eq-hashtable))
(define (metadata-set! obj datum)
  (weak-hashtable-set! store obj datum))
(define (metadata-ref obj)
  (weak-hashtable-ref store obj))
)