;; create the errmsg ptr that is passed to most leveldb operations
  (define-location (errmsg c-string))
  ((foreign-lambda void ((c-string val)) "val = NULL;")
    (location errmsg))

  (define (leveldb-open)
    (let ((leveldb* ((foreign-lambda
                       (c-pointer (struct "leveldb_t"));; The return type of the C function we're binding:
                       leveldb_open ;; The name of the C function we're binding:
                       (c-pointer (struct "leveldb_options_t")) ;; param 1
                       c-string                                 ;; param 2
                       errmsg ))))
      (if leveldb*
        (set-finalizer! (make-leveldb leveldb*) leveldb-close)
        (error errmsg))))