void varargs/apply.
(define-macro (hashx-invoke hashx-proc ht-var . args)
  "Invoke HASHX-PROC, a `hashx-*' procedure taking a hash-function,
assoc-function, and the hash-table as first args."
  `(,hashx-proc (hash-table-hash-function ,ht-var)
		(ht-associator ,ht-var)
		(ht-real-table ,ht-var)
		. ,args))

(define-macro (with-hashx-values bindings ht-var . body-forms)
  "Bind BINDINGS to the hash-function, associator, and real-table of
HT-VAR, while evaluating BODY-FORMS."
  `(let ((,(first bindings) (hash-table-hash-function ,ht-var))
	 (,(second bindings) (ht-associator ,ht-var))
	 (,(third bindings) (ht-real-table ,ht-var)))
     . ,body-forms))