(defmacro symbol-macroletf (((symbol place)) &body body
                            &environment environment)
  "Like SYMBOL-MACROLET but evaluate subforms just once up front.
Binding multiple symbols in the same form has not yet been implemented."
  (multiple-value-bind (vars vals store-vars writer-form reader-form)
      (get-setf-expansion place environment)
    (let ((route (gensym (string symbol))))
      `(let* (,@(mapcar #'list vars vals))
         (flet ((,route () ,reader-form)
                ((setf ,route) (,(first store-vars)) ,writer-form))
           (symbol-macrolet ((,symbol (,route)))
             ,@body))))))

;; this works OK
(let ((x 0)
      (v (copy-seq '(totally alone again))))
  (symbol-macroletf ((s (elt v (incf x))))
    (values (shiftf s 'wasted) s v)))

;; this doesn't
(let ((x 0)
      (v (copy-seq '(totally alone again))))
  (symbol-macroletf ((s (values (elt v (incf x))
                                (elt v (incf x)))))
    (shiftf s (values 'successful 'incubation))))