anchor.diff:                (progn ,@body)
              (update-task-count ,kernel -1))))))
   
  -(defmacro/once force/fast (&once future)
  +(defmacro force/fast (future)
  +  (check-type future symbol)
     `(loop
         (when (fulfilledp ,future)
           (return (force ,future)))
  
positive.code: (defun/type update-task-count/no-lock (kernel delta) (kernel fixnum) t
    (declare #.*normal-optimize*)
    (with-optimizer-slots (optimizer-data optimizer-flag) kernel
      (with-task-counter-slots (task-count) optimizer-data
        (incf task-count delta)
        ;; optimizer-flag == accept-task-p
        ;; `<' returns generalized boolean
        (setf optimizer-flag (to-boolean
                              (<= task-count (%kernel-worker-count kernel)))))))
  
  (defun/type update-task-count (kernel delta) (kernel fixnum) t
    (declare #.*normal-optimize*)
    (with-optimizer-slots (optimizer-data) kernel
      (with-task-counter-slots (lock) optimizer-data
        (with-lock-held (lock)
          (update-task-count/no-lock kernel delta)))))
  
  (defmacro future/fast (&body body)
    (with-gensyms (kernel)
  
negative.code: (defvar *registered-fns* nil)
  
  (defun unchecked-name (name)
    (intern (conc-syms '#:%p name '#:/no-check) (symbol-package name)))
  
  (defun defpun-loaded-p (name)
    (ignore-errors
  