anchor.diff:                               &optional (byte-offset 0))
     (let ((id-name (gensym)))
       (make-assigner
  +     :always-uploadp (varjo:v-typep type :bool)
        :let-forms
        (list (make-assigner-let
               :name id-name
  
positive.code: 
  
  (defun+ make-assigner (&key let-forms uploaders pointer-arg
                          arg-name local-arg-name cleanup)
    (make-instance 'assigner :let-forms let-forms :uploaders uploaders
                   :pointer-arg pointer-arg :arg-name arg-name
                   :local-arg-name local-arg-name
                   :cleanup cleanup))
  
  (defun+ merge-into-assigner (pointer-arg assingers)
    (make-assigner :let-forms (mapcat #'let-forms assingers)
  
negative.code:       (remove nil (mapcar #'inner uniform-args)))))
  
  (defmethod gen-uploaders-block ((assigner assigner))
    (with-slots (arg-name local-arg-name always-uploadp) assigner
  
      `(,@(if always-uploadp
              '(progn)
              `(when ,arg-name))
         (let ((,local-arg-name ,(if (pointer-arg assigner)
                                     `(pointer ,arg-name)
                                     arg-name)))
  