anchor.diff:       ,@(loop for constant in constants
                collect `(export ',(car constant))
                collect `(defconstant ,@constant))))
  +
  +(defmacro defcstruct-export (name &body slots)
  +  `(progn
  +     (defcstruct ,name
  +       ,@slots)
  +     (export ',name)
  +     ,@(loop for slot in slots
  +             collect `(export ',(car slot)))))
   
   #| cl-platform.h |#
   (defctypes
  
positive.code:   (cl-command-type cl-uint)
    (cl-profiling-info cl-uint))
  
  (defcstruct cl-image-format
    (image-channel-order cl-channel-order)
    (image-channel-data-type cl-channel-type))
  
  (defcstruct cl-image-desc
    (image-type cl-mem-object-type)
    (image-width size-t)
    (image-height size-t)
  
negative.code:   (num-samples cl-uint)
    (buffer cl-mem))
  
  (defcstruct-export cl-buffer-region
    (origin size-t)
    (size size-t))
  
  