anchor.diff:                                      size
                                       host-ptr
                                       errcode-ret)))
  -      (if (= +cl-success+ (mem-aref errcode-ret 'cl-int))
  -          buffer
  -          (api-error 'cl-create-buffer
  -                     (mem-aref errcode-ret 'cl-int))))))
  +      (check-errcode-ret buffer 'cl-create-buffer errcode-ret))))
  
positive.code:                                       pfn-notify
                                        user-data
                                        errcode-ret)))
        (if (= +cl-success+ (mem-aref errcode-ret 'cl-int))
            context
            (api-error 'cl-create-context
                       (mem-aref errcode-ret 'cl-int))))))
  
  @export
  (defun create-buffer (context flags size &optional (host-ptr (null-pointer)))
  
negative.code: (defun api-error (name code)
    (when *oclapi-helper-error*
      (error "~s error ~s" name code)))
  
  (defun check-errcode-ret (result name errcode-ret)
    (let ((code (mem-aref errcode-ret 'cl-int)))
      (if (= +cl-success+ code)
          result
          (api-error name code))))
  
  @export
  (defmacro when-success (expr &body body)
  