;;;; -*- Mode: lisp; indent-tabs-mode: nil -*-
;;;
;;; union.lisp --- Tests on C unions.
;;;

;;; Copyright (C) 2005-2006, James Bielman  <jamesjb@jamesjb.com>

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;;;
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(in-package #:cffi-tests)

(defcunion uint32-bytes
  (int-value :unsigned-int)

  (bytes :unsigned-char :count 4))

(defctype uint32-bytes (:union uint32-bytes))

(defun int-to-bytes (n)
  "Convert N to a list of bytes using a union."

  (with-foreign-object (obj 'uint32-bytes)

    (setf (foreign-slot-value obj 'uint32-bytes 'int-value) n)
    (loop for i from 0 below 4

          collect (mem-aref

                   (foreign-slot-value obj 'uint32-bytes 'bytes)
                   :unsigned-char i))))