用ACYCLIC VISITOR解决Shape排序的问题

[swimmer2000]

看电子书《Agile-Principles-Patterns-and-Practices-in-C#》的第176页（OCP一章），有这样一句：
It is possible to solve this problem by using the ACYCLIC VISITOR pattern described in Chapter 35. Showing that solution now
would be getting ahead of ourselves a bit. I'll remind you to come back here at the end of that chapter.

有哪位大侠能展示一下如何使用ACYCLIC VISITOR模式解决Shape排序输出的问题吗？
最好有UML图或者示例代码。

谢谢！

[swimmer2000]

我想到了一个方案，在我博客http://blog.csdn.net/swimmer2000/article/details/51372285里， 如果没人评论，过几天我就结贴。