摘要：
大致看完这篇文章，感觉非常好，人家才四年C++，已经达到此水平，佩服。原文位于：http://www.artima.com/cppsource/cooperative_visitor.htmlThis article presents a flexible and efficient variation of the Visitor design pattern in C++ that accommodates arbitrary argument and return types.The Visitor pattern provides a way to add new polymorphi 阅读全文
