利用命名空间来解决例14.4程序名字冲突问题。 修改两个头文件，把在头文件中声明的类分别放在两个不同的命名空间中。-The use of namespace to resolve the cases of conflict in the name of 14.4 procedures. Modify the first two documents, the documents stated in the first class, respectively, on two different