在一般的程序开发过程中，类或者类库往往是以动态库的形式向用户发布的，所以在程序发布之前必须对程序中的所有函数进行集成测试

1 ）测试头文件给出的Utility类中所有的成员函数

2 ）用四种方式完成1，继承 2，友元 3，访问声明 4，using声明

-Classes or class libraries in the program development process, often based on a dynamic library released to the user, so all the functions in the program must be in the program before the release of the Utility class integration testing) test given by the header file All member functions) with four ways to complete an inherited friend 3 access statement, the using statement