class formation

• 类构造

class formation的用法和样例：

例句

1. The destructor is a special member function that can be used to do whatever resource deallocation is needed.It serves as the complement to the constructors of the class.
   析构函数就是这样的一个特殊函数，它可以完成所需的资源回收，作为类构造函数的补充。