设计一个用于人事管理的“人员”类。由于考虑到通用性，这里只抽象出所有类型人员都具有的属性：编号、性别、出生日期、身份证号等。其中“出生日期”声明为一个“日期”类内嵌子对象。用成员函数实现对人员信息的录入和显示。要求包括：构造函数和析构函数、复制构造函数、内联成员函数、带默认形参值的成员函数、类的组合。

-Personnel management for the design of a " people"　category. Taking into account the versatility, here only the abstract all types of personnel have attributes: number, gender, date of birth, identity card number. The " date of birth"　is declared as a " date"　class inline child objects. With member functions to achieve the personnel information input and display. Requirements include: the constructor and destructor, copy constructor, inline member functions, member functions with default parameter values, class combination.