c++程序语言设计，编写代码

Question

图一所示，Manager类重复继承了Person类的信息，这增加了Manager类在数据一致性维护上的系统开销。图二所示，使用虚基类避免了数据冗余。根据图二编程实现Manager类对象的创建和撤销，并考察在此过程中各类构造函数和析构函数的调用顺序。

Answer 1

#include <iostream>
#include <string>

#define output()                                  \
    do                                            \
    {                                             \
        std::cout << __PRETTY_FUNCTION__ << '\n'; \
    } while (0)

class Person
{
public:
    Person() { output(); }
    virtual ~Person() { output(); }

private:
    std::string _name;
    int _id;
    std::string _tel;
};

class Stuff1 : public Person
{
public:
    Stuff1() { output(); }
    virtual ~Stuff1() { output(); }

private:
    std::string _post;
};

class Technician1 : public Person
{
public:
    Technician1() { output(); }
    virtual ~Technician1() { output(); }

private:
    std::string _major;
};

class Manager1 : public Stuff1, public Technician1
{
public:
    Manager1() { output(); }
    virtual ~Manager1() { output(); }
};

class Stuff2 : virtual public Person
{
public:
    Stuff2() { output(); }
    virtual ~Stuff2() { output(); }

private:
    std::string _post;
};

class Technician2 : virtual public Person
{
public:
    Technician2() { output(); }
    virtual ~Technician2() { output(); }

private:
    std::string _major;
};

class Manager2 : public Stuff2, public Technician2
{
public:
    Manager2() { output(); }
    virtual ~Manager2() { output(); }
};
int main()
{
    {
        std::cout << "The invoke order of constructors and destructors for class Manager1:\n";
        Manager1 m;
    }
    {
        std::cout << "The invoke order of constructors and destructors for class Manager2:\n";
        Manager2 m;
    }
    return 0;
}

编译运行输出

$ g++ -Wall main.cpp -o main
$ ./main
The invoke order of constructors and destructors for class Manager1:
Person::Person()
Stuff1::Stuff1()
Person::Person()
Technician1::Technician1()
Manager1::Manager1()
virtual Manager1::~Manager1()
virtual Technician1::~Technician1()
virtual Person::~Person()
virtual Stuff1::~Stuff1()
virtual Person::~Person()
The invoke order of constructors and destructors for class Manager2:
Person::Person()
Stuff2::Stuff2()
Technician2::Technician2()
Manager2::Manager2()
virtual Manager2::~Manager2()
virtual Technician2::~Technician2()
virtual Stuff2::~Stuff2()
virtual Person::~Person()