C++入门--菱形继承与虚继承

#include <iostream>
#include <string>

using namespace std;

class CFurniture {
public:
    CFurniture() {
        cout << "CFurniture()\r\n";
        m_nFurniture = 0;
    }
    void use() {};
    int m_nFurniture;
};

class CSofa:public CFurniture {
public:
    CSofa() {
        m_nSofa = 1;
        cout << "CSofa()\r\n";
    }
    ~CSofa() { cout << "~CSofa()\r\n"; }
    void sit() { cout << "sit()\r\n"; }
private:
    int m_nSofa;
};

class CBed:public CFurniture {
public:
    CBed() {
        m_nBed = 2;
        cout << "CBed()\r\n";
    }
    ~CBed() { cout << "~CBed()\r\n"; }
    void sleep() { cout << "sleep()\r\n"; }
private:
    int m_nBed;
};

//构造新类，既有sofa特点，又有bed的特点--->多重继承
class CSofaBed :public CSofa, public CBed {
public:
    CSofaBed() { cout << "CSofaBed()\r\n"; }
    ~CSofaBed() { cout << "~CSofaBed()\r\n"; }
};

int main() 
{
    //创建沙发床对象
    CSofaBed sofaBed;
    //调用不明确,sofa和bed中都继承了家具类的m_nFurniture
    //sofaBed.m_nFurniture = 3;
    //指定类域（其实sofaBed本应只有一个m_nFurniture变量，但是由于菱形继承造成了这个
    //天生的漏洞，因此C++提出了虚继承以规避此问题）
    sofaBed.CSofa::m_nFurniture = 1;
    sofaBed.CBed::m_nFurniture = 1;

    


    return 0;
}

class CSofa:virtual public Furniture 

class CBed:virtual public CFurniture