我定义虚基类不是太懂

结构如下

class Furniture
{
public:
    Furniture() {}
};

class Bed:virtual public Furniture
{
public:
    Bed() {}
};

class Sofa:virtual public Furniture
{
public:
    Sofa() {}
};

class SleepSofa:public Bed,public Sofa
{
public:
    SleepSofa():Bed(),Sofa()
    {}
    void FlodOut();    
};