海上钢琴师

class AuServant;
class AuPhysicsBase
{
public:
    AuServant *m_pHired;
};

//>PhysicsBase的仆人类，为雇主实现特定功能
class AuServant
{
public:
 AuServant(AuPhysicsBase * a);
 ~AuServant();
 
 virtual void DoThings(){}
protected:
 AuPhysicsBase * m_pHost;
 
};

AuServant::AuServant(AuPhysicsBase *a)
{
 m_pHost = a;
}

#define DECLARE_PHYSICSBASEHIRED_CLASS( classname, hostclassname)       \
class classname: public AuServant            \
{                    \
public:                   \
 classname(hostclassname *pHost):AuServant(pHost){}       \
 void    DoThings();                          \
};
                   

DECLARE_PHYSICSBASEHIRED_CLASS(AuNewThinker , AuPhysicsBase)

class AuMine: public AuPhysicsBase
{
public:
 void Think(){m_pHired->DoThings();}

};

void AuNewThinker::DoThings()
{
 AuMine *m_thinker = static_cast<AuMine*>(m_pHost);
 int a = 0;
}

int main()
{
 AuMine *a = new AuMine();
    AuNewThinker* think = new AuNewThinker(a);
 a->m_pHired = think;
    a->Think();
}// : baseclassname(pHost)