/**
這就是所謂的多態啊
*/

class?Father{
public:
????virtual?void?func(){std::cout<<"father"<<std::endl;}
};

class?Child:public?Father{
public:
????//?override?Father's?function?func()
????void?func(){std::cout<<"child"<<std::endl;}
};

//?usage
Father?*f?=?new?Father();
f->func();?//?output?"father"
Child?c?=?new?Child();
c->func();?//?output?"child"

Father?*pf?=?NULL;
Father?*pc?=?NULL;

pf?=?c;?//?pointer?of?Father?type?points?to?object?of?Child?which?is?Father's?subclass
pf->func();?//?output?"child",?because?the?real?type?of?the?object?is?Child.?(polymorphic)

//pc?=?f;?//?this?is?WRONG!!?child?pointer?can?not?points?to?father?object
pc?=?dynamic_cast<Child*>(pf);?//?right