class C1
{
public:
    virtual ~C1() {}    
    virtual C1* clone() const
    {
        return new C1(*this);
    }
};

class C2 : public C1
{
public:
    virtual C1* clone() const
    {
        return new C2(*this);
    }
};

inline C1* clone(const C1 *ptr)
{
     return ptr->clone();
}

int main()
{
     C1* c1 = new C1;
     C2* c2 = new C2;
     
     C1* clone1 = clone(c1);
     C1* clone2 = clone(c2);

     delete clone1;
     delete clone2;

     delete c1;
     delete c2;

     return 0;
}