Function main

base_code/rtti.cpp:21–38

class D: public B { };

int main()
{
    B *b = new D;  // 向上转型
    B &obj = *b;
    D *d = dynamic_cast<D*>(b);   // 向下转型
    if(d != nullptr)
        cout << "works"<<endl;
    else
        cout << "cannot cast B* to D*";

    try {
        D& dobj = dynamic_cast<D&>(obj);
        cout << "works" << endl;
    } catch (bad_cast bc)  { // ERROR
        cout << bc.what() << endl;
    }
    return 0;
}