Wat is fout in het onderstaande programma? #include #include struct A { A(): a(0) {} int a; virtual const char* f() const { return "a" ; } }; struct B: public A { B(): b(0) {} int b; virtual const char* f() const { return "b"; } }; int main(int, char**) { const int SZ=10; B bs[SZ]; std::set s; for (size_t i=0; i::const_iterator i=s.begin(); i!=s.end(); ++i) std::cout << i->f(); }