class B;
class A {
virtual void addTo(B*) {}
};
class B : A {
void addTo(B* b) {
// blah blah blah
}
};
int main() {B b;}
Y2xhc3MgQjsKCmNsYXNzIEEgewogICAgdmlydHVhbCB2b2lkIGFkZFRvKEIqKSB7fQp9OwoKY2xhc3MgQiA6IEEgewogICAgdm9pZCBhZGRUbyhCKiBiKSB7CiAgICAgICAgIC8vIGJsYWggYmxhaCBibGFoCiAgICB9Cn07CgppbnQgbWFpbigpIHtCIGI7fQ==