#include <iostream>
#include <boost/shared_ptr.hpp>

struct base {
    int i;
    explicit base(int i) : i(i) {}
    virtual ~base() {}
    virtual int id() const { return i; }
};

struct child : base {
    explicit child(int i) : base(i) {}
    virtual int id() const /*override*/ { return i + 1000; }
};

int main() {
    boost::shared_ptr<base> p(new child(13));
    std::cout << p->id()       << std::endl; //=> 1013
    std::cout << p->base::id() << std::endl; //=> 13
}

1013
13