benben

#include <boost/foreach.hpp>
#include <boost/function.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <boost/variant.hpp>
#include <iostream>
#include <map>
#include <string>
#include <vector>

struct Object1 { std::string hello() const { return "Hi, Object1"; } };

benben

#include <boost/foreach.hpp>
#include <boost/function.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <boost/shared_ptr.hpp>
#include <iostream>
#include <map>
#include <string>
#include <vector>

struct Parent { virtual std::string hello() const = 0; };