+
+template <class F, class T>
+std::list<boost::shared_ptr<T> >
+list_of_type (std::list<boost::shared_ptr<F> > const & from)
+{
+ std::list<boost::shared_ptr<T> > out;
+ for (typename std::list<boost::shared_ptr<F> >::const_iterator i = from.begin(); i != from.end(); ++i) {
+ boost::shared_ptr<T> check = boost::dynamic_pointer_cast<T> (*i);
+ if (check) {
+ out.push_back (check);
+ }
+ }
+
+ return out;
+}