using std::min;
using std::max;
using std::vector;
-using boost::shared_ptr;
-using boost::weak_ptr;
-using boost::dynamic_pointer_cast;
+using std::shared_ptr;
+using std::weak_ptr;
+using std::dynamic_pointer_cast;
using boost::optional;
#if BOOST_VERSION >= 106100
using namespace boost::placeholders;