#ifndef SIMGRID_S4U_FORWARD_HPP
#define SIMGRID_S4U_FORWARD_HPP
+#include <boost/intrusive_ptr.hpp>
+
namespace simgrid {
namespace s4u {
+class Actor;
+using ActorPtr = boost::intrusive_ptr<Actor>;
+
class Activity;
class Comm;
class Engine;
class Host;
class Mailbox;
+using MailboxPtr = boost::intrusive_ptr<Mailbox>;
+
class Storage;
}
