#else
#define DEFINE_EXTERNAL_CLASS(klass) typedef struct klass klass;
#endif
+// ========== User Data ==============
+XBT_PUBLIC(void*) sg_host_user(sg_host_t host);
+XBT_PUBLIC(void) sg_host_user_set(sg_host_t host, void* userdata);
+XBT_PUBLIC(void) sg_host_user_destroy(sg_host_t host);
// ========== MSG Layer ==============
typedef struct s_msg_host_priv *msg_host_priv_t;