+XBT_PUBLIC void intrusive_ptr_release(Mailbox* m);
+XBT_PUBLIC void intrusive_ptr_add_ref(Mailbox* m);
+class Mutex;
+XBT_PUBLIC void intrusive_ptr_release(Mutex* m);
+XBT_PUBLIC void intrusive_ptr_add_ref(Mutex* m);
+class NetZone;
+class VirtualMachine;
+class File;