friend ExecSeq;
friend ExecPar;
friend XBT_PUBLIC void intrusive_ptr_release(Exec* e);
friend XBT_PUBLIC void intrusive_ptr_add_ref(Exec* e);
friend ExecSeq;
friend ExecPar;
friend XBT_PUBLIC void intrusive_ptr_release(Exec* e);
friend XBT_PUBLIC void intrusive_ptr_add_ref(Exec* e);