def ipc_set(msqid_ds)
      unless Msqid_ds === msqid_ds
	raise ArgumentError,
	  "argument to ipc_set must be a Msqid_ds"
      end
      check_result(msgctl(@msgid, IPC_SET, msqid_ds))
    end
def ipc_set(msqid_ds)
      unless Msqid_ds === msqid_ds
	raise ArgumentError,
	  "argument to ipc_set must be a Msqid_ds"
      end
      check_result(msgctl(@msgid, IPC_SET, msqid_ds))
    end
Set the Msqid_ds object. See msgctl(2).