-- PACKED_DESCRIPTOR and DESCRIPTOR are two different types
-- with identical characteristics, apart from their representationtype
DESCRIPTOR is
record
-- components of a descriptor
end record
;type
PACKED_DESCRIPTOR is new
DESCRIPTOR;for
PACKED_DESCRIPTOR use
record
-- component clauses for some or for all components
end record
;
D : DESCRIPTOR;
P : PACKED_DESCRIPTOR;
D := DESCRIPTOR(P); -- unpack P