type InternalSignedSizeType = Integer attribute (Size = BitSizeOf (SizeType)); PObjectType = ^const record Size: SizeType; NegatedSize: InternalSignedSizeType; Parent: PObjectType; Name: ^const String end;
(Note: ^record is not valid syntax. It is just used here in the explanation because the record type has no name by itself. Because of the added method pointers (see below), there is no useful usage of the record type.)
PObjectType is the type returned by TypeOf and required by SetType. In fact, the record pointed to (the VMT, “virtual method table”) also contains pointers to the virtual methods. However, these are not declared in PObjectType because they vary from object type to object type. The fields declared here are those that are shared by every object type and can be accessed via TypeOf.
Size contains the size of the object type, NegatedSize contains the size negated (for runtime checks). Parent contains a pointer to the parent type's VMT (or nil if the type has no parent). Name points to a string containing the type's name.
PObjectType is a GNU Pascal extension.
TypeOf, SetType, OOP.