UMLR — Questions about DataTypes and generalization

I have a few questions regarding section 7.12 entitled "Kernel - the
DataTypes Diagram" in the final adopted Superstructure spec (03-08-02).

DataType specializes Classifier, and as such it also inherits the ability to
have generalization relationships with other Classifiers. Classifier has an
additional operation 'maySpecializeType(Classifier):boolean' that is
described/defined as follows:

"The query maySpecializeType() determines whether this classifier may have a
generalization relationship to classifiers of
the specified type. By default a classifier may specialize classifiers of
the same or a more general type. It is intended to be
redefined by classifiers that have different specialization constraints."
(p. 63)

with the OCL:

Classifier::maySpecializeType(c : Classifier) : Boolean;
maySpecializeType = self.oclIsKindOf(c.oclType)

DataType, nor its subtypes PrimitiveType and Enumeration, defines no
additional constraints or additional operations. These additional
constraints are executed/applied in the UML2 metamodel (rather than in a
UML2 model), correct? If so, then this implies that a DataType may
specialize another DataType, Classifier, Namespace, Type, etc., but that
DataType may not specialize PrimitiveType or Enumeration. Please correct me
if I'm interpreting this incorrectly.

Consider an example with:

• a PrimitiveType named "string"
• a PrimitiveType named "float"
• a DataType named "InternationalPrice" that specializes "float" and
  adds a new attribute/property called "currency" of type "string"

The "InternationalPrice" DataType is conceptually a qualified type, meaning
it is a float plus a qualifier of the value. Examples of instances would be

,

,

.

If my interpretations of the Superstructure spec are correct, then this
example cannot be modeled using UML2. And, in fact, the specification would
actually allow me to create a new PrimitiveType named "double" that actually
specializes my "InternationalPrice" DataType (since DataType is a supertype
of PrimitiveType). My thought is that this is either a issue with the
'maySpecializeType' operation or it is an issue with DataType, PrimitiveType
and Enumeration not being properly constrained.