Maybe I misunderstand, maybe someone can help me with this
In the CENTC251 standard there is a GPIC
IdentifiedLivingSubject. It has two Generalisations: SubjectOfInvestigation
and SubjectOfCareIdentification
This happens a lot in the Standard. In my opinion a class can only be a child
of one parent, and if you want it to associate to more classes, you have to
use Association.
Although multiple inheritance is allowed in UML 2.0 (I don't know about
previous versions), it is stated as not recommended to use as many
programming languages do not support multiple inheritence.
UML 2.0 is released in 2004, the CEN-standard document is from 2002. In this
document is not specified which UML-version they use.
It looks like Generalisation and Association are confused in the UML-scheme of
the standard, but, as I said, maybe I misunderstand
Thanks in advance.
By the way, I did send another email to this list this morning, it did not
appear in the list.
Is/was the list down?
Although multiple inheritance is allowed in UML 2.0 (I don't know about
previous versions), it is stated as not recommended to use as many
programming languages do not support multiple inheritence.
Multiple inheritance has been provided in all versions of UML, and I am unaware of any recommendation in a UML standard to avoid the use of multiple inheritance. Could you please give me a more precise reference to this recommendation?
There is some advice in the UML 2.0 standard regarding the use of powertypes and their implementation in certain programming languages (see para below). Could this be the recommendation you are thinking of? If so, it is not a recommendation against multiple inheritance.
"Power types are a conceptual, or analysis, notion. They express a real-world situation. Implementing, however, them may
not be easy and efficient. To implement power types with a relational database would mean that the instances of a relation
could also be relations in their own right. In object-oriented implementations, the instances of a class could also be
classes. However, if the software implementation can not directly support classes being objects and vice versa, redundant
structures must be defined. In other words, unless you're programming in Smalltalk or CLOS, the designer must be aware
of the integrity problem of keeping the list of power type instances in sync with the existing subclasses."
Thanks
Kerry
Dr Kerry Raymond
Distinguished Research Leader
CRC for Enterprise Distributed Systems Technology
University of Queensland 4072 Australia
Ph: +61 7 3365 4310, Fax: +61 7 3365 4311, www.dstc.edu.au