Issue 2489:  20.17.9 Valuetype Inheritance (cxx_revision)
Source:  (, )
Nature:  Uncategorized Issue
Severity: 
Summary: Summary: For an IDL valuetype derived from other valuetypes or that supports
 interface types, several C++ inheritance scenarios are possible:
 ...
 * Interface classes supported by the IDL valuetype are not inherited. Instead,
 the operations on the interface (and base interfaces, if any) are mapped to
 pure virtual functions in the generated C++ base value class. In addition to
 this abstract base value class and the OBV_ class, the IDL compiler generates
 a POA skeleton for this value type; the name of this skeleton is formed by
 prepending the string "POA_" to the fully-scoped name of the valuetype. The
 base value class and the POA skeleton of the interface type are public virtual
 base classes of this skeleton.
 
 
 Consider this example:
 
 // IDL
 interface I {};
 abstract valuetype A supports I {};
 valuetype B : A {};
 
 Is a POA skeleton generated for A?  Is one generated for B?
 

Resolution: 
Revised Text: 
Actions taken:
February 25, 1999: received issue
Discussion: 

End of Annotations:=====
X-Sender: mark@192.168.1.1
Date: Thu, 25 Feb 1999 11:10:51 -0800
To: cxx_revision@omg.org
From: Mark Spruiell <mes@ooc.com>
Subject: Valuetypes & supported interfaces

Hi,

>From the C++ mapping document 98-09-03:

20.17.9 Valuetype Inheritance

For an IDL valuetype derived from other valuetypes or that supports
interface types, several C++ inheritance scenarios are possible:
...
* Interface classes supported by the IDL valuetype are not
inherited. Instead,
the operations on the interface (and base interfaces, if any) are
mapped to
pure virtual functions in the generated C++ base value class. In
addition to
this abstract base value class and the OBV_ class, the IDL compiler
generates
a POA skeleton for this value type; the name of this skeleton is
formed by
prepending the string "POA_" to the fully-scoped name of the
valuetype. The
base value class and the POA skeleton of the interface type are public
virtual
base classes of this skeleton.


Consider this example:

// IDL
interface I {};
abstract valuetype A supports I {};
valuetype B : A {};

Is a POA skeleton generated for A?  Is one generated for B?

Thanks,

    Mark
--
Mark E. Spruiell
Object-Oriented Concepts, Inc.
mes@ooc.com  *  http://www.ooc.com  *  1-978-439-9285 x 247