Issue 7900: omission from the OMG --Trader spec (corba-rtf) Source: (, ) Nature: Clarification Severity: Significant Summary: Given a property P defined by type B as PROP_NORMAL, two types T1 and T2 inherit from B but each strengthens the mode to PROP_READONLY and PROP_MANDATORY respectively. Then is there an implied strengthening to PROP_MANDATORY_READONLY in a further derived type T3 which inherits from both T1 and T2? Related to this, the OMG spec has nothing to say about waht exception should be raised by an attempted "weakening" of a property mode by a sub-type or exactly what is construed as a "weakening" with multiple inheritance. Another slightly different senario is: Given a property P defined by type B as PROP_READONLY, two types T1 and T2 inherit from B with one of them "strengthening" the mode of B to PROP_MANDATORY_READONLY. Is deriving a type T3 from both T1 and T2 legal? Resolution: Revised Text: Actions taken: November 3, 2004: received issue April 11, 2012: Deferred Discussion: End of Annotations:===== m: webmaster@omg.org Date: 03 Nov 2004 18:04:13 -0500 To: Subject: Issue/Bug Report -------------------------------------------------------------------------------- Name: Bill Somerville Company: Class Design Limited mailFrom: bill@classdesign.com Notification: Yes Specification: Trading Object Service Specification Section: 1.2.4 & 2.3 FormalNumber: 1 Version: 1 RevisionDate: 05/01/2000 Page: Many Nature: Clarification Severity: Significant HTTP User Agent: Mozilla/4.0 (compatible; MSIE 6.0; X11; Linux i686) Opera 7.54 [en] Description I've been trying to resolve some issues with an implementation of the Trader (TAO) and have hit a problem with an omission from the OMG spec. Given a property P defined by type B as PROP_NORMAL, two types T1 and T2 inherit from B but each strengthens the mode to PROP_READONLY and PROP_MANDATORY respectively. Then is there an implied strengthening to PROP_MANDATORY_READONLY in a further derived type T3 which inherits from both T1 and T2? Related to this, the OMG spec has nothing to say about waht exception should be raised by an attempted "weakening" of a property mode by a sub-type or exactly what is construed as a "weakening" with multiple inheritance. Another slightly different senario is: Given a property P defined by type B as PROP_READONLY, two types T1 and T2 inherit from B with one of them "strengthening" the mode of B to PROP_MANDATORY_READONLY. Is deriving a type T3 from both T1 and T2 legal?