Issue 18298: member ID algorithm flawed (dds-xtypes-rtf)
Source: PrismTech (Mr. Erik Hendriks, erik.hendriks(at)prismtech.com)
Nature: Clarification
Severity: Critical
Summary: In section 7.3.1.3.1 is is stated that when explicitly assigning memberID's to some attributes (but not to all attributes), that:


"In such cases, implicit values are assigned in a progression starting from the most-recently specified ID (or an implicit value of zero for the first constant, if there is no previous specified value) and adding one with each successive member." 


This algorithm could result in the same memberId being assigned multiple times. Consider the following example:


struct A {
    long x; //@id 2
    long y; //@id 1
    long z;
};
Resolution: 
Revised Text: 
Actions taken:
December 12, 2012: received issue
Discussion: 

End of Annotations:=====

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Date: 12 Dec 2012 07:38:27 -0500
To: <issues@omg.org>
Subject: Issue/Bug Report
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*******************************************************************************
Name:            Erik Hendriks
Employer:        PrismTech
mailFrom:        erik.hendriks@prismtech,com
Terms_Agreement: I agree
Specification:   Extensible and Dynamic Topic Types for DDS
Section:         7.3.1.3.1
FormalNumber:    ptc/2012-03-26
Version:         1.0
Doc_Year:        2012
Doc_Month:       February
Doc_Day:         Day
Page:            70
Title:           member ID algorithm flawed
Nature:          Clarification
Severity:        Critical
CODE:            3TMw8
B1:              Report Issue


Description:


In section 7.3.1.3.1 is is stated that when explicitly assigning memberID's to some attributes (but not to all attributes), that:


"In such cases, implicit values are assigned in a progression starting from the most-recently specified ID (or an implicit value of zero for the first constant, if there is no previous specified value) and adding one with each successive member." 


This algorithm could result in the same memberId being assigned multiple times. Consider the following example:


struct A {
    long x; //@id 2
    long y; //@id 1
    long z;
};