Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!lupine!rfg
From: rfg@NCD.COM (Ron Guilmette)
Newsgroups: comp.std.c++
Subject: Re: Packing Across Inheritance Boundari
Message-ID: <1316@lupine.NCD.COM>
Date: 24 Aug 90 06:53:33 GMT
References: <6540462@1990Aug3.211414.23872@watmath.wa> <13413@> <56843@microsoft.UUCP>
Organization: Network Computing Devices, Inc., Mt. View, CA
Lines: 34

In article <56843@microsoft.UUCP> jimad@microsoft.UUCP (Jim ADCOCK) writes:
+... {some things} make packing order compatibility a moot issue:
...
+Derived contiguous with parent structures, or references?

I hope so.

+segmented or flat pointers?

Everybody except Intel uses flat.  (No flames please.  All generalizations
are false, including this one.)

+...  Thus, please leave compiler implementation
+details out of the language specification. 

One man's "implementation detail" is another man's language semantics.

I believe that ANSI C requires that:

	(&a[2] - &a[1]) == 1

Are you going to suggest that this should have been left out of ANSI C
because it unduly restricts the implementation of arrays to consecutive
memory locations with ascending addresses?

How about the semantics of `volatile'?  Should that all be tossed out of
ANSI C also?  After all, it does put some rather specific constraints on
implementations.

-- 

// Ron Guilmette  -  C++ Entomologist
// Internet: rfg@ncd.com      uucp: ...uunet!lupine!rfg
// Motto:  If it sticks, force it.  If it breaks, it needed replacing anyway.