Issue 781:  C++ mapping for IN object references (cxx_revision)
Source:  (, )
Nature:  Uncategorized Issue
Severity:  Significant
Summary: Summary: According to C++ mapping spec in the POA document (table 2, section 16.18.1) the signature for an  object reference in argument should be "objref_ptr", not the more likely "const objref_ptr". this is an conflict with the convention for all other in args except numeric, and is in contrast with the table 3, that specifies "const objref_var&".

Resolution:  Duplicate of issue 188 - closed
Revised Text: 
Actions taken:
November 19, 1997: received issue
November 25, 1997: moved to cxx_revision
February 19, 1999: closed issue
Discussion: 
 closed issue
End of Annotations:=====
Return-Path: <paulk@noblenet.com>
Date: Wed, 19 Nov 1997 14:58:30 -0500
From: Paul H Kyzivat <paulk@noblenet.com>
Organization: NobleNet
To: issues@omg.org
Subject: C++ mapping for IN object references

According to the C++ mapping spec in the POA document (Table 2,
section
16.18.1) the signature for an object reference in argument should be
"objref_ptr", not the more likely "const objref_ptr". This is in
conflict with the convention for all other in args except numerics,
and
is in contrast with the table 3, that specifies "const objref_var&".

This means that objref_var.in() must yield a non-const objref_ptr,
even
for const vars, which is counterintuitive at best.

This means that the ability to use compiler diagnostics to catch
errors
is reduced.

Is this a mistake, or is it intended? And, is it normative?
 

Return-Path: <jon@biggar.org>
Sender: jon@biggar.org
Date: Wed, 19 Nov 1997 18:16:22 -0800
From: Jonathan Biggar <jon@biggar.org>
To: Paul H Kyzivat <paulk@noblenet.com>
CC: issues@omg.org
Subject: Re: C++ mapping for IN object references
References: <347344E6.93699216@noblenet.com>

Paul H Kyzivat wrote:

> According to the C++ mapping spec in the POA document (Table 2,
section
> 16.18.1) the signature for an object reference in argument should be
> "objref_ptr", not the more likely "const objref_ptr". This is in
> conflict with the convention for all other in args except numerics,
and
> is in contrast with the table 3, that specifies "const objref_var&".
>
> This means that objref_var.in() must yield a non-const objref_ptr,
even
> for const vars, which is counterintuitive at best.
>
> This means that the ability to use compiler diagnostics to catch
errors
> is reduced.
>
> Is this a mistake, or is it intended? And, is it normative?

This is no mistake and is as intended.  The C++ mapping has assigned
no meaning to
a "const" object_ptr, because an object_ptr is not like a normal C++
pointer, and IDL
has no concept of a "const" object either.  If you think of an
object_ptr like another built-in
C++ type, like int, you will see that the const is unnecessary on an
"in" parameter, because
an "in" parameter is being passed by value, not by reference.

Jon Biggar
jon@biggar.org