RE: Proposal Review: Using C++ Namespace

[David N Bertoni/Cambridge/IBM]

Esmond,

I disagree.  Run this sample through your favorite compiler and see what
happens:

   namespace foo1
   {
       class DOMDocument
       {
       public:
           DOMDocument() {}
       };
   };

   using foo1::DOMDocument;


   namespace foo2
   {
       class DOMDocument
       {
       public:
           DOMDocument() {}
       };
   };


   using foo2::DOMDocument;

   int
   main(int argc, const char* argv[])
   {
       DOMDocument  doc;

       return 0;
   }

Since DOMDocument was hoisted by both header files (assuming the two
namespaces are in separate header files, from separate libraries), you
can't use both libraries together.  That defeats the purpose of using
namespaces in the first place.

Dave



                                                                                       
                                                 
                      "Pitt, Esmond"                                                   
                                                 
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Bertoni/Cambridge/IBM)                                            
                      11/06/2002 03:45         Subject: RE: Proposal Review: Using C++ 
Namespace                                        
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Tinny

As per my previous message, the 'correct' solution is to enumerate all the
namespace exports explicitly with using-declarations, e.g.

using Xerces::XercesDOMParser;
using Xerces::DOMDOcument;
// ...

in XercesDefs.hpp (or in each header file which exports a class). There is
no accidental namespace pollution with this technique, no
order-dependencies, and no user migration is required.

EJP

-----Original Message-----
From: Tinny Ng [mailto:tng-xml@;ca.ibm.com]
Sent: Thursday, 7 November 2002 12:53 AM
To: [EMAIL PROTECTED]
Subject: Re: Proposal Review: Using C++ Namespace


Hi everyone,

I have implemented the proposed C++ Namespace to the latest code base.
Since a number of response indicated no "using" clause in a global header,
I've removed that from the XercesDefs.hpp which then means users'
application has a migration item.

Please review the latest nightly build
(http://xml.apache.org/dist/xerces-c/nightly/2002-11-06/)  and let me know
any comment.

Thanks!

Tinny


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