DOCUMENT:Q98871  05-NOV-1999  [win16sdk]
TITLE   :PRB: Using HSZ in AFXEXT.H and DDEML.H
PRODUCT :Microsoft Windows Software Development Kit
PROD/VER:WINDOWS:3.0,3.1
OPER/SYS:
KEYWORDS:kb16bitonly

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The information in this article applies to:

 - Microsoft Windows Software Development Kit (SDK) versions 3.0, 3.1 
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SYMPTOMS
========

When using both the AFXEXT.H and DDEML.H include files in the same source file,
the following message is received:

   error C2371: 'HSZ' : redefinition; different basic types

CAUSE
=====

The problem is a naming conflict between Dynamic Date Exchange Management
Library (DDEML) and Visual Basic eXtension (VBX) files controls, in which both
use the type HSZ [handle to a string that is zero (NULL) terminated] but with
with different meanings.

AFXEXT.h includes the definition of HSZ in order to support the Control
Development Kit (CDK), and DDEML.H uses HSZ as a string type.

RESOLUTION
==========

Workarounds for this problem include:

 - Separate the DDEML and VBX code into different files, thus preventing
   AFXEXT.H and DDEML.H from being included in the same source file.

-or-

 - Use #define NO_VBX_SUPPORT in the file that implements DDE. This will cause
   DDEML's definition of HSZ to be used.

Additional query words: 3.10 c2371

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Keywords          : kb16bitonly 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK300 kbWinSDK310
Version           : WINDOWS:3.0,3.1

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