DOCUMENT:Q255528  03-MAY-2001  [visualc]
TITLE   :BUG:  Violation in Constructor w/ Variable Number of Arguments
PRODUCT :Microsoft C Compiler
PROD/VER:winnt:
OPER/SYS:
KEYWORDS:kbCPPonly kbSTL kbVS600bug

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

 - The C/C++ Compiler (CL.EXE) 
-------------------------------------------------------------------------------

SYMPTOMS
========

An access violation may occur if you have a class derived from ostringstream and
if this class has a constructor with variable number of arguments.

CAUSE
=====

Incorrect code is generated when the first argument in the variable argument
list is a zero.

RESOLUTION
==========

To workaround the problem, use any one of the following three resolutions:

1. Do not use variable number of arguments for the class constructor.

2. Let the first argument in the constructor's variable argument list be a
   non-zero value.

3. Use a default class constructor with no arguments and then call another
   member function with a variable argument list.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

   Compile Options : cl /GX test.cpp

   //Test.cpp

   #include <iostream>
   #include <sstream>
   using namespace std;

   class Test : public ostringstream
   {
   public:
       Test(bool n,  ...)
   	{
   	}
   };

   void main()
   {
           cout << "Calling Test " << endl;
           Test my_test1(true, 1); //OK.

           cout << "Calling Test again " << endl;
           Test my_test2(true, 0); //Causes Access Violation  

   }

Additional query words:

======================================================================
Keywords          : kbCPPonly kbSTL kbVS600bug 
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : winnt:
Issue type        : kbbug

=============================================================================

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