Q263637: BUG: Class Access Specifier Ignored When Creating Temp Objects

Article: Q263637
Product(s): Microsoft C Compiler
Version(s): 5.0,6.0
Operating System(s): 
Keyword(s): kbCompiler kbCPPonly kbVC500 kbVC500bug kbVC600 kbVC600bug kbDSupport kbGrpDSTools
Last Modified: 03-MAY-2001

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The information in this article applies to:

- The C/C++ Compiler (CL.EXE), included with:
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0 
   - Microsoft Visual C++, 32-bit Professional Edition, version 5.0 
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 6.0 
   - Microsoft Visual C++, 32-bit Professional Edition, version 6.0 
   - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
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SYMPTOMS
========

The compiler incorrectly uses private or protected constructors when temporary
class objects are created.

NOTE: The compiler generates a C4248 warning if compiled with the /W3 or /W4
compiler switch.

Please refer to the sample code in the "More Information" section for details.

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
---------------------------

The following sample code demonstrates the bug:

  // Test.cpp
  // Compiler option needed: /GX
  class A
  {
  protected:
      A(int i) : m_i(i) {}
  private:
      int m_i;
  };

  int main()
  {
   //A a(8); // Error C2248 here, as expected.
   A(8);	// No error here. 
          // Produces warning C4248 with compiler switch /W3 or /W4.    

      try
      {
          throw A(8); // No error here also. 
                 // Produces warning C4248 with compiler switch /W3 or /W4.
      }
      catch (A& a)
      {
      }

      return 0;
  }

Additional query words:

======================================================================
Keywords          : kbCompiler kbCPPonly kbVC500 kbVC500bug kbVC600 kbVC600bug kbDSupport kbGrpDSTools 
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : :5.0,6.0
Issue type        : kbbug

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