DOCUMENT:Q167356  13-MAY-2001  [visualc]
TITLE   :FIX: Same Name for Function and Class Causes C2079
PRODUCT :Microsoft C Compiler
PROD/VER:winnt:5.0
OPER/SYS:
KEYWORDS:kbtool kbVC500bug kbVC600fixkbbuglist

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

 - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0 
 - Microsoft Visual C++, 32-bit Professional Edition, version 5.0 
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SYMPTOMS
========

If a single name refers to both a class name and a function name, errors similar
to the following may be incorrectly generated:

   error C2079: 'g1' uses undefined struct 'g' error C2875: using-declaration
   causes a multiple declaration of 'A::x' error C2513: 'struct B::x' :
   decl-specifier is missing a declarator before '='

RESOLUTION
==========

Replace the using declaration with a using directive. For example, in the
following code replace the using declarations:

      using B::f
      using B::g
      using B::x

with one:

   using namespace B;

Please see the MORE INFORMATION section for a sample that demonstrates the
workaround.

STATUS
======

Microsoft has confirmed this to be a problem in the Microsoft products that are
listed at the beginning of this article.This problem was corrected in Microsoft
Visual C++ version 6.0.

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

Section 7.3.3, paragraphs 4 thru 15 of the C++ Final Draft International
Specification discuss this language behaviour in detail:

   If the set of declarations and using-declarations for a single name are given
   in a declarative region, --they shall all refer to the same, or all refer to
   functions; or --exactly one declaration shall declare a class name or
   enumeration name and the other declarations shall all refer to the same
   entity or all refer to functions; in this case the class name or enumeration
   name is hidden.

Sample Code
-----------

       namespace A {
          int x;
       }
       namespace B {
          int i;
          struct g { };
          struct x { };
          void f(int);
          void f(double);
          void g(char);
       }
       void func()  {
          int i;
          void f(char);
          using B::f;
          f(3.5f);
          using B::g;
          g('a');
          struct g g1;     // error C2079
          using B::x;
          using A::x;     // error C2875
          x = 99;         // error C2513:
          struct x x1;
       }

       //Workaround
       namespace A {
          int x;
       }
       namespace B {
          int i;
          struct g { };
          struct x { };
          void f(int);
          void f(double);
          void g(char);
       }

       void func()  {
          using namespace B ;
          int i;
          void f(char);
          f(3.5f);
          g('a');
          struct g g1;
          using A::x;
          x = 99;
          struct x x1;
       }

Additional query words:

======================================================================
Keywords          : kbtool kbVC500bug kbVC600fix kbbuglist
Technology        : kbVCsearch kbAudDeveloper kbVC500 kbVC32bitSearch kbVC500Search
Version           : winnt:5.0
Issue type        : kbbug
Solution Type     : kbfix

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

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