abdel Meghdir wrote:

> The folowing code generate compiler error  C2385 with VC++ 5.0 .
> DerBase is dervived from both base1 and base2 .    and  the  function  foo()
> is  overloaded .
> is this  a standard  C++ or just an other VC++  bug ?

This is not a VC++ bug.  According to the C++ standard, the code is
ill-formed, and so a diagnostic is required.

> class base1
> {
>    public:
>      virtual void foo() { cout<< "base1::foo"<<endl ; };
> };
>
> class base2
> {
>   public :
>    void foo(int i) { cout<< "base2::foo"<<endl;  };
> };
>
> class DerBase :  public base1 ,  public base2
> {
> };
>
> void main( )
> {
>    DerBase obj;
>     obj.foo( );    // error C2385: 'DerBase::foo' is ambiguous
> }

Overloading only distinguishes between different names defined in
a single scope, not between names defined in different scopes.
See 10.2 [class.member.lookup].

If you want to allow overloading, you can use a `using' directive
in the derived class:

 class DerBase :  public base1 ,  public base2
 {
  using base1::foo;
  using base2::foo;
 };

--
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abdel Meghdir wrote:

> The folowing code generate compiler error  C2385 with VC++ 5.0 .
> DerBase is dervived from both base1 and base2 .    and  the  function  foo()
> is  overloaded .
> is this  a standard  C++ or just an other VC++  bug ?
>
> class base1
> {
>    public:
>      virtual void foo() { cout<< "base1::foo"<<endl ; };
> };
>
> class base2
> {
>   public :
>    void foo(int i) { cout<< "base2::foo"<<endl;  };
> };
>
> class DerBase :  public base1 ,  public base2
> {
> };
>
> void main( )
> {
>    DerBase obj;
>     obj.foo( );    // error C2385: 'DerBase::foo' is ambiguous
> }
>
> ---
> [ comp.std.c++ is moderated.  To submit articles, try just posting with ]
> [ your news-reader.  If that fails, use mailto:std-c++@ncar.ucar.edu    ]
> [              --- Please see the FAQ before posting. ---               ]
> [ FAQ: http://reality.sgi.com/austern_mti/std-c++/faq.html              ]

I have some sympathy for the compiler complaining. If in base2 you had declared
foo with a default argument value, there would be an ambiguity. I suspect that
the default is only used during compilation and not linking.

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-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

"abdel Meghdir" <kmeghdir@yahoo.com> wrote in message
news:8pldhm$pm0$1@reader1.imaginet.fr...
>
> The folowing code generate compiler error  C2385 with VC++ 5.0 .
> DerBase is dervived from both base1 and base2 .    and  the  function
foo()
> is  overloaded .
> is this  a standard  C++ or just an other VC++  bug ?
>
> class base1
> {
>    public:
>      virtual void foo() { cout<< "base1::foo"<<endl ; };
> };
>
> class base2
> {
>   public :
>    void foo(int i) { cout<< "base2::foo"<<endl;  };
> };
>
> class DerBase :  public base1 ,  public base2
> {
> };
>
> void main( )
>

>    DerBase obj;
>     obj.foo( );    // error C2385: 'DerBase::foo' is ambiguous
> }

DerBase has two foo functions, base1::foo and base2::foo. Before checking
the
parameters, the compiler must decide which of the two the name refers to,
which
it cannot. You need to explicitly specify which in the call:

obj.base1::foo();

or add both to DerBase:

class DerBase: public base1, public base2
{
  void foo(){ base1::foo(); }
  void foo(int i) { base2::foo(i); }
};

Anthony
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The folowing code generate compiler error  C2385 with VC++ 5.0 .
DerBase is dervived from both base1 and base2 .    and  the  function  foo()
is  overloaded .
is this  a standard  C++ or just an other VC++  bug ?

class base1
{
   public:
     virtual void foo() { cout<< "base1::foo"<<endl ; };
};

class base2
{
  public :
   void foo(int i) { cout<< "base2::foo"<<endl;  };
};

class DerBase :  public base1 ,  public base2
{
};

void main( )
{
   DerBase obj;
    obj.foo( );    // error C2385: 'DerBase::foo' is ambiguous
}




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