[Bug c++/11750] class scope using-declaration lookup not implemented

["balakrishnan.erode at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11750

Balakrishnan B <balakrishnan.erode at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |balakrishnan.erode at gmail
                   |                            |dot com

--- Comment #6 from Balakrishnan B <balakrishnan.erode at gmail dot com> 2011-01-12 16:57:07 UTC ---
(In reply to comment #0)
> Paragraph 10.3/2 in the C++ standard [ISO/IEC 14882:1998] provides the
> following
> code example:
> 
> <quote>
> 
> struct A {
>     virtual void f();
> };
> struct B : virtual A {
>     virtual void f();
> };
> 
> struct C : B , virtual A {
>     using A::f; 
> };
> void foo() {
>     C c; 
>     c.f();      // calls B::f, the final overrider
>     c.C::f();   // calls A::f because of the using-declaration
> }
> 
> </quote>
> 
> When a similar program is compiled using G++ 3.3, the method call 'c.f()' in
> function foo() incorrectly invokes A::f and not B::f as specified in the
> standard.
> 
> <example>
> <code main.cpp>
> #include <iostream>
> 
> struct A {
>     virtual void f() { std::cout << "A::f()\n"; }
> };
> struct B : virtual A {
>     virtual void f() { std::cout << "B::f()\n"; }
> };
> struct C : B, virtual A {
>     using A::f;
> };
> 
> int main()
> {
>     C c;
>     c.f();      // ERROR - Incorrectly invokes A::f
>     c.C::f();   // OK - Invokes A::f
> }
> </code>
> 
> <build>
> $ g++ main.cpp
> 
> $ ldd a.out
>         libstdc++.so.5 =>
> /usr/local/gcc/3.3/lib/gcc-lib/i686-pc-linux-gnu/3.3/libstdc++.so.5
> (0x40017000)
>         libm.so.6 => /lib/tls/libm.so.6 (0x400e4000)
>         libgcc_s.so.1 =>
> /usr/local/gcc/3.3/lib/gcc-lib/i686-pc-linux-gnu/3.3/libgcc_s.so.1 (0x40106000)
>         libc.so.6 => /lib/tls/libc.so.6 (0x42000000)
>         /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)
> </build>
> 
> <output>
> $ ./a.out
> A::f()
> A::f()
> </output>
> 
> </example>

Im using g++ 4.4.5
With the same example with my main function as below,
int main()
{
      C c;
      c.f() // Calls A::f
      C* pc = &c;
      pc->f() // Calls B::f
}

With the same object when accessed directly produces different results and when
accessed using a pointer of same type produces a different result. Even if gcc
violates standard, there has to be some proper explanation.