[Bug c++/44267] New: SFINAE does not handle down static_cast over virtual inheritance

["cjoldfield at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

g++ fails to overlook template instantiation errors involving down static_casts
over virtual inheritance boundaries. Example:

struct B {};
struct D : B {};
struct VD : virtual B {};

template <class T> T create();

typedef char one[1];
typedef char two[2];

template <class D, class B>
one& f(char (*)[sizeof(static_cast<D>(create<B>()))]);

template <class D, class B>
two& f(...);

int main()
{
   f<D*, int>(0);
   f<D*, B*>(0);
   f<VD*, B*>(0);
   return 0;
}

gives error: cannot convert from base ?B? to derived type ?VD? via virtual base
?B?

Expected behavior is for template instantiation to fail for the first template
f function and selection of the second template f function.  

Same issue for gcc 4.3.4.  

May be related to report 41468.


-- 
           Summary: SFINAE does not handle down static_cast over virtual
                    inheritance
           Product: gcc
           Version: 4.4.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: cjoldfield at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44267