[Bug c++/33821] New: function with ambiguous covariant return-type is not rejected

[peter dot pirkelbauer at tamu dot edu]

struct R1 {};
struct R2 : R1 {};
struct R3 : R1 {};
struct R4 : R2, R3 {};

struct A { virtual R1& foo(); };
struct B : virtual A { R2& foo(); };
struct C : virtual A { R3& foo(); };
struct D : B, C { R4& foo(); };     // should be rejected

R4 contains two subobjects of type R1. When D::foo is invoked in the context of
A (e.g.: in the following function bar) the cast from R4 to R1 is ambiguous.
Therefore D::foo should be rejected.

void bar(D& d)
{ A& a = d;
  R1& res = a.foo();
}


-- 
           Summary: function with ambiguous covariant return-type is not
                    rejected
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: peter dot pirkelbauer at tamu dot edu
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33821