Victor Bazarov wrote:
> The basic idea is: if for two classes B and D exists an implicit
> conversion from { D* to B* } (plain vanilla ptr-to-derived to ptr-to-base
> conversion, see 4.10), then the conversion { D T::* to B T::* } for an
> arbitrary class T should exist as well.  I there anything I am missing?

When the converted pointer is called, there may need to be fixup code
generated to the D -> B conversion, so I don't think handling this is
particularly easy. Here's example code:

struct A { double a; };
struct B { unsigned b; };
struct AB : A, B { long ab; };
struct X { AB ab() { return AB(); } };

int main()
{
     AB (X::*fab)() = &X::ab;
     B (X::*fb)() = fab;      // The suggested conversion
     X x;
     B b = (x.*fb)();
}

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