Re: C++ PATCH for c++/48322 (broken handling of variadic parms on multiple levels)

[Paolo Carlini]

.. also, I was under the impression that c++/48322 was the only reason 
we couldn't write something very simple, thus no __all_convertible, ie, 
something using directly:

    enable_if<__and_<is_convertible<_UElements, 
_Elements>...>::value>::type

That would be a great improvement, even if we need to SFINAE separately 
for equal sizeofs. But maybe it works, have just to clean up the code?!

Paolo.