On 14/01/16 21:22 +0100, Daniel Krügler wrote:
If there were an __is_direct_base_of intrinsic (or is there?), it seems to me that there would be no need for all these specializations (each one nearly taking as much space as the explicit inline definition of operator!) and there could be a single constrained operator!= that would only trigger for types that are direct base classes of __tag.
Yes. In fact we do have a __direct_bases intrinsic, see <tr2/type_traits>. We'd need a bit of metaprogramming to see if the__tag is one of __direct_bases(_Tp)... but that's doable.
