BUGFIX: Use of non-static member in typedef to retrieve the type. clang doesn't allow this even in unevaluated context like decltype.
Breaking change of BOOST_FUSION_ADAPT_ADT_NAMED and BOOST_FUSION_ADAPT_ASSOC_ADT_NAMED API to be coherent with the expressions of BOOST_FUSION_ADAPT_ADT thanks to correct usage of BOOST_FUSION_PROXY_PREFIX.
Fix use of non-static "obj" in unevaluated expression context of decltype.