[boost] [config][type_traits] Support for final keyword in Boost?

Subject: [boost] [config][type_traits] Support for final keyword in Boost?
From: John Maddock (jz.maddock_at_[hidden])
Date: 2014-08-16 03:59:29

I have a couple of pull requests to add support for the final keyword in 
Boost.Config and an is_final trait to type traits, so my questions are:

1) Are these generally useful?
2) Do we need BOOST_NO_CXX11_FINAL_CLASS and 
BOOST_NO_CXX11_FINAL_OVERRIDE or will a single BOOST_NO_CXX11_FINAL do?
3) The trait appears to be unimplementable via SFINAE (anyone care to 
prove me wrong?) which means it's only usable on GCC and lookalikes 
which have an __is_final intrinsic.  Should we still add this to Boost 
or is the answer "use GCC's native features" given that a Boost version 
effectively adds nothing?

Thanks!  John.