[boost] [type_traits][general] Best practice for inline namespaces?

I was thinking of adding inline namespace support (ie lib versioning) to type_traits, but what's the best practice for naming the inline namespace? I was thinking of going with some mangled version of BOOST_VERSION which would effectively change the namespace with each release. That feels like it's probably right to me: old versions of any traits would then be archived in boost::tt105600:: or whatever version the change happened. Comments? Thanks, John.