->type_traits is something I reluctantly accepted when I added make_shared, because it needs aligned storage. It brings in -> mpl -> pp, which I hate, but at that point it was dawning on me that striving to minimize dependencies in the current structure is a lost cause. I'll probably need to do a local copy of type_with_alignment and alignment_of too, but that's not going to be easy.
I can't help but wonder if type_traits could be reimplemented in C++11 without any dependencies at all (and still interoperate correctly with MPL etc). Certainly now that compiler requirements have been bumped up, I suspect there's a bunch of stuff in there that could be removed. Probably. Maybe. I don't really know for sure, and I'm certainly not convinced it's worth the effort... John.