Summary:
This patch is pretty simple. It just adds the _v traits from <ratio>.
The draft can be found here.
Reviewers: jroelofs, K-ballo, mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D7351
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@229509 91177308-0d34-0410-b5e6-96231b3b80d8
