message: Fix "namespace uses itself"
  iterator_category_to_traversal.h(36): warning C4515: 'detail':
  namespace uses itself
  No need to bring the `thrust::detail` namespace into `thrust::detail`.
diff: @@ -32,9 +32,6 @@ namespace detail
  template <typename> struct is_iterator_system;
  template <typename> struct is_iterator_traversal;
  -// make type_traits easy to access
  -using namespace thrust::detail;
  -
  template <typename Category>
  struct host_system_category_to_traversal
  : eval_if<
  