message: Use is_arithmetic<T>::value for C++11 compatibility
  Summary:
  Some xplat build platforms only support C++11, where is_arithmetic_v is not a
  thing yet.
diff: @@ -34,7 +34,8 @@ template <
  typename TimeT,
  typename TimeDeltaT,
  typename = std::enable_if_t<
  - std::is_arithmetic_v<TimeT> && std::is_arithmetic_v<TimeDeltaT>>>
  + std::is_arithmetic<TimeT>::value &&
  + std::is_arithmetic<TimeDeltaT>::value>>
  class WindowedCounter {
  public:
  /**
  