message: Add round_down() function for integers
diff: @@ -279,6 +279,16 @@ inline typename std::enable_if<std::is_integral<T>::value, T>::type round_up(T a
  return div_up(a, b) * b;
  }
  +//-------------------------------------------------------------------------------------------------
  +// Round (a) down to the nearest multiple of (b)
  +//
  +
  +template <typename T>
  +inline typename std::enable_if<std::is_integral<T>::value, T>::type round_down(T a, T b)
  +{
  + return (a / b) * b;
  +}
  +
  namespace simd
  {
  