message: add parenthesis around variadic expression (quenches GCC warning)
diff: @@ -119,7 +119,7 @@ NAMESPACE_BEGIN(detail)
  template <typename Array, size_t... Index, typename Value = value_t<Array>>
  ENOKI_INLINE Array sample_shifted(Value sample, std::index_sequence<Index...>) {
  - const Array shift(Value(Index) / Value(Array::Size)...);
  + const Array shift((Value(Index) / Value(Array::Size))...);
  Array value = Array(sample) + shift;
  value[value > Value(1)] -= Value(1);
  