message: fix GCC compilation failure
diff: @@ -972,7 +972,8 @@ ENOKI_INLINE E pow(const T &x_, const int &y) {
  return (y >= 0) ? result : rcp(result);
  }
  -template <typename T, typename E = expr_t<T, float>>
  +template <typename T, typename E = expr_t<T, float>,
  + enable_if_t<is_array_v<T>> = 0>
  ENOKI_INLINE E pow(const T &x, const float &y) {
  if (enoki::round(y) == y)
  return enoki::pow(E(x), (int) y);
  @@ -980,7 +981,8 @@ ENOKI_INLINE E pow(const T &x, const float &y) {
  return enoki::pow(E(x), E(y));
  }
  -template <typename T, typename E = expr_t<T, double>>
  +template <typename T, typename E = expr_t<T, double>,
  + enable_if_t<is_array_v<T>> = 0>
  ENOKI_INLINE E pow(const T &x, const double &y) {
  if (enoki::round(y) == y)
  return enoki::pow(E(x), (int) y);
  