return r;
  }
  /*CCTK_ATTRIBUTE_ALWAYS_INLINE*/ constexpr bool all() const {
    bool r = true;
    for (int d = 0; d < D; ++d)
      r &= elts[d];
    return r;
  }
  /*CCTK_ATTRIBUTE_ALWAYS_INLINE*/ constexpr bool any() const {
    bool r = false;
    for (int d = 0; d < D; ++d)
      r |= elts[d];

  /*CCTK_ATTRIBUTE_ALWAYS_INLINE*/ constexpr T maxabs() const {
    T r = 0;
    for (int d = 0; d < D; ++d)
      r = fmax(r, fabs(elts[d]));
    return r;
  }
  /*CCTK_ATTRIBUTE_ALWAYS_INLINE*/ constexpr T prod() const {
    T r = 1;
    for (int d = 0; d < D; ++d)
      r *= elts[d];
    return r;
  }
  /*CCTK_ATTRIBUTE_ALWAYS_INLINE*/ constexpr T sum() const {
    T r = 0;
    for (int d = 0; d < D; ++d)
      r += elts[d];
    return r;
  }