string filename = [&]() {

      const string filename = [&]() {

        string visitname = [&]() {

        const string visitname = [&]() {

      }
    }
  }
}
template <typename T>
void write_arrays(ostream &os, const cGH *restrict cctkGH, int level,
                  int component, const vector<const T *> ptrs,
                  const GridDesc &grid) {
  DECLARE_CCTK_ARGUMENTS;
  const int levfac = 1 << level;
  CCTK_REAL x0[dim], dx[dim];
  for (int d = 0; d < dim; ++d) {
    dx[d] = cctk_delta_space[d] / levfac;
    x0[d] = cctk_origin_space[d] + 0.5 * dx[d];
  }
  int imin[dim], imax[dim];
  for (int d = 0; d < dim; ++d) {
    imin[d] = grid.bbox[2 * d] ? 0 : grid.nghostzones[d];
    imax[d] = grid.lsh[d] - (grid.bbox[2 * d + 1] ? 0 : grid.nghostzones[d]);
  }
  constexpr int di = 1;
  const int dj = di * grid.ash[0];
  const int dk = dj * grid.ash[1];
  for (int k = 0; k < grid.lsh[2]; ++k) {
    for (int j = 0; j < grid.lsh[1]; ++j) {
      for (int i = 0; i < grid.lsh[0]; ++i) {
        const int idx = di * i + dj * j + dk * k;
        const int isghost = !(i >= imin[0] && i < imax[0] && j >= imin[1] &&
                              j < imax[1] && k >= imin[2] && k < imax[2]);
        T x = x0[0] + (grid.lbnd[0] + i) * dx[0];
        T y = x0[1] + (grid.lbnd[1] + j) * dx[1];
        T z = x0[2] + (grid.lbnd[2] + k) * dx[2];
        os << cctk_iteration << "\t" << cctk_time << "\t" << level << "\t"
           << component << "\t" << isghost << "\t" << (grid.lbnd[0] + i) << "\t"
           << (grid.lbnd[1] + j) << "\t" << (grid.lbnd[2] + k) << "\t" << x
           << "\t" << y << "\t" << z;
        for (const auto &ptr : ptrs)
          os << "\t" << ptr[idx];
        os << "\n";

       // << "\t"
       // << "isghost"

      string filename = buf.str();

      const string filename = buf.str();