* User code which adds or changes subdomain names should call this
   * method.
   */
  void unset_has_synched_subdomain_name_map()
  { _preparation.has_synched_subdomain_name_map = false; }

  /**
   * \returns \p true if all elements and nodes of the mesh

   * \returns A writable reference to the whole subdomain name map
   */
  std::map<subdomain_id_type, std::string> & set_subdomain_name_map ()
  { this->unset_has_synched_subdomain_name_map(); return _block_id_to_name; }
  const std::map<subdomain_id_type, std::string> & get_subdomain_name_map () const
  { return _block_id_to_name; }

  this->set_subdomain_name_map() = other_mesh.get_subdomain_name_map();

  this->_preparation = other_mesh.preparation();

#ifdef LIBMESH_ENABLE_UNIQUE_ID
  _next_unique_id = other_mesh.parallel_max_unique_id() +

  // name, but distributed mesh generators may only have set names for
  // the part of the mesh they know about, so make sure the map is
  // consistent everywhere.
  if (!_preparation.has_synched_subdomain_name_map)
    this->sync_subdomain_name_map();

  // Search the mesh for elements that have a neighboring element
  // of dim+1 and set that element as the interior parent

std::string & MeshBase::subdomain_name(subdomain_id_type id)
{
  this->unset_has_synched_subdomain_name_map();
  return _block_id_to_name[id];
}

  this->comm().set_union(_block_id_to_name);

  _preparation.has_synched_subdomain_name_map = true;
}

  has_removed_remote_elements(false),
  has_removed_orphaned_nodes(false),
  has_boundary_id_sets(false),
  has_reinit_ghosting_functors(false),
  has_synched_subdomain_name_map(false)
{}

MeshBase::Preparation::operator bool() const

         has_removed_remote_elements &&
         has_removed_orphaned_nodes &&
         has_reinit_ghosting_functors &&
         has_boundary_id_sets &&
         has_synched_subdomain_name_map;
}

MeshBase::Preparation &

  has_removed_orphaned_nodes = set_all;
  has_reinit_ghosting_functors = set_all;
  has_boundary_id_sets = set_all;
  has_synched_subdomain_name_map = set_all;

  return *this;
}

  if (has_reinit_ghosting_functors != other.has_reinit_ghosting_functors)
    return false;
  if (has_boundary_id_sets != other.has_boundary_id_sets)
    return false;
  if (has_synched_subdomain_name_map != other.has_synched_subdomain_name_map)
    return false;

  return true;

  this->set_subdomain_name_map() = other_mesh.get_subdomain_name_map();

  this->_preparation = other_mesh.preparation();

  // If other_mesh is distributed, then we've got parts of it on each
  // processor but we're not replicated yet; fix that.

  // We can't even afford any unset neighbor links here.
  if (!this->is_prepared())
    this->find_neighbors();

  // FIXME: make distributed mesh support efficient.
  // Yes, we currently suck.