bool fk_modifies_child(enum_fk_option opt)
{
  static bool can_write[]= { false, false, true, true, false, true };
  return can_write[opt];
}
bool fk_modifies_child(enum_fk_option opt)
{
  static bool can_write[]= { false, false, true, true, false, true };
  return can_write[opt];
}