do_something (...)
{
  nested_code_block (...)
  {
    ...
  }

  rcv_thread_parameters args = { ... };

  ulong thread_id = start (nested_code_block,                                  /*  "thread should belong to a top-level function in a separate namespace" */
                           &args, -_, &thread_struct),
  {
    thread_struct = {
                      ...
                    }
  };
}