import vibe.d;

static this()
  WebSocket[] client_list;

  auto router = new UrlRouter;
  router.get("/", handleWebSockets(delegate(WebSocket sock){
    client_list ~= sock;
    while( sock.connected ){
      auto msg = sock.receive();
      foreach(client; client_list) client.send(msg); //=>"ERROR: Operating on TcpConnection owned by a different fiber!"

  auto settings = new HttpServerSettings;
  settings.port = 9998;
  listenHttp(settings, router);

I found
I want to call acquire(), but WebSocket class don't have acquire().
How do you think most simple websocket chat?