c++ - FILE_NOTIFY_INFORMATION 構造体でファイル名を読み取るにはどうすればよいですか

Question

ファイルの変更を監視しようとしていますが、FILE_NOTIFY_INFORMATION 構造体でファイル名を読み取る方法がよくわかりません。

    HANDLE dwChangeHandles[2];
    DWORD dwWaitStatus;
    wChangeHandles[0] = FindFirstChangeNotification(dirname.c_str(), FALSE, FILE_NOTIFY_CHANGE_LAST_WRITE);
    if (dwChangeHandles[0] == INVALID_HANDLE_VALUE) printerr(__FILE__,__LINE__,"FindFirstChangeNotification function failed.\n");
    ...
    if ((dwChangeHandles[0] == NULL) || (dwChangeHandles[1] == NULL))  //final validation
        printerr(__FILE__,__LINE__,"Unexpected NULL from FindFirstChangeNotification.\n");

    while (TRUE) {
        std::cout << "Waiting for notification...\n";
        dwWaitStatus = WaitForMultipleObjects(2, dwChangeHandles, FALSE, INFINITE);
        if(dwWaitStatus==WAIT_OBJECT_0){
            std::cout << "Something changed\n";

            DWORD BytesReturned;
            size_t bufLen = 1024;
            FILE_NOTIFY_INFORMATION buffer[bufLen];
            if (ReadDirectoryChangesW(dwChangeHandles[0], buffer, bufLen, FALSE, FILE_NOTIFY_CHANGE_LAST_WRITE, &BytesReturned, NULL, NULL)){
                std::wcout << std::wstring(buffer->FileName)<< std::endl; //THERE IS NOTHING IN THE EXPECTED OUTPUT HERE
            }
            if (FindNextChangeNotification(dwChangeHandles[0]) == FALSE ) printerr(__FILE__,__LINE__,"FindNextChangeNotification function failed.\n");
        }

        else if(dwWaitStatus==WAIT_TIMEOUT) printerr(__FILE__,__LINE__,"No changes in the timeout period.\n");
        else printerr(__FILE__,__LINE__,"Unhandled dwWaitStatus.\n");
    }

私が間違っていることはありますか