connect 可以连接 两个signal？ [复制链接]

   这是什么搞法？

  在 StdoutRedirector 里竟然看到了 ：
   connect(pipeReader, SIGNAL(readyRead()), this, SIGNAL(readyRead()));


StdoutRedirector::StdoutRedirector(QObject *parent, ProcessChannels channels) :
    QObject(parent), m_channels(channels)
{
#ifdef Q_OS_WIN
    createWinPipe(hRead, hWrite);
    if (m_channels & StandardOutput)
        ::SetStdHandle(STD_OUTPUT_HANDLE, hWrite);
    if (m_channels & StandardError)
        ::SetStdHandle(STD_ERROR_HANDLE, hWrite);

    int fd = _open_osfhandle((intptr_t)hWrite, _O_WRONLY|_O_TEXT);
    if (m_channels & StandardOutput)
        _dup2(fd, 1);
    if (m_channels & StandardError)
        _dup2(fd, 2);
    _close(fd);

    pipeReader = new QWindowsPipeReader(this);
    pipeReader->setHandle(hRead);
    pipeReader->startAsyncRead();
    connect(pipeReader, SIGNAL(readyRead()), this, SIGNAL(readyRead()));
#else
    ::pipe(pipeEnds);
    if (m_channels & StandardOutput)
        ::dup2(pipeEnds[1], 1);
    if (m_channels & StandardError)
        ::dup2(pipeEnds[1], 2);
    ::close(pipeEnds[1]);

    buffer = new QRingBuffer();
    socketNotifier = new QSocketNotifier(pipeEnds[0], QSocketNotifier::Read, this);
    connect(socketNotifier, SIGNAL(activated(int)), this, SLOT(onSocketActivated()));
#endif
}

这是正常用法，在Qt4时代，信号只可以和 SIGNAL，SLOT，METHOD 3种东西相连。而到了Qt5时代，可以连接的东西就更多了

我记得Qt4时代两个信号就能连接了，可以一个信号发出后去激活另一个信号的发出
好像Qt5连普通函数都能connect了？