title: Trying to connect a signal from another class to a slot in the main class
body: <p>I needed a clickable QLabel, so I've created a class called "clickablelabel" which is a QLabel having the mouseReleaseEvent. Once that is called it will emit "clicked(cid)". "cid" is a public variable inside clickablelabel, set by clickablelabel.</p>
  
  <p>When "clicked" is emit I want the UI in my main window changed, so I have done this:</p>
  
  <p><em>clickablelabel.h</em></p>
  
  <pre><code>signals:
      void clicked(int id);
  </code></pre>
  
  <p><em>clickablelabel.cpp</em></p>
  
  <pre><code>void clickableLabel::mouseReleaseEvent ( QMouseEvent * event )
  {
      emit clicked(cid);
  }
  </code></pre>
  
  <p><em>mainwindow.h</em></p>
  
  <pre><code>private slots:
      void test(int id);
  </code></pre>
  
  <p><em>mainwindow.cpp</em></p>
  
  <pre><code>void MainWindow::test(int id){
      qDebug() &lt;&lt; id;
  }
  
  MainWindow::MainWindow(QWidget *parent) :
  QMainWindow(parent),
  ui(new Ui::MainWindow)
  {
      connect(clickableLabel, SIGNAL(clicked(int)), this, SLOT(test(int)));
      ui-&gt;setupUi(this);
  }
  </code></pre>
  
  <p>This is the error I am getting when I try to run the program:</p>
  
  <pre><code>"expected primary-expression before ',' token
   connect(clickableLabel, SIGNAL(clicked(int)), this, SLOT(test(int)));
                         ^"
  </code></pre>