类中使用了connect，一直报错：
clientstart.cpp:68:63: error: no matching function for call to ‘ClientStart::connect(int&, sockaddr*, long unsigned int)’
if(connect(clientSocketFd, (SA *) &servaddr, sizeof(servaddr)) < 0) return 0;
^
clientstart.cpp:68:63: note: candidates are:
In file included from /opt/Qt5.3.2/5.3/gcc_64/include/QtWidgets/qwidget.h:46:0,
from /opt/Qt5.3.2/5.3/gcc_64/include/QtWidgets/qmainwindow.h:45,
from /opt/Qt5.3.2/5.3/gcc_64/include/QtWidgets/QMainWindow:1,
from clientstart.h:4,
from clientstart.cpp:1:
/opt/Qt5.3.2/5.3/gcc_64/include/QtCore/qobject.h:198:36: note: static QMetaObject::Connection QObject::connect(const QObject*, const char*, const QObject*, const char*, Qt::ConnectionType)
static QMetaObject::Connection connect(const QObject *sender, const char *signal,
其实就是socket里的connect与qt的发生冲突，把含有connect的代码改成：
if(::connect(clientSocketFd, (SA *) &servaddr, sizeof(servaddr)) < 0)
done!