qt #include question

[marf]

I just have a general question.

When including QT libraries, is it better to

a)


#include <QDomDocument>
#include <QDomElement>
#include <QDomText>
...More Includes...


or

b)


#include <QtXml>


I'm just wondering, at what point should you just use the overall generic include of the whole QtXml library, rather than each specific class/object that you use?

Is there speed benefits to using one or the other?

[jpn]

See thread: Qt modules (http://www.qtcentre.org/forum/f-qt-programming-2/t-qt-modules-7287.html)