deermine if Qt is installed

[GrahamLabdon]

Hi all
What is the best practice to programatically determine in Qt is installed on a given machine?
I use the following

QDir dir (QLibraryInfo::location(QLibraryInfo::BinariesPath) + QDir::separator());

QDir dir (QLibraryInfo::location(QLibraryInfo::BinariesPath) + QDir::separator());

To copy to clipboard, switch view to plain text mode 

and then check if the directory exits.
Being new yo Qt I would appreciate feedback as to whether this is the best way

TIA

Graham