qHash function for QRect

Question

What is the best way to calculate the qHash value of a QRect? I need to use QRect (and maybe QRectF) as the key of QCache. Right now I am using something like this:

inline uint qHash(const QRect & r)
{
 return qHash(QByteArray::fromRawData((const char*)&r, sizeof(r)));
}

It seems to work but I don't like casting it into some raw bytes and since QRect is noy a simple struct, this may break sooner than later in future versions of Qt.

BTW. I don't store the hash values so it doesn't have to be persistent or cross-platform. But it does need to be reliable and fast.

Thanks.

Answer 1

I would simply do return qHash(QString("%1,%2,%3,%4").arg(r.x()).arg(r.y()).arg(r.width()).arg(r.height())))

Also I've found this solution: http://thesmithfam.org/blog/2008/01/17/using-qrect-with-qhash/ (read comment)