QQmlProperty::read should take a const QObject *

QQmlProperty has static read and write convenience methods. They both accept a non-const QObject * as their target, but only the write methods require a non-const QObject *.

The read convenience methods thus can't be used from a const method without doing a const_cast.

edit:

Actually, it's the constructor which doesn't accept a const QObject *. This may be by design, but it prevents QQmlProperty from being used in a const method.