In the string-based overloads:

bool QObject::{dis,}connect(const QObject *sender, const char *signal,
                         const QObject *receiver, const char *method)

For testing, method must be a function declared as a signal or as a slot, not other member functions work with these overloads. Unlike the pointer-to-member-function overloads, where "method" can be any member function that can be connected to the signal, regardless of whether it's declared as a slot or not.

I propose adding something like:

    \a signal must be a function declared as a signal in \a sender.
    \a method must be a function declared as a signal or a slot in \a receiver.