At least not here, because we don't know the deep details.
It's a twofold problem:
The connect needs a context QObject, if not specified that's the sender.
Then the question becomes is the following the same connection:
QObject * otherObject;
void freeFunction();
QObject::connect(this, &MyClass::someSignal, otherObject, freeFunction);
QObject::connect(this, &MyClass::someSignal, this, freeFunction);
where, conceivably, otherObject may be in a different thread. Nobody knows how these two should be distinguished exactly - in some cases they may be considered the same, in some they may not. freeFunction isn't attached to the class of this, nor to the class of otherObject.
A functor (a.k.a. lamda, a.k.a. function object, std::function, etc.) more often than not has (internal) state. So two instances of the same type (i.e. two lambdas) can't be distinguished due to the fact that the state is not known to Qt. Example:
auto functor1 = [this] () -> void {
qDebug() << "Functor";
}
auto functor2 = functor1; //< Object copy here! We are dealing with another entity entirely!
QObject::connect(this, &MyClass::someSignal, this, functor1);
QObject::connect(this, &MyClass::someSignal, this, functor2); //< functor2 isn't functor1
And to add insult to injury:
QObject::connect(this, &MyClass::someSignal, this, functor1); //< Object copy of functor1!
QObject::connect(this, &MyClass::someSignal, this, functor1); //< Object copy of functor1, again!
