[Interest] connect() is copying lambdas - can this be avoided?

[Nikos Chantziaras]

It seems that connect() is copying its lambda parameter around. That 
means that if a lambda capture contains a non-copyable object, like a 
unique_ptr, connect() cannot be used:

   {
       auto ptr = std::make_unique<int>(0);
       connect(this, &MyQObject::mySignal,
               [ptr = std::move(ptr)]() mutable { });
   }

(This is just an example. In reality, ptr would manage something 
non-trivial.)

It's useful to have the lambda take ownership of ptr, but currently 
that's not possible and we have to resort to shared_ptr. (Which is not 
the end of the world, but still.)

Is this a problem the Qt project is aware of and the design is intended, 
or is this something that can be considered a defect?