qml can not recognize the c++ parameters with &

[wysota]

But before I can return the modified list, I need to get the data from qml site
It would be great if the return data could be moved(rvalue reference, rvo) to the qml site

It can't because C++ and QML use different representation for the data.

What would you try to do if there are a lot of data need to transfer between c++ and qml?

I would probably not move betweeen C++ and QML at all.

If you don't modify the lists then use const references but that will make a copy anyway.