// .rep file
class MyClass {
    SLOT(bool mySlot())
};

// Rep_MyClass_Replica.h by REPC
...
public Q_SLOTS:
    QRemoteObjectPendingReply<bool> mySlot() {
        ...
    }
...

// qml file
...
var result = myClass.mySlot() --> Error: Unknown method return type: QRemoteObjectPendingReply<bool>
result.waitForFinished();
...