When using right click on a variable/object, in common words - user defined "entity", and selecting "Refactor -> Rename Symbol Under Cursor" it works fine. But when trying to rename the defined class name (defined in Qt), for instance in this code:

//header file
//....
private:
    QVBoxLayout* m_documents_layout;
//......

//cpp file
//...
m_documents_layout = new QVBoxLayout(this);
m_documents_layout->addWidget(m_documents_view);
//....

by renaming the QVBoxLayout (to me it should work fine, because I've decided to use QHBoxLayout instead), the editor/IDE renames also the QVBoxLayout declared in qboxlayout.h. E.g. it doesn't restricts itself to "refactor" only in local workspace area.
After this the build is going fail with error like "Redefinition of class QHBoxLayout"(actually the QVBoxLayout replaced with QHBoxLayout after refactoring and there are two QHBoxLayouts )