How to add label to a bounding box in dlib c++

I have several face shapes and their corresponding labels. I wanna print the labels along side of the face bounding boxes. So far what I have found is the following:

            win.clear_overlay();
            win.set_image(cimg);
            for (size_t i = 0; i < input_face_descriptors.size(); ++i)
            { 
                win.add_overlay(face_position[i], rgb_pixel(255, 0, 0));
                label::draw(face_position[i]);
                const rectangle r;
                win.add_overlay(image_window::overlay_rect(r, rgb_pixel(255, 0, 0), labels[i]));
            }

But this adds the text to the right hand corner of the frame and the labels are displayed one over the other.