Add Label to rectangle overlay

Have you considered adding label to rectangle overlay? I found this function in dlib documentation

void add_overlay(
            const rectangle& r, 
            pixel_type p, 
            const std::string& l
        );

Would it be hard to implement? As far as i can tell - usage of std::string is the biggest problem here: https://github.com/davisking/dlib/blob/6b581d91f6b9b847a8163420630ef947e7cc88db/dlib/gui_widgets/widgets_abstract.h#L2951

[takuya-takeuchi]

ok. give a bit time to implenent.

[jakoss]

Thanks, works like a charm 😃