UserDefaultAttrprop::set_enum_labels: Does append enum labels

Our code:

    void set_enum_labels(const std::vector<std::string> &def_enum_labels)
    {
        for(size_t loop = 0; loop < def_enum_labels.size(); loop++)
        {
            enum_labels = enum_labels + def_enum_labels[loop];
            if(loop != def_enum_labels.size() - 1)
            {
                enum_labels = enum_labels + ',';
            }
        }
    }

I would expect a "set" function to replace the existing values.