Function is_text_node

Source/ThirdParty/pugixml/pugixml_extra.cpp:20–25

This comes from pugi::impl::is_text_node

    // This comes from pugi::impl::is_text_node
    inline bool is_text_node(const xml_node& node)
    {
        xml_node_type type = node.type();

        return type == node_pcdata || type == node_cdata;
    }

    xml_node_extra::xml_node_extra(xml_node child) : xml_node(child)
    {