id_placeholder* id_state::add_placeholder( std::string const& id, id_category category, id_placeholder* parent) { placeholders.push_back(id_placeholder( placeholders.size(), id, category, parent)); return &placeholders.back(); }
id_placeholder const* document_state_impl::add_placeholder( boost::string_ref id, id_category category, id_placeholder const* parent) { placeholders.push_back(id_placeholder( placeholders.size(), id, category, parent)); return &placeholders.back(); }