Such as it's the case for `names()`, it would be extremely convenient to have `rownames()` and `colnames()` in cpp codes. My idea (sorry that I don't enough C++) would be like: ``` // THIS WORKS [[cpp11::register]] doubles cpp_names(writable::doubles X) { X.attr("names") = {"a","b"}; return X; } // THIS WON'T // [[cpp11::register]] // doubles_matrix<> cpp_colnames(writable::doubles_matrix<> X) { // writable::list dimnames; // dimnames.push_back(NULL); // dimnames.push_back({"a","b"}); // X.attr("dimnames") = dimnames; // return X; // } ```