Another rchk issue to look into

``` Function cpp11::writable::r_vector<SEXPREC*>::r_vector(std::initializer_list<cpp11::named_arg>)::{lambda()#1}::operator()() const [UP] unprotected variable names while calling allocating function Rf_mkCharCE cpp11/include/cpp11/list.hpp:91 Function cpp11::writable::r_vector<cpp11::r_bool>::r_vector(std::initializer_list<cpp11::named_arg>)::{lambda()#1}::operator()() const [UP] unprotected variable names while calling allocating function Rf_mkCharCE cpp11/include/cpp11/r_vector.hpp:890 ``` https://raw.githubusercontent.com/kalibera/cran-checks/master/rchk/results/adfExplorer.out https://raw.githubusercontent.com/kalibera/cran-checks/master/rchk/results/cpp11bigwig.out I believe it is saying we have an unprotected SEXP called `names` at the point that we call `Rf_mkCharCE()`. This is surely a false alarm, because `Rf_setAttrib()` protects `names` by installed it as an attribute on `data_`, but I guess we can try to work around it. ```c++ template <> inline r_vector<SEXP>::r_vector(std::initializer_list<named_arg> il) : cpp11::r_vector<SEXP>(safe[Rf_allocVector](VECSXP, il.size())), capacity_(il.size()) { unwind_protect([&] { SEXP names = Rf_allocVector(STRSXP, capacity_); Rf_setAttrib(data_, R_NamesSymbol, names); auto it = il.begin(); for (R_xlen_t i = 0; i < capacity_; ++i, ++it) { SEXP elt = it->value(); set_elt(data_, i, elt); SEXP name = Rf_mkCharCE(it->name(), CE_UTF8); SET_STRING_ELT(names, i, name); } }); } ```