pub(crate) const OPTION_SCALAR_NAMES: &[&str];Expand description
Scalar types accepted inside Option<…> as a struct-path field (#1437):
every T here has IntoR for Vec<Option<T>> (typed NA for None) in
miniextendr-api::into_r. The reader side is gated separately by
is_reader_scalar_ty, so Option<u64> / Option<usize> fields are
write-only, like their bare counterparts.