pub fn derive_altrep_string(input: DeriveInput) -> Result<TokenStream>Expand description
Derive macro entry point for AltrepString.
Auto-implements AltrepLen and AltStringData for a struct with a length field.
The elt() method returns Some(self.{elt_field}.as_ref()) as Option<&str> if
#[altrep(elt = "...")] is specified, or None (R’s NA_character_) by default.
String ALTREP supports #[altrep(dataptr)] for materialized STRSXP dataptr
(via __impl_altvec_string_dataptr) and #[altrep(subset)] for Extract_subset.
Note: String dataptr materializes the entire vector into a cached STRSXP in the
data2 slot.