Module cow_and_paths 

Cow, PathBuf, OsString, and string collection conversions.

• Cow<'static, [T]> — zero-copy borrow of R native vectors
• Cow<'static, str> — zero-copy borrow of R character scalars
• PathBuf / OsString — from STRSXP via String intermediary
• HashSet<String> / BTreeSet<String> — string set conversions

Tradeoff

These TryFromSexp impls reject mismatched [SEXPTYPE]s — there is no looser coercion path for Cow / PathBuf / OsString. The 'static lifetime on Cow borrows is valid only for the duration of the enclosing .Call; if you need an owned value that outlives R’s GC, take String or Vec<T> instead (see strings and references).

Macros

impl_set_string_try_from_sexp 🔒

impl_string_wrapper_try_from_sexp 🔒

Generate TryFromSexp impls for types that are From<String> (scalar, Option, Vec, Vec<Option>). Used for PathBuf and OsString which delegate to String conversion.