fn slice_borrow_kind(ty: &Type) -> Option<SliceBorrow>Expand description
Classify ty as a zero-copy slice borrow of R’s data pointer, if it is one.
Vec<T> / Box<[T]> copy the R vector and never alias R’s buffer, so they
are not classified. match_arg + several_ok &mut [T] params get their
own owned Vec<T> storage and are excluded by the caller, not here.