fn parse_attrs(attr: TokenStream) -> Result<StructEnumAttrs>Expand description
Parses the attribute arguments of #[miniextendr(...)] when applied to a struct or enum.
Supports path-style flags (list, dataframe, externalptr, match_arg, factor)
and key-value pairs (class = "...", base = "...", prefer = "...").
Returns a StructEnumAttrs on success, or a compile error if an unknown attribute is found.