Function is_miniextendr_match_arg_attr 

pub(crate) fn is_miniextendr_match_arg_attr(attr: &Attribute) -> bool

Returns true if attr is a #[miniextendr(...)] attribute containing match_arg.

The match_arg flag may be combined with other per-parameter options (e.g., #[miniextendr(match_arg, choices("a", "b"))]).