fn parse_fn_arg_or_variadic(
input: ParseStream<'_>,
attrs: Vec<Attribute>,
allow_variadic: bool,
) -> Result<FnArgOrVariadic>
fn parse_fn_arg_or_variadic(
input: ParseStream<'_>,
attrs: Vec<Attribute>,
allow_variadic: bool,
) -> Result<FnArgOrVariadic>