		arg.into()
	};
	let file = File::open(&path).unwrap_or_else(|e| {
		panic!("Unable to open {:?}: {}", path, e);
	});
	let file = BufReader::new(file);

	// Verify that the struct looks like `[pub] struct name;`

	let input = parse_macro_input!(input as syn::DeriveInput);
	let name = input.ident;
	let is_unit_struct = match input.data {
		syn::Data::Struct(s) => match s.fields {