3 macro_rules! higher_order {
4 (subst $lhs:tt => $rhs:tt) => ({
5 macro_rules! anon { $lhs => $rhs }
6 anon!(1_usize, 2_usize, "foo")
11 ($x:expr; $fragment:ident) => {
12 macro_rules! inner { ($y:$fragment) => { $x + $y } }
17 let val = higher_order!(subst ($x:expr, $y:expr, $foo:expr) => (($x + $y, $foo)));
18 assert_eq!(val, (3, "foo"));
21 assert_eq!(inner!(3), 5);