mirror of
https://github.com/rust-lang/rust.git
synced 2024-10-31 22:41:50 +00:00
23 lines
492 B
Rust
23 lines
492 B
Rust
// run-pass
|
|
|
|
macro_rules! higher_order {
|
|
(subst $lhs:tt => $rhs:tt) => ({
|
|
macro_rules! anon { $lhs => $rhs }
|
|
anon!(1_usize, 2_usize, "foo")
|
|
});
|
|
}
|
|
|
|
macro_rules! outer {
|
|
($x:expr; $fragment:ident) => {
|
|
macro_rules! inner { ($y:$fragment) => { $x + $y } }
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
let val = higher_order!(subst ($x:expr, $y:expr, $foo:expr) => (($x + $y, $foo)));
|
|
assert_eq!(val, (3, "foo"));
|
|
|
|
outer!(2; expr);
|
|
assert_eq!(inner!(3), 5);
|
|
}
|