| //@ run-pass | |
| macro_rules! pat_in { | |
| ($p:pat in $e:expr) => {{ | |
| let mut iter = $e.into_iter(); | |
| while let $p = iter.next() {} | |
| }}; | |
| } | |
| macro_rules! pat_if { | |
| ($p:pat if $e:expr) => {{ | |
| match Some(1u8) { | |
| $p if $e => {} | |
| _ => {} | |
| } | |
| }}; | |
| } | |
| fn main() { | |
| pat_in!(Some(_) in 0..10); | |
| pat_if!(Some(x) if x > 0); | |
| } |