// edition:2021 #![allow(unused_macros)] macro_rules! foo { ($x:pat | $y:pat) => {} } //~ ERROR `$x:pat` is followed by `|`, which is not allowed for `pat` fragments macro_rules! bar { ($($x:pat)+ | $($y:pat)+) => {} } //~ ERROR `$x:pat` is followed by `|`, which is not allowed for `pat` fragments macro_rules! qux { ($x:pat, $y:pat) => {} } // should be ok macro_rules! match_any { ( $expr:expr , $( $( $pat:pat )|+ => $expr_arm:expr ),+ ) => { //~ ERROR `$pat:pat` may be followed by `|`, which is not allowed for `pat` fragments match $expr { $( $( $pat => $expr_arm, )+ )+ } }; } fn main() { let result: Result = Err(42); let int: i64 = match_any!(result, Ok(i) | Err(i) => i.into()); assert_eq!(int, 42); }