mirror of
https://github.com/rust-lang/rust.git
synced 2024-10-31 22:41:50 +00:00
21 lines
800 B
Rust
21 lines
800 B
Rust
// 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<i64, i32> = Err(42);
|
|
let int: i64 = match_any!(result, Ok(i) | Err(i) => i.into());
|
|
assert_eq!(int, 42);
|
|
}
|