#![allow(unreachable_code)]


fn main() {
    println!("{:?}", {
        macro_rules! foo { ($(a)?) => {} } foo!()
    });
}


/* ~~~~=== stderr ===~~~~
   Compiling playground v0.0.1 (/playground)
error: macro expansion ends with an incomplete expression: expected expression
 --> src/main.rs:6:44
  |
6 |         macro_rules! foo { ($(a)?) => {} } foo!()
  |                                       --   ^^^^^^ expected expression
  |                                       |
  |                                       in this macro arm

error: aborting due to previous error

error: Could not compile `playground`.

To learn more, run the command again with --verbose.

*/

/* ~~~~=== stdout ===~~~~

*/