error: no rules expected `c`
  --> tests/ui/compile-fail/init/missing_comma.rs:16:9
   |
16 |         c: Bar,
   |         ^ no rules expected this token in macro call
   |
note: while trying to match `,`
  --> src/macros.rs
   |
   |         @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
   |                                                   ^

error: no rules expected `c`
  --> tests/ui/compile-fail/init/missing_comma.rs:16:9
   |
16 |         c: Bar,
   |         ^ no rules expected this token in macro call
   |
note: while trying to match `,`
  --> src/macros.rs
   |
   |         @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
   |                                                   ^