|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:8:7 | 
|  | | | 
|  | LL |     ($($($i:ident)?)+) => {}; | 
|  | |       ^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:13:7 | 
|  | | | 
|  | LL |     ($($($i:ident)?)*) => {}; | 
|  | |       ^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:18:7 | 
|  | | | 
|  | LL |     ($($($i:ident)?)?) => {}; | 
|  | |       ^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:23:7 | 
|  | | | 
|  | LL |     ($($($($i:ident)?)?)?) => {}; | 
|  | |       ^^^^^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:28:7 | 
|  | | | 
|  | LL |     ($($($($i:ident)*)?)?) => {}; | 
|  | |       ^^^^^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:33:7 | 
|  | | | 
|  | LL |     ($($($($i:ident)?)*)?) => {}; | 
|  | |       ^^^^^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:38:7 | 
|  | | | 
|  | LL |     ($($($($i:ident)?)?)*) => {}; | 
|  | |       ^^^^^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:43:7 | 
|  | | | 
|  | LL |     ($($($($i:ident)*)*)?) => {}; | 
|  | |       ^^^^^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:48:7 | 
|  | | | 
|  | LL |     ($($($($i:ident)?)*)*) => {}; | 
|  | |       ^^^^^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:53:7 | 
|  | | | 
|  | LL |     ($($($($i:ident)?)*)+) => {}; | 
|  | |       ^^^^^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:58:7 | 
|  | | | 
|  | LL |     ($($($($i:ident)+)?)*) => {}; | 
|  | |       ^^^^^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: repetition matches empty token tree | 
|  | --> $DIR/issue-57597.rs:63:7 | 
|  | | | 
|  | LL |     ($($($($i:ident)+)*)?) => {}; | 
|  | |       ^^^^^^^^^^^^^^^^^^ | 
|  |  | 
|  | error: aborting due to 12 previous errors | 
|  |  |