error: mismatched closing delimiter: `]`
  --> $DIR/issue-63116.rs:4:14
   |
LL | impl W <s(f;Y(;]
   |              ^ ^ mismatched closing delimiter
   |              |
   |              unclosed delimiter

error: this file contains an unclosed delimiter
  --> $DIR/issue-63116.rs:4:18
   |
LL | impl W <s(f;Y(;]
   |          -      ^
   |          |
   |          unclosed delimiter

error: aborting due to 2 previous errors