error: `?` may only modify trait bounds, not lifetime bounds
  --> $DIR/issue-68890.rs:1:11
   |
LL | enum e{A((?'a a+?+l))}
   |           ^

error: expected one of `)`, `+`, or `,`, found `a`
  --> $DIR/issue-68890.rs:1:15
   |
LL | enum e{A((?'a a+?+l))}
   |      -        ^ expected one of `)`, `+`, or `,`
   |      |
   |      while parsing this enum
   |
   = help: enum variants can be `Variant`, `Variant = <integer>`, `Variant(Type, ..., TypeN)` or `Variant { fields: Types }`

error: expected item, found `)`
  --> $DIR/issue-68890.rs:1:21
   |
LL | enum e{A((?'a a+?+l))}
   |                     ^ expected item
   |
   = note: for a full list of items that can appear in modules, see <https://doc.rust-lang.org/reference/items.html>

error: aborting due to 3 previous errors