error: expected one of `>`, a const expression, lifetime, or type, found `,` --> $DIR/issue-20616-5.rs:22:34 | LL | type Type_5<'a> = Type_1_<'a, (),,>; | ^ expected one of `>`, a const expression, lifetime, or type | help: you might have meant to end the type parameters here | LL | type Type_5<'a> = Type_1_<'a, ()>,,>; | + error: aborting due to 1 previous error