error: expected `:` followed by trait or lifetime
  --> $DIR/issue-95208-ignore-qself.rs:6:88
   |
LL | impl<T: Iterator> Struct<T> where <T as std:: iter::Iterator>::Item:: std::fmt::Display {
   |                                                                    ---                 ^
   |                                                                    |
   |                                                                    help: use single colon: `:`

error: aborting due to previous error