error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in variable binding
  --> $DIR/issue-87295.rs:16:31
   |
LL |     let _do_not_waste: Struct<impl Trait<Output = i32>> = Struct::new(());
   |                               ^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to previous error

For more information about this error, try `rustc --explain E0562`.