error: implementation of `Trait` is not general enough --> $DIR/hrtb-exists-forall-trait-invariant.rs:28:5 | LL | foo::<()>(); | ^^^^^^^^^^^ implementation of `Trait` is not general enough | = note: `()` must implement `Trait<for<'b> fn(Cell<&'b u32>)>` = note: ...but it actually implements `Trait<fn(Cell<&'0 u32>)>`, for some specific lifetime `'0` error: aborting due to previous error