error[E0277]: expected a `Fn(&'w ())` closure, found `fn(&'w ())`
  --> $DIR/fn-ptr.rs:12:5
   |
LL |     ice();
   |     ^^^ expected an `Fn(&'w ())` closure, found `fn(&'w ())`
   |
   = help: the trait `for<'w> Fn<(&'w (),)>` is not implemented for `fn(&'w ())`
note: required by a bound in `ice`
  --> $DIR/fn-ptr.rs:7:25
   |
LL | fn ice()
   |    --- required by a bound in this function
LL | where
LL |     for<'w> fn(&'w ()): Fn(&'w ()),
   |                         ^^^^^^^^^^ required by this bound in `ice`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0277`.