error[E0515]: cannot return reference to local data `x`
  --> $DIR/issue-11925.rs:8:35
   |
LL |         let f = to_fn_once(move|| &x);
   |                                   ^^ returns a reference to data owned by the current function

error: aborting due to previous error

For more information about this error, try `rustc --explain E0515`.