error[E0161]: cannot move a value of type `[u8]`
  --> $DIR/return-unsized-from-trait-method.rs:9:17
   |
LL |         let _ = f.foo();
   |                 ^^^^^^^ the size of `[u8]` cannot be statically determined

error: aborting due to previous error

For more information about this error, try `rustc --explain E0161`.