error[E0512]: transmute called with types of different sizes
  --> $DIR/issue-32377.rs:15:14
   |
LL |     unsafe { mem::transmute(x) }
   |              ^^^^^^^^^^^^^^
   |
   = note: source type: [usize; 2] (N bits)
   = note: target type: Bar<U> (N bits)

error: aborting due to previous error

For more information about this error, try `rustc --explain E0512`.