warning: creating a shared reference to mutable static is discouraged
  --> $DIR/issue-23611-enum-swap-in-drop.rs:189:31
   |
LL |             (mem::size_of_val(&trails) * 8) as u32
   |                               ^^^^^^^ shared reference to mutable static
   |
   = note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
   = note: this will be a hard error in the 2024 edition
   = note: this shared reference has lifetime `'static`, but if the static ever gets mutated, or a mutable reference is created, then any further use of this shared reference is Undefined Behavior
   = note: `#[warn(static_mut_refs)]` on by default
help: use `addr_of!` instead to create a raw pointer
   |
LL |             (mem::size_of_val(addr_of!(trails)) * 8) as u32
   |                               ~~~~~~~~~~~~~~~~

warning: 1 warning emitted