error[E0038]: the trait `Bar` cannot be made into an object
  --> $DIR/object-safety-associated-consts.rs:14:5
   |
LL | trait Bar {
   |       --- this trait cannot be made into an object...
LL |     const X: usize;
   |           - ...because it contains this associated `const`
...
LL |     t
   |     ^ the trait `Bar` cannot be made into an object
   |
   = help: consider moving `X` to another trait
   = note: required because of the requirements on the impl of `std::ops::CoerceUnsized<&dyn Bar>` for `&T`
   = note: required by cast to type `&dyn Bar`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0038`.