error[E0038]: the trait `Bar` cannot be made into an object --> $DIR/object-safety-associated-consts.rs:14:5 | LL | t | ^ `Bar` cannot be made into an object | note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit --> $DIR/object-safety-associated-consts.rs:9:11 | LL | trait Bar { | --- this trait cannot be made into an object... LL | const X: usize; | ^ ...because it contains this associated `const` = help: consider moving `X` to another trait = note: required for the cast from `&T` to `&dyn Bar` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0038`.