error[E0038]: the trait `Bar` cannot be made into an object --> $DIR/object-safety-associated-consts.rs:12:31 | LL | fn make_bar<T:Bar>(t: &T) -> &dyn Bar { | ^^^^^^^ `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 <https://doc.rust-lang.org/reference/items/traits.html#object-safety> --> $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 error: aborting due to previous error For more information about this error, try `rustc --explain E0038`.