1 error[E0277]: the trait bound `Box<dyn Map<isize, isize>>: Map<usize, isize>` is not satisfied
2 --> $DIR/map-types.rs:17:41
4 LL | let y: Box<dyn Map<usize, isize>> = Box::new(x);
5 | ^^^^^^^^^^^ the trait `Map<usize, isize>` is not implemented for `Box<dyn Map<isize, isize>>`
7 = help: the trait `Map<K, V>` is implemented for `HashMap<K, V>`
8 = note: required for the cast to the object type `dyn Map<usize, isize>`
10 error: aborting due to previous error
12 For more information about this error, try `rustc --explain E0277`.