1 error[E0277]: the trait bound `std::boxed::Box<dyn Map<isize, isize>>: Map<usize, isize>` is not satisfied
2 --> $DIR/map-types.rs:17:37
4 LL | let y: Box<Map<usize, isize>> = Box::new(x);
5 | ^^^^^^^^^^^ the trait `Map<usize, isize>` is not implemented for `std::boxed::Box<dyn Map<isize, isize>>`
7 = note: required for the cast to the object type `dyn Map<usize, isize>`
9 error: aborting due to previous error
11 For more information about this error, try `rustc --explain E0277`.