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