| The `Copy` trait was implemented on a type which is neither a struct, an | |
| enum, nor a union. | |
| Erroneous code example: | |
| ```compile_fail,E0206 | |
| #[derive(Copy, Clone)] | |
| struct Bar; | |
| impl Copy for &'static mut Bar { } // error! | |
| ``` | |
| You can only implement `Copy` for a struct, an enum, or a union. | |
| The previous example will fail because `&'static mut Bar` | |
| is not a struct, an enum, or a union. |