1 error[E0120]: the `Drop` trait may only be implemented for structs, enums, and unions
4 LL | impl Drop for u32 {}
5 | ^^^ must be a struct, enum, or union
7 error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
10 LL | impl Drop for u32 {}
13 | | `u32` is not defined in the current crate
14 | impl doesn't use only types from inside the current crate
16 = note: define and implement a trait or new type instead
18 error: aborting due to 2 previous errors
20 Some errors have detailed explanations: E0117, E0120.
21 For more information about an error, try `rustc --explain E0117`.