1 The `Copy` trait was implemented on a type which contains a field that doesn't
2 implement the `Copy` trait.
4 Erroneous code example:
11 impl Copy for Foo { } // error!
14 The `Copy` trait is implemented by default only on primitive types. If your
15 type only contains primitive types, you'll be able to implement `Copy` on it.
16 Otherwise, it won't be possible.
18 Here's another example that will fail:
21 #[derive(Copy)] // error!
27 This fails because `&mut T` is not `Copy`, even when `T` is `Copy` (this
28 differs from the behavior for `&T`, which is always `Copy`).