Error code E0206

The Copy trait was implemented on a type which is neither a struct nor an enum.

Erroneous code example:

#![allow(unused)]
fn main() {
#[derive(Copy, Clone)]
struct Bar;

impl Copy for &'static mut Bar { } // error!
}
ⓘ

You can only implement Copy for a struct or an enum. The previous example will fail because &'static mut Bar is not a struct or enum.