src/test/ui/union/union-derive-clone.rs

// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

#![feature(untagged_unions)]

#[derive(Clone)] //~ ERROR the trait bound `U1: std::marker::Copy` is not satisfied
union U1 {
    a: u8,
}

#[derive(Clone)]
union U2 {
    a: u8, // OK
}

impl Copy for U2 {}

#[derive(Clone, Copy)]
union U3 {
    a: u8, // OK
}

#[derive(Clone, Copy)]
union U4<T> {
    a: T, // OK
}

#[derive(Clone)]
struct CloneNoCopy;

fn main() {
    let u = U4 { a: CloneNoCopy };
    let w = u.clone(); //~ ERROR no method named `clone` found for type `U4<CloneNoCopy>`
}