rust/src/test/compile-fail/E0506.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.

// revisions: ast mir
//[mir]compile-flags: -Z emit-end-regions -Z borrowck-mir

struct FancyNum {
    num: u8,
}

fn main() {
    let mut fancy_num = FancyNum { num: 5 };
    let fancy_ref = &fancy_num;
    fancy_num = FancyNum { num: 6 }; //[ast]~ ERROR E0506
                                     //[mir]~^ ERROR (Mir) [E0506]
                                     //[mir]~| ERROR (Ast) [E0506]

    println!("Num: {}, Ref: {}", fancy_num.num, fancy_ref.num);
}