// Copyright 2018 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(nll)]

fn flatten<'a, 'b, T>(x: &'a &'b T) -> &'a T {
    x
}

fn main() {
    let mut x = "original";
    let y = &x;
    let z = &y;
    let w = flatten(z);
    x = "modified";
    //~^ ERROR cannot assign to `x` because it is borrowed [E0506]
    println!("{}", w); // prints "modified"
}