rust/src/test/compile-fail/pattern-bindings-after-at.rs

// Copyright 2014 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.

enum Option<T> {
    None,
    Some(T),
}

fn main() {
    match &mut Some(1) {
        ref mut z @ &mut Some(ref a) => {
        //~^ ERROR pattern bindings are not allowed after an `@`
            **z = None;
            println!("{}", *a);
        }
        _ => ()
    }
}