os-rust/src/test/run-pass/regions-copy-closure.rs

// Copyright 2012 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.

struct closure_box<'a> {
    cl: 'a ||,
}

fn box_it<'r>(x: 'r ||) -> closure_box<'r> {
    closure_box {cl: x}
}

pub fn main() {
    let mut i = 3;
    let cl_box = box_it(|| i += 1);
    assert_eq!(i, 3);
    (cl_box.cl)();
    assert_eq!(i, 4);
}