rust/src/test/compile-fail/regions-infer-borrow-scope-within-loop.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.


fn borrow<T>(x: &T) -> &T {x}

fn foo<C, M>(mut cond: C, mut make_box: M) where
    C: FnMut() -> bool,
    M: FnMut() -> Box<isize>,
{
    let mut y: &isize;
    loop {
        let x = make_box();

        // Here we complain because the resulting region
        // of this borrow is the fn body as a whole.
        y = borrow(&*x); //~ ERROR `*x` does not live long enough

        assert_eq!(*x, *y);
        if cond() { break; }
    }
    assert!(*y != 0);
}

fn main() {}