rust/src/test/compile-fail/borrowck-loan-vec-content.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.

// Here we check that it is allowed to lend out an element of a
// (locally rooted) mutable, unique vector, and that we then prevent
// modifications to the contents.

fn takes_imm_elt<F>(_v: &int, f: F) where F: FnOnce() {
    f();
}

fn has_mut_vec_and_does_not_try_to_change_it() {
    let mut v: Vec<int> = vec!(1, 2, 3);
    takes_imm_elt(&v[0], || {})
}

fn has_mut_vec_but_tries_to_change_it() {
    let mut v: Vec<int> = vec!(1, 2, 3);
    takes_imm_elt(
        &v[0],
        || { //~ ERROR cannot borrow `v` as mutable
            v[1] = 4;
        })
}

fn main() {
}