// 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 or the MIT license // , 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(_v: &int, f: F) where F: FnOnce() { f(); } fn has_mut_vec_and_does_not_try_to_change_it() { let mut v = vec!(1, 2, 3); takes_imm_elt(&v[0], || {}) } fn has_mut_vec_but_tries_to_change_it() { let mut v = vec!(1, 2, 3); takes_imm_elt( &v[0], || { //~ ERROR cannot borrow `v` as mutable v[1] = 4; }) } fn main() { }