rust/src/test/compile-fail/borrowck-assign-comp-idx.rs
2014-03-21 23:37:21 +11:00

50 lines
1.1 KiB
Rust

// 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 Point {
x: int,
y: int,
}
fn a() {
let mut p = vec!(1);
// Create an immutable pointer into p's contents:
let q: &int = &p[0];
p[0] = 5; //~ ERROR cannot assign
println!("{}", *q);
}
fn borrow(_x: &[int], _f: ||) {}
fn b() {
// here we alias the mutable vector into an imm slice and try to
// modify the original:
let mut p = vec!(1);
borrow(
p,
|| p[0] = 5); //~ ERROR cannot borrow `p` as mutable
}
fn c() {
// Legal because the scope of the borrow does not include the
// modification:
let mut p = vec!(1);
borrow(p, ||{});
p[0] = 5;
}
fn main() {
}