61 lines
1.6 KiB
Rust
61 lines
1.6 KiB
Rust
// Copyright 2012-2014 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.
|
|
|
|
// ignore-pretty -- comments are unfaithfully preserved
|
|
|
|
#[allow(unused_variable)];
|
|
#[allow(dead_assignment)];
|
|
|
|
fn cond() -> bool { fail!() }
|
|
fn link<'a>(v: &'a uint, w: &mut &'a uint) -> bool { *w = v; true }
|
|
|
|
fn separate_arms() {
|
|
// Here both arms perform assignments, but only is illegal.
|
|
|
|
let mut x = None;
|
|
match x {
|
|
None => {
|
|
// It is ok to reassign x here, because there is in
|
|
// fact no outstanding loan of x!
|
|
x = Some(0);
|
|
}
|
|
Some(ref _i) => {
|
|
x = Some(1); //~ ERROR cannot assign
|
|
}
|
|
}
|
|
x.clone(); // just to prevent liveness warnings
|
|
}
|
|
|
|
fn guard() {
|
|
// Here the guard performs a borrow. This borrow "infects" all
|
|
// subsequent arms (but not the prior ones).
|
|
|
|
let mut a = ~3;
|
|
let mut b = ~4;
|
|
let mut w = &*a;
|
|
match 22 {
|
|
_ if cond() => {
|
|
b = ~5;
|
|
}
|
|
|
|
_ if link(&*b, &mut w) => {
|
|
b = ~6; //~ ERROR cannot assign
|
|
}
|
|
|
|
_ => {
|
|
b = ~7; //~ ERROR cannot assign
|
|
}
|
|
}
|
|
|
|
b = ~8; //~ ERROR cannot assign
|
|
}
|
|
|
|
fn main() {}
|