rust/src/test/compile-fail/borrowck-lend-flow-match.rs
Niko Matsakis 9e3d0b002a librustc: Remove the fallback to int from typechecking.
This breaks a fair amount of code. The typical patterns are:

* `for _ in range(0, 10)`: change to `for _ in range(0u, 10)`;

* `println!("{}", 3)`: change to `println!("{}", 3i)`;

* `[1, 2, 3].len()`: change to `[1i, 2, 3].len()`.

RFC #30. Closes #6023.

[breaking-change]
2014-06-24 17:18:48 -07:00

59 lines
1.5 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.
#![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(0i);
}
Some(ref _i) => {
x = Some(1i); //~ 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 = box 3;
let mut b = box 4;
let mut w = &*a;
match 22 {
_ if cond() => {
b = box 5;
}
_ if link(&*b, &mut w) => {
b = box 6; //~ ERROR cannot assign
}
_ => {
b = box 7; //~ ERROR cannot assign
}
}
b = box 8; //~ ERROR cannot assign
}
fn main() {}