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1 | // Copyright 2015 The Rust Project Developers. See the COPYRIGHT |
2 | // file at the top-level directory of this distribution and at | |
3 | // http://rust-lang.org/COPYRIGHT. | |
4 | // | |
5 | // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or | |
6 | // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license | |
7 | // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your | |
8 | // option. This file may not be copied, modified, or distributed | |
9 | // except according to those terms. | |
10 | ||
11 | // Reject mixing cyclic structure and Drop when using fixed length | |
12 | // arrays. | |
13 | // | |
14 | // (Compare against compile-fail/dropck_vec_cycle_checked.rs) | |
15 | ||
85aaf69f SL |
16 | use std::cell::Cell; |
17 | use id::Id; | |
18 | ||
19 | mod s { | |
20 | #![allow(unstable)] | |
c34b1796 | 21 | use std::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering}; |
85aaf69f | 22 | |
c34b1796 | 23 | static S_COUNT: AtomicUsize = ATOMIC_USIZE_INIT; |
85aaf69f SL |
24 | |
25 | pub fn next_count() -> usize { | |
26 | S_COUNT.fetch_add(1, Ordering::SeqCst) + 1 | |
27 | } | |
28 | } | |
29 | ||
30 | mod id { | |
31 | use s; | |
32 | #[derive(Debug)] | |
33 | pub struct Id { | |
34 | orig_count: usize, | |
35 | count: usize, | |
36 | } | |
37 | ||
38 | impl Id { | |
39 | pub fn new() -> Id { | |
40 | let c = s::next_count(); | |
41 | println!("building Id {}", c); | |
42 | Id { orig_count: c, count: c } | |
43 | } | |
44 | pub fn count(&self) -> usize { | |
45 | println!("Id::count on {} returns {}", self.orig_count, self.count); | |
46 | self.count | |
47 | } | |
48 | } | |
49 | ||
50 | impl Drop for Id { | |
51 | fn drop(&mut self) { | |
52 | println!("dropping Id {}", self.count); | |
53 | self.count = 0; | |
54 | } | |
55 | } | |
56 | } | |
57 | ||
58 | trait HasId { | |
59 | fn count(&self) -> usize; | |
60 | } | |
61 | ||
62 | #[derive(Debug)] | |
63 | struct CheckId<T:HasId> { | |
64 | v: T | |
65 | } | |
66 | ||
67 | #[allow(non_snake_case)] | |
68 | fn CheckId<T:HasId>(t: T) -> CheckId<T> { CheckId{ v: t } } | |
69 | ||
85aaf69f SL |
70 | impl<T:HasId> Drop for CheckId<T> { |
71 | fn drop(&mut self) { | |
72 | assert!(self.v.count() > 0); | |
73 | } | |
74 | } | |
75 | ||
76 | #[derive(Debug)] | |
77 | struct B<'a> { | |
78 | id: Id, | |
79 | a: [CheckId<Cell<Option<&'a B<'a>>>>; 2] | |
80 | } | |
81 | ||
82 | impl<'a> HasId for Cell<Option<&'a B<'a>>> { | |
83 | fn count(&self) -> usize { | |
84 | match self.get() { | |
85 | None => 1, | |
86 | Some(b) => b.id.count(), | |
87 | } | |
88 | } | |
89 | } | |
90 | ||
91 | impl<'a> B<'a> { | |
92 | fn new() -> B<'a> { | |
93 | B { id: Id::new(), a: [CheckId(Cell::new(None)), CheckId(Cell::new(None))] } | |
94 | } | |
95 | } | |
96 | ||
97 | fn f() { | |
98 | let (b1, b2, b3); | |
99 | b1 = B::new(); | |
100 | b2 = B::new(); | |
101 | b3 = B::new(); | |
102 | b1.a[0].v.set(Some(&b2)); //~ ERROR `b2` does not live long enough | |
103 | b1.a[1].v.set(Some(&b3)); //~ ERROR `b3` does not live long enough | |
104 | b2.a[0].v.set(Some(&b2)); //~ ERROR `b2` does not live long enough | |
105 | b2.a[1].v.set(Some(&b3)); //~ ERROR `b3` does not live long enough | |
106 | b3.a[0].v.set(Some(&b1)); //~ ERROR `b1` does not live long enough | |
107 | b3.a[1].v.set(Some(&b2)); //~ ERROR `b2` does not live long enough | |
108 | } | |
109 | ||
110 | fn main() { | |
111 | f(); | |
112 | } |