1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
//@revisions: stack tree
//@[tree]compile-flags: -Zmiri-tree-borrows
//@compile-flags: -Zmiri-strict-provenance
#![feature(get_mut_unchecked)]
#![allow(ambiguous_wide_pointer_comparisons)]
use std::cell::{Cell, RefCell};
use std::fmt::Debug;
use std::rc::{Rc, Weak};
use std::sync::{Arc, Weak as ArcWeak};
fn rc_refcell() {
let r = Rc::new(RefCell::new(42));
let r2 = r.clone();
*r.borrow_mut() += 10;
let x = *r2.borrow();
assert_eq!(x, 52);
}
fn rc_cell() {
let r = Rc::new(Cell::new(42));
let r2 = r.clone();
let x = r.get();
r2.set(x + x);
assert_eq!(r.get(), 84);
}
fn rc_refcell2() {
let r = Rc::new(RefCell::new(42));
let r2 = r.clone();
*r.borrow_mut() += 10;
let x = r2.borrow();
let r3 = r.clone();
let y = r3.borrow();
assert_eq!((*x + *y) / 2, 52);
}
fn rc_raw() {
let r = Rc::new(0);
let r2 = Rc::into_raw(r.clone());
let r2 = unsafe { Rc::from_raw(r2) };
assert!(Rc::ptr_eq(&r, &r2));
drop(r);
assert!(Rc::try_unwrap(r2).is_ok());
}
fn arc() {
fn test() -> Arc<i32> {
let a = Arc::new(42);
a
}
assert_eq!(*test(), 42);
let raw = ArcWeak::into_raw(ArcWeak::<usize>::new());
drop(unsafe { ArcWeak::from_raw(raw) });
}
// Make sure this Rc doesn't fall apart when touched
fn check_unique_rc<T: ?Sized>(mut r: Rc<T>) {
let r2 = r.clone();
assert!(Rc::get_mut(&mut r).is_none());
drop(r2);
assert!(Rc::get_mut(&mut r).is_some());
}
fn rc_from() {
check_unique_rc::<[_]>(Rc::from(&[1, 2, 3] as &[_]));
check_unique_rc::<[_]>(Rc::from(vec![1, 2, 3]));
check_unique_rc::<[_]>(Rc::from(Box::new([1, 2, 3]) as Box<[_]>));
check_unique_rc::<str>(Rc::from("Hello, World!"));
}
fn rc_fat_ptr_eq() {
let p = Rc::new(1) as Rc<dyn Debug>;
let a: *const dyn Debug = &*p;
let r = Rc::into_raw(p);
// Only compare the pointer parts, as the vtable might differ.
assert!(a as *const () == r as *const ());
drop(unsafe { Rc::from_raw(r) });
}
/// Taken from the `Weak::into_raw` doctest.
fn weak_into_raw() {
let strong = Rc::new(42);
let weak = Rc::downgrade(&strong);
let raw = Weak::into_raw(weak);
assert_eq!(1, Rc::weak_count(&strong));
assert_eq!(42, unsafe { *raw });
drop(unsafe { Weak::from_raw(raw) });
assert_eq!(0, Rc::weak_count(&strong));
let raw = Weak::into_raw(Weak::<usize>::new());
drop(unsafe { Weak::from_raw(raw) });
}
/// Taken from the `Weak::from_raw` doctest.
fn weak_from_raw() {
let strong = Rc::new(42);
let raw_1 = Weak::into_raw(Rc::downgrade(&strong));
let raw_2 = Weak::into_raw(Rc::downgrade(&strong));
assert_eq!(2, Rc::weak_count(&strong));
assert_eq!(42, *Weak::upgrade(&unsafe { Weak::from_raw(raw_1) }).unwrap());
assert_eq!(1, Rc::weak_count(&strong));
drop(strong);
// Decrement the last weak count.
assert!(Weak::upgrade(&unsafe { Weak::from_raw(raw_2) }).is_none());
}
fn rc_uninit() {
let mut five = Rc::<Box<u32>>::new_uninit();
let five = unsafe {
// Deferred initialization:
Rc::get_mut_unchecked(&mut five).as_mut_ptr().write(Box::new(5));
five.assume_init()
};
assert_eq!(**five, 5)
}
fn rc_uninit_slice() {
let mut values = Rc::<[Box<usize>]>::new_uninit_slice(3);
let values = unsafe {
// Deferred initialization:
Rc::get_mut_unchecked(&mut values)[0].as_mut_ptr().write(Box::new(0));
Rc::get_mut_unchecked(&mut values)[1].as_mut_ptr().write(Box::new(1));
Rc::get_mut_unchecked(&mut values)[2].as_mut_ptr().write(Box::new(2));
values.assume_init()
};
for (idx, i) in values.iter().enumerate() {
assert_eq!(idx, **i);
}
}
fn main() {
rc_fat_ptr_eq();
rc_refcell();
rc_refcell2();
rc_cell();
rc_raw();
rc_from();
weak_into_raw();
weak_from_raw();
rc_uninit();
rc_uninit_slice();
arc();
}
|
