2 use core::default::Default;
6 fn smoketest_unsafe_cell() {
7 let mut x = UnsafeCell::new(10);
10 // The asserts are repeated in order to ensure that `get()`
12 assert_eq!(*ref_mut.get(), 10);
13 assert_eq!(*ref_mut.get(), 10);
14 *ref_mut.get_mut() += 5;
15 assert_eq!(*ref_mut.get(), 15);
16 assert_eq!(*ref_mut.get(), 15);
17 assert_eq!(x.into_inner(), 15);
22 fn unsafe_cell_raw_get() {
23 let x = UnsafeCell::new(10);
24 let ptr = &x as *const UnsafeCell<i32>;
26 // The asserts are repeated in order to ensure that `raw_get()`
28 assert_eq!(*UnsafeCell::raw_get(ptr), 10);
29 assert_eq!(*UnsafeCell::raw_get(ptr), 10);
30 *UnsafeCell::raw_get(ptr) += 5;
31 assert_eq!(*UnsafeCell::raw_get(ptr), 15);
32 assert_eq!(*UnsafeCell::raw_get(ptr), 15);
33 assert_eq!(x.into_inner(), 15);
39 let x = Cell::new(10);
40 assert_eq!(x, Cell::new(10));
41 assert_eq!(x.get(), 10);
43 assert_eq!(x, Cell::new(20));
44 assert_eq!(x.get(), 20);
46 let y = Cell::new((30, 40));
47 assert_eq!(y, Cell::new((30, 40)));
48 assert_eq!(y.get(), (30, 40));
53 let x = Cell::new(10);
55 assert_eq!(x.update(|x| x + 5), 15);
56 assert_eq!(x.get(), 15);
58 assert_eq!(x.update(|x| x / 3), 5);
59 assert_eq!(x.get(), 5);
63 fn cell_has_sensible_show() {
64 let x = Cell::new("foo bar");
65 assert!(format!("{x:?}").contains(x.get()));
68 assert!(format!("{x:?}").contains(x.get()));
72 fn ref_and_refmut_have_sensible_show() {
73 let refcell = RefCell::new("foo");
75 let refcell_refmut = refcell.borrow_mut();
76 assert!(format!("{refcell_refmut:?}").contains("foo"));
79 let refcell_ref = refcell.borrow();
80 assert!(format!("{refcell_ref:?}").contains("foo"));
85 fn double_imm_borrow() {
86 let x = RefCell::new(0);
92 fn no_mut_then_imm_borrow() {
93 let x = RefCell::new(0);
94 let _b1 = x.borrow_mut();
95 assert!(x.try_borrow().is_err());
99 fn no_imm_then_borrow_mut() {
100 let x = RefCell::new(0);
101 let _b1 = x.borrow();
102 assert!(x.try_borrow_mut().is_err());
106 fn no_double_borrow_mut() {
107 let x = RefCell::new(0);
108 assert!(x.try_borrow().is_ok());
109 let _b1 = x.borrow_mut();
110 assert!(x.try_borrow().is_err());
114 fn imm_release_borrow_mut() {
115 let x = RefCell::new(0);
117 let _b1 = x.borrow();
123 fn mut_release_borrow_mut() {
124 let x = RefCell::new(0);
126 let _b1 = x.borrow_mut();
132 fn double_borrow_single_release_no_borrow_mut() {
133 let x = RefCell::new(0);
134 let _b1 = x.borrow();
136 let _b2 = x.borrow();
138 assert!(x.try_borrow().is_ok());
139 assert!(x.try_borrow_mut().is_err());
144 fn discard_doesnt_unborrow() {
145 let x = RefCell::new(0);
148 let _b = x.borrow_mut();
152 fn ref_clone_updates_flag() {
153 let x = RefCell::new(0);
156 assert!(x.try_borrow().is_ok());
157 assert!(x.try_borrow_mut().is_err());
159 let _b2 = Ref::clone(&b1);
160 assert!(x.try_borrow().is_ok());
161 assert!(x.try_borrow_mut().is_err());
163 assert!(x.try_borrow().is_ok());
164 assert!(x.try_borrow_mut().is_err());
166 assert!(x.try_borrow().is_ok());
167 assert!(x.try_borrow_mut().is_ok());
171 fn ref_map_does_not_update_flag() {
172 let x = RefCell::new(Some(5));
174 let b1: Ref<'_, Option<u32>> = x.borrow();
175 assert!(x.try_borrow().is_ok());
176 assert!(x.try_borrow_mut().is_err());
178 let b2: Ref<'_, u32> = Ref::map(b1, |o| o.as_ref().unwrap());
180 assert!(x.try_borrow().is_ok());
181 assert!(x.try_borrow_mut().is_err());
183 assert!(x.try_borrow().is_ok());
184 assert!(x.try_borrow_mut().is_ok());
186 assert!(x.try_borrow().is_ok());
187 assert!(x.try_borrow_mut().is_ok());
191 fn ref_map_split_updates_flag() {
192 let x = RefCell::new([1, 2]);
195 assert!(x.try_borrow().is_ok());
196 assert!(x.try_borrow_mut().is_err());
198 let (_b2, _b3) = Ref::map_split(b1, |slc| slc.split_at(1));
199 assert!(x.try_borrow().is_ok());
200 assert!(x.try_borrow_mut().is_err());
202 assert!(x.try_borrow().is_ok());
203 assert!(x.try_borrow_mut().is_ok());
205 assert!(x.try_borrow().is_ok());
206 assert!(x.try_borrow_mut().is_ok());
209 let b1 = x.borrow_mut();
210 assert!(x.try_borrow().is_err());
211 assert!(x.try_borrow_mut().is_err());
213 let (_b2, _b3) = RefMut::map_split(b1, |slc| slc.split_at_mut(1));
214 assert!(x.try_borrow().is_err());
215 assert!(x.try_borrow_mut().is_err());
217 assert!(x.try_borrow().is_err());
218 assert!(x.try_borrow_mut().is_err());
220 assert!(x.try_borrow().is_ok());
221 assert!(x.try_borrow_mut().is_ok());
223 assert!(x.try_borrow().is_ok());
224 assert!(x.try_borrow_mut().is_ok());
229 let x = RefCell::new([1, 2]);
230 let (b1, b2) = Ref::map_split(x.borrow(), |slc| slc.split_at(1));
231 assert_eq!(*b1, [1]);
232 assert_eq!(*b2, [2]);
236 fn ref_mut_map_split() {
237 let x = RefCell::new([1, 2]);
239 let (mut b1, mut b2) = RefMut::map_split(x.borrow_mut(), |slc| slc.split_at_mut(1));
240 assert_eq!(*b1, [1]);
241 assert_eq!(*b2, [2]);
245 assert_eq!(*x.borrow(), [2, 1]);
249 fn ref_map_accessor() {
250 struct X(RefCell<(u32, char)>);
252 fn accessor(&self) -> Ref<'_, u32> {
253 Ref::map(self.0.borrow(), |tuple| &tuple.0)
256 let x = X(RefCell::new((7, 'z')));
257 let d: Ref<'_, u32> = x.accessor();
262 fn ref_mut_map_accessor() {
263 struct X(RefCell<(u32, char)>);
265 fn accessor(&self) -> RefMut<'_, u32> {
266 RefMut::map(self.0.borrow_mut(), |tuple| &mut tuple.0)
269 let x = X(RefCell::new((7, 'z')));
271 let mut d: RefMut<'_, u32> = x.accessor();
275 assert_eq!(*x.0.borrow(), (8, 'z'));
280 let c1: Cell<usize> = Cell::new(0);
282 assert_eq!(1, unsafe { *c1.as_ptr() });
284 let c2: Cell<usize> = Cell::new(0);
288 assert_eq!(1, c2.get());
290 let r1: RefCell<usize> = RefCell::new(0);
291 *r1.borrow_mut() = 1;
292 assert_eq!(1, unsafe { *r1.as_ptr() });
294 let r2: RefCell<usize> = RefCell::new(0);
298 assert_eq!(1, *r2.borrow());
303 let cell: Cell<u32> = Default::default();
304 assert_eq!(0, cell.get());
309 let cell = Cell::new(10);
311 assert_eq!(20, cell.get());
313 let cell = Cell::new("Hello".to_owned());
314 cell.set("World".to_owned());
315 assert_eq!("World".to_owned(), cell.into_inner());
320 let cell = Cell::new(10);
321 assert_eq!(10, cell.replace(20));
322 assert_eq!(20, cell.get());
324 let cell = Cell::new("Hello".to_owned());
325 assert_eq!("Hello".to_owned(), cell.replace("World".to_owned()));
326 assert_eq!("World".to_owned(), cell.into_inner());
330 fn cell_into_inner() {
331 let cell = Cell::new(10);
332 assert_eq!(10, cell.into_inner());
334 let cell = Cell::new("Hello world".to_owned());
335 assert_eq!("Hello world".to_owned(), cell.into_inner());
340 #[derive(Copy, Clone)]
348 fn f(p: &Cell<Point>) {
349 assert_eq!(p.get().z, 12);
350 p.set(Point { x: 10, y: 11, z: 13 });
351 assert_eq!(p.get().z, 13);
354 let a = Point { x: 10, y: 11, z: 12 };
355 let b = &Cell::new(a);
356 assert_eq!(b.get().z, 12);
359 assert_eq!(b.get().z, 13);
363 fn cell_does_not_clone() {
371 fn clone(&self) -> Foo {
372 // Using Cell in any way should never cause clone() to be
373 // invoked -- after all, that would permit evil user code to
374 // abuse `Cell` and trigger crashes.
380 let x = Cell::new(Foo { x: 22 });
386 fn refcell_default() {
387 let cell: RefCell<u64> = Default::default();
388 assert_eq!(0, *cell.borrow());
392 fn unsafe_cell_unsized() {
393 let cell: &UnsafeCell<[i32]> = &UnsafeCell::new([1, 2, 3]);
395 let val: &mut [i32] = unsafe { &mut *cell.get() };
399 let comp: &mut [i32] = &mut [4, 2, 5];
400 assert_eq!(unsafe { &mut *cell.get() }, comp);
404 fn refcell_unsized() {
405 let cell: &RefCell<[i32]> = &RefCell::new([1, 2, 3]);
407 let b = &mut *cell.borrow_mut();
411 let comp: &mut [i32] = &mut [4, 2, 5];
412 assert_eq!(&*cell.borrow(), comp);
416 fn refcell_ref_coercion() {
417 let cell: RefCell<[i32; 3]> = RefCell::new([1, 2, 3]);
419 let mut cellref: RefMut<'_, [i32; 3]> = cell.borrow_mut();
421 let mut coerced: RefMut<'_, [i32]> = cellref;
425 let comp: &mut [i32] = &mut [4, 2, 5];
426 let cellref: Ref<'_, [i32; 3]> = cell.borrow();
427 assert_eq!(&*cellref, comp);
428 let coerced: Ref<'_, [i32]> = cellref;
429 assert_eq!(&*coerced, comp);
435 fn refcell_swap_borrows() {
436 let x = RefCell::new(0);
438 let y = RefCell::new(1);
444 fn refcell_replace_borrows() {
445 let x = RefCell::new(0);
451 fn refcell_format() {
452 let name = RefCell::new("rust");
453 let what = RefCell::new("rocks");
454 let msg = format!("{name} {}", &*what.borrow(), name = &*name.borrow());
455 assert_eq!(msg, "rust rocks".to_string());
460 const UNSAFE_CELL: UnsafeCell<i32> = UnsafeCell::new(3);
461 const _: i32 = UNSAFE_CELL.into_inner();
463 const REF_CELL: RefCell<i32> = RefCell::new(3);
464 const _: i32 = REF_CELL.into_inner();
466 const CELL: Cell<i32> = Cell::new(3);
467 const _: i32 = CELL.into_inner();
469 const UNSAFE_CELL_FROM: UnsafeCell<i32> = UnsafeCell::from(3);
470 const _: i32 = UNSAFE_CELL.into_inner();
472 const REF_CELL_FROM: RefCell<i32> = RefCell::from(3);
473 const _: i32 = REF_CELL.into_inner();
475 const CELL_FROM: Cell<i32> = Cell::from(3);
476 const _: i32 = CELL.into_inner();