1 use core::array::{FixedSizeArray, IntoIter};
2 use core::convert::TryFrom;
5 fn fixed_size_array() {
6 let mut array = [0; 64];
7 let mut zero_sized = [(); 64];
8 let mut empty_array = [0; 0];
9 let mut empty_zero_sized = [(); 0];
11 assert_eq!(FixedSizeArray::as_slice(&array).len(), 64);
12 assert_eq!(FixedSizeArray::as_slice(&zero_sized).len(), 64);
13 assert_eq!(FixedSizeArray::as_slice(&empty_array).len(), 0);
14 assert_eq!(FixedSizeArray::as_slice(&empty_zero_sized).len(), 0);
16 assert_eq!(FixedSizeArray::as_mut_slice(&mut array).len(), 64);
17 assert_eq!(FixedSizeArray::as_mut_slice(&mut zero_sized).len(), 64);
18 assert_eq!(FixedSizeArray::as_mut_slice(&mut empty_array).len(), 0);
19 assert_eq!(FixedSizeArray::as_mut_slice(&mut empty_zero_sized).len(), 0);
27 type Array = [u8; $N];
28 let array: Array = [0; $N];
29 let slice: &[u8] = &array[..];
31 let result = <&Array>::try_from(slice);
32 assert_eq!(&array, result.unwrap());
38 10 11 12 13 14 15 16 17 18 19
39 20 21 22 23 24 25 26 27 28 29
45 fn iterator_collect() {
46 let arr = [0, 1, 2, 5, 9];
47 let v: Vec<_> = IntoIter::new(arr.clone()).collect();
48 assert_eq!(&arr[..], &v[..]);
52 fn iterator_rev_collect() {
53 let arr = [0, 1, 2, 5, 9];
54 let v: Vec<_> = IntoIter::new(arr.clone()).rev().collect();
55 assert_eq!(&v[..], &[9, 5, 2, 1, 0]);
60 let v = [0, 1, 2, 3, 4];
62 assert_eq!(IntoIter::new(v.clone()).nth(i).unwrap(), v[i]);
64 assert_eq!(IntoIter::new(v.clone()).nth(v.len()), None);
66 let mut iter = IntoIter::new(v);
67 assert_eq!(iter.nth(2).unwrap(), v[2]);
68 assert_eq!(iter.nth(1).unwrap(), v[4]);
73 let v = [0, 1, 2, 3, 4];
74 assert_eq!(IntoIter::new(v).last().unwrap(), 4);
75 assert_eq!(IntoIter::new([0]).last().unwrap(), 0);
77 let mut it = IntoIter::new([0, 9, 2, 4]);
78 assert_eq!(it.next_back(), Some(4));
79 assert_eq!(it.last(), Some(2));
84 let mut it = IntoIter::new([0, 2, 4, 6, 8]);
85 assert_eq!(it.next(), Some(0));
86 assert_eq!(it.next_back(), Some(8));
87 let mut clone = it.clone();
88 assert_eq!(it.next_back(), Some(6));
89 assert_eq!(clone.next_back(), Some(6));
90 assert_eq!(it.next_back(), Some(4));
91 assert_eq!(clone.next_back(), Some(4));
92 assert_eq!(it.next(), Some(2));
93 assert_eq!(clone.next(), Some(2));
98 let mut it = IntoIter::new([0, 9, 2]);
99 assert_eq!(it.next(), Some(0));
100 assert_eq!(it.next(), Some(9));
101 assert_eq!(it.next(), Some(2));
102 assert_eq!(it.next(), None);
103 assert_eq!(it.next(), None);
104 assert_eq!(it.next(), None);
105 assert_eq!(it.next(), None);
106 assert_eq!(it.next(), None);
111 let mut it = IntoIter::new([0, 1, 2, 5, 9]);
112 assert_eq!(it.size_hint(), (5, Some(5)));
113 assert_eq!(it.len(), 5);
114 assert_eq!(it.is_empty(), false);
116 assert_eq!(it.next(), Some(0));
117 assert_eq!(it.size_hint(), (4, Some(4)));
118 assert_eq!(it.len(), 4);
119 assert_eq!(it.is_empty(), false);
121 assert_eq!(it.next_back(), Some(9));
122 assert_eq!(it.size_hint(), (3, Some(3)));
123 assert_eq!(it.len(), 3);
124 assert_eq!(it.is_empty(), false);
127 let it = IntoIter::new([] as [String; 0]);
128 assert_eq!(it.size_hint(), (0, Some(0)));
129 assert_eq!(it.len(), 0);
130 assert_eq!(it.is_empty(), true);
134 fn iterator_count() {
135 let v = [0, 1, 2, 3, 4];
136 assert_eq!(IntoIter::new(v.clone()).count(), 5);
138 let mut iter2 = IntoIter::new(v);
141 assert_eq!(iter2.count(), 3);
145 fn iterator_flat_map() {
146 assert!((0..5).flat_map(|i| IntoIter::new([2 * i, 2 * i + 1])).eq(0..10));
150 fn iterator_debug() {
151 let arr = [0, 1, 2, 5, 9];
152 assert_eq!(format!("{:?}", IntoIter::new(arr)), "IntoIter([0, 1, 2, 5, 9])",);
156 fn iterator_drops() {
157 use core::cell::Cell;
159 // This test makes sure the correct number of elements are dropped. The `R`
160 // type is just a reference to a `Cell` that is incremented when an `R` is
164 struct Foo<'a>(&'a Cell<usize>);
166 impl Drop for Foo<'_> {
168 self.0.set(self.0.get() + 1);
172 fn five(i: &Cell<usize>) -> [Foo<'_>; 5] {
173 // This is somewhat verbose because `Foo` does not implement `Copy`
174 // since it implements `Drop`. Consequently, we cannot write
176 [Foo(i), Foo(i), Foo(i), Foo(i), Foo(i)]
179 // Simple: drop new iterator.
180 let i = Cell::new(0);
182 IntoIter::new(five(&i));
184 assert_eq!(i.get(), 5);
186 // Call `next()` once.
187 let i = Cell::new(0);
189 let mut iter = IntoIter::new(five(&i));
190 let _x = iter.next();
191 assert_eq!(i.get(), 0);
192 assert_eq!(iter.count(), 4);
193 assert_eq!(i.get(), 4);
195 assert_eq!(i.get(), 5);
197 // Check `clone` and calling `next`/`next_back`.
198 let i = Cell::new(0);
200 let mut iter = IntoIter::new(five(&i));
202 assert_eq!(i.get(), 1);
204 assert_eq!(i.get(), 2);
206 let mut clone = iter.clone();
207 assert_eq!(i.get(), 2);
210 assert_eq!(i.get(), 3);
213 assert_eq!(i.get(), 4);
215 assert_eq!(clone.count(), 2);
216 assert_eq!(i.get(), 6);
218 assert_eq!(i.get(), 8);
221 let i = Cell::new(0);
223 let mut iter = IntoIter::new(five(&i));
224 let _x = iter.nth(2);
225 assert_eq!(i.get(), 2);
226 let _y = iter.last();
227 assert_eq!(i.get(), 3);
229 assert_eq!(i.get(), 5);
231 // Check every element.
232 let i = Cell::new(0);
233 for (index, _x) in IntoIter::new(five(&i)).enumerate() {
234 assert_eq!(i.get(), index);
236 assert_eq!(i.get(), 5);
238 let i = Cell::new(0);
239 for (index, _x) in IntoIter::new(five(&i)).rev().enumerate() {
240 assert_eq!(i.get(), index);
242 assert_eq!(i.get(), 5);
245 // This test does not work on targets without panic=unwind support.
246 // To work around this problem, test is marked is should_panic, so it will
247 // be automagically skipped on unsuitable targets, such as
248 // wasm32-unknown-unkown.
250 // It means that we use panic for indicating success.
252 #[should_panic(expected = "test succeeded")]
253 fn array_default_impl_avoids_leaks_on_panic() {
254 use core::sync::atomic::{AtomicUsize, Ordering::Relaxed};
255 static COUNTER: AtomicUsize = AtomicUsize::new(0);
259 impl Default for Bomb {
260 fn default() -> Bomb {
261 if COUNTER.load(Relaxed) == 3 {
262 panic!("bomb limit exceeded");
265 COUNTER.fetch_add(1, Relaxed);
266 Bomb(COUNTER.load(Relaxed))
272 COUNTER.fetch_sub(1, Relaxed);
276 let res = std::panic::catch_unwind(|| <[Bomb; 5]>::default());
277 let panic_msg = match res {
278 Ok(_) => unreachable!(),
279 Err(p) => p.downcast::<&'static str>().unwrap(),
281 assert_eq!(*panic_msg, "bomb limit exceeded");
282 // check that all bombs are successfully dropped
283 assert_eq!(COUNTER.load(Relaxed), 0);
284 panic!("test succeeded")
288 fn empty_array_is_always_default() {
289 struct DoesNotImplDefault;
291 let _arr = <[DoesNotImplDefault; 0]>::default();