use core::array; use core::convert::TryFrom; use core::sync::atomic::{AtomicUsize, Ordering}; #[test] fn array_from_ref() { let value: String = "Hello World!".into(); let arr: &[String; 1] = array::from_ref(&value); assert_eq!(&[value.clone()], arr); const VALUE: &&str = &"Hello World!"; const ARR: &[&str; 1] = array::from_ref(VALUE); assert_eq!(&[*VALUE], ARR); assert!(core::ptr::eq(VALUE, &ARR[0])); } #[test] fn array_from_mut() { let mut value: String = "Hello World".into(); let arr: &mut [String; 1] = array::from_mut(&mut value); arr[0].push_str("!"); assert_eq!(&value, "Hello World!"); } #[test] fn array_try_from() { macro_rules! test { ($($N:expr)+) => { $({ type Array = [u8; $N]; let mut array: Array = [0; $N]; let slice: &[u8] = &array[..]; let result = <&Array>::try_from(slice); assert_eq!(&array, result.unwrap()); let result = ::try_from(slice); assert_eq!(&array, &result.unwrap()); let mut_slice: &mut [u8] = &mut array[..]; let result = <&mut Array>::try_from(mut_slice); assert_eq!(&[0; $N], result.unwrap()); let mut_slice: &mut [u8] = &mut array[..]; let result = ::try_from(mut_slice); assert_eq!(&array, &result.unwrap()); })+ } } test! { 0 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 } } #[test] fn iterator_collect() { let arr = [0, 1, 2, 5, 9]; let v: Vec<_> = IntoIterator::into_iter(arr.clone()).collect(); assert_eq!(&arr[..], &v[..]); } #[test] fn iterator_rev_collect() { let arr = [0, 1, 2, 5, 9]; let v: Vec<_> = IntoIterator::into_iter(arr.clone()).rev().collect(); assert_eq!(&v[..], &[9, 5, 2, 1, 0]); } #[test] fn iterator_nth() { let v = [0, 1, 2, 3, 4]; for i in 0..v.len() { assert_eq!(IntoIterator::into_iter(v.clone()).nth(i).unwrap(), v[i]); } assert_eq!(IntoIterator::into_iter(v.clone()).nth(v.len()), None); let mut iter = IntoIterator::into_iter(v); assert_eq!(iter.nth(2).unwrap(), v[2]); assert_eq!(iter.nth(1).unwrap(), v[4]); } #[test] fn iterator_last() { let v = [0, 1, 2, 3, 4]; assert_eq!(IntoIterator::into_iter(v).last().unwrap(), 4); assert_eq!(IntoIterator::into_iter([0]).last().unwrap(), 0); let mut it = IntoIterator::into_iter([0, 9, 2, 4]); assert_eq!(it.next_back(), Some(4)); assert_eq!(it.last(), Some(2)); } #[test] fn iterator_clone() { let mut it = IntoIterator::into_iter([0, 2, 4, 6, 8]); assert_eq!(it.next(), Some(0)); assert_eq!(it.next_back(), Some(8)); let mut clone = it.clone(); assert_eq!(it.next_back(), Some(6)); assert_eq!(clone.next_back(), Some(6)); assert_eq!(it.next_back(), Some(4)); assert_eq!(clone.next_back(), Some(4)); assert_eq!(it.next(), Some(2)); assert_eq!(clone.next(), Some(2)); } #[test] fn iterator_fused() { let mut it = IntoIterator::into_iter([0, 9, 2]); assert_eq!(it.next(), Some(0)); assert_eq!(it.next(), Some(9)); assert_eq!(it.next(), Some(2)); assert_eq!(it.next(), None); assert_eq!(it.next(), None); assert_eq!(it.next(), None); assert_eq!(it.next(), None); assert_eq!(it.next(), None); } #[test] fn iterator_len() { let mut it = IntoIterator::into_iter([0, 1, 2, 5, 9]); assert_eq!(it.size_hint(), (5, Some(5))); assert_eq!(it.len(), 5); assert_eq!(it.is_empty(), false); assert_eq!(it.next(), Some(0)); assert_eq!(it.size_hint(), (4, Some(4))); assert_eq!(it.len(), 4); assert_eq!(it.is_empty(), false); assert_eq!(it.next_back(), Some(9)); assert_eq!(it.size_hint(), (3, Some(3))); assert_eq!(it.len(), 3); assert_eq!(it.is_empty(), false); // Empty let it = IntoIterator::into_iter([] as [String; 0]); assert_eq!(it.size_hint(), (0, Some(0))); assert_eq!(it.len(), 0); assert_eq!(it.is_empty(), true); } #[test] fn iterator_count() { let v = [0, 1, 2, 3, 4]; assert_eq!(IntoIterator::into_iter(v.clone()).count(), 5); let mut iter2 = IntoIterator::into_iter(v); iter2.next(); iter2.next(); assert_eq!(iter2.count(), 3); } #[test] fn iterator_flat_map() { assert!((0..5).flat_map(|i| IntoIterator::into_iter([2 * i, 2 * i + 1])).eq(0..10)); } #[test] fn iterator_debug() { let arr = [0, 1, 2, 5, 9]; assert_eq!(format!("{:?}", IntoIterator::into_iter(arr)), "IntoIter([0, 1, 2, 5, 9])",); } #[test] fn iterator_drops() { use core::cell::Cell; // This test makes sure the correct number of elements are dropped. The `R` // type is just a reference to a `Cell` that is incremented when an `R` is // dropped. #[derive(Clone)] struct Foo<'a>(&'a Cell); impl Drop for Foo<'_> { fn drop(&mut self) { self.0.set(self.0.get() + 1); } } fn five(i: &Cell) -> [Foo<'_>; 5] { // This is somewhat verbose because `Foo` does not implement `Copy` // since it implements `Drop`. Consequently, we cannot write // `[Foo(i); 5]`. [Foo(i), Foo(i), Foo(i), Foo(i), Foo(i)] } // Simple: drop new iterator. let i = Cell::new(0); { IntoIterator::into_iter(five(&i)); } assert_eq!(i.get(), 5); // Call `next()` once. let i = Cell::new(0); { let mut iter = IntoIterator::into_iter(five(&i)); let _x = iter.next(); assert_eq!(i.get(), 0); assert_eq!(iter.count(), 4); assert_eq!(i.get(), 4); } assert_eq!(i.get(), 5); // Check `clone` and calling `next`/`next_back`. let i = Cell::new(0); { let mut iter = IntoIterator::into_iter(five(&i)); iter.next(); assert_eq!(i.get(), 1); iter.next_back(); assert_eq!(i.get(), 2); let mut clone = iter.clone(); assert_eq!(i.get(), 2); iter.next(); assert_eq!(i.get(), 3); clone.next(); assert_eq!(i.get(), 4); assert_eq!(clone.count(), 2); assert_eq!(i.get(), 6); } assert_eq!(i.get(), 8); // Check via `nth`. let i = Cell::new(0); { let mut iter = IntoIterator::into_iter(five(&i)); let _x = iter.nth(2); assert_eq!(i.get(), 2); let _y = iter.last(); assert_eq!(i.get(), 3); } assert_eq!(i.get(), 5); // Check every element. let i = Cell::new(0); for (index, _x) in IntoIterator::into_iter(five(&i)).enumerate() { assert_eq!(i.get(), index); } assert_eq!(i.get(), 5); let i = Cell::new(0); for (index, _x) in IntoIterator::into_iter(five(&i)).rev().enumerate() { assert_eq!(i.get(), index); } assert_eq!(i.get(), 5); } // This test does not work on targets without panic=unwind support. // To work around this problem, test is marked is should_panic, so it will // be automagically skipped on unsuitable targets, such as // wasm32-unknown-unknown. // // It means that we use panic for indicating success. #[test] #[should_panic(expected = "test succeeded")] fn array_default_impl_avoids_leaks_on_panic() { use core::sync::atomic::{AtomicUsize, Ordering::Relaxed}; static COUNTER: AtomicUsize = AtomicUsize::new(0); #[derive(Debug)] struct Bomb(usize); impl Default for Bomb { fn default() -> Bomb { if COUNTER.load(Relaxed) == 3 { panic!("bomb limit exceeded"); } COUNTER.fetch_add(1, Relaxed); Bomb(COUNTER.load(Relaxed)) } } impl Drop for Bomb { fn drop(&mut self) { COUNTER.fetch_sub(1, Relaxed); } } let res = std::panic::catch_unwind(|| <[Bomb; 5]>::default()); let panic_msg = match res { Ok(_) => unreachable!(), Err(p) => p.downcast::<&'static str>().unwrap(), }; assert_eq!(*panic_msg, "bomb limit exceeded"); // check that all bombs are successfully dropped assert_eq!(COUNTER.load(Relaxed), 0); panic!("test succeeded") } #[test] fn empty_array_is_always_default() { struct DoesNotImplDefault; let _arr = <[DoesNotImplDefault; 0]>::default(); } #[test] fn array_map() { let a = [1, 2, 3]; let b = a.map(|v| v + 1); assert_eq!(b, [2, 3, 4]); let a = [1u8, 2, 3]; let b = a.map(|v| v as u64); assert_eq!(b, [1, 2, 3]); } // See note on above test for why `should_panic` is used. #[test] #[should_panic(expected = "test succeeded")] fn array_map_drop_safety() { static DROPPED: AtomicUsize = AtomicUsize::new(0); struct DropCounter; impl Drop for DropCounter { fn drop(&mut self) { DROPPED.fetch_add(1, Ordering::SeqCst); } } let num_to_create = 5; let success = std::panic::catch_unwind(|| { let items = [0; 10]; let mut nth = 0; items.map(|_| { assert!(nth < num_to_create); nth += 1; DropCounter }); }); assert!(success.is_err()); assert_eq!(DROPPED.load(Ordering::SeqCst), num_to_create); panic!("test succeeded") } #[test] fn cell_allows_array_cycle() { use core::cell::Cell; #[derive(Debug)] struct B<'a> { a: [Cell>>; 2], } impl<'a> B<'a> { fn new() -> B<'a> { B { a: [Cell::new(None), Cell::new(None)] } } } let b1 = B::new(); let b2 = B::new(); let b3 = B::new(); b1.a[0].set(Some(&b2)); b1.a[1].set(Some(&b3)); b2.a[0].set(Some(&b2)); b2.a[1].set(Some(&b3)); b3.a[0].set(Some(&b1)); b3.a[1].set(Some(&b2)); } #[test] fn array_from_fn() { let array = core::array::from_fn(|idx| idx); assert_eq!(array, [0, 1, 2, 3, 4]); } #[test] fn array_try_from_fn() { #[derive(Debug, PartialEq)] enum SomeError { Foo, } let array = core::array::try_from_fn(|i| Ok::<_, SomeError>(i)); assert_eq!(array, Ok([0, 1, 2, 3, 4])); let another_array = core::array::try_from_fn::, 2, _>(|_| Err(SomeError::Foo)); assert_eq!(another_array, Err(SomeError::Foo)); } #[cfg(not(panic = "abort"))] #[test] fn array_try_from_fn_drops_inserted_elements_on_err() { static DROP_COUNTER: AtomicUsize = AtomicUsize::new(0); struct CountDrop; impl Drop for CountDrop { fn drop(&mut self) { DROP_COUNTER.fetch_add(1, Ordering::SeqCst); } } let _ = catch_unwind_silent(move || { let _: Result<[CountDrop; 4], ()> = core::array::try_from_fn(|idx| { if idx == 2 { return Err(()); } Ok(CountDrop) }); }); assert_eq!(DROP_COUNTER.load(Ordering::SeqCst), 2); } #[cfg(not(panic = "abort"))] #[test] fn array_try_from_fn_drops_inserted_elements_on_panic() { static DROP_COUNTER: AtomicUsize = AtomicUsize::new(0); struct CountDrop; impl Drop for CountDrop { fn drop(&mut self) { DROP_COUNTER.fetch_add(1, Ordering::SeqCst); } } let _ = catch_unwind_silent(move || { let _: Result<[CountDrop; 4], ()> = core::array::try_from_fn(|idx| { if idx == 2 { panic!("peek a boo"); } Ok(CountDrop) }); }); assert_eq!(DROP_COUNTER.load(Ordering::SeqCst), 2); } #[cfg(not(panic = "abort"))] // https://stackoverflow.com/a/59211505 fn catch_unwind_silent(f: F) -> std::thread::Result where F: FnOnce() -> R + core::panic::UnwindSafe, { let prev_hook = std::panic::take_hook(); std::panic::set_hook(Box::new(|_| {})); let result = std::panic::catch_unwind(f); std::panic::set_hook(prev_hook); result } #[test] fn array_split_array_mut() { let mut v = [1, 2, 3, 4, 5, 6]; { let (left, right) = v.split_array_mut::<0>(); assert_eq!(left, &mut []); assert_eq!(right, &mut [1, 2, 3, 4, 5, 6]); } { let (left, right) = v.split_array_mut::<6>(); assert_eq!(left, &mut [1, 2, 3, 4, 5, 6]); assert_eq!(right, &mut []); } } #[test] fn array_rsplit_array_mut() { let mut v = [1, 2, 3, 4, 5, 6]; { let (left, right) = v.rsplit_array_mut::<0>(); assert_eq!(left, &mut [1, 2, 3, 4, 5, 6]); assert_eq!(right, &mut []); } { let (left, right) = v.rsplit_array_mut::<6>(); assert_eq!(left, &mut []); assert_eq!(right, &mut [1, 2, 3, 4, 5, 6]); } } #[should_panic] #[test] fn array_split_array_ref_out_of_bounds() { let v = [1, 2, 3, 4, 5, 6]; v.split_array_ref::<7>(); } #[should_panic] #[test] fn array_split_array_mut_out_of_bounds() { let mut v = [1, 2, 3, 4, 5, 6]; v.split_array_mut::<7>(); } #[should_panic] #[test] fn array_rsplit_array_ref_out_of_bounds() { let v = [1, 2, 3, 4, 5, 6]; v.rsplit_array_ref::<7>(); } #[should_panic] #[test] fn array_rsplit_array_mut_out_of_bounds() { let mut v = [1, 2, 3, 4, 5, 6]; v.rsplit_array_mut::<7>(); } #[test] fn array_intoiter_advance_by() { use std::cell::Cell; struct DropCounter<'a>(usize, &'a Cell); impl Drop for DropCounter<'_> { fn drop(&mut self) { let x = self.1.get(); self.1.set(x + 1); } } let counter = Cell::new(0); let a: [_; 100] = std::array::from_fn(|i| DropCounter(i, &counter)); let mut it = IntoIterator::into_iter(a); let r = it.advance_by(1); assert_eq!(r, Ok(())); assert_eq!(it.len(), 99); assert_eq!(counter.get(), 1); let r = it.advance_by(0); assert_eq!(r, Ok(())); assert_eq!(it.len(), 99); assert_eq!(counter.get(), 1); let r = it.advance_by(11); assert_eq!(r, Ok(())); assert_eq!(it.len(), 88); assert_eq!(counter.get(), 12); let x = it.next(); assert_eq!(x.as_ref().map(|x| x.0), Some(12)); assert_eq!(it.len(), 87); assert_eq!(counter.get(), 12); drop(x); assert_eq!(counter.get(), 13); let r = it.advance_by(123456); assert_eq!(r, Err(87)); assert_eq!(it.len(), 0); assert_eq!(counter.get(), 100); let r = it.advance_by(0); assert_eq!(r, Ok(())); assert_eq!(it.len(), 0); assert_eq!(counter.get(), 100); let r = it.advance_by(10); assert_eq!(r, Err(0)); assert_eq!(it.len(), 0); assert_eq!(counter.get(), 100); } #[test] fn array_intoiter_advance_back_by() { use std::cell::Cell; struct DropCounter<'a>(usize, &'a Cell); impl Drop for DropCounter<'_> { fn drop(&mut self) { let x = self.1.get(); self.1.set(x + 1); } } let counter = Cell::new(0); let a: [_; 100] = std::array::from_fn(|i| DropCounter(i, &counter)); let mut it = IntoIterator::into_iter(a); let r = it.advance_back_by(1); assert_eq!(r, Ok(())); assert_eq!(it.len(), 99); assert_eq!(counter.get(), 1); let r = it.advance_back_by(0); assert_eq!(r, Ok(())); assert_eq!(it.len(), 99); assert_eq!(counter.get(), 1); let r = it.advance_back_by(11); assert_eq!(r, Ok(())); assert_eq!(it.len(), 88); assert_eq!(counter.get(), 12); let x = it.next_back(); assert_eq!(x.as_ref().map(|x| x.0), Some(87)); assert_eq!(it.len(), 87); assert_eq!(counter.get(), 12); drop(x); assert_eq!(counter.get(), 13); let r = it.advance_back_by(123456); assert_eq!(r, Err(87)); assert_eq!(it.len(), 0); assert_eq!(counter.get(), 100); let r = it.advance_back_by(0); assert_eq!(r, Ok(())); assert_eq!(it.len(), 0); assert_eq!(counter.get(), 100); let r = it.advance_back_by(10); assert_eq!(r, Err(0)); assert_eq!(it.len(), 0); assert_eq!(counter.get(), 100); } #[test] fn array_mixed_equality_integers() { let array3: [i32; 3] = [1, 2, 3]; let array3b: [i32; 3] = [3, 2, 1]; let array4: [i32; 4] = [1, 2, 3, 4]; let slice3: &[i32] = &{ array3 }; let slice3b: &[i32] = &{ array3b }; let slice4: &[i32] = &{ array4 }; assert!(array3 == slice3); assert!(array3 != slice3b); assert!(array3 != slice4); assert!(slice3 == array3); assert!(slice3b != array3); assert!(slice4 != array3); let mut3: &mut [i32] = &mut { array3 }; let mut3b: &mut [i32] = &mut { array3b }; let mut4: &mut [i32] = &mut { array4 }; assert!(array3 == mut3); assert!(array3 != mut3b); assert!(array3 != mut4); assert!(mut3 == array3); assert!(mut3b != array3); assert!(mut4 != array3); } #[test] fn array_mixed_equality_nans() { let array3: [f32; 3] = [1.0, std::f32::NAN, 3.0]; let slice3: &[f32] = &{ array3 }; assert!(!(array3 == slice3)); assert!(array3 != slice3); assert!(!(slice3 == array3)); assert!(slice3 != array3); let mut3: &mut [f32] = &mut { array3 }; assert!(!(array3 == mut3)); assert!(array3 != mut3); assert!(!(mut3 == array3)); assert!(mut3 != array3); } #[test] fn array_into_iter_fold() { // Strings to help MIRI catch if we double-free or something let a = ["Aa".to_string(), "Bb".to_string(), "Cc".to_string()]; let mut s = "s".to_string(); a.into_iter().for_each(|b| s += &b); assert_eq!(s, "sAaBbCc"); let a = [1, 2, 3, 4, 5, 6]; let mut it = a.into_iter(); it.advance_by(1).unwrap(); it.advance_back_by(2).unwrap(); let s = it.fold(10, |a, b| 10 * a + b); assert_eq!(s, 10234); } #[test] fn array_into_iter_rfold() { // Strings to help MIRI catch if we double-free or something let a = ["Aa".to_string(), "Bb".to_string(), "Cc".to_string()]; let mut s = "s".to_string(); a.into_iter().rev().for_each(|b| s += &b); assert_eq!(s, "sCcBbAa"); let a = [1, 2, 3, 4, 5, 6]; let mut it = a.into_iter(); it.advance_by(1).unwrap(); it.advance_back_by(2).unwrap(); let s = it.rfold(10, |a, b| 10 * a + b); assert_eq!(s, 10432); }