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69db91b8b2
rust/library/core/tests/slice.rs
The 8472 69db91b8b2 Change advance(_back)_by to return usize instead of Result<(), usize> 
A successful advance is now signalled by returning `0` and other values now represent the remaining number
of steps that couldn't be advanced as opposed to the amount of steps that have been advanced during a partial advance_by.

This simplifies adapters a bit, replacing some `match`/`if` with arithmetic. Whether this is beneficial overall depends
on whether `advance_by` is mostly used as a building-block for other iterator methods and adapters or whether
we also see uses by users where `Result` might be more useful.
2023-03-27 14:11:49 +02:00

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use core::cell::Cell;
use core::cmp::Ordering;
use core::mem::MaybeUninit;
use core::result::Result::{Err, Ok};
use core::slice;
#[test]
fn test_position() {
let b = [1, 2, 3, 5, 5];
assert_eq!(b.iter().position(|&v| v == 9), None);
assert_eq!(b.iter().position(|&v| v == 5), Some(3));
assert_eq!(b.iter().position(|&v| v == 3), Some(2));
assert_eq!(b.iter().position(|&v| v == 0), None);
}
#[test]
fn test_rposition() {
let b = [1, 2, 3, 5, 5];
assert_eq!(b.iter().rposition(|&v| v == 9), None);
assert_eq!(b.iter().rposition(|&v| v == 5), Some(4));
assert_eq!(b.iter().rposition(|&v| v == 3), Some(2));
assert_eq!(b.iter().rposition(|&v| v == 0), None);
}
#[test]
fn test_binary_search() {
let b: [i32; 0] = [];
assert_eq!(b.binary_search(&5), Err(0));
let b = [4];
assert_eq!(b.binary_search(&3), Err(0));
assert_eq!(b.binary_search(&4), Ok(0));
assert_eq!(b.binary_search(&5), Err(1));
let b = [1, 2, 4, 6, 8, 9];
assert_eq!(b.binary_search(&5), Err(3));
assert_eq!(b.binary_search(&6), Ok(3));
assert_eq!(b.binary_search(&7), Err(4));
assert_eq!(b.binary_search(&8), Ok(4));
let b = [1, 2, 4, 5, 6, 8];
assert_eq!(b.binary_search(&9), Err(6));
let b = [1, 2, 4, 6, 7, 8, 9];
assert_eq!(b.binary_search(&6), Ok(3));
assert_eq!(b.binary_search(&5), Err(3));
assert_eq!(b.binary_search(&8), Ok(5));
let b = [1, 2, 4, 5, 6, 8, 9];
assert_eq!(b.binary_search(&7), Err(5));
assert_eq!(b.binary_search(&0), Err(0));
let b = [1, 3, 3, 3, 7];
assert_eq!(b.binary_search(&0), Err(0));
assert_eq!(b.binary_search(&1), Ok(0));
assert_eq!(b.binary_search(&2), Err(1));
assert!(match b.binary_search(&3) {
Ok(1..=3) => true,
_ => false,
});
assert!(match b.binary_search(&3) {
Ok(1..=3) => true,
_ => false,
});
assert_eq!(b.binary_search(&4), Err(4));
assert_eq!(b.binary_search(&5), Err(4));
assert_eq!(b.binary_search(&6), Err(4));
assert_eq!(b.binary_search(&7), Ok(4));
assert_eq!(b.binary_search(&8), Err(5));
let b = [(); usize::MAX];
assert_eq!(b.binary_search(&()), Ok(usize::MAX / 2));
}
#[test]
fn test_binary_search_by_overflow() {
let b = [(); usize::MAX];
assert_eq!(b.binary_search_by(|_| Ordering::Equal), Ok(usize::MAX / 2));
assert_eq!(b.binary_search_by(|_| Ordering::Greater), Err(0));
assert_eq!(b.binary_search_by(|_| Ordering::Less), Err(usize::MAX));
}
#[test]
// Test implementation specific behavior when finding equivalent elements.
// It is ok to break this test but when you do a crater run is highly advisable.
fn test_binary_search_implementation_details() {
let b = [1, 1, 2, 2, 3, 3, 3];
assert_eq!(b.binary_search(&1), Ok(1));
assert_eq!(b.binary_search(&2), Ok(3));
assert_eq!(b.binary_search(&3), Ok(5));
let b = [1, 1, 1, 1, 1, 3, 3, 3, 3];
assert_eq!(b.binary_search(&1), Ok(4));
assert_eq!(b.binary_search(&3), Ok(7));
let b = [1, 1, 1, 1, 3, 3, 3, 3, 3];
assert_eq!(b.binary_search(&1), Ok(2));
assert_eq!(b.binary_search(&3), Ok(4));
}
#[test]
fn test_partition_point() {
let b: [i32; 0] = [];
assert_eq!(b.partition_point(|&x| x < 5), 0);
let b = [4];
assert_eq!(b.partition_point(|&x| x < 3), 0);
assert_eq!(b.partition_point(|&x| x < 4), 0);
assert_eq!(b.partition_point(|&x| x < 5), 1);
let b = [1, 2, 4, 6, 8, 9];
assert_eq!(b.partition_point(|&x| x < 5), 3);
assert_eq!(b.partition_point(|&x| x < 6), 3);
assert_eq!(b.partition_point(|&x| x < 7), 4);
assert_eq!(b.partition_point(|&x| x < 8), 4);
let b = [1, 2, 4, 5, 6, 8];
assert_eq!(b.partition_point(|&x| x < 9), 6);
let b = [1, 2, 4, 6, 7, 8, 9];
assert_eq!(b.partition_point(|&x| x < 6), 3);
assert_eq!(b.partition_point(|&x| x < 5), 3);
assert_eq!(b.partition_point(|&x| x < 8), 5);
let b = [1, 2, 4, 5, 6, 8, 9];
assert_eq!(b.partition_point(|&x| x < 7), 5);
assert_eq!(b.partition_point(|&x| x < 0), 0);
let b = [1, 3, 3, 3, 7];
assert_eq!(b.partition_point(|&x| x < 0), 0);
assert_eq!(b.partition_point(|&x| x < 1), 0);
assert_eq!(b.partition_point(|&x| x < 2), 1);
assert_eq!(b.partition_point(|&x| x < 3), 1);
assert_eq!(b.partition_point(|&x| x < 4), 4);
assert_eq!(b.partition_point(|&x| x < 5), 4);
assert_eq!(b.partition_point(|&x| x < 6), 4);
assert_eq!(b.partition_point(|&x| x < 7), 4);
assert_eq!(b.partition_point(|&x| x < 8), 5);
}
#[test]
fn test_iterator_advance_by() {
let v = &[0, 1, 2, 3, 4];
for i in 0..=v.len() {
let mut iter = v.iter();
assert_eq!(iter.advance_by(i), 0);
assert_eq!(iter.as_slice(), &v[i..]);
}
let mut iter = v.iter();
assert_eq!(iter.advance_by(v.len() + 1), 1);
assert_eq!(iter.as_slice(), &[]);
let mut iter = v.iter();
assert_eq!(iter.advance_by(3), 0);
assert_eq!(iter.as_slice(), &v[3..]);
assert_eq!(iter.advance_by(2), 0);
assert_eq!(iter.as_slice(), &[]);
assert_eq!(iter.advance_by(0), 0);
}
#[test]
fn test_iterator_advance_back_by() {
let v = &[0, 1, 2, 3, 4];
for i in 0..=v.len() {
let mut iter = v.iter();
assert_eq!(iter.advance_back_by(i), 0);
assert_eq!(iter.as_slice(), &v[..v.len() - i]);
}
let mut iter = v.iter();
assert_eq!(iter.advance_back_by(v.len() + 1), 1);
assert_eq!(iter.as_slice(), &[]);
let mut iter = v.iter();
assert_eq!(iter.advance_back_by(3), 0);
assert_eq!(iter.as_slice(), &v[..v.len() - 3]);
assert_eq!(iter.advance_back_by(2), 0);
assert_eq!(iter.as_slice(), &[]);
assert_eq!(iter.advance_back_by(0), 0);
}
#[test]
fn test_iterator_nth() {
let v: &[_] = &[0, 1, 2, 3, 4];
for i in 0..v.len() {
assert_eq!(v.iter().nth(i).unwrap(), &v[i]);
}
assert_eq!(v.iter().nth(v.len()), None);
let mut iter = v.iter();
assert_eq!(iter.nth(2).unwrap(), &v[2]);
assert_eq!(iter.nth(1).unwrap(), &v[4]);
}
#[test]
fn test_iterator_nth_back() {
let v: &[_] = &[0, 1, 2, 3, 4];
for i in 0..v.len() {
assert_eq!(v.iter().nth_back(i).unwrap(), &v[v.len() - i - 1]);
}
assert_eq!(v.iter().nth_back(v.len()), None);
let mut iter = v.iter();
assert_eq!(iter.nth_back(2).unwrap(), &v[2]);
assert_eq!(iter.nth_back(1).unwrap(), &v[0]);
}
#[test]
fn test_iterator_last() {
let v: &[_] = &[0, 1, 2, 3, 4];
assert_eq!(v.iter().last().unwrap(), &4);
assert_eq!(v[..1].iter().last().unwrap(), &0);
}
#[test]
fn test_iterator_count() {
let v: &[_] = &[0, 1, 2, 3, 4];
assert_eq!(v.iter().count(), 5);
let mut iter2 = v.iter();
iter2.next();
iter2.next();
assert_eq!(iter2.count(), 3);
}
#[test]
fn test_chunks_count() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.chunks(3);
assert_eq!(c.count(), 2);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.chunks(2);
assert_eq!(c2.count(), 3);
let v3: &[i32] = &[];
let c3 = v3.chunks(2);
assert_eq!(c3.count(), 0);
}
#[test]
fn test_chunks_nth() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.chunks(2);
assert_eq!(c.nth(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[4, 5]);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let mut c2 = v2.chunks(3);
assert_eq!(c2.nth(1).unwrap(), &[3, 4]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_chunks_next() {
let v = [0, 1, 2, 3, 4, 5];
let mut c = v.chunks(2);
assert_eq!(c.next().unwrap(), &[0, 1]);
assert_eq!(c.next().unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[4, 5]);
assert_eq!(c.next(), None);
let v = [0, 1, 2, 3, 4, 5, 6, 7];
let mut c = v.chunks(3);
assert_eq!(c.next().unwrap(), &[0, 1, 2]);
assert_eq!(c.next().unwrap(), &[3, 4, 5]);
assert_eq!(c.next().unwrap(), &[6, 7]);
assert_eq!(c.next(), None);
}
#[test]
fn test_chunks_next_back() {
let v = [0, 1, 2, 3, 4, 5];
let mut c = v.chunks(2);
assert_eq!(c.next_back().unwrap(), &[4, 5]);
assert_eq!(c.next_back().unwrap(), &[2, 3]);
assert_eq!(c.next_back().unwrap(), &[0, 1]);
assert_eq!(c.next_back(), None);
let v = [0, 1, 2, 3, 4, 5, 6, 7];
let mut c = v.chunks(3);
assert_eq!(c.next_back().unwrap(), &[6, 7]);
assert_eq!(c.next_back().unwrap(), &[3, 4, 5]);
assert_eq!(c.next_back().unwrap(), &[0, 1, 2]);
assert_eq!(c.next_back(), None);
}
#[test]
fn test_chunks_nth_back() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.chunks(2);
assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[0, 1]);
assert_eq!(c.next(), None);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let mut c2 = v2.chunks(3);
assert_eq!(c2.nth_back(1).unwrap(), &[0, 1, 2]);
assert_eq!(c2.next(), None);
assert_eq!(c2.next_back(), None);
let v3: &[i32] = &[0, 1, 2, 3, 4];
let mut c3 = v3.chunks(10);
assert_eq!(c3.nth_back(0).unwrap(), &[0, 1, 2, 3, 4]);
assert_eq!(c3.next(), None);
let v4: &[i32] = &[0, 1, 2];
let mut c4 = v4.chunks(10);
assert_eq!(c4.nth_back(1_000_000_000usize), None);
}
#[test]
fn test_chunks_last() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.chunks(2);
assert_eq!(c.last().unwrap()[1], 5);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.chunks(2);
assert_eq!(c2.last().unwrap()[0], 4);
}
#[test]
fn test_chunks_zip() {
let v1: &[i32] = &[0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
let res = v1
.chunks(2)
.zip(v2.chunks(2))
.map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
.collect::<Vec<_>>();
assert_eq!(res, vec![14, 22, 14]);
}
#[test]
fn test_chunks_mut_count() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let c = v.chunks_mut(3);
assert_eq!(c.count(), 2);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c2 = v2.chunks_mut(2);
assert_eq!(c2.count(), 3);
let v3: &mut [i32] = &mut [];
let c3 = v3.chunks_mut(2);
assert_eq!(c3.count(), 0);
}
#[test]
fn test_chunks_mut_nth() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let mut c = v.chunks_mut(2);
assert_eq!(c.nth(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[4, 5]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let mut c2 = v2.chunks_mut(3);
assert_eq!(c2.nth(1).unwrap(), &[3, 4]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_chunks_mut_nth_back() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let mut c = v.chunks_mut(2);
assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[0, 1]);
let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
let mut c1 = v1.chunks_mut(3);
assert_eq!(c1.nth_back(1).unwrap(), &[0, 1, 2]);
assert_eq!(c1.next(), None);
let v3: &mut [i32] = &mut [0, 1, 2, 3, 4];
let mut c3 = v3.chunks_mut(10);
assert_eq!(c3.nth_back(0).unwrap(), &[0, 1, 2, 3, 4]);
assert_eq!(c3.next(), None);
let v4: &mut [i32] = &mut [0, 1, 2];
let mut c4 = v4.chunks_mut(10);
assert_eq!(c4.nth_back(1_000_000_000usize), None);
}
#[test]
fn test_chunks_mut_last() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let c = v.chunks_mut(2);
assert_eq!(c.last().unwrap(), &[4, 5]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c2 = v2.chunks_mut(2);
assert_eq!(c2.last().unwrap(), &[4]);
}
#[test]
fn test_chunks_mut_zip() {
let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
for (a, b) in v1.chunks_mut(2).zip(v2.chunks(2)) {
let sum = b.iter().sum::<i32>();
for v in a {
*v += sum;
}
}
assert_eq!(v1, [13, 14, 19, 20, 14]);
}
#[test]
fn test_chunks_mut_zip_aliasing() {
let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
let mut it = v1.chunks_mut(2).zip(v2.chunks(2));
let first = it.next().unwrap();
let _ = it.next().unwrap();
assert_eq!(first, (&mut [0, 1][..], &[6, 7][..]));
}
#[test]
fn test_chunks_exact_mut_zip_aliasing() {
let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
let mut it = v1.chunks_exact_mut(2).zip(v2.chunks(2));
let first = it.next().unwrap();
let _ = it.next().unwrap();
assert_eq!(first, (&mut [0, 1][..], &[6, 7][..]));
}
#[test]
fn test_rchunks_mut_zip_aliasing() {
let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
let mut it = v1.rchunks_mut(2).zip(v2.chunks(2));
let first = it.next().unwrap();
let _ = it.next().unwrap();
assert_eq!(first, (&mut [3, 4][..], &[6, 7][..]));
}
#[test]
fn test_rchunks_exact_mut_zip_aliasing() {
let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
let mut it = v1.rchunks_exact_mut(2).zip(v2.chunks(2));
let first = it.next().unwrap();
let _ = it.next().unwrap();
assert_eq!(first, (&mut [3, 4][..], &[6, 7][..]));
}
#[test]
fn test_chunks_exact_count() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.chunks_exact(3);
assert_eq!(c.count(), 2);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.chunks_exact(2);
assert_eq!(c2.count(), 2);
let v3: &[i32] = &[];
let c3 = v3.chunks_exact(2);
assert_eq!(c3.count(), 0);
}
#[test]
fn test_chunks_exact_nth() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.chunks_exact(2);
assert_eq!(c.nth(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[4, 5]);
let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
let mut c2 = v2.chunks_exact(3);
assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_chunks_exact_nth_back() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.chunks_exact(2);
assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[0, 1]);
assert_eq!(c.next(), None);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let mut c2 = v2.chunks_exact(3);
assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
assert_eq!(c2.next(), None);
assert_eq!(c2.next_back(), None);
let v3: &[i32] = &[0, 1, 2, 3, 4];
let mut c3 = v3.chunks_exact(10);
assert_eq!(c3.nth_back(0), None);
}
#[test]
fn test_chunks_exact_last() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.chunks_exact(2);
assert_eq!(c.last().unwrap(), &[4, 5]);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.chunks_exact(2);
assert_eq!(c2.last().unwrap(), &[2, 3]);
}
#[test]
fn test_chunks_exact_remainder() {
let v: &[i32] = &[0, 1, 2, 3, 4];
let c = v.chunks_exact(2);
assert_eq!(c.remainder(), &[4]);
}
#[test]
fn test_chunks_exact_zip() {
let v1: &[i32] = &[0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
let res = v1
.chunks_exact(2)
.zip(v2.chunks_exact(2))
.map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
.collect::<Vec<_>>();
assert_eq!(res, vec![14, 22]);
}
#[test]
fn test_chunks_exact_mut_count() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let c = v.chunks_exact_mut(3);
assert_eq!(c.count(), 2);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c2 = v2.chunks_exact_mut(2);
assert_eq!(c2.count(), 2);
let v3: &mut [i32] = &mut [];
let c3 = v3.chunks_exact_mut(2);
assert_eq!(c3.count(), 0);
}
#[test]
fn test_chunks_exact_mut_nth() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let mut c = v.chunks_exact_mut(2);
assert_eq!(c.nth(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[4, 5]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
let mut c2 = v2.chunks_exact_mut(3);
assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_chunks_exact_mut_nth_back() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let mut c = v.chunks_exact_mut(2);
assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[0, 1]);
assert_eq!(c.next(), None);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let mut c2 = v2.chunks_exact_mut(3);
assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
assert_eq!(c2.next(), None);
assert_eq!(c2.next_back(), None);
let v3: &mut [i32] = &mut [0, 1, 2, 3, 4];
let mut c3 = v3.chunks_exact_mut(10);
assert_eq!(c3.nth_back(0), None);
}
#[test]
fn test_chunks_exact_mut_last() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let c = v.chunks_exact_mut(2);
assert_eq!(c.last().unwrap(), &[4, 5]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c2 = v2.chunks_exact_mut(2);
assert_eq!(c2.last().unwrap(), &[2, 3]);
}
#[test]
fn test_chunks_exact_mut_remainder() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c = v.chunks_exact_mut(2);
assert_eq!(c.into_remainder(), &[4]);
}
#[test]
fn test_chunks_exact_mut_zip() {
let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
for (a, b) in v1.chunks_exact_mut(2).zip(v2.chunks_exact(2)) {
let sum = b.iter().sum::<i32>();
for v in a {
*v += sum;
}
}
assert_eq!(v1, [13, 14, 19, 20, 4]);
}
#[test]
fn test_array_chunks_infer() {
let v: &[i32] = &[0, 1, 2, 3, 4, -4];
let c = v.array_chunks();
for &[a, b, c] in c {
assert_eq!(a + b + c, 3);
}
let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
let total = v2.array_chunks().map(|&[a, b]| a * b).sum::<i32>();
assert_eq!(total, 2 * 3 + 4 * 5);
}
#[test]
fn test_array_chunks_count() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.array_chunks::<3>();
assert_eq!(c.count(), 2);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.array_chunks::<2>();
assert_eq!(c2.count(), 2);
let v3: &[i32] = &[];
let c3 = v3.array_chunks::<2>();
assert_eq!(c3.count(), 0);
}
#[test]
fn test_array_chunks_nth() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.array_chunks::<2>();
assert_eq!(c.nth(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[4, 5]);
let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
let mut c2 = v2.array_chunks::<3>();
assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_array_chunks_nth_back() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.array_chunks::<2>();
assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[0, 1]);
assert_eq!(c.next(), None);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let mut c2 = v2.array_chunks::<3>();
assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
assert_eq!(c2.next(), None);
assert_eq!(c2.next_back(), None);
let v3: &[i32] = &[0, 1, 2, 3, 4];
let mut c3 = v3.array_chunks::<10>();
assert_eq!(c3.nth_back(0), None);
}
#[test]
fn test_array_chunks_last() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.array_chunks::<2>();
assert_eq!(c.last().unwrap(), &[4, 5]);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.array_chunks::<2>();
assert_eq!(c2.last().unwrap(), &[2, 3]);
}
#[test]
fn test_array_chunks_remainder() {
let v: &[i32] = &[0, 1, 2, 3, 4];
let c = v.array_chunks::<2>();
assert_eq!(c.remainder(), &[4]);
}
#[test]
fn test_array_chunks_zip() {
let v1: &[i32] = &[0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
let res = v1
.array_chunks::<2>()
.zip(v2.array_chunks::<2>())
.map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
.collect::<Vec<_>>();
assert_eq!(res, vec![14, 22]);
}
#[test]
fn test_array_chunks_mut_infer() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
for a in v.array_chunks_mut() {
let sum = a.iter().sum::<i32>();
*a = [sum; 3];
}
assert_eq!(v, &[3, 3, 3, 12, 12, 12, 6]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
v2.array_chunks_mut().for_each(|[a, b]| core::mem::swap(a, b));
assert_eq!(v2, &[1, 0, 3, 2, 5, 4, 6]);
}
#[test]
fn test_array_chunks_mut_count() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let c = v.array_chunks_mut::<3>();
assert_eq!(c.count(), 2);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c2 = v2.array_chunks_mut::<2>();
assert_eq!(c2.count(), 2);
let v3: &mut [i32] = &mut [];
let c3 = v3.array_chunks_mut::<2>();
assert_eq!(c3.count(), 0);
}
#[test]
fn test_array_chunks_mut_nth() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let mut c = v.array_chunks_mut::<2>();
assert_eq!(c.nth(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[4, 5]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
let mut c2 = v2.array_chunks_mut::<3>();
assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_array_chunks_mut_nth_back() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let mut c = v.array_chunks_mut::<2>();
assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[0, 1]);
assert_eq!(c.next(), None);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let mut c2 = v2.array_chunks_mut::<3>();
assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
assert_eq!(c2.next(), None);
assert_eq!(c2.next_back(), None);
let v3: &mut [i32] = &mut [0, 1, 2, 3, 4];
let mut c3 = v3.array_chunks_mut::<10>();
assert_eq!(c3.nth_back(0), None);
}
#[test]
fn test_array_chunks_mut_last() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let c = v.array_chunks_mut::<2>();
assert_eq!(c.last().unwrap(), &[4, 5]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c2 = v2.array_chunks_mut::<2>();
assert_eq!(c2.last().unwrap(), &[2, 3]);
}
#[test]
fn test_array_chunks_mut_remainder() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c = v.array_chunks_mut::<2>();
assert_eq!(c.into_remainder(), &[4]);
}
#[test]
fn test_array_chunks_mut_zip() {
let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
for (a, b) in v1.array_chunks_mut::<2>().zip(v2.array_chunks::<2>()) {
let sum = b.iter().sum::<i32>();
for v in a {
*v += sum;
}
}
assert_eq!(v1, [13, 14, 19, 20, 4]);
}
#[test]
fn test_array_windows_infer() {
let v: &[i32] = &[0, 1, 0, 1];
assert_eq!(v.array_windows::<2>().count(), 3);
let c = v.array_windows();
for &[a, b] in c {
assert_eq!(a + b, 1);
}
let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
let total = v2.array_windows().map(|&[a, b, c]| a + b + c).sum::<i32>();
assert_eq!(total, 3 + 6 + 9 + 12 + 15);
}
#[test]
fn test_array_windows_count() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.array_windows::<3>();
assert_eq!(c.count(), 4);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.array_windows::<6>();
assert_eq!(c2.count(), 0);
let v3: &[i32] = &[];
let c3 = v3.array_windows::<2>();
assert_eq!(c3.count(), 0);
let v4: &[()] = &[(); usize::MAX];
let c4 = v4.array_windows::<1>();
assert_eq!(c4.count(), usize::MAX);
}
#[test]
fn test_array_windows_nth() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let snd = v.array_windows::<4>().nth(1);
assert_eq!(snd, Some(&[1, 2, 3, 4]));
let mut arr_windows = v.array_windows::<2>();
assert_ne!(arr_windows.nth(0), arr_windows.nth(0));
let last = v.array_windows::<3>().last();
assert_eq!(last, Some(&[3, 4, 5]));
}
#[test]
fn test_array_windows_nth_back() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let snd = v.array_windows::<4>().nth_back(1);
assert_eq!(snd, Some(&[1, 2, 3, 4]));
let mut arr_windows = v.array_windows::<2>();
assert_ne!(arr_windows.nth_back(0), arr_windows.nth_back(0));
}
#[test]
fn test_rchunks_count() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.rchunks(3);
assert_eq!(c.count(), 2);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.rchunks(2);
assert_eq!(c2.count(), 3);
let v3: &[i32] = &[];
let c3 = v3.rchunks(2);
assert_eq!(c3.count(), 0);
}
#[test]
fn test_rchunks_nth() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.rchunks(2);
assert_eq!(c.nth(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[0, 1]);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let mut c2 = v2.rchunks(3);
assert_eq!(c2.nth(1).unwrap(), &[0, 1]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_rchunks_nth_back() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.rchunks(2);
assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
assert_eq!(c.next_back().unwrap(), &[4, 5]);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let mut c2 = v2.rchunks(3);
assert_eq!(c2.nth_back(1).unwrap(), &[2, 3, 4]);
assert_eq!(c2.next_back(), None);
}
#[test]
fn test_rchunks_next() {
let v = [0, 1, 2, 3, 4, 5];
let mut c = v.rchunks(2);
assert_eq!(c.next().unwrap(), &[4, 5]);
assert_eq!(c.next().unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[0, 1]);
assert_eq!(c.next(), None);
let v = [0, 1, 2, 3, 4, 5, 6, 7];
let mut c = v.rchunks(3);
assert_eq!(c.next().unwrap(), &[5, 6, 7]);
assert_eq!(c.next().unwrap(), &[2, 3, 4]);
assert_eq!(c.next().unwrap(), &[0, 1]);
assert_eq!(c.next(), None);
}
#[test]
fn test_rchunks_next_back() {
let v = [0, 1, 2, 3, 4, 5];
let mut c = v.rchunks(2);
assert_eq!(c.next_back().unwrap(), &[0, 1]);
assert_eq!(c.next_back().unwrap(), &[2, 3]);
assert_eq!(c.next_back().unwrap(), &[4, 5]);
assert_eq!(c.next_back(), None);
let v = [0, 1, 2, 3, 4, 5, 6, 7];
let mut c = v.rchunks(3);
assert_eq!(c.next_back().unwrap(), &[0, 1]);
assert_eq!(c.next_back().unwrap(), &[2, 3, 4]);
assert_eq!(c.next_back().unwrap(), &[5, 6, 7]);
assert_eq!(c.next_back(), None);
}
#[test]
fn test_rchunks_last() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.rchunks(2);
assert_eq!(c.last().unwrap()[1], 1);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.rchunks(2);
assert_eq!(c2.last().unwrap()[0], 0);
}
#[test]
fn test_rchunks_zip() {
let v1: &[i32] = &[0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
let res = v1
.rchunks(2)
.zip(v2.rchunks(2))
.map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
.collect::<Vec<_>>();
assert_eq!(res, vec![26, 18, 6]);
}
#[test]
fn test_rchunks_mut_count() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let c = v.rchunks_mut(3);
assert_eq!(c.count(), 2);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c2 = v2.rchunks_mut(2);
assert_eq!(c2.count(), 3);
let v3: &mut [i32] = &mut [];
let c3 = v3.rchunks_mut(2);
assert_eq!(c3.count(), 0);
}
#[test]
fn test_rchunks_mut_nth() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let mut c = v.rchunks_mut(2);
assert_eq!(c.nth(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[0, 1]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let mut c2 = v2.rchunks_mut(3);
assert_eq!(c2.nth(1).unwrap(), &[0, 1]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_rchunks_mut_nth_back() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let mut c = v.rchunks_mut(2);
assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
assert_eq!(c.next_back().unwrap(), &[4, 5]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let mut c2 = v2.rchunks_mut(3);
assert_eq!(c2.nth_back(1).unwrap(), &[2, 3, 4]);
assert_eq!(c2.next_back(), None);
}
#[test]
fn test_rchunks_mut_next() {
let mut v = [0, 1, 2, 3, 4, 5];
let mut c = v.rchunks_mut(2);
assert_eq!(c.next().unwrap(), &mut [4, 5]);
assert_eq!(c.next().unwrap(), &mut [2, 3]);
assert_eq!(c.next().unwrap(), &mut [0, 1]);
assert_eq!(c.next(), None);
let mut v = [0, 1, 2, 3, 4, 5, 6, 7];
let mut c = v.rchunks_mut(3);
assert_eq!(c.next().unwrap(), &mut [5, 6, 7]);
assert_eq!(c.next().unwrap(), &mut [2, 3, 4]);
assert_eq!(c.next().unwrap(), &mut [0, 1]);
assert_eq!(c.next(), None);
}
#[test]
fn test_rchunks_mut_next_back() {
let mut v = [0, 1, 2, 3, 4, 5];
let mut c = v.rchunks_mut(2);
assert_eq!(c.next_back().unwrap(), &mut [0, 1]);
assert_eq!(c.next_back().unwrap(), &mut [2, 3]);
assert_eq!(c.next_back().unwrap(), &mut [4, 5]);
assert_eq!(c.next_back(), None);
let mut v = [0, 1, 2, 3, 4, 5, 6, 7];
let mut c = v.rchunks_mut(3);
assert_eq!(c.next_back().unwrap(), &mut [0, 1]);
assert_eq!(c.next_back().unwrap(), &mut [2, 3, 4]);
assert_eq!(c.next_back().unwrap(), &mut [5, 6, 7]);
assert_eq!(c.next_back(), None);
}
#[test]
fn test_rchunks_mut_last() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let c = v.rchunks_mut(2);
assert_eq!(c.last().unwrap(), &[0, 1]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c2 = v2.rchunks_mut(2);
assert_eq!(c2.last().unwrap(), &[0]);
}
#[test]
fn test_rchunks_mut_zip() {
let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
for (a, b) in v1.rchunks_mut(2).zip(v2.rchunks(2)) {
let sum = b.iter().sum::<i32>();
for v in a {
*v += sum;
}
}
assert_eq!(v1, [6, 16, 17, 22, 23]);
}
#[test]
fn test_rchunks_exact_count() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.rchunks_exact(3);
assert_eq!(c.count(), 2);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.rchunks_exact(2);
assert_eq!(c2.count(), 2);
let v3: &[i32] = &[];
let c3 = v3.rchunks_exact(2);
assert_eq!(c3.count(), 0);
}
#[test]
fn test_rchunks_exact_nth() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.rchunks_exact(2);
assert_eq!(c.nth(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[0, 1]);
let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
let mut c2 = v2.rchunks_exact(3);
assert_eq!(c2.nth(1).unwrap(), &[1, 2, 3]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_rchunks_exact_nth_back() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.rchunks_exact(2);
assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
assert_eq!(c.next_back().unwrap(), &[4, 5]);
let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
let mut c2 = v2.rchunks_exact(3);
assert_eq!(c2.nth_back(1).unwrap(), &[4, 5, 6]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_rchunks_exact_last() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.rchunks_exact(2);
assert_eq!(c.last().unwrap(), &[0, 1]);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.rchunks_exact(2);
assert_eq!(c2.last().unwrap(), &[1, 2]);
}
#[test]
fn test_rchunks_exact_remainder() {
let v: &[i32] = &[0, 1, 2, 3, 4];
let c = v.rchunks_exact(2);
assert_eq!(c.remainder(), &[0]);
}
#[test]
fn test_rchunks_exact_zip() {
let v1: &[i32] = &[0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
let res = v1
.rchunks_exact(2)
.zip(v2.rchunks_exact(2))
.map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
.collect::<Vec<_>>();
assert_eq!(res, vec![26, 18]);
}
#[test]
fn test_rchunks_exact_mut_count() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let c = v.rchunks_exact_mut(3);
assert_eq!(c.count(), 2);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c2 = v2.rchunks_exact_mut(2);
assert_eq!(c2.count(), 2);
let v3: &mut [i32] = &mut [];
let c3 = v3.rchunks_exact_mut(2);
assert_eq!(c3.count(), 0);
}
#[test]
fn test_rchunks_exact_mut_nth() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let mut c = v.rchunks_exact_mut(2);
assert_eq!(c.nth(1).unwrap(), &[2, 3]);
assert_eq!(c.next().unwrap(), &[0, 1]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
let mut c2 = v2.rchunks_exact_mut(3);
assert_eq!(c2.nth(1).unwrap(), &[1, 2, 3]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_rchunks_exact_mut_nth_back() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let mut c = v.rchunks_exact_mut(2);
assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
assert_eq!(c.next_back().unwrap(), &[4, 5]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
let mut c2 = v2.rchunks_exact_mut(3);
assert_eq!(c2.nth_back(1).unwrap(), &[4, 5, 6]);
assert_eq!(c2.next(), None);
}
#[test]
fn test_rchunks_exact_mut_last() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
let c = v.rchunks_exact_mut(2);
assert_eq!(c.last().unwrap(), &[0, 1]);
let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c2 = v2.rchunks_exact_mut(2);
assert_eq!(c2.last().unwrap(), &[1, 2]);
}
#[test]
fn test_rchunks_exact_mut_remainder() {
let v: &mut [i32] = &mut [0, 1, 2, 3, 4];
let c = v.rchunks_exact_mut(2);
assert_eq!(c.into_remainder(), &[0]);
}
#[test]
fn test_rchunks_exact_mut_zip() {
let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
for (a, b) in v1.rchunks_exact_mut(2).zip(v2.rchunks_exact(2)) {
let sum = b.iter().sum::<i32>();
for v in a {
*v += sum;
}
}
assert_eq!(v1, [0, 16, 17, 22, 23]);
}
#[test]
fn chunks_mut_are_send_and_sync() {
use std::cell::Cell;
use std::slice::{ChunksExactMut, ChunksMut, RChunksExactMut, RChunksMut};
use std::sync::MutexGuard;
fn assert_send_and_sync()
where
ChunksMut<'static, Cell<i32>>: Send,
ChunksMut<'static, MutexGuard<'static, u32>>: Sync,
ChunksExactMut<'static, Cell<i32>>: Send,
ChunksExactMut<'static, MutexGuard<'static, u32>>: Sync,
RChunksMut<'static, Cell<i32>>: Send,
RChunksMut<'static, MutexGuard<'static, u32>>: Sync,
RChunksExactMut<'static, Cell<i32>>: Send,
RChunksExactMut<'static, MutexGuard<'static, u32>>: Sync,
{
}
assert_send_and_sync();
}
#[test]
fn test_windows_count() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.windows(3);
assert_eq!(c.count(), 4);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.windows(6);
assert_eq!(c2.count(), 0);
let v3: &[i32] = &[];
let c3 = v3.windows(2);
assert_eq!(c3.count(), 0);
let v4 = &[(); usize::MAX];
let c4 = v4.windows(1);
assert_eq!(c4.count(), usize::MAX);
}
#[test]
fn test_windows_nth() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.windows(2);
assert_eq!(c.nth(2).unwrap()[1], 3);
assert_eq!(c.next().unwrap()[0], 3);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let mut c2 = v2.windows(4);
assert_eq!(c2.nth(1).unwrap()[1], 2);
assert_eq!(c2.next(), None);
}
#[test]
fn test_windows_nth_back() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let mut c = v.windows(2);
assert_eq!(c.nth_back(2).unwrap()[0], 2);
assert_eq!(c.next_back().unwrap()[1], 2);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let mut c2 = v2.windows(4);
assert_eq!(c2.nth_back(1).unwrap()[1], 1);
assert_eq!(c2.next_back(), None);
}
#[test]
fn test_windows_last() {
let v: &[i32] = &[0, 1, 2, 3, 4, 5];
let c = v.windows(2);
assert_eq!(c.last().unwrap()[1], 5);
let v2: &[i32] = &[0, 1, 2, 3, 4];
let c2 = v2.windows(2);
assert_eq!(c2.last().unwrap()[0], 3);
}
#[test]
fn test_windows_zip() {
let v1: &[i32] = &[0, 1, 2, 3, 4];
let v2: &[i32] = &[6, 7, 8, 9, 10];
let res = v1
.windows(2)
.zip(v2.windows(2))
.map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
.collect::<Vec<_>>();
assert_eq!(res, [14, 18, 22, 26]);
}
#[test]
fn test_iter_ref_consistency() {
use std::fmt::Debug;
fn test<T: Copy + Debug + PartialEq>(x: T) {
let v: &[T] = &[x, x, x];
let v_ptrs: [*const T; 3] = match v {
[ref v1, ref v2, ref v3] => [v1 as *const _, v2 as *const _, v3 as *const _],
_ => unreachable!(),
};
let len = v.len();
// nth(i)
for i in 0..len {
assert_eq!(&v[i] as *const _, v_ptrs[i]); // check the v_ptrs array, just to be sure
let nth = v.iter().nth(i).unwrap();
assert_eq!(nth as *const _, v_ptrs[i]);
}
assert_eq!(v.iter().nth(len), None, "nth(len) should return None");
// stepping through with nth(0)
{
let mut it = v.iter();
for i in 0..len {
let next = it.nth(0).unwrap();
assert_eq!(next as *const _, v_ptrs[i]);
}
assert_eq!(it.nth(0), None);
}
// next()
{
let mut it = v.iter();
for i in 0..len {
let remaining = len - i;
assert_eq!(it.size_hint(), (remaining, Some(remaining)));
let next = it.next().unwrap();
assert_eq!(next as *const _, v_ptrs[i]);
}
assert_eq!(it.size_hint(), (0, Some(0)));
assert_eq!(it.next(), None, "The final call to next() should return None");
}
// next_back()
{
let mut it = v.iter();
for i in 0..len {
let remaining = len - i;
assert_eq!(it.size_hint(), (remaining, Some(remaining)));
let prev = it.next_back().unwrap();
assert_eq!(prev as *const _, v_ptrs[remaining - 1]);
}
assert_eq!(it.size_hint(), (0, Some(0)));
assert_eq!(it.next_back(), None, "The final call to next_back() should return None");
}
}
fn test_mut<T: Copy + Debug + PartialEq>(x: T) {
let v: &mut [T] = &mut [x, x, x];
let v_ptrs: [*mut T; 3] = match v {
[ref v1, ref v2, ref v3] => {
[v1 as *const _ as *mut _, v2 as *const _ as *mut _, v3 as *const _ as *mut _]
}
_ => unreachable!(),
};
let len = v.len();
// nth(i)
for i in 0..len {
assert_eq!(&mut v[i] as *mut _, v_ptrs[i]); // check the v_ptrs array, just to be sure
let nth = v.iter_mut().nth(i).unwrap();
assert_eq!(nth as *mut _, v_ptrs[i]);
}
assert_eq!(v.iter().nth(len), None, "nth(len) should return None");
// stepping through with nth(0)
{
let mut it = v.iter();
for i in 0..len {
let next = it.nth(0).unwrap();
assert_eq!(next as *const _, v_ptrs[i]);
}
assert_eq!(it.nth(0), None);
}
// next()
{
let mut it = v.iter_mut();
for i in 0..len {
let remaining = len - i;
assert_eq!(it.size_hint(), (remaining, Some(remaining)));
let next = it.next().unwrap();
assert_eq!(next as *mut _, v_ptrs[i]);
}
assert_eq!(it.size_hint(), (0, Some(0)));
assert_eq!(it.next(), None, "The final call to next() should return None");
}
// next_back()
{
let mut it = v.iter_mut();
for i in 0..len {
let remaining = len - i;
assert_eq!(it.size_hint(), (remaining, Some(remaining)));
let prev = it.next_back().unwrap();
assert_eq!(prev as *mut _, v_ptrs[remaining - 1]);
}
assert_eq!(it.size_hint(), (0, Some(0)));
assert_eq!(it.next_back(), None, "The final call to next_back() should return None");
}
}
// Make sure iterators and slice patterns yield consistent addresses for various types,
// including ZSTs.
test(0u32);
test(());
test([0u32; 0]); // ZST with alignment > 0
test_mut(0u32);
test_mut(());
test_mut([0u32; 0]); // ZST with alignment > 0
}
// The current implementation of SliceIndex fails to handle methods
// orthogonally from range types; therefore, it is worth testing
// all of the indexing operations on each input.
mod slice_index {
// This checks all six indexing methods, given an input range that
// should succeed. (it is NOT suitable for testing invalid inputs)
macro_rules! assert_range_eq {
($arr:expr, $range:expr, $expected:expr) => {
let mut arr = $arr;
let mut expected = $expected;
{
let s: &[_] = &arr;
let expected: &[_] = &expected;
assert_eq!(&s[$range], expected, "(in assertion for: index)");
assert_eq!(s.get($range), Some(expected), "(in assertion for: get)");
unsafe {
assert_eq!(
s.get_unchecked($range),
expected,
"(in assertion for: get_unchecked)",
);
}
}
{
let s: &mut [_] = &mut arr;
let expected: &mut [_] = &mut expected;
assert_eq!(&mut s[$range], expected, "(in assertion for: index_mut)",);
assert_eq!(
s.get_mut($range),
Some(&mut expected[..]),
"(in assertion for: get_mut)",
);
unsafe {
assert_eq!(
s.get_unchecked_mut($range),
expected,
"(in assertion for: get_unchecked_mut)",
);
}
}
};
}
// Make sure the macro can actually detect bugs,
// because if it can't, then what are we even doing here?
//
// (Be aware this only demonstrates the ability to detect bugs
// in the FIRST method that panics, as the macro is not designed
// to be used in `should_panic`)
#[test]
#[should_panic(expected = "out of range")]
fn assert_range_eq_can_fail_by_panic() {
assert_range_eq!([0, 1, 2], 0..5, [0, 1, 2]);
}
// (Be aware this only demonstrates the ability to detect bugs
// in the FIRST method it calls, as the macro is not designed
// to be used in `should_panic`)
#[test]
#[should_panic(expected = "==")]
fn assert_range_eq_can_fail_by_inequality() {
assert_range_eq!([0, 1, 2], 0..2, [0, 1, 2]);
}
// Test cases for bad index operations.
//
// This generates `should_panic` test cases for Index/IndexMut
// and `None` test cases for get/get_mut.
macro_rules! panic_cases {
($(
// each test case needs a unique name to namespace the tests
in mod $case_name:ident {
data: $data:expr;
// optional:
//
// one or more similar inputs for which data[input] succeeds,
// and the corresponding output as an array. This helps validate
// "critical points" where an input range straddles the boundary
// between valid and invalid.
// (such as the input `len..len`, which is just barely valid)
$(
good: data[$good:expr] == $output:expr;
)*
bad: data[$bad:expr];
message: $expect_msg:expr;
}
)*) => {$(
mod $case_name {
#[allow(unused_imports)]
use core::ops::Bound;
#[test]
fn pass() {
let mut v = $data;
$( assert_range_eq!($data, $good, $output); )*
{
let v: &[_] = &v;
assert_eq!(v.get($bad), None, "(in None assertion for get)");
}
{
let v: &mut [_] = &mut v;
assert_eq!(v.get_mut($bad), None, "(in None assertion for get_mut)");
}
}
#[test]
#[should_panic(expected = $expect_msg)]
fn index_fail() {
let v = $data;
let v: &[_] = &v;
let _v = &v[$bad];
}
#[test]
#[should_panic(expected = $expect_msg)]
fn index_mut_fail() {
let mut v = $data;
let v: &mut [_] = &mut v;
let _v = &mut v[$bad];
}
}
)*};
}
#[test]
fn simple() {
let v = [0, 1, 2, 3, 4, 5];
assert_range_eq!(v, .., [0, 1, 2, 3, 4, 5]);
assert_range_eq!(v, ..2, [0, 1]);
assert_range_eq!(v, ..=1, [0, 1]);
assert_range_eq!(v, 2.., [2, 3, 4, 5]);
assert_range_eq!(v, 1..4, [1, 2, 3]);
assert_range_eq!(v, 1..=3, [1, 2, 3]);
}
panic_cases! {
in mod rangefrom_len {
data: [0, 1, 2, 3, 4, 5];
good: data[6..] == [];
bad: data[7..];
message: "out of range";
}
in mod rangeto_len {
data: [0, 1, 2, 3, 4, 5];
good: data[..6] == [0, 1, 2, 3, 4, 5];
bad: data[..7];
message: "out of range";
}
in mod rangetoinclusive_len {
data: [0, 1, 2, 3, 4, 5];
good: data[..=5] == [0, 1, 2, 3, 4, 5];
bad: data[..=6];
message: "out of range";
}
in mod rangeinclusive_len {
data: [0, 1, 2, 3, 4, 5];
good: data[0..=5] == [0, 1, 2, 3, 4, 5];
bad: data[0..=6];
message: "out of range";
}
in mod range_len_len {
data: [0, 1, 2, 3, 4, 5];
good: data[6..6] == [];
bad: data[7..7];
message: "out of range";
}
in mod rangeinclusive_len_len {
data: [0, 1, 2, 3, 4, 5];
good: data[6..=5] == [];
bad: data[7..=6];
message: "out of range";
}
in mod boundpair_len {
data: [0, 1, 2, 3, 4, 5];
good: data[(Bound::Included(6), Bound::Unbounded)] == [];
good: data[(Bound::Unbounded, Bound::Included(5))] == [0, 1, 2, 3, 4, 5];
good: data[(Bound::Unbounded, Bound::Excluded(6))] == [0, 1, 2, 3, 4, 5];
good: data[(Bound::Included(0), Bound::Included(5))] == [0, 1, 2, 3, 4, 5];
good: data[(Bound::Included(0), Bound::Excluded(6))] == [0, 1, 2, 3, 4, 5];
good: data[(Bound::Included(2), Bound::Excluded(4))] == [2, 3];
good: data[(Bound::Excluded(1), Bound::Included(4))] == [2, 3, 4];
good: data[(Bound::Excluded(5), Bound::Excluded(6))] == [];
good: data[(Bound::Included(6), Bound::Excluded(6))] == [];
good: data[(Bound::Excluded(5), Bound::Included(5))] == [];
good: data[(Bound::Included(6), Bound::Included(5))] == [];
bad: data[(Bound::Unbounded, Bound::Included(6))];
message: "out of range";
}
}
panic_cases! {
in mod rangeinclusive_exhausted {
data: [0, 1, 2, 3, 4, 5];
good: data[0..=5] == [0, 1, 2, 3, 4, 5];
good: data[{
let mut iter = 0..=5;
iter.by_ref().count(); // exhaust it
iter
}] == [];
// 0..=6 is out of range before exhaustion, so it
// stands to reason that it still would be after.
bad: data[{
let mut iter = 0..=6;
iter.by_ref().count(); // exhaust it
iter
}];
message: "out of range";
}
}
panic_cases! {
in mod range_neg_width {
data: [0, 1, 2, 3, 4, 5];
good: data[4..4] == [];
bad: data[4..3];
message: "but ends at";
}
in mod rangeinclusive_neg_width {
data: [0, 1, 2, 3, 4, 5];
good: data[4..=3] == [];
bad: data[4..=2];
message: "but ends at";
}
in mod boundpair_neg_width {
data: [0, 1, 2, 3, 4, 5];
good: data[(Bound::Included(4), Bound::Excluded(4))] == [];
bad: data[(Bound::Included(4), Bound::Excluded(3))];
message: "but ends at";
}
}
panic_cases! {
in mod rangeinclusive_overflow {
data: [0, 1];
// note: using 0 specifically ensures that the result of overflowing is 0..0,
// so that `get` doesn't simply return None for the wrong reason.
bad: data[0 ..= usize::MAX];
message: "maximum usize";
}
in mod rangetoinclusive_overflow {
data: [0, 1];
bad: data[..= usize::MAX];
message: "maximum usize";
}
in mod boundpair_overflow_end {
data: [0; 1];
bad: data[(Bound::Unbounded, Bound::Included(usize::MAX))];
message: "maximum usize";
}
in mod boundpair_overflow_start {
data: [0; 1];
bad: data[(Bound::Excluded(usize::MAX), Bound::Unbounded)];
message: "maximum usize";
}
} // panic_cases!
}
#[test]
fn test_find_rfind() {
let v = [0, 1, 2, 3, 4, 5];
let mut iter = v.iter();
let mut i = v.len();
while let Some(&elt) = iter.rfind(|_| true) {
i -= 1;
assert_eq!(elt, v[i]);
}
assert_eq!(i, 0);
assert_eq!(v.iter().rfind(|&&x| x <= 3), Some(&3));
}
#[test]
fn test_iter_folds() {
let a = [1, 2, 3, 4, 5]; // len>4 so the unroll is used
assert_eq!(a.iter().fold(0, |acc, &x| 2 * acc + x), 57);
assert_eq!(a.iter().rfold(0, |acc, &x| 2 * acc + x), 129);
let fold = |acc: i32, &x| acc.checked_mul(2)?.checked_add(x);
assert_eq!(a.iter().try_fold(0, &fold), Some(57));
assert_eq!(a.iter().try_rfold(0, &fold), Some(129));
// short-circuiting try_fold, through other methods
let a = [0, 1, 2, 3, 5, 5, 5, 7, 8, 9];
let mut iter = a.iter();
assert_eq!(iter.position(|&x| x == 3), Some(3));
assert_eq!(iter.rfind(|&&x| x == 5), Some(&5));
assert_eq!(iter.len(), 2);
}
#[test]
fn test_rotate_left() {
const N: usize = 600;
let a: &mut [_] = &mut [0; N];
for i in 0..N {
a[i] = i;
}
a.rotate_left(42);
let k = N - 42;
for i in 0..N {
assert_eq!(a[(i + k) % N], i);
}
}
#[test]
fn test_rotate_right() {
const N: usize = 600;
let a: &mut [_] = &mut [0; N];
for i in 0..N {
a[i] = i;
}
a.rotate_right(42);
for i in 0..N {
assert_eq!(a[(i + 42) % N], i);
}
}
#[test]
#[cfg_attr(miri, ignore)] // Miri is too slow
fn brute_force_rotate_test_0() {
// In case of edge cases involving multiple algorithms
let n = 300;
for len in 0..n {
for s in 0..len {
let mut v = Vec::with_capacity(len);
for i in 0..len {
v.push(i);
}
v[..].rotate_right(s);
for i in 0..v.len() {
assert_eq!(v[i], v.len().wrapping_add(i.wrapping_sub(s)) % v.len());
}
}
}
}
#[test]
fn brute_force_rotate_test_1() {
// `ptr_rotate` covers so many kinds of pointer usage, that this is just a good test for
// pointers in general. This uses a `[usize; 4]` to hit all algorithms without overwhelming miri
let n = 30;
for len in 0..n {
for s in 0..len {
let mut v: Vec<[usize; 4]> = Vec::with_capacity(len);
for i in 0..len {
v.push([i, 0, 0, 0]);
}
v[..].rotate_right(s);
for i in 0..v.len() {
assert_eq!(v[i][0], v.len().wrapping_add(i.wrapping_sub(s)) % v.len());
}
}
}
}
#[test]
#[cfg(not(target_arch = "wasm32"))]
fn sort_unstable() {
use core::cmp::Ordering::{Equal, Greater, Less};
use core::slice::heapsort;
use rand::{seq::SliceRandom, Rng};
// Miri is too slow (but still need to `chain` to make the types match)
let lens = if cfg!(miri) { (2..20).chain(0..0) } else { (2..25).chain(500..510) };
let rounds = if cfg!(miri) { 1 } else { 100 };
let mut v = [0; 600];
let mut tmp = [0; 600];
let mut rng = crate::test_rng();
for len in lens {
let v = &mut v[0..len];
let tmp = &mut tmp[0..len];
for &modulus in &[5, 10, 100, 1000] {
for _ in 0..rounds {
for i in 0..len {
v[i] = rng.gen::<i32>() % modulus;
}
// Sort in default order.
tmp.copy_from_slice(v);
tmp.sort_unstable();
assert!(tmp.windows(2).all(|w| w[0] <= w[1]));
// Sort in ascending order.
tmp.copy_from_slice(v);
tmp.sort_unstable_by(|a, b| a.cmp(b));
assert!(tmp.windows(2).all(|w| w[0] <= w[1]));
// Sort in descending order.
tmp.copy_from_slice(v);
tmp.sort_unstable_by(|a, b| b.cmp(a));
assert!(tmp.windows(2).all(|w| w[0] >= w[1]));
// Test heapsort using `<` operator.
tmp.copy_from_slice(v);
heapsort(tmp, |a, b| a < b);
assert!(tmp.windows(2).all(|w| w[0] <= w[1]));
// Test heapsort using `>` operator.
tmp.copy_from_slice(v);
heapsort(tmp, |a, b| a > b);
assert!(tmp.windows(2).all(|w| w[0] >= w[1]));
}
}
}
// Sort using a completely random comparison function.
// This will reorder the elements *somehow*, but won't panic.
for i in 0..v.len() {
v[i] = i as i32;
}
v.sort_unstable_by(|_, _| *[Less, Equal, Greater].choose(&mut rng).unwrap());
v.sort_unstable();
for i in 0..v.len() {
assert_eq!(v[i], i as i32);
}
// Should not panic.
[0i32; 0].sort_unstable();
[(); 10].sort_unstable();
[(); 100].sort_unstable();
let mut v = [0xDEADBEEFu64];
v.sort_unstable();
assert!(v == [0xDEADBEEF]);
}
#[test]
#[cfg(not(target_arch = "wasm32"))]
#[cfg_attr(miri, ignore)] // Miri is too slow
fn select_nth_unstable() {
use core::cmp::Ordering::{Equal, Greater, Less};
use rand::seq::SliceRandom;
use rand::Rng;
let mut rng = crate::test_rng();
for len in (2..21).chain(500..501) {
let mut orig = vec![0; len];
for &modulus in &[5, 10, 1000] {
for _ in 0..10 {
for i in 0..len {
orig[i] = rng.gen::<i32>() % modulus;
}
let v_sorted = {
let mut v = orig.clone();
v.sort();
v
};
// Sort in default order.
for pivot in 0..len {
let mut v = orig.clone();
v.select_nth_unstable(pivot);
assert_eq!(v_sorted[pivot], v[pivot]);
for i in 0..pivot {
for j in pivot..len {
assert!(v[i] <= v[j]);
}
}
}
// Sort in ascending order.
for pivot in 0..len {
let mut v = orig.clone();
let (left, pivot, right) = v.select_nth_unstable_by(pivot, |a, b| a.cmp(b));
assert_eq!(left.len() + right.len(), len - 1);
for l in left {
assert!(l <= pivot);
for r in right.iter_mut() {
assert!(l <= r);
assert!(pivot <= r);
}
}
}
// Sort in descending order.
let sort_descending_comparator = |a: &i32, b: &i32| b.cmp(a);
let v_sorted_descending = {
let mut v = orig.clone();
v.sort_by(sort_descending_comparator);
v
};
for pivot in 0..len {
let mut v = orig.clone();
v.select_nth_unstable_by(pivot, sort_descending_comparator);
assert_eq!(v_sorted_descending[pivot], v[pivot]);
for i in 0..pivot {
for j in pivot..len {
assert!(v[j] <= v[i]);
}
}
}
}
}
}
// Sort at index using a completely random comparison function.
// This will reorder the elements *somehow*, but won't panic.
let mut v = [0; 500];
for i in 0..v.len() {
v[i] = i as i32;
}
for pivot in 0..v.len() {
v.select_nth_unstable_by(pivot, |_, _| *[Less, Equal, Greater].choose(&mut rng).unwrap());
v.sort();
for i in 0..v.len() {
assert_eq!(v[i], i as i32);
}
}
// Should not panic.
[(); 10].select_nth_unstable(0);
[(); 10].select_nth_unstable(5);
[(); 10].select_nth_unstable(9);
[(); 100].select_nth_unstable(0);
[(); 100].select_nth_unstable(50);
[(); 100].select_nth_unstable(99);
let mut v = [0xDEADBEEFu64];
v.select_nth_unstable(0);
assert!(v == [0xDEADBEEF]);
}
#[test]
#[should_panic(expected = "index 0 greater than length of slice")]
fn select_nth_unstable_zero_length() {
[0i32; 0].select_nth_unstable(0);
}
#[test]
#[should_panic(expected = "index 20 greater than length of slice")]
fn select_nth_unstable_past_length() {
[0i32; 10].select_nth_unstable(20);
}
pub mod memchr {
use core::slice::memchr::{memchr, memrchr};
// test fallback implementations on all platforms
#[test]
fn matches_one() {
assert_eq!(Some(0), memchr(b'a', b"a"));
}
#[test]
fn matches_begin() {
assert_eq!(Some(0), memchr(b'a', b"aaaa"));
}
#[test]
fn matches_end() {
assert_eq!(Some(4), memchr(b'z', b"aaaaz"));
}
#[test]
fn matches_nul() {
assert_eq!(Some(4), memchr(b'\x00', b"aaaa\x00"));
}
#[test]
fn matches_past_nul() {
assert_eq!(Some(5), memchr(b'z', b"aaaa\x00z"));
}
#[test]
fn no_match_empty() {
assert_eq!(None, memchr(b'a', b""));
}
#[test]
fn no_match() {
assert_eq!(None, memchr(b'a', b"xyz"));
}
#[test]
fn matches_one_reversed() {
assert_eq!(Some(0), memrchr(b'a', b"a"));
}
#[test]
fn matches_begin_reversed() {
assert_eq!(Some(3), memrchr(b'a', b"aaaa"));
}
#[test]
fn matches_end_reversed() {
assert_eq!(Some(0), memrchr(b'z', b"zaaaa"));
}
#[test]
fn matches_nul_reversed() {
assert_eq!(Some(4), memrchr(b'\x00', b"aaaa\x00"));
}
#[test]
fn matches_past_nul_reversed() {
assert_eq!(Some(0), memrchr(b'z', b"z\x00aaaa"));
}
#[test]
fn no_match_empty_reversed() {
assert_eq!(None, memrchr(b'a', b""));
}
#[test]
fn no_match_reversed() {
assert_eq!(None, memrchr(b'a', b"xyz"));
}
#[test]
fn each_alignment_reversed() {
let mut data = [1u8; 64];
let needle = 2;
let pos = 40;
data[pos] = needle;
for start in 0..16 {
assert_eq!(Some(pos - start), memrchr(needle, &data[start..]));
}
}
}
#[test]
fn test_align_to_simple() {
let bytes = [1u8, 2, 3, 4, 5, 6, 7];
let (prefix, aligned, suffix) = unsafe { bytes.align_to::<u16>() };
assert_eq!(aligned.len(), 3);
assert!(prefix == [1] || suffix == [7]);
let expect1 = [1 << 8 | 2, 3 << 8 | 4, 5 << 8 | 6];
let expect2 = [1 | 2 << 8, 3 | 4 << 8, 5 | 6 << 8];
let expect3 = [2 << 8 | 3, 4 << 8 | 5, 6 << 8 | 7];
let expect4 = [2 | 3 << 8, 4 | 5 << 8, 6 | 7 << 8];
assert!(
aligned == expect1 || aligned == expect2 || aligned == expect3 || aligned == expect4,
"aligned={:?} expected={:?} || {:?} || {:?} || {:?}",
aligned,
expect1,
expect2,
expect3,
expect4
);
}
#[test]
fn test_align_to_zst() {
let bytes = [1, 2, 3, 4, 5, 6, 7];
let (prefix, aligned, suffix) = unsafe { bytes.align_to::<()>() };
assert_eq!(aligned.len(), 0);
assert!(prefix == [1, 2, 3, 4, 5, 6, 7] || suffix == [1, 2, 3, 4, 5, 6, 7]);
}
#[test]
fn test_align_to_non_trivial() {
#[repr(align(8))]
struct U64(u64, u64);
#[repr(align(8))]
struct U64U64U32(u64, u64, u32);
let data = [
U64(1, 2),
U64(3, 4),
U64(5, 6),
U64(7, 8),
U64(9, 10),
U64(11, 12),
U64(13, 14),
U64(15, 16),
];
let (prefix, aligned, suffix) = unsafe { data.align_to::<U64U64U32>() };
assert_eq!(aligned.len(), 4);
assert_eq!(prefix.len() + suffix.len(), 2);
}
#[test]
fn test_align_to_empty_mid() {
use core::mem;
// Make sure that we do not create empty unaligned slices for the mid part, even when the
// overall slice is too short to contain an aligned address.
let bytes = [1, 2, 3, 4, 5, 6, 7];
type Chunk = u32;
for offset in 0..4 {
let (_, mid, _) = unsafe { bytes[offset..offset + 1].align_to::<Chunk>() };
assert_eq!(mid.as_ptr() as usize % mem::align_of::<Chunk>(), 0);
}
}
#[test]
fn test_align_to_mut_aliasing() {
let mut val = [1u8, 2, 3, 4, 5];
// `align_to_mut` used to create `mid` in a way that there was some intermediate
// incorrect aliasing, invalidating the resulting `mid` slice.
let (begin, mid, end) = unsafe { val.align_to_mut::<[u8; 2]>() };
assert!(begin.len() == 0);
assert!(end.len() == 1);
mid[0] = mid[1];
assert_eq!(val, [3, 4, 3, 4, 5])
}
#[test]
fn test_slice_partition_dedup_by() {
let mut slice: [i32; 9] = [1, -1, 2, 3, 1, -5, 5, -2, 2];
let (dedup, duplicates) = slice.partition_dedup_by(|a, b| a.abs() == b.abs());
assert_eq!(dedup, [1, 2, 3, 1, -5, -2]);
assert_eq!(duplicates, [5, -1, 2]);
}
#[test]
fn test_slice_partition_dedup_empty() {
let mut slice: [i32; 0] = [];
let (dedup, duplicates) = slice.partition_dedup();
assert_eq!(dedup, []);
assert_eq!(duplicates, []);
}
#[test]
fn test_slice_partition_dedup_one() {
let mut slice = [12];
let (dedup, duplicates) = slice.partition_dedup();
assert_eq!(dedup, [12]);
assert_eq!(duplicates, []);
}
#[test]
fn test_slice_partition_dedup_multiple_ident() {
let mut slice = [12, 12, 12, 12, 12, 11, 11, 11, 11, 11, 11];
let (dedup, duplicates) = slice.partition_dedup();
assert_eq!(dedup, [12, 11]);
assert_eq!(duplicates, [12, 12, 12, 12, 11, 11, 11, 11, 11]);
}
#[test]
fn test_slice_partition_dedup_partialeq() {
#[derive(Debug)]
struct Foo(i32, i32);
impl PartialEq for Foo {
fn eq(&self, other: &Foo) -> bool {
self.0 == other.0
}
}
let mut slice = [Foo(0, 1), Foo(0, 5), Foo(1, 7), Foo(1, 9)];
let (dedup, duplicates) = slice.partition_dedup();
assert_eq!(dedup, [Foo(0, 1), Foo(1, 7)]);
assert_eq!(duplicates, [Foo(0, 5), Foo(1, 9)]);
}
#[test]
fn test_copy_within() {
// Start to end, with a RangeTo.
let mut bytes = *b"Hello, World!";
bytes.copy_within(..3, 10);
assert_eq!(&bytes, b"Hello, WorHel");
// End to start, with a RangeFrom.
let mut bytes = *b"Hello, World!";
bytes.copy_within(10.., 0);
assert_eq!(&bytes, b"ld!lo, World!");
// Overlapping, with a RangeInclusive.
let mut bytes = *b"Hello, World!";
bytes.copy_within(0..=11, 1);
assert_eq!(&bytes, b"HHello, World");
// Whole slice, with a RangeFull.
let mut bytes = *b"Hello, World!";
bytes.copy_within(.., 0);
assert_eq!(&bytes, b"Hello, World!");
// Ensure that copying at the end of slice won't cause UB.
let mut bytes = *b"Hello, World!";
bytes.copy_within(13..13, 5);
assert_eq!(&bytes, b"Hello, World!");
bytes.copy_within(5..5, 13);
assert_eq!(&bytes, b"Hello, World!");
}
#[test]
#[should_panic(expected = "range end index 14 out of range for slice of length 13")]
fn test_copy_within_panics_src_too_long() {
let mut bytes = *b"Hello, World!";
// The length is only 13, so 14 is out of bounds.
bytes.copy_within(10..14, 0);
}
#[test]
#[should_panic(expected = "dest is out of bounds")]
fn test_copy_within_panics_dest_too_long() {
let mut bytes = *b"Hello, World!";
// The length is only 13, so a slice of length 4 starting at index 10 is out of bounds.
bytes.copy_within(0..4, 10);
}
#[test]
#[should_panic(expected = "slice index starts at 2 but ends at 1")]
fn test_copy_within_panics_src_inverted() {
let mut bytes = *b"Hello, World!";
// 2 is greater than 1, so this range is invalid.
bytes.copy_within(2..1, 0);
}
#[test]
#[should_panic(expected = "attempted to index slice up to maximum usize")]
fn test_copy_within_panics_src_out_of_bounds() {
let mut bytes = *b"Hello, World!";
// an inclusive range ending at usize::MAX would make src_end overflow
bytes.copy_within(usize::MAX..=usize::MAX, 0);
}
#[test]
fn test_is_sorted() {
let empty: [i32; 0] = [];
assert!([1, 2, 2, 9].is_sorted());
assert!(![1, 3, 2].is_sorted());
assert!([0].is_sorted());
assert!(empty.is_sorted());
assert!(![0.0, 1.0, f32::NAN].is_sorted());
assert!([-2, -1, 0, 3].is_sorted());
assert!(![-2i32, -1, 0, 3].is_sorted_by_key(|n| n.abs()));
assert!(!["c", "bb", "aaa"].is_sorted());
assert!(["c", "bb", "aaa"].is_sorted_by_key(|s| s.len()));
}
#[test]
fn test_slice_run_destructors() {
// Make sure that destructors get run on slice literals
struct Foo<'a> {
x: &'a Cell<isize>,
}
impl<'a> Drop for Foo<'a> {
fn drop(&mut self) {
self.x.set(self.x.get() + 1);
}
}
fn foo(x: &Cell<isize>) -> Foo<'_> {
Foo { x }
}
let x = &Cell::new(0);
{
let l = &[foo(x)];
assert_eq!(l[0].x.get(), 0);
}
assert_eq!(x.get(), 1);
}
#[test]
fn test_const_from_ref() {
const VALUE: &i32 = &1;
const SLICE: &[i32] = core::slice::from_ref(VALUE);
assert!(core::ptr::eq(VALUE, &SLICE[0]))
}
#[test]
fn test_slice_fill_with_uninit() {
// This should not UB. See #87891
let mut a = [MaybeUninit::<u8>::uninit(); 10];
a.fill(MaybeUninit::uninit());
}
#[test]
fn test_swap() {
let mut x = ["a", "b", "c", "d"];
x.swap(1, 3);
assert_eq!(x, ["a", "d", "c", "b"]);
x.swap(0, 3);
assert_eq!(x, ["b", "d", "c", "a"]);
}
mod swap_panics {
#[test]
#[should_panic(expected = "index out of bounds: the len is 4 but the index is 4")]
fn index_a_equals_len() {
let mut x = ["a", "b", "c", "d"];
x.swap(4, 2);
}
#[test]
#[should_panic(expected = "index out of bounds: the len is 4 but the index is 4")]
fn index_b_equals_len() {
let mut x = ["a", "b", "c", "d"];
x.swap(2, 4);
}
#[test]
#[should_panic(expected = "index out of bounds: the len is 4 but the index is 5")]
fn index_a_greater_than_len() {
let mut x = ["a", "b", "c", "d"];
x.swap(5, 2);
}
#[test]
#[should_panic(expected = "index out of bounds: the len is 4 but the index is 5")]
fn index_b_greater_than_len() {
let mut x = ["a", "b", "c", "d"];
x.swap(2, 5);
}
}
#[test]
fn slice_split_array_mut() {
let v = &mut [1, 2, 3, 4, 5, 6][..];
{
let (left, right) = v.split_array_mut::<0>();
assert_eq!(left, &mut []);
assert_eq!(right, [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, []);
}
}
#[test]
fn slice_rsplit_array_mut() {
let v = &mut [1, 2, 3, 4, 5, 6][..];
{
let (left, right) = v.rsplit_array_mut::<0>();
assert_eq!(left, [1, 2, 3, 4, 5, 6]);
assert_eq!(right, &mut []);
}
{
let (left, right) = v.rsplit_array_mut::<6>();
assert_eq!(left, []);
assert_eq!(right, &mut [1, 2, 3, 4, 5, 6]);
}
}
#[test]
fn split_as_slice() {
let arr = [1, 2, 3, 4, 5, 6];
let mut split = arr.split(|v| v % 2 == 0);
assert_eq!(split.as_slice(), &[1, 2, 3, 4, 5, 6]);
assert!(split.next().is_some());
assert_eq!(split.as_slice(), &[3, 4, 5, 6]);
assert!(split.next().is_some());
assert!(split.next().is_some());
assert_eq!(split.as_slice(), &[]);
}
#[should_panic]
#[test]
fn slice_split_array_ref_out_of_bounds() {
let v = &[1, 2, 3, 4, 5, 6][..];
let _ = v.split_array_ref::<7>();
}
#[should_panic]
#[test]
fn slice_split_array_mut_out_of_bounds() {
let v = &mut [1, 2, 3, 4, 5, 6][..];
let _ = v.split_array_mut::<7>();
}
#[should_panic]
#[test]
fn slice_rsplit_array_ref_out_of_bounds() {
let v = &[1, 2, 3, 4, 5, 6][..];
let _ = v.rsplit_array_ref::<7>();
}
#[should_panic]
#[test]
fn slice_rsplit_array_mut_out_of_bounds() {
let v = &mut [1, 2, 3, 4, 5, 6][..];
let _ = v.rsplit_array_mut::<7>();
}
macro_rules! take_tests {
(slice: &[], $($tts:tt)*) => {
take_tests!(ty: &[()], slice: &[], $($tts)*);
};
(slice: &mut [], $($tts:tt)*) => {
take_tests!(ty: &mut [()], slice: &mut [], $($tts)*);
};
(slice: &$slice:expr, $($tts:tt)*) => {
take_tests!(ty: &[_], slice: &$slice, $($tts)*);
};
(slice: &mut $slice:expr, $($tts:tt)*) => {
take_tests!(ty: &mut [_], slice: &mut $slice, $($tts)*);
};
(ty: $ty:ty, slice: $slice:expr, method: $method:ident, $(($test_name:ident, ($($args:expr),*), $output:expr, $remaining:expr),)*) => {
$(
#[test]
fn $test_name() {
let mut slice: $ty = $slice;
assert_eq!($output, slice.$method($($args)*));
let remaining: $ty = $remaining;
assert_eq!(remaining, slice);
}
)*
};
}
take_tests! {
slice: &[0, 1, 2, 3], method: take,
(take_in_bounds_range_to, (..1), Some(&[0] as _), &[1, 2, 3]),
(take_in_bounds_range_to_inclusive, (..=0), Some(&[0] as _), &[1, 2, 3]),
(take_in_bounds_range_from, (2..), Some(&[2, 3] as _), &[0, 1]),
(take_oob_range_to, (..5), None, &[0, 1, 2, 3]),
(take_oob_range_to_inclusive, (..=4), None, &[0, 1, 2, 3]),
(take_oob_range_from, (5..), None, &[0, 1, 2, 3]),
}
take_tests! {
slice: &mut [0, 1, 2, 3], method: take_mut,
(take_mut_in_bounds_range_to, (..1), Some(&mut [0] as _), &mut [1, 2, 3]),
(take_mut_in_bounds_range_to_inclusive, (..=0), Some(&mut [0] as _), &mut [1, 2, 3]),
(take_mut_in_bounds_range_from, (2..), Some(&mut [2, 3] as _), &mut [0, 1]),
(take_mut_oob_range_to, (..5), None, &mut [0, 1, 2, 3]),
(take_mut_oob_range_to_inclusive, (..=4), None, &mut [0, 1, 2, 3]),
(take_mut_oob_range_from, (5..), None, &mut [0, 1, 2, 3]),
}
take_tests! {
slice: &[1, 2], method: take_first,
(take_first_nonempty, (), Some(&1), &[2]),
}
take_tests! {
slice: &mut [1, 2], method: take_first_mut,
(take_first_mut_nonempty, (), Some(&mut 1), &mut [2]),
}
take_tests! {
slice: &[1, 2], method: take_last,
(take_last_nonempty, (), Some(&2), &[1]),
}
take_tests! {
slice: &mut [1, 2], method: take_last_mut,
(take_last_mut_nonempty, (), Some(&mut 2), &mut [1]),
}
take_tests! {
slice: &[], method: take_first,
(take_first_empty, (), None, &[]),
}
take_tests! {
slice: &mut [], method: take_first_mut,
(take_first_mut_empty, (), None, &mut []),
}
take_tests! {
slice: &[], method: take_last,
(take_last_empty, (), None, &[]),
}
take_tests! {
slice: &mut [], method: take_last_mut,
(take_last_mut_empty, (), None, &mut []),
}
#[cfg(not(miri))] // unused in Miri
const EMPTY_MAX: &'static [()] = &[(); usize::MAX];
// can't be a constant due to const mutability rules
#[cfg(not(miri))] // unused in Miri
macro_rules! empty_max_mut {
() => {
&mut [(); usize::MAX] as _
};
}
#[cfg(not(miri))] // Comparing usize::MAX many elements takes forever in Miri (and in rustc without optimizations)
take_tests! {
slice: &[(); usize::MAX], method: take,
(take_in_bounds_max_range_to, (..usize::MAX), Some(EMPTY_MAX), &[(); 0]),
(take_oob_max_range_to_inclusive, (..=usize::MAX), None, EMPTY_MAX),
(take_in_bounds_max_range_from, (usize::MAX..), Some(&[] as _), EMPTY_MAX),
}
#[cfg(not(miri))] // Comparing usize::MAX many elements takes forever in Miri (and in rustc without optimizations)
take_tests! {
slice: &mut [(); usize::MAX], method: take_mut,
(take_mut_in_bounds_max_range_to, (..usize::MAX), Some(empty_max_mut!()), &mut [(); 0]),
(take_mut_oob_max_range_to_inclusive, (..=usize::MAX), None, empty_max_mut!()),
(take_mut_in_bounds_max_range_from, (usize::MAX..), Some(&mut [] as _), empty_max_mut!()),
}
#[test]
fn test_slice_from_ptr_range() {
let arr = ["foo".to_owned(), "bar".to_owned()];
let range = arr.as_ptr_range();
unsafe {
assert_eq!(slice::from_ptr_range(range), &arr);
}
let mut arr = [1, 2, 3];
let range = arr.as_mut_ptr_range();
unsafe {
assert_eq!(slice::from_mut_ptr_range(range), &mut [1, 2, 3]);
}
let arr: [Vec<String>; 0] = [];
let range = arr.as_ptr_range();
unsafe {
assert_eq!(slice::from_ptr_range(range), &arr);
}
}
#[test]
#[should_panic = "slice len overflow"]
fn test_flatten_size_overflow() {
let x = &[[(); usize::MAX]; 2][..];
let _ = x.flatten();
}
#[test]
#[should_panic = "slice len overflow"]
fn test_flatten_mut_size_overflow() {
let x = &mut [[(); usize::MAX]; 2][..];
let _ = x.flatten_mut();
}
#[test]
fn test_get_many_mut_normal_2() {
let mut v = vec![1, 2, 3, 4, 5];
let [a, b] = v.get_many_mut([3, 0]).unwrap();
*a += 10;
*b += 100;
assert_eq!(v, vec![101, 2, 3, 14, 5]);
}
#[test]
fn test_get_many_mut_normal_3() {
let mut v = vec![1, 2, 3, 4, 5];
let [a, b, c] = v.get_many_mut([0, 4, 2]).unwrap();
*a += 10;
*b += 100;
*c += 1000;
assert_eq!(v, vec![11, 2, 1003, 4, 105]);
}
#[test]
fn test_get_many_mut_empty() {
let mut v = vec![1, 2, 3, 4, 5];
let [] = v.get_many_mut([]).unwrap();
assert_eq!(v, vec![1, 2, 3, 4, 5]);
}
#[test]
fn test_get_many_mut_single_first() {
let mut v = vec![1, 2, 3, 4, 5];
let [a] = v.get_many_mut([0]).unwrap();
*a += 10;
assert_eq!(v, vec![11, 2, 3, 4, 5]);
}
#[test]
fn test_get_many_mut_single_last() {
let mut v = vec![1, 2, 3, 4, 5];
let [a] = v.get_many_mut([4]).unwrap();
*a += 10;
assert_eq!(v, vec![1, 2, 3, 4, 15]);
}
#[test]
fn test_get_many_mut_oob_nonempty() {
let mut v = vec![1, 2, 3, 4, 5];
assert!(v.get_many_mut([5]).is_err());
}
#[test]
fn test_get_many_mut_oob_empty() {
let mut v: Vec<i32> = vec![];
assert!(v.get_many_mut([0]).is_err());
}
#[test]
fn test_get_many_mut_duplicate() {
let mut v = vec![1, 2, 3, 4, 5];
assert!(v.get_many_mut([1, 3, 3, 4]).is_err());
}
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