Struct arrayvec::ArrayVec

pub struct ArrayVec<A: Array> { /* fields omitted */ }

A vector with a fixed capacity.

The ArrayVec is a vector backed by a fixed size array. It keeps track of the number of initialized elements.

The vector is a contiguous value that you can store directly on the stack if needed.

It offers a simple API but also dereferences to a slice, so that the full slice API is available.

ArrayVec can be converted into a by value iterator.

Methods

impl<A: Array> ArrayVec<A>

fn new() -> ArrayVec<A>

Create a new empty ArrayVec.

Capacity is inferred from the type parameter.

use arrayvec::ArrayVec;

let mut array = ArrayVec::<[_; 16]>::new();
array.push(1);
array.push(2);
assert_eq!(&array[..], &[1, 2]);
assert_eq!(array.capacity(), 16);

fn len(&self) -> usize

Return the number of elements in the ArrayVec.

use arrayvec::ArrayVec;

let mut array = ArrayVec::from([1, 2, 3]);
array.pop();
assert_eq!(array.len(), 2);

fn capacity(&self) -> usize

Return the capacity of the ArrayVec.

use arrayvec::ArrayVec;

let array = ArrayVec::from([1, 2, 3]);
assert_eq!(array.capacity(), 3);

fn is_full(&self) -> bool

Return if the ArrayVec is completely filled.

use arrayvec::ArrayVec;

let mut array = ArrayVec::<[_; 1]>::new();
assert!(!array.is_full());
array.push(1);
assert!(array.is_full());

fn push(&mut self, element: A::Item) -> Option<A::Item>

Push element to the end of the vector.

Return None if the push succeeds, or and return Some( element ) if the vector is full.

use arrayvec::ArrayVec;

let mut array = ArrayVec::<[_; 2]>::new();

array.push(1);
array.push(2);
let overflow = array.push(3);

assert_eq!(&array[..], &[1, 2]);
assert_eq!(overflow, Some(3));

fn insert(&mut self, index: usize, element: A::Item) -> Option<A::Item>

Insert element in position index.

Shift up all elements after index. If any is pushed out, it is returned.

Return None if no element is shifted out.

index must be <= self.len() and < self.capacity(). Note that any out of bounds index insert results in the element being "shifted out" and returned directly.

use arrayvec::ArrayVec;

let mut array = ArrayVec::<[_; 2]>::new();

assert_eq!(array.insert(0, "x"), None);
assert_eq!(array.insert(0, "y"), None);
assert_eq!(array.insert(0, "z"), Some("x"));
assert_eq!(array.insert(1, "w"), Some("y"));
assert_eq!(&array[..], &["z", "w"]);

fn pop(&mut self) -> Option<A::Item>

Remove the last element in the vector.

Return Some( element ) if the vector is non-empty, else None.

use arrayvec::ArrayVec;

let mut array = ArrayVec::<[_; 2]>::new();

array.push(1);

assert_eq!(array.pop(), Some(1));
assert_eq!(array.pop(), None);

fn swap_remove(&mut self, index: usize) -> Option<A::Item>

Remove the element at index and swap the last element into its place.

This operation is O(1).

Return Some( element ) if the index is in bounds, else None.

use arrayvec::ArrayVec;

let mut array = ArrayVec::from([1, 2, 3]);

assert_eq!(array.swap_remove(0), Some(1));
assert_eq!(&array[..], &[3, 2]);

assert_eq!(array.swap_remove(10), None);

fn remove(&mut self, index: usize) -> Option<A::Item>

Remove the element at index and shift down the following elements.

Return Some( element ) if the index is in bounds, else None.

use arrayvec::ArrayVec;

let mut array = ArrayVec::from([1, 2, 3]);

assert_eq!(array.remove(0), Some(1));
assert_eq!(&array[..], &[2, 3]);

assert_eq!(array.remove(10), None);

fn clear(&mut self)

Remove all elements in the vector.

fn retain<F>(&mut self, f: F) where
    F: FnMut(&mut A::Item) -> bool, 

Retains only the elements specified by the predicate.

In other words, remove all elements e such that f(&mut e) returns false. This method operates in place and preserves the order of the retained elements.

use arrayvec::ArrayVec;

let mut array = ArrayVec::from([1, 2, 3, 4]);
array.retain(|x| *x & 1 != 0 );
assert_eq!(&array[..], &[1, 3]);

unsafe fn set_len(&mut self, length: usize)

Set the vector's length without dropping or moving out elements

May panic if length is greater than the capacity.

This function is unsafe because it changes the notion of the number of “valid” elements in the vector. Use with care.

fn drain<R: RangeArgument>(&mut self, range: R) -> Drain<A>

Create a draining iterator that removes the specified range in the vector and yields the removed items from start to end. The element range is removed even if the iterator is not consumed until the end.

Note: It is unspecified how many elements are removed from the vector, if the Drain value is leaked.

Panics if the starting point is greater than the end point or if the end point is greater than the length of the vector.

use arrayvec::ArrayVec;

let mut v = ArrayVec::from([1, 2, 3]);
let u: Vec<_> = v.drain(0..2).collect();
assert_eq!(&v[..], &[3]);
assert_eq!(&u[..], &[1, 2]);

fn into_inner(self) -> Result<A, Self>

Return the inner fixed size array, if it is full to its capacity.

Return an Ok value with the array if length equals capacity, return an Err with self otherwise.

Note: This function may incur unproportionally large overhead to move the array out, its performance is not optimal.

fn dispose(self)

Dispose of self without the overwriting that is needed in Drop.

fn as_slice(&self) -> &[A::Item]

Return a slice containing all elements of the vector.

fn as_mut_slice(&mut self) -> &mut [A::Item]

Return a mutable slice containing all elements of the vector.

Methods from Deref<Target = [A::Item]>

fn len(&self) -> usize

Returns the number of elements in the slice.

Examples

let a = [1, 2, 3];
assert_eq!(a.len(), 3);

fn is_empty(&self) -> bool

Returns true if the slice has a length of 0.

Examples

let a = [1, 2, 3];
assert!(!a.is_empty());

fn first(&self) -> Option<&T>

Returns the first element of the slice, or None if it is empty.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&10), v.first());

let w: &[i32] = &[];
assert_eq!(None, w.first());

fn first_mut(&mut self) -> Option<&mut T>

Returns a mutable pointer to the first element of the slice, or None if it is empty.

Examples

let x = &mut [0, 1, 2];

if let Some(first) = x.first_mut() {
    *first = 5;
}
assert_eq!(x, &[5, 1, 2]);

fn split_first(&self) -> Option<(&T, &[T])>

Returns the first and all the rest of the elements of the slice, or None if it is empty.

Examples

let x = &[0, 1, 2];

if let Some((first, elements)) = x.split_first() {
    assert_eq!(first, &0);
    assert_eq!(elements, &[1, 2]);
}

fn split_first_mut(&mut self) -> Option<(&mut T, &mut [T])>

Returns the first and all the rest of the elements of the slice, or None if it is empty.

Examples

let x = &mut [0, 1, 2];

if let Some((first, elements)) = x.split_first_mut() {
    *first = 3;
    elements[0] = 4;
    elements[1] = 5;
}
assert_eq!(x, &[3, 4, 5]);

fn split_last(&self) -> Option<(&T, &[T])>

Returns the last and all the rest of the elements of the slice, or None if it is empty.

Examples

let x = &[0, 1, 2];

if let Some((last, elements)) = x.split_last() {
    assert_eq!(last, &2);
    assert_eq!(elements, &[0, 1]);
}

fn split_last_mut(&mut self) -> Option<(&mut T, &mut [T])>

Returns the last and all the rest of the elements of the slice, or None if it is empty.

Examples

let x = &mut [0, 1, 2];

if let Some((last, elements)) = x.split_last_mut() {
    *last = 3;
    elements[0] = 4;
    elements[1] = 5;
}
assert_eq!(x, &[4, 5, 3]);

fn last(&self) -> Option<&T>

Returns the last element of the slice, or None if it is empty.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&30), v.last());

let w: &[i32] = &[];
assert_eq!(None, w.last());

fn last_mut(&mut self) -> Option<&mut T>

Returns a mutable pointer to the last item in the slice.

Examples

let x = &mut [0, 1, 2];

if let Some(last) = x.last_mut() {
    *last = 10;
}
assert_eq!(x, &[0, 1, 10]);

fn get<I>(&self, index: I) -> Option<&<I as SliceIndex<[T]>>::Output> where
    I: SliceIndex<[T]>, 

Returns a reference to an element or subslice depending on the type of index.

• If given a position, returns a reference to the element at that position or None if out of bounds.
• If given a range, returns the subslice corresponding to that range, or None if out of bounds.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&40), v.get(1));
assert_eq!(Some(&[10, 40][..]), v.get(0..2));
assert_eq!(None, v.get(3));
assert_eq!(None, v.get(0..4));

fn get_mut<I>(
    &mut self,
    index: I
) -> Option<&mut <I as SliceIndex<[T]>>::Output> where
    I: SliceIndex<[T]>, 

Returns a mutable reference to an element or subslice depending on the type of index (see get) or None if the index is out of bounds.

Examples

let x = &mut [0, 1, 2];

if let Some(elem) = x.get_mut(1) {
    *elem = 42;
}
assert_eq!(x, &[0, 42, 2]);

unsafe fn get_unchecked<I>(&self, index: I) -> &<I as SliceIndex<[T]>>::Output where
    I: SliceIndex<[T]>, 

Returns a reference to an element or subslice, without doing bounds checking.

This is generally not recommended, use with caution! For a safe alternative see get.

Examples

let x = &[1, 2, 4];

unsafe {
    assert_eq!(x.get_unchecked(1), &2);
}

unsafe fn get_unchecked_mut<I>(
    &mut self,
    index: I
) -> &mut <I as SliceIndex<[T]>>::Output where
    I: SliceIndex<[T]>, 

Returns a mutable reference to an element or subslice, without doing bounds checking.

This is generally not recommended, use with caution! For a safe alternative see get_mut.

Examples

let x = &mut [1, 2, 4];

unsafe {
    let elem = x.get_unchecked_mut(1);
    *elem = 13;
}
assert_eq!(x, &[1, 13, 4]);

fn as_ptr(&self) -> *const T

Returns a raw pointer to the slice's buffer.

The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.

Modifying the container referenced by this slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.

Examples

let x = &[1, 2, 4];
let x_ptr = x.as_ptr();

unsafe {
    for i in 0..x.len() {
        assert_eq!(x.get_unchecked(i), &*x_ptr.offset(i as isize));
    }
}

fn as_mut_ptr(&mut self) -> *mut T

Returns an unsafe mutable pointer to the slice's buffer.

The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.

Modifying the container referenced by this slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.

Examples

let x = &mut [1, 2, 4];
let x_ptr = x.as_mut_ptr();

unsafe {
    for i in 0..x.len() {
        *x_ptr.offset(i as isize) += 2;
    }
}
assert_eq!(x, &[3, 4, 6]);

fn swap(&mut self, a: usize, b: usize)

Swaps two elements in the slice.

Arguments

• a - The index of the first element
• b - The index of the second element

Panics

Panics if a or b are out of bounds.

Examples

let mut v = ["a", "b", "c", "d"];
v.swap(1, 3);
assert!(v == ["a", "d", "c", "b"]);

fn reverse(&mut self)

Reverses the order of elements in the slice, in place.

Examples

let mut v = [1, 2, 3];
v.reverse();
assert!(v == [3, 2, 1]);

fn iter(&self) -> Iter<T>

Returns an iterator over the slice.

Examples

let x = &[1, 2, 4];
let mut iterator = x.iter();

assert_eq!(iterator.next(), Some(&1));
assert_eq!(iterator.next(), Some(&2));
assert_eq!(iterator.next(), Some(&4));
assert_eq!(iterator.next(), None);

fn iter_mut(&mut self) -> IterMut<T>

Returns an iterator that allows modifying each value.

Examples

let x = &mut [1, 2, 4];
for elem in x.iter_mut() {
    *elem += 2;
}
assert_eq!(x, &[3, 4, 6]);

fn windows(&self, size: usize) -> Windows<T>

Returns an iterator over all contiguous windows of length size. The windows overlap. If the slice is shorter than size, the iterator returns no values.

Panics

Panics if size is 0.

Examples

let slice = ['r', 'u', 's', 't'];
let mut iter = slice.windows(2);
assert_eq!(iter.next().unwrap(), &['r', 'u']);
assert_eq!(iter.next().unwrap(), &['u', 's']);
assert_eq!(iter.next().unwrap(), &['s', 't']);
assert!(iter.next().is_none());

If the slice is shorter than size:

let slice = ['f', 'o', 'o'];
let mut iter = slice.windows(4);
assert!(iter.next().is_none());

fn chunks(&self, size: usize) -> Chunks<T>

Returns an iterator over size elements of the slice at a time. The chunks are slices and do not overlap. If size does not divide the length of the slice, then the last chunk will not have length size.

Panics

Panics if size is 0.

Examples

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.chunks(2);
assert_eq!(iter.next().unwrap(), &['l', 'o']);
assert_eq!(iter.next().unwrap(), &['r', 'e']);
assert_eq!(iter.next().unwrap(), &['m']);
assert!(iter.next().is_none());

fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<T>

Returns an iterator over chunk_size elements of the slice at a time. The chunks are mutable slices, and do not overlap. If chunk_size does not divide the length of the slice, then the last chunk will not have length chunk_size.

Panics

Panics if chunk_size is 0.

Examples

let v = &mut [0, 0, 0, 0, 0];
let mut count = 1;

for chunk in v.chunks_mut(2) {
    for elem in chunk.iter_mut() {
        *elem += count;
    }
    count += 1;
}
assert_eq!(v, &[1, 1, 2, 2, 3]);

fn split_at(&self, mid: usize) -> (&[T], &[T])

Divides one slice into two at an index.

The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

Panics

Panics if mid > len.

Examples

let v = [1, 2, 3, 4, 5, 6];

{
   let (left, right) = v.split_at(0);
   assert!(left == []);
   assert!(right == [1, 2, 3, 4, 5, 6]);
}

{
    let (left, right) = v.split_at(2);
    assert!(left == [1, 2]);
    assert!(right == [3, 4, 5, 6]);
}

{
    let (left, right) = v.split_at(6);
    assert!(left == [1, 2, 3, 4, 5, 6]);
    assert!(right == []);
}

fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T])

Divides one &mut into two at an index.

The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

Panics

Panics if mid > len.

Examples

let mut v = [1, 0, 3, 0, 5, 6];
// scoped to restrict the lifetime of the borrows
{
    let (left, right) = v.split_at_mut(2);
    assert!(left == [1, 0]);
    assert!(right == [3, 0, 5, 6]);
    left[1] = 2;
    right[1] = 4;
}
assert!(v == [1, 2, 3, 4, 5, 6]);

fn split<F>(&self, pred: F) -> Split<T, F> where
    F: FnMut(&T) -> bool, 

Returns an iterator over subslices separated by elements that match pred. The matched element is not contained in the subslices.

Examples

let slice = [10, 40, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

If the first element is matched, an empty slice will be the first item returned by the iterator. Similarly, if the last element in the slice is matched, an empty slice will be the last item returned by the iterator:

let slice = [10, 40, 33];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[]);
assert!(iter.next().is_none());

If two matched elements are directly adjacent, an empty slice will be present between them:

let slice = [10, 6, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10]);
assert_eq!(iter.next().unwrap(), &[]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

fn split_mut<F>(&mut self, pred: F) -> SplitMut<T, F> where
    F: FnMut(&T) -> bool, 

Returns an iterator over mutable subslices separated by elements that match pred. The matched element is not contained in the subslices.

Examples

let mut v = [10, 40, 30, 20, 60, 50];

for group in v.split_mut(|num| *num % 3 == 0) {
    group[0] = 1;
}
assert_eq!(v, [1, 40, 30, 1, 60, 1]);

fn rsplit<F>(&self, pred: F) -> RSplit<T, F> where
    F: FnMut(&T) -> bool, 

🔬 This is a nightly-only experimental API. (slice_rsplit)

Returns an iterator over subslices separated by elements that match pred, starting at the end of the slice and working backwards. The matched element is not contained in the subslices.

Examples

#![feature(slice_rsplit)]

let slice = [11, 22, 33, 0, 44, 55];
let mut iter = slice.rsplit(|num| *num == 0);

assert_eq!(iter.next().unwrap(), &[44, 55]);
assert_eq!(iter.next().unwrap(), &[11, 22, 33]);
assert_eq!(iter.next(), None);

As with split(), if the first or last element is matched, an empty slice will be the first (or last) item returned by the iterator.

#![feature(slice_rsplit)]

let v = &[0, 1, 1, 2, 3, 5, 8];
let mut it = v.rsplit(|n| *n % 2 == 0);
assert_eq!(it.next().unwrap(), &[]);
assert_eq!(it.next().unwrap(), &[3, 5]);
assert_eq!(it.next().unwrap(), &[1, 1]);
assert_eq!(it.next().unwrap(), &[]);
assert_eq!(it.next(), None);

fn rsplit_mut<F>(&mut self, pred: F) -> RSplitMut<T, F> where
    F: FnMut(&T) -> bool, 

🔬 This is a nightly-only experimental API. (slice_rsplit)

Returns an iterator over mutable subslices separated by elements that match pred, starting at the end of the slice and working backwards. The matched element is not contained in the subslices.

Examples

#![feature(slice_rsplit)]

let mut v = [100, 400, 300, 200, 600, 500];

let mut count = 0;
for group in v.rsplit_mut(|num| *num % 3 == 0) {
    count += 1;
    group[0] = count;
}
assert_eq!(v, [3, 400, 300, 2, 600, 1]);

fn splitn<F>(&self, n: usize, pred: F) -> SplitN<T, F> where
    F: FnMut(&T) -> bool, 

Returns an iterator over subslices separated by elements that match pred, limited to returning at most n items. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once by numbers divisible by 3 (i.e. [10, 40], [20, 60, 50]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.splitn(2, |num| *num % 3 == 0) {
    println!("{:?}", group);
}

fn splitn_mut<F>(&mut self, n: usize, pred: F) -> SplitNMut<T, F> where
    F: FnMut(&T) -> bool, 

Returns an iterator over subslices separated by elements that match pred, limited to returning at most n items. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

let mut v = [10, 40, 30, 20, 60, 50];

for group in v.splitn_mut(2, |num| *num % 3 == 0) {
    group[0] = 1;
}
assert_eq!(v, [1, 40, 30, 1, 60, 50]);

fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<T, F> where
    F: FnMut(&T) -> bool, 

Returns an iterator over subslices separated by elements that match pred limited to returning at most n items. This starts at the end of the slice and works backwards. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once, starting from the end, by numbers divisible by 3 (i.e. [50], [10, 40, 30, 20]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.rsplitn(2, |num| *num % 3 == 0) {
    println!("{:?}", group);
}

fn rsplitn_mut<F>(&mut self, n: usize, pred: F) -> RSplitNMut<T, F> where
    F: FnMut(&T) -> bool, 

Returns an iterator over subslices separated by elements that match pred limited to returning at most n items. This starts at the end of the slice and works backwards. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

let mut s = [10, 40, 30, 20, 60, 50];

for group in s.rsplitn_mut(2, |num| *num % 3 == 0) {
    group[0] = 1;
}
assert_eq!(s, [1, 40, 30, 20, 60, 1]);

fn contains(&self, x: &T) -> bool where
    T: PartialEq<T>, 

Returns true if the slice contains an element with the given value.

Examples

let v = [10, 40, 30];
assert!(v.contains(&30));
assert!(!v.contains(&50));

fn starts_with(&self, needle: &[T]) -> bool where
    T: PartialEq<T>, 

Returns true if needle is a prefix of the slice.

Examples

let v = [10, 40, 30];
assert!(v.starts_with(&[10]));
assert!(v.starts_with(&[10, 40]));
assert!(!v.starts_with(&[50]));
assert!(!v.starts_with(&[10, 50]));

Always returns true if needle is an empty slice:

let v = &[10, 40, 30];
assert!(v.starts_with(&[]));
let v: &[u8] = &[];
assert!(v.starts_with(&[]));

fn ends_with(&self, needle: &[T]) -> bool where
    T: PartialEq<T>, 

Returns true if needle is a suffix of the slice.

Examples

let v = [10, 40, 30];
assert!(v.ends_with(&[30]));
assert!(v.ends_with(&[40, 30]));
assert!(!v.ends_with(&[50]));
assert!(!v.ends_with(&[50, 30]));

Always returns true if needle is an empty slice:

let v = &[10, 40, 30];
assert!(v.ends_with(&[]));
let v: &[u8] = &[];
assert!(v.ends_with(&[]));

fn binary_search(&self, x: &T) -> Result<usize, usize> where
    T: Ord, 

Binary searches this sorted slice for a given element.

If the value is found then Ok is returned, containing the index of the matching element; if the value is not found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Examples

Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

assert_eq!(s.binary_search(&13),  Ok(9));
assert_eq!(s.binary_search(&4),   Err(7));
assert_eq!(s.binary_search(&100), Err(13));
let r = s.binary_search(&1);
assert!(match r { Ok(1...4) => true, _ => false, });

fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize> where
    F: FnMut(&'a T) -> Ordering, 

Binary searches this sorted slice with a comparator function.

The comparator function should implement an order consistent with the sort order of the underlying slice, returning an order code that indicates whether its argument is Less, Equal or Greater the desired target.

If a matching value is found then returns Ok, containing the index for the matched element; if no match is found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Examples

Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

let seek = 13;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Ok(9));
let seek = 4;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(7));
let seek = 100;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(13));
let seek = 1;
let r = s.binary_search_by(|probe| probe.cmp(&seek));
assert!(match r { Ok(1...4) => true, _ => false, });

fn binary_search_by_key<'a, B, F>(&'a self, b: &B, f: F) -> Result<usize, usize> where
    B: Ord,
    F: FnMut(&'a T) -> B, 

Binary searches this sorted slice with a key extraction function.

Assumes that the slice is sorted by the key, for instance with sort_by_key using the same key extraction function.

If a matching value is found then returns Ok, containing the index for the matched element; if no match is found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Examples

Looks up a series of four elements in a slice of pairs sorted by their second elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [(0, 0), (2, 1), (4, 1), (5, 1), (3, 1),
         (1, 2), (2, 3), (4, 5), (5, 8), (3, 13),
         (1, 21), (2, 34), (4, 55)];

assert_eq!(s.binary_search_by_key(&13, |&(a,b)| b),  Ok(9));
assert_eq!(s.binary_search_by_key(&4, |&(a,b)| b),   Err(7));
assert_eq!(s.binary_search_by_key(&100, |&(a,b)| b), Err(13));
let r = s.binary_search_by_key(&1, |&(a,b)| b);
assert!(match r { Ok(1...4) => true, _ => false, });

fn sort(&mut self) where
    T: Ord, 

Sorts the slice.

This sort is stable (i.e. does not reorder equal elements) and O(n log n) worst-case.

When applicable, unstable sorting is preferred because it is generally faster than stable sorting and it doesn't allocate auxiliary memory. See sort_unstable.

Current implementation

The current algorithm is an adaptive, iterative merge sort inspired by timsort. It is designed to be very fast in cases where the slice is nearly sorted, or consists of two or more sorted sequences concatenated one after another.

Also, it allocates temporary storage half the size of self, but for short slices a non-allocating insertion sort is used instead.

Examples

let mut v = [-5, 4, 1, -3, 2];

v.sort();
assert!(v == [-5, -3, 1, 2, 4]);

fn sort_by<F>(&mut self, compare: F) where
    F: FnMut(&T, &T) -> Ordering, 

Sorts the slice with a comparator function.

This sort is stable (i.e. does not reorder equal elements) and O(n log n) worst-case.

When applicable, unstable sorting is preferred because it is generally faster than stable sorting and it doesn't allocate auxiliary memory. See sort_unstable_by.

Current implementation

The current algorithm is an adaptive, iterative merge sort inspired by timsort. It is designed to be very fast in cases where the slice is nearly sorted, or consists of two or more sorted sequences concatenated one after another.

Also, it allocates temporary storage half the size of self, but for short slices a non-allocating insertion sort is used instead.

Examples

let mut v = [5, 4, 1, 3, 2];
v.sort_by(|a, b| a.cmp(b));
assert!(v == [1, 2, 3, 4, 5]);

// reverse sorting
v.sort_by(|a, b| b.cmp(a));
assert!(v == [5, 4, 3, 2, 1]);

fn sort_by_key<B, F>(&mut self, f: F) where
    B: Ord,
    F: FnMut(&T) -> B, 

Sorts the slice with a key extraction function.

This sort is stable (i.e. does not reorder equal elements) and O(n log n) worst-case.

When applicable, unstable sorting is preferred because it is generally faster than stable sorting and it doesn't allocate auxiliary memory. See sort_unstable_by_key.

Current implementation

The current algorithm is an adaptive, iterative merge sort inspired by timsort. It is designed to be very fast in cases where the slice is nearly sorted, or consists of two or more sorted sequences concatenated one after another.

Also, it allocates temporary storage half the size of self, but for short slices a non-allocating insertion sort is used instead.

Examples

let mut v = [-5i32, 4, 1, -3, 2];

v.sort_by_key(|k| k.abs());
assert!(v == [1, 2, -3, 4, -5]);

fn sort_unstable(&mut self) where
    T: Ord, 

Sorts the slice, but may not preserve the order of equal elements.

This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), and O(n log n) worst-case.

Current implementation

The current algorithm is based on pattern-defeating quicksort by Orson Peters, which combines the fast average case of randomized quicksort with the fast worst case of heapsort, while achieving linear time on slices with certain patterns. It uses some randomization to avoid degenerate cases, but with a fixed seed to always provide deterministic behavior.

It is typically faster than stable sorting, except in a few special cases, e.g. when the slice consists of several concatenated sorted sequences.

Examples

let mut v = [-5, 4, 1, -3, 2];

v.sort_unstable();
assert!(v == [-5, -3, 1, 2, 4]);

fn sort_unstable_by<F>(&mut self, compare: F) where
    F: FnMut(&T, &T) -> Ordering, 

Sorts the slice with a comparator function, but may not preserve the order of equal elements.

This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), and O(n log n) worst-case.

Current implementation

The current algorithm is based on pattern-defeating quicksort by Orson Peters, which combines the fast average case of randomized quicksort with the fast worst case of heapsort, while achieving linear time on slices with certain patterns. It uses some randomization to avoid degenerate cases, but with a fixed seed to always provide deterministic behavior.

It is typically faster than stable sorting, except in a few special cases, e.g. when the slice consists of several concatenated sorted sequences.

Examples

let mut v = [5, 4, 1, 3, 2];
v.sort_unstable_by(|a, b| a.cmp(b));
assert!(v == [1, 2, 3, 4, 5]);

// reverse sorting
v.sort_unstable_by(|a, b| b.cmp(a));
assert!(v == [5, 4, 3, 2, 1]);

fn sort_unstable_by_key<B, F>(&mut self, f: F) where
    B: Ord,
    F: FnMut(&T) -> B, 

Sorts the slice with a key extraction function, but may not preserve the order of equal elements.

This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), and O(n log n) worst-case.

Current implementation

The current algorithm is based on pattern-defeating quicksort by Orson Peters, which combines the fast average case of randomized quicksort with the fast worst case of heapsort, while achieving linear time on slices with certain patterns. It uses some randomization to avoid degenerate cases, but with a fixed seed to always provide deterministic behavior.

It is typically faster than stable sorting, except in a few special cases, e.g. when the slice consists of several concatenated sorted sequences.

Examples

let mut v = [-5i32, 4, 1, -3, 2];

v.sort_unstable_by_key(|k| k.abs());
assert!(v == [1, 2, -3, 4, -5]);

fn rotate(&mut self, mid: usize)

🔬 This is a nightly-only experimental API. (slice_rotate)

Permutes the slice in-place such that self[mid..] moves to the beginning of the slice while self[..mid] moves to the end of the slice. Equivalently, rotates the slice mid places to the left or k = self.len() - mid places to the right.

This is a "k-rotation", a permutation in which item i moves to position i + k, modulo the length of the slice. See Elements of Programming §10.4.

Rotation by mid and rotation by k are inverse operations.

Panics

This function will panic if mid is greater than the length of the slice. (Note that mid == self.len() does not panic; it's a nop rotation with k == 0, the inverse of a rotation with mid == 0.)

Complexity

Takes linear (in self.len()) time.

Examples

#![feature(slice_rotate)]

let mut a = [1, 2, 3, 4, 5, 6, 7];
let mid = 2;
a.rotate(mid);
assert_eq!(&a, &[3, 4, 5, 6, 7, 1, 2]);
let k = a.len() - mid;
a.rotate(k);
assert_eq!(&a, &[1, 2, 3, 4, 5, 6, 7]);

use std::ops::Range;
fn slide<T>(slice: &mut [T], range: Range<usize>, to: usize) {
    if to < range.start {
        slice[to..range.end].rotate(range.start-to);
    } else if to > range.end {
        slice[range.start..to].rotate(range.end-range.start);
    }
}
let mut v: Vec<_> = (0..10).collect();
slide(&mut v, 1..4, 7);
assert_eq!(&v, &[0, 4, 5, 6, 1, 2, 3, 7, 8, 9]);
slide(&mut v, 6..8, 1);
assert_eq!(&v, &[0, 3, 7, 4, 5, 6, 1, 2, 8, 9]);

fn clone_from_slice(&mut self, src: &[T]) where
    T: Clone, 

Copies the elements from src into self.

The length of src must be the same as self.

If src implements Copy, it can be more performant to use copy_from_slice.

Panics

This function will panic if the two slices have different lengths.

Examples

let mut dst = [0, 0, 0];
let src = [1, 2, 3];

dst.clone_from_slice(&src);
assert!(dst == [1, 2, 3]);

fn copy_from_slice(&mut self, src: &[T]) where
    T: Copy, 

Copies all elements from src into self, using a memcpy.

The length of src must be the same as self.

If src does not implement Copy, use clone_from_slice.

Panics

This function will panic if the two slices have different lengths.

Examples

let mut dst = [0, 0, 0];
let src = [1, 2, 3];

dst.copy_from_slice(&src);
assert_eq!(src, dst);

fn swap_with_slice(&mut self, src: &mut [T])

🔬 This is a nightly-only experimental API. (swap_with_slice)

Swaps all elements in self with those in src.

The length of src must be the same as self.

Panics

This function will panic if the two slices have different lengths.

Example

#![feature(swap_with_slice)]

let mut src = [1, 2, 3];
let mut dst = [7, 8, 9];

src.swap_with_slice(&mut dst);
assert_eq!(src, [7, 8, 9]);
assert_eq!(dst, [1, 2, 3]);

fn to_vec(&self) -> Vec<T> where
    T: Clone, 

Copies self into a new Vec.

Examples

let s = [10, 40, 30];
let x = s.to_vec();
// Here, `s` and `x` can be modified independently.

Trait Implementations

impl<A: Array> Drop for ArrayVec<A>

fn drop(&mut self)

Executes the destructor for this type.

impl<A: Array> Deref for ArrayVec<A>

type Target = [A::Item]

The resulting type after dereferencing.

fn deref(&self) -> &[A::Item]

Dereferences the value.

impl<A: Array> DerefMut for ArrayVec<A>

fn deref_mut(&mut self) -> &mut [A::Item]

Mutably dereferences the value.

impl<A: Array> From<A> for ArrayVec<A>

Create an ArrayVec from an array.

use arrayvec::ArrayVec;

let mut array = ArrayVec::from([1, 2, 3]);
assert_eq!(array.len(), 3);
assert_eq!(array.capacity(), 3);

fn from(array: A) -> Self

Performs the conversion.

impl<'a, A: Array> IntoIterator for &'a ArrayVec<A>

Iterate the ArrayVec with references to each element.

use arrayvec::ArrayVec;

let array = ArrayVec::from([1, 2, 3]);

for elt in &array {
    // ...
}

type Item = &'a A::Item

The type of the elements being iterated over.

type IntoIter = Iter<'a, A::Item>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'a, A: Array> IntoIterator for &'a mut ArrayVec<A>

Iterate the ArrayVec with mutable references to each element.

use arrayvec::ArrayVec;

let mut array = ArrayVec::from([1, 2, 3]);

for elt in &mut array {
    // ...
}

type Item = &'a mut A::Item

The type of the elements being iterated over.

type IntoIter = IterMut<'a, A::Item>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<A: Array> IntoIterator for ArrayVec<A>

Iterate the ArrayVec with each element by value.

The vector is consumed by this operation.

use arrayvec::ArrayVec;

for elt in ArrayVec::from([1, 2, 3]) {
    // ...
}

type Item = A::Item

The type of the elements being iterated over.

type IntoIter = IntoIter<A>

Which kind of iterator are we turning this into?

fn into_iter(self) -> IntoIter<A>

Creates an iterator from a value.

impl<A: Array> Extend<A::Item> for ArrayVec<A>

Extend the ArrayVec with an iterator.

Does not extract more items than there is space for. No error occurs if there are more iterator elements.

fn extend<T: IntoIterator<Item = A::Item>>(&mut self, iter: T)

Extends a collection with the contents of an iterator.

impl<A: Array> FromIterator<A::Item> for ArrayVec<A>

Create an ArrayVec from an iterator.

Does not extract more items than there is space for. No error occurs if there are more iterator elements.

fn from_iter<T: IntoIterator<Item = A::Item>>(iter: T) -> Self

Creates a value from an iterator.

impl<A: Array> Clone for ArrayVec<A> where
    A::Item: Clone, 

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, rhs: &Self)

Performs copy-assignment from source.

impl<A: Array> Hash for ArrayVec<A> where
    A::Item: Hash, 

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl<A: Array> PartialEq for ArrayVec<A> where
    A::Item: PartialEq, 

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<A: Array> PartialEq<[A::Item]> for ArrayVec<A> where
    A::Item: PartialEq, 

fn eq(&self, other: &[A::Item]) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<A: Array> Eq for ArrayVec<A> where
    A::Item: Eq, 

impl<A: Array> Borrow<[A::Item]> for ArrayVec<A>

fn borrow(&self) -> &[A::Item]

Immutably borrows from an owned value.

impl<A: Array> BorrowMut<[A::Item]> for ArrayVec<A>

fn borrow_mut(&mut self) -> &mut [A::Item]

Mutably borrows from an owned value.

impl<A: Array> AsRef<[A::Item]> for ArrayVec<A>

fn as_ref(&self) -> &[A::Item]

Performs the conversion.

impl<A: Array> AsMut<[A::Item]> for ArrayVec<A>

fn as_mut(&mut self) -> &mut [A::Item]

Performs the conversion.

impl<A: Array> Debug for ArrayVec<A> where
    A::Item: Debug, 

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<A: Array> Default for ArrayVec<A>

fn default() -> ArrayVec<A>

Returns the "default value" for a type.

impl<A: Array> PartialOrd for ArrayVec<A> where
    A::Item: PartialOrd, 

fn partial_cmp(&self, other: &ArrayVec<A>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Self) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Self) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn ge(&self, other: &Self) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

fn gt(&self, other: &Self) -> bool

This method tests greater than (for self and other) and is used by the > operator.

impl<A: Array> Ord for ArrayVec<A> where
    A::Item: Ord, 

fn cmp(&self, other: &ArrayVec<A>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

impl<A: Array<Item = u8>> Write for ArrayVec<A>

Write appends written data to the end of the vector.

Requires features="std".

fn write(&mut self, data: &[u8]) -> Result<usize>

Write a buffer into this object, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this write.

fn write_fmt(&mut self, fmt: Arguments) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

Creates a "by reference" adaptor for this instance of Write.