/Rust

# Struct std::vec::Vec

`pub struct Vec<T> { /* fields omitted */ }`

A contiguous growable array type, written `Vec<T>` but pronounced 'vector'.

## Examples

```let mut vec = Vec::new();
vec.push(1);
vec.push(2);

assert_eq!(vec.len(), 2);
assert_eq!(vec, 1);

assert_eq!(vec.pop(), Some(2));
assert_eq!(vec.len(), 1);

vec = 7;
assert_eq!(vec, 7);

vec.extend([1, 2, 3].iter().cloned());

for x in &vec {
println!("{}", x);
}
assert_eq!(vec, [7, 1, 2, 3]);```

The `vec!` macro is provided to make initialization more convenient:

```let mut vec = vec![1, 2, 3];
vec.push(4);
assert_eq!(vec, [1, 2, 3, 4]);```

It can also initialize each element of a `Vec<T>` with a given value. This may be more efficient than performing allocation and initialization in separate steps, especially when initializing a vector of zeros:

```let vec = vec![0; 5];
assert_eq!(vec, [0, 0, 0, 0, 0]);

// The following is equivalent, but potentially slower:
let mut vec1 = Vec::with_capacity(5);
vec1.resize(5, 0);```

Use a `Vec<T>` as an efficient stack:

```let mut stack = Vec::new();

stack.push(1);
stack.push(2);
stack.push(3);

while let Some(top) = stack.pop() {
// Prints 3, 2, 1
println!("{}", top);
}```

## Indexing

The `Vec` type allows to access values by index, because it implements the `Index` trait. An example will be more explicit:

```let v = vec![0, 2, 4, 6];
println!("{}", v); // it will display '2'```

However be careful: if you try to access an index which isn't in the `Vec`, your software will panic! You cannot do this:

```let v = vec![0, 2, 4, 6];
println!("{}", v); // it will panic!```

In conclusion: always check if the index you want to get really exists before doing it.

## Slicing

A `Vec` can be mutable. Slices, on the other hand, are read-only objects. To get a slice, use `&`. Example:

```fn read_slice(slice: &[usize]) {
// ...
}

let v = vec![0, 1];

// ... and that's all!
// you can also do it like this:
let x : &[usize] = &v;```

In Rust, it's more common to pass slices as arguments rather than vectors when you just want to provide a read access. The same goes for `String` and `&str`.

## Capacity and reallocation

The capacity of a vector is the amount of space allocated for any future elements that will be added onto the vector. This is not to be confused with the length of a vector, which specifies the number of actual elements within the vector. If a vector's length exceeds its capacity, its capacity will automatically be increased, but its elements will have to be reallocated.

For example, a vector with capacity 10 and length 0 would be an empty vector with space for 10 more elements. Pushing 10 or fewer elements onto the vector will not change its capacity or cause reallocation to occur. However, if the vector's length is increased to 11, it will have to reallocate, which can be slow. For this reason, it is recommended to use `Vec::with_capacity` whenever possible to specify how big the vector is expected to get.

## Guarantees

Due to its incredibly fundamental nature, `Vec` makes a lot of guarantees about its design. This ensures that it's as low-overhead as possible in the general case, and can be correctly manipulated in primitive ways by unsafe code. Note that these guarantees refer to an unqualified `Vec<T>`. If additional type parameters are added (e.g., to support custom allocators), overriding their defaults may change the behavior.

Most fundamentally, `Vec` is and always will be a (pointer, capacity, length) triplet. No more, no less. The order of these fields is completely unspecified, and you should use the appropriate methods to modify these. The pointer will never be null, so this type is null-pointer-optimized.

However, the pointer may not actually point to allocated memory. In particular, if you construct a `Vec` with capacity 0 via `Vec::new`, `vec![]`, `Vec::with_capacity(0)`, or by calling `shrink_to_fit` on an empty Vec, it will not allocate memory. Similarly, if you store zero-sized types inside a `Vec`, it will not allocate space for them. Note that in this case the `Vec` may not report a `capacity` of 0. `Vec` will allocate if and only if `mem::size_of::<T>``() * capacity() > 0`. In general, `Vec`'s allocation details are very subtle — if you intend to allocate memory using a `Vec` and use it for something else (either to pass to unsafe code, or to build your own memory-backed collection), be sure to deallocate this memory by using `from_raw_parts` to recover the `Vec` and then dropping it.

If a `Vec` has allocated memory, then the memory it points to is on the heap (as defined by the allocator Rust is configured to use by default), and its pointer points to `len` initialized, contiguous elements in order (what you would see if you coerced it to a slice), followed by `capacity``-``len` logically uninitialized, contiguous elements.

`Vec` will never perform a "small optimization" where elements are actually stored on the stack for two reasons:

• It would make it more difficult for unsafe code to correctly manipulate a `Vec`. The contents of a `Vec` wouldn't have a stable address if it were only moved, and it would be more difficult to determine if a `Vec` had actually allocated memory.

• It would penalize the general case, incurring an additional branch on every access.

`Vec` will never automatically shrink itself, even if completely empty. This ensures no unnecessary allocations or deallocations occur. Emptying a `Vec` and then filling it back up to the same `len` should incur no calls to the allocator. If you wish to free up unused memory, use `shrink_to_fit`.

`push` and `insert` will never (re)allocate if the reported capacity is sufficient. `push` and `insert` will (re)allocate if `len``==``capacity`. That is, the reported capacity is completely accurate, and can be relied on. It can even be used to manually free the memory allocated by a `Vec` if desired. Bulk insertion methods may reallocate, even when not necessary.

`Vec` does not guarantee any particular growth strategy when reallocating when full, nor when `reserve` is called. The current strategy is basic and it may prove desirable to use a non-constant growth factor. Whatever strategy is used will of course guarantee `O(1)` amortized `push`.

`vec![x; n]`, `vec![a, b, c, d]`, and `Vec::with_capacity(n)`, will all produce a `Vec` with exactly the requested capacity. If `len``==``capacity`, (as is the case for the `vec!` macro), then a `Vec<T>` can be converted to and from a `Box<[T]>` without reallocating or moving the elements.

`Vec` will not specifically overwrite any data that is removed from it, but also won't specifically preserve it. Its uninitialized memory is scratch space that it may use however it wants. It will generally just do whatever is most efficient or otherwise easy to implement. Do not rely on removed data to be erased for security purposes. Even if you drop a `Vec`, its buffer may simply be reused by another `Vec`. Even if you zero a `Vec`'s memory first, that may not actually happen because the optimizer does not consider this a side-effect that must be preserved. There is one case which we will not break, however: using `unsafe` code to write to the excess capacity, and then increasing the length to match, is always valid.

`Vec` does not currently guarantee the order in which elements are dropped. The order has changed in the past and may change again.

## Methods

### `impl<T> Vec<T>`[src]

#### `pub fn new() -> Vec<T>`[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

Constructs a new, empty `Vec<T>`.

The vector will not allocate until elements are pushed onto it.

## Examples

`let mut vec: Vec<i32> = Vec::new();`

#### `pub fn with_capacity(capacity: usize) -> Vec<T>`[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

Constructs a new, empty `Vec<T>` with the specified capacity.

The vector will be able to hold exactly `capacity` elements without reallocating. If `capacity` is 0, the vector will not allocate.

It is important to note that although the returned vector has the capacity specified, the vector will have a zero length. For an explanation of the difference between length and capacity, see Capacity and reallocation.

## Examples

```let mut vec = Vec::with_capacity(10);

// The vector contains no items, even though it has capacity for more
assert_eq!(vec.len(), 0);

// These are all done without reallocating...
for i in 0..10 {
vec.push(i);
}

// ...but this may make the vector reallocate
vec.push(11);```

#### `pub unsafe fn from_raw_parts(    ptr: *mut T,     length: usize,     capacity: usize) -> Vec<T>`[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

Creates a `Vec<T>` directly from the raw components of another vector.

## Safety

This is highly unsafe, due to the number of invariants that aren't checked:

• `ptr` needs to have been previously allocated via `String`/`Vec<T>` (at least, it's highly likely to be incorrect if it wasn't).
• `ptr`'s `T` needs to have the same size and alignment as it was allocated with.
• `length` needs to be less than or equal to `capacity`.
• `capacity` needs to be the capacity that the pointer was allocated with.

Violating these may cause problems like corrupting the allocator's internal data structures. For example it is not safe to build a `Vec<u8>` from a pointer to a C `char` array and a `size_t`.

The ownership of `ptr` is effectively transferred to the `Vec<T>` which may then deallocate, reallocate or change the contents of memory pointed to by the pointer at will. Ensure that nothing else uses the pointer after calling this function.

## Examples

```use std::ptr;
use std::mem;

fn main() {
let mut v = vec![1, 2, 3];

// Pull out the various important pieces of information about `v`
let p = v.as_mut_ptr();
let len = v.len();
let cap = v.capacity();

unsafe {
// Cast `v` into the void: no destructor run, so we are in
// complete control of the allocation to which `p` points.
mem::forget(v);

// Overwrite memory with 4, 5, 6
for i in 0..len as isize {
ptr::write(p.offset(i), 4 + i);
}

// Put everything back together into a Vec
let rebuilt = Vec::from_raw_parts(p, len, cap);
assert_eq!(rebuilt, [4, 5, 6]);
}
}```

#### `pub fn capacity(&self) -> usize`[src]

Returns the number of elements the vector can hold without reallocating.

## Examples

```let vec: Vec<i32> = Vec::with_capacity(10);
assert_eq!(vec.capacity(), 10);```

#### `pub fn reserve(&mut self, additional: usize)`[src]

Reserves capacity for at least `additional` more elements to be inserted in the given `Vec<T>`. The collection may reserve more space to avoid frequent reallocations. After calling `reserve`, capacity will be greater than or equal to `self.len() + additional`. Does nothing if capacity is already sufficient.

## Panics

Panics if the new capacity overflows `usize`.

## Examples

```let mut vec = vec!;
vec.reserve(10);
assert!(vec.capacity() >= 11);```

#### `pub fn reserve_exact(&mut self, additional: usize)`[src]

Reserves the minimum capacity for exactly `additional` more elements to be inserted in the given `Vec<T>`. After calling `reserve_exact`, capacity will be greater than or equal to `self.len() + additional`. Does nothing if the capacity is already sufficient.

Note that the allocator may give the collection more space than it requests. Therefore, capacity can not be relied upon to be precisely minimal. Prefer `reserve` if future insertions are expected.

## Panics

Panics if the new capacity overflows `usize`.

## Examples

```let mut vec = vec!;
vec.reserve_exact(10);
assert!(vec.capacity() >= 11);```

#### `pub fn try_reserve(    &mut self,     additional: usize) -> Result<(), CollectionAllocErr>`[src]

🔬 This is a nightly-only experimental API. (try_reserve #48043)new API

Tries to reserve capacity for at least `additional` more elements to be inserted in the given `Vec<T>`. The collection may reserve more space to avoid frequent reallocations. After calling `reserve`, capacity will be greater than or equal to `self.len() + additional`. Does nothing if capacity is already sufficient.

## Errors

If the capacity overflows, or the allocator reports a failure, then an error is returned.

## Examples

```#![feature(try_reserve)]
use std::collections::CollectionAllocErr;

fn process_data(data: &[u32]) -> Result<Vec<u32>, CollectionAllocErr> {
let mut output = Vec::new();

// Pre-reserve the memory, exiting if we can't
output.try_reserve(data.len())?;

// Now we know this can't OOM in the middle of our complex work
output.extend(data.iter().map(|&val| {
val * 2 + 5 // very complicated
}));

Ok(output)
}```

#### `pub fn try_reserve_exact(    &mut self,     additional: usize) -> Result<(), CollectionAllocErr>`[src]

🔬 This is a nightly-only experimental API. (try_reserve #48043)new API

Tries to reserves the minimum capacity for exactly `additional` more elements to be inserted in the given `Vec<T>`. After calling `reserve_exact`, capacity will be greater than or equal to `self.len() + additional`. Does nothing if the capacity is already sufficient.

Note that the allocator may give the collection more space than it requests. Therefore, capacity can not be relied upon to be precisely minimal. Prefer `reserve` if future insertions are expected.

## Errors

If the capacity overflows, or the allocator reports a failure, then an error is returned.

## Examples

```#![feature(try_reserve)]
use std::collections::CollectionAllocErr;

fn process_data(data: &[u32]) -> Result<Vec<u32>, CollectionAllocErr> {
let mut output = Vec::new();

// Pre-reserve the memory, exiting if we can't
output.try_reserve(data.len())?;

// Now we know this can't OOM in the middle of our complex work
output.extend(data.iter().map(|&val| {
val * 2 + 5 // very complicated
}));

Ok(output)
}```

#### `pub fn shrink_to_fit(&mut self)`[src]

Shrinks the capacity of the vector as much as possible.

It will drop down as close as possible to the length but the allocator may still inform the vector that there is space for a few more elements.

## Examples

```let mut vec = Vec::with_capacity(10);
vec.extend([1, 2, 3].iter().cloned());
assert_eq!(vec.capacity(), 10);
vec.shrink_to_fit();
assert!(vec.capacity() >= 3);```

#### `pub fn shrink_to(&mut self, min_capacity: usize)`[src]

🔬 This is a nightly-only experimental API. (shrink_to #56431)new API

Shrinks the capacity of the vector with a lower bound.

The capacity will remain at least as large as both the length and the supplied value.

Panics if the current capacity is smaller than the supplied minimum capacity.

## Examples

```#![feature(shrink_to)]
let mut vec = Vec::with_capacity(10);
vec.extend([1, 2, 3].iter().cloned());
assert_eq!(vec.capacity(), 10);
vec.shrink_to(4);
assert!(vec.capacity() >= 4);
vec.shrink_to(0);
assert!(vec.capacity() >= 3);```

#### `pub fn into_boxed_slice(self) -> Box<[T]>`[src]

ⓘImportant traits for Box<I>
```impl<I> Iterator for Box<I> where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<F> Future for Box<F> where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<W: Write + ?Sized> Write for Box<W>
```

Converts the vector into `Box<[T]>`.

Note that this will drop any excess capacity.

## Examples

```let v = vec![1, 2, 3];

let slice = v.into_boxed_slice();```

Any excess capacity is removed:

```let mut vec = Vec::with_capacity(10);
vec.extend([1, 2, 3].iter().cloned());

assert_eq!(vec.capacity(), 10);
let slice = vec.into_boxed_slice();
assert_eq!(slice.into_vec().capacity(), 3);```

#### `pub fn truncate(&mut self, len: usize)`[src]

Shortens the vector, keeping the first `len` elements and dropping the rest.

If `len` is greater than the vector's current length, this has no effect.

The `drain` method can emulate `truncate`, but causes the excess elements to be returned instead of dropped.

Note that this method has no effect on the allocated capacity of the vector.

## Examples

Truncating a five element vector to two elements:

```let mut vec = vec![1, 2, 3, 4, 5];
vec.truncate(2);
assert_eq!(vec, [1, 2]);```

No truncation occurs when `len` is greater than the vector's current length:

```let mut vec = vec![1, 2, 3];
vec.truncate(8);
assert_eq!(vec, [1, 2, 3]);```

Truncating when `len == 0` is equivalent to calling the `clear` method.

```let mut vec = vec![1, 2, 3];
vec.truncate(0);
assert_eq!(vec, []);```

#### `pub fn as_slice(&self) -> &[T]`[src]1.7.0

ⓘImportant traits for &'_ [u8]
```impl<'_> Read for &'_ [u8]
impl<'_> Write for &'_ mut [u8]
```

Extracts a slice containing the entire vector.

Equivalent to `&s[..]`.

## Examples

```use std::io::{self, Write};
let buffer = vec![1, 2, 3, 5, 8];
io::sink().write(buffer.as_slice()).unwrap();```

#### `pub fn as_mut_slice(&mut self) -> &mut [T]`[src]1.7.0

ⓘImportant traits for &'_ [u8]
```impl<'_> Read for &'_ [u8]
impl<'_> Write for &'_ mut [u8]
```

Extracts a mutable slice of the entire vector.

Equivalent to `&mut s[..]`.

## Examples

```use std::io::{self, Read};
let mut buffer = vec![0; 3];

#### `pub fn as_ptr(&self) -> *const T`[src]1.37.0

Returns a raw pointer to the vector's buffer.

The caller must ensure that the vector outlives the pointer this function returns, or else it will end up pointing to garbage. Modifying the vector may cause its buffer to be reallocated, which would also make any pointers to it invalid.

The caller must also ensure that the memory the pointer (non-transitively) points to is never written to (except inside an `UnsafeCell`) using this pointer or any pointer derived from it. If you need to mutate the contents of the slice, use `as_mut_ptr`.

## Examples

```let x = vec![1, 2, 4];
let x_ptr = x.as_ptr();

unsafe {
for i in 0..x.len() {
}
}```

#### `pub fn as_mut_ptr(&mut self) -> *mut T`[src]1.37.0

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

The caller must ensure that the vector outlives the pointer this function returns, or else it will end up pointing to garbage. Modifying the vector may cause its buffer to be reallocated, which would also make any pointers to it invalid.

## Examples

```// Allocate vector big enough for 4 elements.
let size = 4;
let mut x: Vec<i32> = Vec::with_capacity(size);
let x_ptr = x.as_mut_ptr();

// Initialize elements via raw pointer writes, then set length.
unsafe {
for i in 0..size {
}
x.set_len(size);
}
assert_eq!(&*x, &[0,1,2,3]);```

#### `pub unsafe fn set_len(&mut self, new_len: usize)`[src]

Forces the length of the vector to `new_len`.

This is a low-level operation that maintains none of the normal invariants of the type. Normally changing the length of a vector is done using one of the safe operations instead, such as `truncate`, `resize`, `extend`, or `clear`.

## Safety

• `new_len` must be less than or equal to `capacity()`.
• The elements at `old_len..new_len` must be initialized.

## Examples

This method can be useful for situations in which the vector is serving as a buffer for other code, particularly over FFI:

```pub fn get_dictionary(&self) -> Option<Vec<u8>> {
// Per the FFI method's docs, "32768 bytes is always enough".
let mut dict = Vec::with_capacity(32_768);
let mut dict_length = 0;
// SAFETY: When `deflateGetDictionary` returns `Z_OK`, it holds that:
// 1. `dict_length` elements were initialized.
// 2. `dict_length` <= the capacity (32_768)
// which makes `set_len` safe to call.
unsafe {
// Make the FFI call...
let r = deflateGetDictionary(self.strm, dict.as_mut_ptr(), &mut dict_length);
if r == Z_OK {
// ...and update the length to what was initialized.
dict.set_len(dict_length);
Some(dict)
} else {
None
}
}
}```

While the following example is sound, there is a memory leak since the inner vectors were not freed prior to the `set_len` call:

```let mut vec = vec![vec![1, 0, 0],
vec![0, 1, 0],
vec![0, 0, 1]];
// SAFETY:
// 1. `old_len..0` is empty so no elements need to be initialized.
// 2. `0 <= capacity` always holds whatever `capacity` is.
unsafe {
vec.set_len(0);
}```

Normally, here, one would use `clear` instead to correctly drop the contents and thus not leak memory.

#### `pub fn swap_remove(&mut self, index: usize) -> T`[src]

Removes an element from the vector and returns it.

The removed element is replaced by the last element of the vector.

This does not preserve ordering, but is O(1).

## Panics

Panics if `index` is out of bounds.

## Examples

```let mut v = vec!["foo", "bar", "baz", "qux"];

assert_eq!(v.swap_remove(1), "bar");
assert_eq!(v, ["foo", "qux", "baz"]);

assert_eq!(v.swap_remove(0), "foo");
assert_eq!(v, ["baz", "qux"]);```

#### `pub fn insert(&mut self, index: usize, element: T)`[src]

Inserts an element at position `index` within the vector, shifting all elements after it to the right.

## Panics

Panics if `index > len`.

## Examples

```let mut vec = vec![1, 2, 3];
vec.insert(1, 4);
assert_eq!(vec, [1, 4, 2, 3]);
vec.insert(4, 5);
assert_eq!(vec, [1, 4, 2, 3, 5]);```

#### `pub fn remove(&mut self, index: usize) -> T`[src]

Removes and returns the element at position `index` within the vector, shifting all elements after it to the left.

## Panics

Panics if `index` is out of bounds.

## Examples

```let mut v = vec![1, 2, 3];
assert_eq!(v.remove(1), 2);
assert_eq!(v, [1, 3]);```

#### `pub fn retain<F>(&mut self, f: F) where    F: FnMut(&T) -> bool, `[src]

Retains only the elements specified by the predicate.

In other words, remove all elements `e` such that `f(&e)` returns `false`. This method operates in place, visiting each element exactly once in the original order, and preserves the order of the retained elements.

## Examples

```let mut vec = vec![1, 2, 3, 4];
vec.retain(|&x| x%2 == 0);
assert_eq!(vec, [2, 4]);```

The exact order may be useful for tracking external state, like an index.

```let mut vec = vec![1, 2, 3, 4, 5];
let keep = [false, true, true, false, true];
let mut i = 0;
vec.retain(|_| (keep[i], i += 1).0);
assert_eq!(vec, [2, 3, 5]);```

#### `pub fn dedup_by_key<F, K>(&mut self, key: F) where    F: FnMut(&mut T) -> K,    K: PartialEq<K>, `[src]1.16.0

Removes all but the first of consecutive elements in the vector that resolve to the same key.

If the vector is sorted, this removes all duplicates.

## Examples

```let mut vec = vec![10, 20, 21, 30, 20];

vec.dedup_by_key(|i| *i / 10);

assert_eq!(vec, [10, 20, 30, 20]);```

#### `pub fn dedup_by<F>(&mut self, same_bucket: F) where    F: FnMut(&mut T, &mut T) -> bool, `[src]1.16.0

Removes all but the first of consecutive elements in the vector satisfying a given equality relation.

The `same_bucket` function is passed references to two elements from the vector and must determine if the elements compare equal. The elements are passed in opposite order from their order in the slice, so if `same_bucket(a, b)` returns `true`, `a` is removed.

If the vector is sorted, this removes all duplicates.

## Examples

```let mut vec = vec!["foo", "bar", "Bar", "baz", "bar"];

vec.dedup_by(|a, b| a.eq_ignore_ascii_case(b));

assert_eq!(vec, ["foo", "bar", "baz", "bar"]);```

#### `pub fn push(&mut self, value: T)`[src]

Appends an element to the back of a collection.

## Panics

Panics if the number of elements in the vector overflows a `usize`.

## Examples

```let mut vec = vec![1, 2];
vec.push(3);
assert_eq!(vec, [1, 2, 3]);```

#### `pub fn pop(&mut self) -> Option<T>`[src]

Removes the last element from a vector and returns it, or `None` if it is empty.

## Examples

```let mut vec = vec![1, 2, 3];
assert_eq!(vec.pop(), Some(3));
assert_eq!(vec, [1, 2]);```

#### `pub fn append(&mut self, other: &mut Vec<T>)`[src]1.4.0

Moves all the elements of `other` into `Self`, leaving `other` empty.

## Panics

Panics if the number of elements in the vector overflows a `usize`.

## Examples

```let mut vec = vec![1, 2, 3];
let mut vec2 = vec![4, 5, 6];
vec.append(&mut vec2);
assert_eq!(vec, [1, 2, 3, 4, 5, 6]);
assert_eq!(vec2, []);```

#### `pub fn drain<R>(&mut self, range: R) -> Drain<T> where    R: RangeBounds<usize>, `[src]1.6.0

ⓘImportant traits for Drain<'_, T>
```impl<'_, T> Iterator for Drain<'_, T>
type Item = T;
```

Creates a draining iterator that removes the specified range in the vector and yields the removed items.

Note 1: The element range is removed even if the iterator is only partially consumed or not consumed at all.

Note 2: It is unspecified how many elements are removed from the vector if the `Drain` value is leaked.

## Panics

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

## Examples

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

// A full range clears the vector
v.drain(..);
assert_eq!(v, &[]);```

#### `pub fn clear(&mut self)`[src]

Clears the vector, removing all values.

Note that this method has no effect on the allocated capacity of the vector.

## Examples

```let mut v = vec![1, 2, 3];

v.clear();

assert!(v.is_empty());```

#### `pub fn len(&self) -> usize`[src]

Returns the number of elements in the vector, also referred to as its 'length'.

## Examples

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

#### `pub fn is_empty(&self) -> bool`[src]

Returns `true` if the vector contains no elements.

## Examples

```let mut v = Vec::new();
assert!(v.is_empty());

v.push(1);
assert!(!v.is_empty());```

#### `pub fn split_off(&mut self, at: usize) -> Vec<T>`[src]1.4.0

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

Splits the collection into two at the given index.

Returns a newly allocated `Self`. `self` contains elements `[0, at)`, and the returned `Self` contains elements `[at, len)`.

Note that the capacity of `self` does not change.

## Panics

Panics if `at > len`.

## Examples

```let mut vec = vec![1,2,3];
let vec2 = vec.split_off(1);
assert_eq!(vec, );
assert_eq!(vec2, [2, 3]);```

#### `pub fn resize_with<F>(&mut self, new_len: usize, f: F) where    F: FnMut() -> T, `[src]1.33.0

Resizes the `Vec` in-place so that `len` is equal to `new_len`.

If `new_len` is greater than `len`, the `Vec` is extended by the difference, with each additional slot filled with the result of calling the closure `f`. The return values from `f` will end up in the `Vec` in the order they have been generated.

If `new_len` is less than `len`, the `Vec` is simply truncated.

This method uses a closure to create new values on every push. If you'd rather `Clone` a given value, use `resize`. If you want to use the `Default` trait to generate values, you can pass `Default::default()` as the second argument.

## Examples

```let mut vec = vec![1, 2, 3];
vec.resize_with(5, Default::default);
assert_eq!(vec, [1, 2, 3, 0, 0]);

let mut vec = vec![];
let mut p = 1;
vec.resize_with(4, || { p *= 2; p });
assert_eq!(vec, [2, 4, 8, 16]);```

### `impl<T> Vec<T> where    T: Clone, `[src]

#### `pub fn resize(&mut self, new_len: usize, value: T)`[src]1.5.0

Resizes the `Vec` in-place so that `len` is equal to `new_len`.

If `new_len` is greater than `len`, the `Vec` is extended by the difference, with each additional slot filled with `value`. If `new_len` is less than `len`, the `Vec` is simply truncated.

This method requires `Clone` to be able clone the passed value. If you need more flexibility (or want to rely on `Default` instead of `Clone`), use `resize_with`.

## Examples

```let mut vec = vec!["hello"];
vec.resize(3, "world");
assert_eq!(vec, ["hello", "world", "world"]);

let mut vec = vec![1, 2, 3, 4];
vec.resize(2, 0);
assert_eq!(vec, [1, 2]);```

#### `pub fn extend_from_slice(&mut self, other: &[T])`[src]1.6.0

Clones and appends all elements in a slice to the `Vec`.

Iterates over the slice `other`, clones each element, and then appends it to this `Vec`. The `other` vector is traversed in-order.

Note that this function is same as `extend` except that it is specialized to work with slices instead. If and when Rust gets specialization this function will likely be deprecated (but still available).

## Examples

```let mut vec = vec!;
vec.extend_from_slice(&[2, 3, 4]);
assert_eq!(vec, [1, 2, 3, 4]);```

### `impl<T> Vec<T> where    T: Default, `[src]

#### `pub fn resize_default(&mut self, new_len: usize)`[src]

Deprecated since 1.33.0: This is moving towards being removed in favor of .resize_with(Default::default). If you disagree, please comment in the tracking issue. 🔬 This is a nightly-only experimental API. (vec_resize_default #41758)

Resizes the `Vec` in-place so that `len` is equal to `new_len`.

If `new_len` is greater than `len`, the `Vec` is extended by the difference, with each additional slot filled with `Default::default()`. If `new_len` is less than `len`, the `Vec` is simply truncated.

This method uses `Default` to create new values on every push. If you'd rather `Clone` a given value, use `resize`.

## Examples

```#![feature(vec_resize_default)]

let mut vec = vec![1, 2, 3];
vec.resize_default(5);
assert_eq!(vec, [1, 2, 3, 0, 0]);

let mut vec = vec![1, 2, 3, 4];
vec.resize_default(2);
assert_eq!(vec, [1, 2]);```

### `impl<T> Vec<T> where    T: PartialEq<T>, `[src]

#### `pub fn dedup(&mut self)`[src]

Removes consecutive repeated elements in the vector according to the `PartialEq` trait implementation.

If the vector is sorted, this removes all duplicates.

## Examples

```let mut vec = vec![1, 2, 2, 3, 2];

vec.dedup();

assert_eq!(vec, [1, 2, 3, 2]);```

#### `pub fn remove_item(&mut self, item: &T) -> Option<T>`[src]

🔬 This is a nightly-only experimental API. (vec_remove_item #40062)recently added

Removes the first instance of `item` from the vector if the item exists.

## Examples

```let mut vec = vec![1, 2, 3, 1];

vec.remove_item(&1);

assert_eq!(vec, vec![2, 3, 1]);```

### `impl<T> Vec<T>`[src]

#### `pub fn splice<R, I>(    &mut self,     range: R,     replace_with: I) -> Splice<<I as IntoIterator>::IntoIter> where    I: IntoIterator<Item = T>,    R: RangeBounds<usize>, `[src]1.21.0

ⓘImportant traits for Splice<'_, I>
```impl<'_, I> Iterator for Splice<'_, I> where
I: Iterator,
type Item = <I as Iterator>::Item;
```

Creates a splicing iterator that replaces the specified range in the vector with the given `replace_with` iterator and yields the removed items. `replace_with` does not need to be the same length as `range`.

The element range is removed even if the iterator is not consumed until the end.

It is unspecified how many elements are removed from the vector if the `Splice` value is leaked.

The input iterator `replace_with` is only consumed when the `Splice` value is dropped.

This is optimal if:

• The tail (elements in the vector after `range`) is empty,
• or `replace_with` yields fewer elements than `range`’s length
• or the lower bound of its `size_hint()` is exact.

Otherwise, a temporary vector is allocated and the tail is moved twice.

## Panics

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

## Examples

```let mut v = vec![1, 2, 3];
let new = [7, 8];
let u: Vec<_> = v.splice(..2, new.iter().cloned()).collect();
assert_eq!(v, &[7, 8, 3]);
assert_eq!(u, &[1, 2]);```

#### `pub fn drain_filter<F>(&mut self, filter: F) -> DrainFilter<T, F> where    F: FnMut(&mut T) -> bool, `[src]

ⓘImportant traits for DrainFilter<'_, T, F>
```impl<'_, T, F> Iterator for DrainFilter<'_, T, F> where
F: FnMut(&mut T) -> bool,
type Item = T;
```
🔬 This is a nightly-only experimental API. (drain_filter #43244)recently added

Creates an iterator which uses a closure to determine if an element should be removed.

If the closure returns true, then the element is removed and yielded. If the closure returns false, the element will remain in the vector and will not be yielded by the iterator.

Using this method is equivalent to the following code:

```let mut i = 0;
while i != vec.len() {
if some_predicate(&mut vec[i]) {
let val = vec.remove(i);
} else {
i += 1;
}
}
```

But `drain_filter` is easier to use. `drain_filter` is also more efficient, because it can backshift the elements of the array in bulk.

Note that `drain_filter` also lets you mutate every element in the filter closure, regardless of whether you choose to keep or remove it.

## Examples

Splitting an array into evens and odds, reusing the original allocation:

```#![feature(drain_filter)]
let mut numbers = vec![1, 2, 3, 4, 5, 6, 8, 9, 11, 13, 14, 15];

let evens = numbers.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>();
let odds = numbers;

assert_eq!(evens, vec![2, 4, 6, 8, 14]);
assert_eq!(odds, vec![1, 3, 5, 9, 11, 13, 15]);```

## Methods from Deref<Target = [T]>

#### `pub fn len(&self) -> usize`[src]

Returns the number of elements in the slice.

## Examples

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

#### `pub fn is_empty(&self) -> bool`[src]

Returns `true` if the slice has a length of 0.

## Examples

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

#### `pub fn first(&self) -> Option<&T>`[src]

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());```

#### `pub fn first_mut(&mut self) -> Option<&mut T>`[src]

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]);```

#### `pub fn split_first(&self) -> Option<(&T, &[T])>`[src]1.5.0

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]);
}```

#### `pub fn split_first_mut(&mut self) -> Option<(&mut T, &mut [T])>`[src]1.5.0

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 = 4;
elements = 5;
}
assert_eq!(x, &[3, 4, 5]);```

#### `pub fn split_last(&self) -> Option<(&T, &[T])>`[src]1.5.0

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]);
}```

#### `pub fn split_last_mut(&mut self) -> Option<(&mut T, &mut [T])>`[src]1.5.0

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 = 4;
elements = 5;
}
assert_eq!(x, &[4, 5, 3]);```

#### `pub fn last(&self) -> Option<&T>`[src]

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());```

#### `pub fn last_mut(&mut self) -> Option<&mut T>`[src]

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]);```

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

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));```

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

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]);```

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

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);
}```

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

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]);```

#### `pub const fn as_ptr(&self) -> *const T`[src]

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.

The caller must also ensure that the memory the pointer (non-transitively) points to is never written to (except inside an `UnsafeCell`) using this pointer or any pointer derived from it. If you need to mutate the contents of the slice, use `as_mut_ptr`.

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() {
}
}```

#### `pub fn as_mut_ptr(&mut self) -> *mut T`[src]

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() {
}
}
assert_eq!(x, &[3, 4, 6]);```

#### `pub fn swap(&mut self, a: usize, b: usize)`[src]

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"]);```

#### `pub fn reverse(&mut self)`[src]

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

## Examples

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

#### `pub fn iter(&self) -> Iter<T>`[src]

ⓘImportant traits for Iter<'a, T>
```impl<'a, T> Iterator for Iter<'a, T>
type Item = &'a 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);```

#### `pub fn iter_mut(&mut self) -> IterMut<T>`[src]

ⓘImportant traits for IterMut<'a, T>
```impl<'a, T> Iterator for IterMut<'a, T>
type Item = &'a mut 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]);```

#### `pub fn windows(&self, size: usize) -> Windows<T>`[src]

ⓘImportant traits for Windows<'a, T>
```impl<'a, T> Iterator for Windows<'a, T>
type Item = &'a [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());```

#### `pub fn chunks(&self, chunk_size: usize) -> Chunks<T>`[src]

ⓘImportant traits for Chunks<'a, T>
```impl<'a, T> Iterator for Chunks<'a, T>
type Item = &'a [T];
```

Returns an iterator over `chunk_size` elements of the slice at a time, starting at the beginning of the slice.

The chunks are 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`.

See `chunks_exact` for a variant of this iterator that returns chunks of always exactly `chunk_size` elements, and `rchunks` for the same iterator but starting at the end of the slice of the slice.

## Panics

Panics if `chunk_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());```

#### `pub fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<T>`[src]

ⓘImportant traits for ChunksMut<'a, T>
```impl<'a, T> Iterator for ChunksMut<'a, T>
type Item = &'a mut [T];
```

Returns an iterator over `chunk_size` elements of the slice at a time, starting at the beginning of the slice.

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`.

See `chunks_exact_mut` for a variant of this iterator that returns chunks of always exactly `chunk_size` elements, and `rchunks_mut` for the same iterator but starting at the end of the slice of the slice.

## 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]);```

#### `pub fn chunks_exact(&self, chunk_size: usize) -> ChunksExact<T>`[src]1.31.0

ⓘImportant traits for ChunksExact<'a, T>
```impl<'a, T> Iterator for ChunksExact<'a, T>
type Item = &'a [T];
```

Returns an iterator over `chunk_size` elements of the slice at a time, starting at the beginning of the slice.

The chunks are slices and do not overlap. If `chunk_size` does not divide the length of the slice, then the last up to `chunk_size-1` elements will be omitted and can be retrieved from the `remainder` function of the iterator.

Due to each chunk having exactly `chunk_size` elements, the compiler can often optimize the resulting code better than in the case of `chunks`.

See `chunks` for a variant of this iterator that also returns the remainder as a smaller chunk, and `rchunks_exact` for the same iterator but starting at the end of the slice.

## Panics

Panics if `chunk_size` is 0.

## Examples

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

#### `pub fn chunks_exact_mut(&mut self, chunk_size: usize) -> ChunksExactMut<T>`[src]1.31.0

ⓘImportant traits for ChunksExactMut<'a, T>
```impl<'a, T> Iterator for ChunksExactMut<'a, T>
type Item = &'a mut [T];
```

Returns an iterator over `chunk_size` elements of the slice at a time, starting at the beginning of the slice.

The chunks are mutable slices, and do not overlap. If `chunk_size` does not divide the length of the slice, then the last up to `chunk_size-1` elements will be omitted and can be retrieved from the `into_remainder` function of the iterator.

Due to each chunk having exactly `chunk_size` elements, the compiler can often optimize the resulting code better than in the case of `chunks_mut`.

See `chunks_mut` for a variant of this iterator that also returns the remainder as a smaller chunk, and `rchunks_exact_mut` for the same iterator but starting at the end of the slice of the slice.

## 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_exact_mut(2) {
for elem in chunk.iter_mut() {
*elem += count;
}
count += 1;
}
assert_eq!(v, &[1, 1, 2, 2, 0]);```

#### `pub fn rchunks(&self, chunk_size: usize) -> RChunks<T>`[src]1.31.0

ⓘImportant traits for RChunks<'a, T>
```impl<'a, T> Iterator for RChunks<'a, T>
type Item = &'a [T];
```

Returns an iterator over `chunk_size` elements of the slice at a time, starting at the end of the slice.

The chunks are 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`.

See `rchunks_exact` for a variant of this iterator that returns chunks of always exactly `chunk_size` elements, and `chunks` for the same iterator but starting at the beginning of the slice.

## Panics

Panics if `chunk_size` is 0.

## Examples

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

#### `pub fn rchunks_mut(&mut self, chunk_size: usize) -> RChunksMut<T>`[src]1.31.0

ⓘImportant traits for RChunksMut<'a, T>
```impl<'a, T> Iterator for RChunksMut<'a, T>
type Item = &'a mut [T];
```

Returns an iterator over `chunk_size` elements of the slice at a time, starting at the end of the slice.

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`.

See `rchunks_exact_mut` for a variant of this iterator that returns chunks of always exactly `chunk_size` elements, and `chunks_mut` for the same iterator but starting at the beginning of the slice.

## Panics

Panics if `chunk_size` is 0.

## Examples

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

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

#### `pub fn rchunks_exact(&self, chunk_size: usize) -> RChunksExact<T>`[src]1.31.0

ⓘImportant traits for RChunksExact<'a, T>
```impl<'a, T> Iterator for RChunksExact<'a, T>
type Item = &'a [T];
```

Returns an iterator over `chunk_size` elements of the slice at a time, starting at the end of the slice.

The chunks are slices and do not overlap. If `chunk_size` does not divide the length of the slice, then the last up to `chunk_size-1` elements will be omitted and can be retrieved from the `remainder` function of the iterator.

Due to each chunk having exactly `chunk_size` elements, the compiler can often optimize the resulting code better than in the case of `chunks`.

See `rchunks` for a variant of this iterator that also returns the remainder as a smaller chunk, and `chunks_exact` for the same iterator but starting at the beginning of the slice.

## Panics

Panics if `chunk_size` is 0.

## Examples

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

#### `pub fn rchunks_exact_mut(&mut self, chunk_size: usize) -> RChunksExactMut<T>`[src]1.31.0

ⓘImportant traits for RChunksExactMut<'a, T>
```impl<'a, T> Iterator for RChunksExactMut<'a, T>
type Item = &'a mut [T];
```

Returns an iterator over `chunk_size` elements of the slice at a time, starting at the end of the slice.

The chunks are mutable slices, and do not overlap. If `chunk_size` does not divide the length of the slice, then the last up to `chunk_size-1` elements will be omitted and can be retrieved from the `into_remainder` function of the iterator.

Due to each chunk having exactly `chunk_size` elements, the compiler can often optimize the resulting code better than in the case of `chunks_mut`.

See `rchunks_mut` for a variant of this iterator that also returns the remainder as a smaller chunk, and `chunks_exact_mut` for the same iterator but starting at the beginning of the slice.

## Panics

Panics if `chunk_size` is 0.

## Examples

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

for chunk in v.rchunks_exact_mut(2) {
for elem in chunk.iter_mut() {
*elem += count;
}
count += 1;
}
assert_eq!(v, &[0, 2, 2, 1, 1]);```

#### `pub fn split_at(&self, mid: usize) -> (&[T], &[T])`[src]

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 == []);
}```

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

Divides one mutable 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 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 = 2;
right = 4;
}
assert!(v == [1, 2, 3, 4, 5, 6]);```

#### `pub fn split<F>(&self, pred: F) -> Split<T, F> where    F: FnMut(&T) -> bool, `[src]

ⓘImportant traits for Split<'a, T, P>
```impl<'a, T, P> Iterator for Split<'a, T, P> where
P: FnMut(&T) -> bool,
type Item = &'a [T];
```

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

#### `pub fn split_mut<F>(&mut self, pred: F) -> SplitMut<T, F> where    F: FnMut(&T) -> bool, `[src]

ⓘImportant traits for SplitMut<'a, T, P>
```impl<'a, T, P> Iterator for SplitMut<'a, T, P> where
P: FnMut(&T) -> bool,
type Item = &'a mut [T];
```

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 = 1;
}
assert_eq!(v, [1, 40, 30, 1, 60, 1]);```

#### `pub fn rsplit<F>(&self, pred: F) -> RSplit<T, F> where    F: FnMut(&T) -> bool, `[src]1.27.0

ⓘImportant traits for RSplit<'a, T, P>
```impl<'a, T, P> Iterator for RSplit<'a, T, P> where
P: FnMut(&T) -> bool,
type Item = &'a [T];
```

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

```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.

```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);```

#### `pub fn rsplit_mut<F>(&mut self, pred: F) -> RSplitMut<T, F> where    F: FnMut(&T) -> bool, `[src]1.27.0

ⓘImportant traits for RSplitMut<'a, T, P>
```impl<'a, T, P> Iterator for RSplitMut<'a, T, P> where
P: FnMut(&T) -> bool,
type Item = &'a mut [T];
```

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

```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 = count;
}
assert_eq!(v, [3, 400, 300, 2, 600, 1]);```

#### `pub fn splitn<F>(&self, n: usize, pred: F) -> SplitN<T, F> where    F: FnMut(&T) -> bool, `[src]

ⓘImportant traits for SplitN<'a, T, P>
```impl<'a, T, P> Iterator for SplitN<'a, T, P> where
P: FnMut(&T) -> bool,
type Item = &'a [T];
```

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);
}```

#### `pub fn splitn_mut<F>(&mut self, n: usize, pred: F) -> SplitNMut<T, F> where    F: FnMut(&T) -> bool, `[src]

ⓘImportant traits for SplitNMut<'a, T, P>
```impl<'a, T, P> Iterator for SplitNMut<'a, T, P> where
P: FnMut(&T) -> bool,
type Item = &'a mut [T];
```

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 = 1;
}
assert_eq!(v, [1, 40, 30, 1, 60, 50]);```

#### `pub fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<T, F> where    F: FnMut(&T) -> bool, `[src]

ⓘImportant traits for RSplitN<'a, T, P>
```impl<'a, T, P> Iterator for RSplitN<'a, T, P> where
P: FnMut(&T) -> bool,
type Item = &'a [T];
```

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., ``, `[10, 40, 30, 20]`):

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

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

#### `pub fn rsplitn_mut<F>(&mut self, n: usize, pred: F) -> RSplitNMut<T, F> where    F: FnMut(&T) -> bool, `[src]

ⓘImportant traits for RSplitNMut<'a, T, P>
```impl<'a, T, P> Iterator for RSplitNMut<'a, T, P> where
P: FnMut(&T) -> bool,
type Item = &'a mut [T];
```

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 = 1;
}
assert_eq!(s, [1, 40, 30, 20, 60, 1]);```

#### `pub fn contains(&self, x: &T) -> bool where    T: PartialEq<T>, `[src]

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));```

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

Returns `true` if `needle` is a prefix of the slice.

## Examples

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

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

Returns `true` if `needle` is a suffix of the slice.

## Examples

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

Binary searches this sorted slice for a given element.

If the value is found then `Result::Ok` is returned, containing the index of the matching element. If there are multiple matches, then any one of the matches could be returned. If the value is not found then `Result::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, });```

#### `pub fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize> where    F: FnMut(&'a T) -> Ordering, `[src]

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 the value is found then `Result::Ok` is returned, containing the index of the matching element. If there are multiple matches, then any one of the matches could be returned. If the value is not found then `Result::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, });```

#### `pub 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, `[src]1.10.0

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 the value is found then `Result::Ok` is returned, containing the index of the matching element. If there are multiple matches, then any one of the matches could be returned. If the value is not found then `Result::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, });```

#### `pub fn sort_unstable(&mut self) where    T: Ord, `[src]1.20.0

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]);```

#### `pub fn sort_unstable_by<F>(&mut self, compare: F) where    F: FnMut(&T, &T) -> Ordering, `[src]1.20.0

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.

The comparator function must define a total ordering for the elements in the slice. If the ordering is not total, the order of the elements is unspecified. An order is a total order if it is (for all a, b and c):

• total and antisymmetric: exactly one of a < b, a == b or a > b is true; and
• transitive, a < b and b < c implies a < c. The same must hold for both == and >.

For example, while `f64` doesn't implement `Ord` because `NaN != NaN`, we can use `partial_cmp` as our sort function when we know the slice doesn't contain a `NaN`.

```let mut floats = [5f64, 4.0, 1.0, 3.0, 2.0];
floats.sort_by(|a, b| a.partial_cmp(b).unwrap());
assert_eq!(floats, [1.0, 2.0, 3.0, 4.0, 5.0]);```

## 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]);```

#### `pub fn sort_unstable_by_key<K, F>(&mut self, f: F) where    F: FnMut(&T) -> K,    K: Ord, `[src]1.20.0

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(m n log(m n))` worst-case, where the key function is `O(m)`.

## 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.

Due to its key calling strategy, `sort_unstable_by_key` is likely to be slower than `sort_by_cached_key` in cases where the key function is expensive.

## Examples

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

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

#### `pub fn partition_at_index(    &mut self,     index: usize) -> (&mut [T], &mut T, &mut [T]) where    T: Ord, `[src]

🔬 This is a nightly-only experimental API. (slice_partition_at_index #55300)

Reorder the slice such that the element at `index` is at its final sorted position.

This reordering has the additional property that any value at position `i < index` will be less than or equal to any value at a position `j > index`. Additionally, this reordering is unstable (i.e. any number of equal elements may end up at position `index`), in-place (i.e. does not allocate), and `O(n)` worst-case. This function is also/ known as "kth element" in other libraries. It returns a triplet of the following values: all elements less than the one at the given index, the value at the given index, and all elements greater than the one at the given index.

## Current implementation

The current algorithm is based on the quickselect portion of the same quicksort algorithm used for `sort_unstable`.

## Panics

Panics when `index >= len()`, meaning it always panics on empty slices.

## Examples

```#![feature(slice_partition_at_index)]

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

// Find the median
v.partition_at_index(2);

// We are only guaranteed the slice will be one of the following, based on the way we sort
assert!(v == [-3, -5, 1, 2, 4] ||
v == [-5, -3, 1, 2, 4] ||
v == [-3, -5, 1, 4, 2] ||
v == [-5, -3, 1, 4, 2]);```

#### `pub fn partition_at_index_by<F>(    &mut self,     index: usize,     compare: F) -> (&mut [T], &mut T, &mut [T]) where    F: FnMut(&T, &T) -> Ordering, `[src]

🔬 This is a nightly-only experimental API. (slice_partition_at_index #55300)

Reorder the slice with a comparator function such that the element at `index` is at its final sorted position.

This reordering has the additional property that any value at position `i < index` will be less than or equal to any value at a position `j > index` using the comparator function. Additionally, this reordering is unstable (i.e. any number of equal elements may end up at position `index`), in-place (i.e. does not allocate), and `O(n)` worst-case. This function is also known as "kth element" in other libraries. It returns a triplet of the following values: all elements less than the one at the given index, the value at the given index, and all elements greater than the one at the given index, using the provided comparator function.

## Current implementation

The current algorithm is based on the quickselect portion of the same quicksort algorithm used for `sort_unstable`.

## Panics

Panics when `index >= len()`, meaning it always panics on empty slices.

## Examples

```#![feature(slice_partition_at_index)]

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

// Find the median as if the slice were sorted in descending order.
v.partition_at_index_by(2, |a, b| b.cmp(a));

// We are only guaranteed the slice will be one of the following, based on the way we sort
assert!(v == [2, 4, 1, -5, -3] ||
v == [2, 4, 1, -3, -5] ||
v == [4, 2, 1, -5, -3] ||
v == [4, 2, 1, -3, -5]);```

#### `pub fn partition_at_index_by_key<K, F>(    &mut self,     index: usize,     f: F) -> (&mut [T], &mut T, &mut [T]) where    F: FnMut(&T) -> K,    K: Ord, `[src]

🔬 This is a nightly-only experimental API. (slice_partition_at_index #55300)

Reorder the slice with a key extraction function such that the element at `index` is at its final sorted position.

This reordering has the additional property that any value at position `i < index` will be less than or equal to any value at a position `j > index` using the key extraction function. Additionally, this reordering is unstable (i.e. any number of equal elements may end up at position `index`), in-place (i.e. does not allocate), and `O(n)` worst-case. This function is also known as "kth element" in other libraries. It returns a triplet of the following values: all elements less than the one at the given index, the value at the given index, and all elements greater than the one at the given index, using the provided key extraction function.

## Current implementation

The current algorithm is based on the quickselect portion of the same quicksort algorithm used for `sort_unstable`.

## Panics

Panics when `index >= len()`, meaning it always panics on empty slices.

## Examples

```#![feature(slice_partition_at_index)]

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

// Return the median as if the array were sorted according to absolute value.
v.partition_at_index_by_key(2, |a| a.abs());

// We are only guaranteed the slice will be one of the following, based on the way we sort
assert!(v == [1, 2, -3, 4, -5] ||
v == [1, 2, -3, -5, 4] ||
v == [2, 1, -3, 4, -5] ||
v == [2, 1, -3, -5, 4]);```

#### `pub fn partition_dedup(&mut self) -> (&mut [T], &mut [T]) where    T: PartialEq<T>, `[src]

🔬 This is a nightly-only experimental API. (slice_partition_dedup #54279)

Moves all consecutive repeated elements to the end of the slice according to the `PartialEq` trait implementation.

Returns two slices. The first contains no consecutive repeated elements. The second contains all the duplicates in no specified order.

If the slice is sorted, the first returned slice contains no duplicates.

## Examples

```#![feature(slice_partition_dedup)]

let mut slice = [1, 2, 2, 3, 3, 2, 1, 1];

let (dedup, duplicates) = slice.partition_dedup();

assert_eq!(dedup, [1, 2, 3, 2, 1]);
assert_eq!(duplicates, [2, 3, 1]);```

#### `pub fn partition_dedup_by<F>(&mut self, same_bucket: F) -> (&mut [T], &mut [T]) where    F: FnMut(&mut T, &mut T) -> bool, `[src]

🔬 This is a nightly-only experimental API. (slice_partition_dedup #54279)

Moves all but the first of consecutive elements to the end of the slice satisfying a given equality relation.

Returns two slices. The first contains no consecutive repeated elements. The second contains all the duplicates in no specified order.

The `same_bucket` function is passed references to two elements from the slice and must determine if the elements compare equal. The elements are passed in opposite order from their order in the slice, so if `same_bucket(a, b)` returns `true`, `a` is moved at the end of the slice.

If the slice is sorted, the first returned slice contains no duplicates.

## Examples

```#![feature(slice_partition_dedup)]

let mut slice = ["foo", "Foo", "BAZ", "Bar", "bar", "baz", "BAZ"];

let (dedup, duplicates) = slice.partition_dedup_by(|a, b| a.eq_ignore_ascii_case(b));

assert_eq!(dedup, ["foo", "BAZ", "Bar", "baz"]);
assert_eq!(duplicates, ["bar", "Foo", "BAZ"]);```

#### `pub fn partition_dedup_by_key<K, F>(&mut self, key: F) -> (&mut [T], &mut [T]) where    F: FnMut(&mut T) -> K,    K: PartialEq<K>, `[src]

🔬 This is a nightly-only experimental API. (slice_partition_dedup #54279)

Moves all but the first of consecutive elements to the end of the slice that resolve to the same key.

Returns two slices. The first contains no consecutive repeated elements. The second contains all the duplicates in no specified order.

If the slice is sorted, the first returned slice contains no duplicates.

## Examples

```#![feature(slice_partition_dedup)]

let mut slice = [10, 20, 21, 30, 30, 20, 11, 13];

let (dedup, duplicates) = slice.partition_dedup_by_key(|i| *i / 10);

assert_eq!(dedup, [10, 20, 30, 20, 11]);
assert_eq!(duplicates, [21, 30, 13]);```

#### `pub fn rotate_left(&mut self, mid: usize)`[src]1.26.0

Rotates the slice in-place such that the first `mid` elements of the slice move to the end while the last `self.len() - mid` elements move to the front. After calling `rotate_left`, the element previously at index `mid` will become the first element in the slice.

## Panics

This function will panic if `mid` is greater than the length of the slice. Note that `mid == self.len()` does not panic and is a no-op rotation.

## Complexity

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

## Examples

```let mut a = ['a', 'b', 'c', 'd', 'e', 'f'];
a.rotate_left(2);
assert_eq!(a, ['c', 'd', 'e', 'f', 'a', 'b']);```

Rotating a subslice:

```let mut a = ['a', 'b', 'c', 'd', 'e', 'f'];
a[1..5].rotate_left(1);
assert_eq!(a, ['a', 'c', 'd', 'e', 'b', 'f']);```

#### `pub fn rotate_right(&mut self, k: usize)`[src]1.26.0

Rotates the slice in-place such that the first `self.len() - k` elements of the slice move to the end while the last `k` elements move to the front. After calling `rotate_right`, the element previously at index `self.len() - k` will become the first element in the slice.

## Panics

This function will panic if `k` is greater than the length of the slice. Note that `k == self.len()` does not panic and is a no-op rotation.

## Complexity

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

## Examples

```let mut a = ['a', 'b', 'c', 'd', 'e', 'f'];
a.rotate_right(2);
assert_eq!(a, ['e', 'f', 'a', 'b', 'c', 'd']);```

Rotate a subslice:

```let mut a = ['a', 'b', 'c', 'd', 'e', 'f'];
a[1..5].rotate_right(1);
assert_eq!(a, ['a', 'e', 'b', 'c', 'd', 'f']);```

#### `pub fn clone_from_slice(&mut self, src: &[T]) where    T: Clone, `[src]1.7.0

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

Cloning two elements from a slice into another:

```let src = [1, 2, 3, 4];
let mut dst = [0, 0];

// Because the slices have to be the same length,
// we slice the source slice from four elements
// to two. It will panic if we don't do this.
dst.clone_from_slice(&src[2..]);

assert_eq!(src, [1, 2, 3, 4]);
assert_eq!(dst, [3, 4]);```

Rust enforces that there can only be one mutable reference with no immutable references to a particular piece of data in a particular scope. Because of this, attempting to use `clone_from_slice` on a single slice will result in a compile failure:

ⓘThis example deliberately fails to compile
```let mut slice = [1, 2, 3, 4, 5];

slice[..2].clone_from_slice(&slice[3..]); // compile fail!```

To work around this, we can use `split_at_mut` to create two distinct sub-slices from a slice:

```let mut slice = [1, 2, 3, 4, 5];

{
let (left, right) = slice.split_at_mut(2);
left.clone_from_slice(&right[1..]);
}

assert_eq!(slice, [4, 5, 3, 4, 5]);```

#### `pub fn copy_from_slice(&mut self, src: &[T]) where    T: Copy, `[src]1.9.0

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

Copying two elements from a slice into another:

```let src = [1, 2, 3, 4];
let mut dst = [0, 0];

// Because the slices have to be the same length,
// we slice the source slice from four elements
// to two. It will panic if we don't do this.
dst.copy_from_slice(&src[2..]);

assert_eq!(src, [1, 2, 3, 4]);
assert_eq!(dst, [3, 4]);```

Rust enforces that there can only be one mutable reference with no immutable references to a particular piece of data in a particular scope. Because of this, attempting to use `copy_from_slice` on a single slice will result in a compile failure:

ⓘThis example deliberately fails to compile
```let mut slice = [1, 2, 3, 4, 5];

slice[..2].copy_from_slice(&slice[3..]); // compile fail!```

To work around this, we can use `split_at_mut` to create two distinct sub-slices from a slice:

```let mut slice = [1, 2, 3, 4, 5];

{
let (left, right) = slice.split_at_mut(2);
left.copy_from_slice(&right[1..]);
}

assert_eq!(slice, [4, 5, 3, 4, 5]);```

#### `pub fn copy_within<R>(&mut self, src: R, dest: usize) where    R: RangeBounds<usize>,    T: Copy, `[src]1.37.0

Copies elements from one part of the slice to another part of itself, using a memmove.

`src` is the range within `self` to copy from. `dest` is the starting index of the range within `self` to copy to, which will have the same length as `src`. The two ranges may overlap. The ends of the two ranges must be less than or equal to `self.len()`.

## Panics

This function will panic if either range exceeds the end of the slice, or if the end of `src` is before the start.

## Examples

Copying four bytes within a slice:

```let mut bytes = *b"Hello, World!";

bytes.copy_within(1..5, 8);

assert_eq!(&bytes, b"Hello, Wello!");```

#### `pub fn swap_with_slice(&mut self, other: &mut [T])`[src]1.27.0

Swaps all elements in `self` with those in `other`.

The length of `other` must be the same as `self`.

## Panics

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

## Example

Swapping two elements across slices:

```let mut slice1 = [0, 0];
let mut slice2 = [1, 2, 3, 4];

slice1.swap_with_slice(&mut slice2[2..]);

assert_eq!(slice1, [3, 4]);
assert_eq!(slice2, [1, 2, 0, 0]);```

Rust enforces that there can only be one mutable reference to a particular piece of data in a particular scope. Because of this, attempting to use `swap_with_slice` on a single slice will result in a compile failure:

ⓘThis example deliberately fails to compile
```let mut slice = [1, 2, 3, 4, 5];
slice[..2].swap_with_slice(&mut slice[3..]); // compile fail!```

To work around this, we can use `split_at_mut` to create two distinct mutable sub-slices from a slice:

```let mut slice = [1, 2, 3, 4, 5];

{
let (left, right) = slice.split_at_mut(2);
left.swap_with_slice(&mut right[1..]);
}

assert_eq!(slice, [4, 5, 3, 1, 2]);```

#### `pub unsafe fn align_to<U>(&self) -> (&[T], &[U], &[T])`[src]1.30.0

Transmute the slice to a slice of another type, ensuring alignment of the types is maintained.

This method splits the slice into three distinct slices: prefix, correctly aligned middle slice of a new type, and the suffix slice. The method does a best effort to make the middle slice the greatest length possible for a given type and input slice, but only your algorithm's performance should depend on that, not its correctness.

This method has no purpose when either input element `T` or output element `U` are zero-sized and will return the original slice without splitting anything.

## Safety

This method is essentially a `transmute` with respect to the elements in the returned middle slice, so all the usual caveats pertaining to `transmute::<T, U>` also apply here.

## Examples

Basic usage:

```unsafe {
let bytes: [u8; 7] = [1, 2, 3, 4, 5, 6, 7];
let (prefix, shorts, suffix) = bytes.align_to::<u16>();
// less_efficient_algorithm_for_bytes(prefix);
// more_efficient_algorithm_for_aligned_shorts(shorts);
// less_efficient_algorithm_for_bytes(suffix);
}```

#### `pub unsafe fn align_to_mut<U>(&mut self) -> (&mut [T], &mut [U], &mut [T])`[src]1.30.0

Transmute the slice to a slice of another type, ensuring alignment of the types is maintained.

This method splits the slice into three distinct slices: prefix, correctly aligned middle slice of a new type, and the suffix slice. The method does a best effort to make the middle slice the greatest length possible for a given type and input slice, but only your algorithm's performance should depend on that, not its correctness.

This method has no purpose when either input element `T` or output element `U` are zero-sized and will return the original slice without splitting anything.

## Safety

This method is essentially a `transmute` with respect to the elements in the returned middle slice, so all the usual caveats pertaining to `transmute::<T, U>` also apply here.

## Examples

Basic usage:

```unsafe {
let mut bytes: [u8; 7] = [1, 2, 3, 4, 5, 6, 7];
let (prefix, shorts, suffix) = bytes.align_to_mut::<u16>();
// less_efficient_algorithm_for_bytes(prefix);
// more_efficient_algorithm_for_aligned_shorts(shorts);
// less_efficient_algorithm_for_bytes(suffix);
}```

#### `pub fn is_sorted(&self) -> bool where    T: PartialOrd<T>, `[src]

🔬 This is a nightly-only experimental API. (is_sorted #53485)new API

Checks if the elements of this slice are sorted.

That is, for each element `a` and its following element `b`, `a <= b` must hold. If the slice yields exactly zero or one element, `true` is returned.

Note that if `Self::Item` is only `PartialOrd`, but not `Ord`, the above definition implies that this function returns `false` if any two consecutive items are not comparable.

## Examples

```#![feature(is_sorted)]
let empty: [i32; 0] = [];

assert!([1, 2, 2, 9].is_sorted());
assert!(![1, 3, 2, 4].is_sorted());
assert!(.is_sorted());
assert!(empty.is_sorted());
assert!(![0.0, 1.0, std::f32::NAN].is_sorted());```

#### `pub fn is_sorted_by<F>(&self, compare: F) -> bool where    F: FnMut(&T, &T) -> Option<Ordering>, `[src]

🔬 This is a nightly-only experimental API. (is_sorted #53485)new API

Checks if the elements of this slice are sorted using the given comparator function.

Instead of using `PartialOrd::partial_cmp`, this function uses the given `compare` function to determine the ordering of two elements. Apart from that, it's equivalent to `is_sorted`; see its documentation for more information.

#### `pub fn is_sorted_by_key<F, K>(&self, f: F) -> bool where    F: FnMut(&T) -> K,    K: PartialOrd<K>, `[src]

🔬 This is a nightly-only experimental API. (is_sorted #53485)new API

Checks if the elements of this slice are sorted using the given key extraction function.

Instead of comparing the slice's elements directly, this function compares the keys of the elements, as determined by `f`. Apart from that, it's equivalent to `is_sorted`; see its documentation for more information.

## Examples

```#![feature(is_sorted)]

assert!(["c", "bb", "aaa"].is_sorted_by_key(|s| s.len()));
assert!(![-2i32, -1, 0, 3].is_sorted_by_key(|n| n.abs()));```

#### `pub fn is_ascii(&self) -> bool`[src]1.23.0

Checks if all bytes in this slice are within the ASCII range.

#### `pub fn eq_ignore_ascii_case(&self, other: &[u8]) -> bool`[src]1.23.0

Checks that two slices are an ASCII case-insensitive match.

Same as `to_ascii_lowercase(a) == to_ascii_lowercase(b)`, but without allocating and copying temporaries.

#### `pub fn make_ascii_uppercase(&mut self)`[src]1.23.0

Converts this slice to its ASCII upper case equivalent in-place.

ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', but non-ASCII letters are unchanged.

To return a new uppercased value without modifying the existing one, use `to_ascii_uppercase`.

#### `pub fn make_ascii_lowercase(&mut self)`[src]1.23.0

Converts this slice to its ASCII lower case equivalent in-place.

ASCII letters 'A' to 'Z' are mapped to 'a' to 'z', but non-ASCII letters are unchanged.

To return a new lowercased value without modifying the existing one, use `to_ascii_lowercase`.

#### `pub fn sort(&mut self) where    T: Ord, `[src]

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]);```

#### `pub fn sort_by<F>(&mut self, compare: F) where    F: FnMut(&T, &T) -> Ordering, `[src]

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.

The comparator function must define a total ordering for the elements in the slice. If the ordering is not total, the order of the elements is unspecified. An order is a total order if it is (for all `a`, `b` and `c`):

• total and antisymmetric: exactly one of `a < b`, `a == b` or `a > b` is true, and
• transitive, `a < b` and `b < c` implies `a < c`. The same must hold for both `==` and `>`.

For example, while `f64` doesn't implement `Ord` because `NaN != NaN`, we can use `partial_cmp` as our sort function when we know the slice doesn't contain a `NaN`.

```let mut floats = [5f64, 4.0, 1.0, 3.0, 2.0];
floats.sort_by(|a, b| a.partial_cmp(b).unwrap());
assert_eq!(floats, [1.0, 2.0, 3.0, 4.0, 5.0]);```

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]);```

#### `pub fn sort_by_key<K, F>(&mut self, f: F) where    F: FnMut(&T) -> K,    K: Ord, `[src]1.7.0

Sorts the slice with a key extraction function.

This sort is stable (i.e., does not reorder equal elements) and `O(m n log(m n))` worst-case, where the key function is `O(m)`.

For expensive key functions (e.g. functions that are not simple property accesses or basic operations), `sort_by_cached_key` is likely to be significantly faster, as it does not recompute element keys.

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]);```

#### `pub fn sort_by_cached_key<K, F>(&mut self, f: F) where    F: FnMut(&T) -> K,    K: Ord, `[src]1.34.0

Sorts the slice with a key extraction function.

During sorting, the key function is called only once per element.

This sort is stable (i.e., does not reorder equal elements) and `O(m n + n log n)` worst-case, where the key function is `O(m)`.

For simple key functions (e.g., functions that are property accesses or basic operations), `sort_by_key` is likely to be faster.

## 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.

In the worst case, the algorithm allocates temporary storage in a `Vec<(K, usize)>` the length of the slice.

## Examples

```let mut v = [-5i32, 4, 32, -3, 2];

v.sort_by_cached_key(|k| k.to_string());
assert!(v == [-3, -5, 2, 32, 4]);```

#### `pub fn to_vec(&self) -> Vec<T> where    T: Clone, `[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

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.```

#### `pub fn repeat(&self, n: usize) -> Vec<T> where    T: Copy, `[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```
🔬 This is a nightly-only experimental API. (repeat_generic_slice #48784)it's on str, why not on slice?

Creates a vector by repeating a slice `n` times.

## Panics

This function will panic if the capacity would overflow.

## Examples

Basic usage:

```#![feature(repeat_generic_slice)]

fn main() {
assert_eq!([1, 2].repeat(3), vec![1, 2, 1, 2, 1, 2]);
}```

A panic upon overflow:

```#![feature(repeat_generic_slice)]
fn main() {
// this will panic at runtime
b"0123456789abcdef".repeat(usize::max_value());
}```

#### `pub fn to_ascii_uppercase(&self) -> Vec<u8>`[src]1.23.0

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

Returns a vector containing a copy of this slice where each byte is mapped to its ASCII upper case equivalent.

ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', but non-ASCII letters are unchanged.

To uppercase the value in-place, use `make_ascii_uppercase`.

#### `pub fn to_ascii_lowercase(&self) -> Vec<u8>`[src]1.23.0

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

Returns a vector containing a copy of this slice where each byte is mapped to its ASCII lower case equivalent.

ASCII letters 'A' to 'Z' are mapped to 'a' to 'z', but non-ASCII letters are unchanged.

To lowercase the value in-place, use `make_ascii_lowercase`.

## Trait Implementations

### `impl<T> AsMut<Vec<T>> for Vec<T>`[src]1.5.0

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl<T> AsMut<[T]> for Vec<T>`[src]1.5.0

ⓘImportant traits for &'_ [u8]
```impl<'_> Read for &'_ [u8]
impl<'_> Write for &'_ mut [u8]
```

### `impl<T> AsRef<[T]> for Vec<T>`[src]

ⓘImportant traits for &'_ [u8]
```impl<'_> Read for &'_ [u8]
impl<'_> Write for &'_ mut [u8]
```

### `impl<T> AsRef<Vec<T>> for Vec<T>`[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl<T> Hash for Vec<T> where    T: Hash, `[src]

#### `fn hash_slice<H>(data: &[Self], state: &mut H) where    H: Hasher, `[src]1.3.0

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

### `impl<T> From<VecDeque<T>> for Vec<T>`[src]1.10.0

#### `fn from(other: VecDeque<T>) -> Vec<T>`[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

Turn a [`VecDeque<T>`] into a [`Vec<T>`].

This never needs to re-allocate, but does need to do O(n) data movement if the circular buffer doesn't happen to be at the beginning of the allocation.

## Examples

```use std::collections::VecDeque;

// This one is O(1).
let deque: VecDeque<_> = (1..5).collect();
let ptr = deque.as_slices().0.as_ptr();
let vec = Vec::from(deque);
assert_eq!(vec, [1, 2, 3, 4]);
assert_eq!(vec.as_ptr(), ptr);

// This one needs data rearranging.
let mut deque: VecDeque<_> = (1..5).collect();
deque.push_front(9);
deque.push_front(8);
let ptr = deque.as_slices().1.as_ptr();
let vec = Vec::from(deque);
assert_eq!(vec, [8, 9, 1, 2, 3, 4]);
assert_eq!(vec.as_ptr(), ptr);```

### `impl<'_, T> From<&'_ [T]> for Vec<T> where    T: Clone, `[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl From<String> for Vec<u8>`[src]1.14.0

#### `fn from(string: String) -> Vec<u8>`[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

Converts the given `String` to a vector `Vec` that holds values of type `u8`.

## Examples

Basic usage:

```let s1 = String::from("hello world");
let v1 = Vec::from(s1);

for b in v1 {
println!("{}", b);
}```

### `impl<T> From<Box<[T]>> for Vec<T>`[src]1.18.0

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl<'a, T> From<Cow<'a, [T]>> for Vec<T> where    [T]: ToOwned,    <[T] as ToOwned>::Owned == Vec<T>, `[src]1.14.0

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl<T> From<Vec<T>> for Box<[T]>`[src]1.20.0

ⓘImportant traits for Box<I>
```impl<I> Iterator for Box<I> where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<F> Future for Box<F> where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<W: Write + ?Sized> Write for Box<W>
```

### `impl<T> From<Vec<T>> for VecDeque<T>`[src]1.10.0

#### `fn from(other: Vec<T>) -> VecDeque<T>`[src]

Turn a [`Vec<T>`] into a [`VecDeque<T>`].

This avoids reallocating where possible, but the conditions for that are strict, and subject to change, and so shouldn't be relied upon unless the `Vec<T>` came from `From<VecDeque<T>>` and hasn't been reallocated.

### `impl<'_> From<&'_ str> for Vec<u8>`[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl<'_, T> From<&'_ mut [T]> for Vec<T> where    T: Clone, `[src]1.19.0

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl<T> From<BinaryHeap<T>> for Vec<T>`[src]1.5.0

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl<'a, T> Extend<&'a T> for Vec<T> where    T: 'a + Copy, `[src]1.2.0

Extend implementation that copies elements out of references before pushing them onto the Vec.

This implementation is specialized for slice iterators, where it uses `copy_from_slice` to append the entire slice at once.

### `impl<T> Ord for Vec<T> where    T: Ord, `[src]

Implements ordering of vectors, lexicographically.

#### `fn max(self, other: Self) -> Self`[src]1.21.0

Compares and returns the maximum of two values. Read more

#### `fn min(self, other: Self) -> Self`[src]1.21.0

Compares and returns the minimum of two values. Read more

#### `fn clamp(self, min: Self, max: Self) -> Self`[src]

🔬 This is a nightly-only experimental API. (clamp #44095)

Restrict a value to a certain interval. Read more

### `impl<'a, T> IntoIterator for &'a mut Vec<T>`[src]

#### `type Item = &'a mut T`

The type of the elements being iterated over.

#### `type IntoIter = IterMut<'a, T>`

Which kind of iterator are we turning this into?

ⓘImportant traits for IterMut<'a, T>
```impl<'a, T> Iterator for IterMut<'a, T>
type Item = &'a mut T;
```

### `impl<'a, T> IntoIterator for &'a Vec<T>`[src]

#### `type Item = &'a T`

The type of the elements being iterated over.

#### `type IntoIter = Iter<'a, T>`

Which kind of iterator are we turning this into?

ⓘImportant traits for Iter<'a, T>
```impl<'a, T> Iterator for Iter<'a, T>
type Item = &'a T;
```

### `impl<T> IntoIterator for Vec<T>`[src]

#### `type Item = T`

The type of the elements being iterated over.

#### `type IntoIter = IntoIter<T>`

Which kind of iterator are we turning this into?

#### `fn into_iter(self) -> IntoIter<T>`[src]

ⓘImportant traits for IntoIter<T>
```impl<T> Iterator for IntoIter<T>
type Item = T;
```

Creates a consuming iterator, that is, one that moves each value out of the vector (from start to end). The vector cannot be used after calling this.

## Examples

```let v = vec!["a".to_string(), "b".to_string()];
for s in v.into_iter() {
// s has type String, not &String
println!("{}", s);
}```

### `impl<T, I> Index<I> for Vec<T> where    I: SliceIndex<[T]>, `[src]

#### `type Output = <I as SliceIndex<[T]>>::Output`

The returned type after indexing.

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl<A, B> PartialEq<Vec<B>> for VecDeque<A> where    A: PartialEq<B>, `[src]1.17.0

#### `fn ne(&self, other: &Rhs) -> bool`[src]

This method tests for `!=`.

### `impl<T> Deref for Vec<T>`[src]

#### `type Target = [T]`

The resulting type after dereferencing.

ⓘImportant traits for &'_ [u8]
```impl<'_> Read for &'_ [u8]
impl<'_> Write for &'_ mut [u8]
```

### `impl<T> Clone for Vec<T> where    T: Clone, `[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl<T> BorrowMut<[T]> for Vec<T>`[src]

ⓘImportant traits for &'_ [u8]
```impl<'_> Read for &'_ [u8]
impl<'_> Write for &'_ mut [u8]
```

### `impl<T> FromIterator<T> for Vec<T>`[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl<T> Default for Vec<T>`[src]

#### `fn default() -> Vec<T>`[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

Creates an empty `Vec<T>`.

### `impl<T, I> IndexMut<I> for Vec<T> where    I: SliceIndex<[T]>, `[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

### `impl<T> DerefMut for Vec<T>`[src]

ⓘImportant traits for &'_ [u8]
```impl<'_> Read for &'_ [u8]
impl<'_> Write for &'_ mut [u8]
```

### `impl<T> Borrow<[T]> for Vec<T>`[src]

ⓘImportant traits for &'_ [u8]
```impl<'_> Read for &'_ [u8]
impl<'_> Write for &'_ mut [u8]
```

### `impl<T> PartialOrd<Vec<T>> for Vec<T> where    T: PartialOrd<T>, `[src]

Implements comparison of vectors, lexicographically.

#### `fn lt(&self, other: &Rhs) -> bool`[src]

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

#### `fn le(&self, other: &Rhs) -> bool`[src]

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

#### `fn gt(&self, other: &Rhs) -> bool`[src]

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

#### `fn ge(&self, other: &Rhs) -> bool`[src]

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

### `impl Write for Vec<u8>`[src]

Write is implemented for `Vec<u8>` by appending to the vector. The vector will grow as needed.

#### `fn write_fmt(&mut self, fmt: Arguments) -> Result<()>`[src]

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

#### `fn by_ref(&mut self) -> &mut Self where    Self: Sized, `[src]

ⓘImportant traits for &'_ mut F
```impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<'_, W: Write + ?Sized> Write for &'_ mut W
```

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

### `impl From<CString> for Vec<u8>`[src]1.7.0

#### `fn from(s: CString) -> Vec<u8>`[src]

ⓘImportant traits for Vec<u8>
```impl Write for Vec<u8>
```

Converts a `CString` into a `Vec``<u8>`.

The conversion consumes the `CString`, and removes the terminating NUL byte.

## Blanket Implementations

### `impl<T, U> TryFrom<U> for T where    U: Into<T>, `[src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

### `impl<I> IntoIterator for I where    I: Iterator, `[src]

#### `type Item = <I as Iterator>::Item`

The type of the elements being iterated over.

#### `type IntoIter = I`

Which kind of iterator are we turning this into?

### `impl<T, U> TryInto<U> for T where    U: TryFrom<T>, `[src]

#### `type Error = <U as TryFrom<T>>::Error`

The type returned in the event of a conversion error.

### `impl<T> Borrow<T> for T where    T: ?Sized, `[src]

ⓘImportant traits for &'_ mut F
```impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<'_, W: Write + ?Sized> Write for &'_ mut W
```

### `impl<T> BorrowMut<T> for T where    T: ?Sized, `[src]

ⓘImportant traits for &'_ mut F
```impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<'_, W: Write + ?Sized> Write for &'_ mut W
```

### `impl<T> ToOwned for T where    T: Clone, `[src]

#### `type Owned = T`

The resulting type after obtaining ownership.

© 2010 The Rust Project Developers