std::io::IoSlice - Rust
Description: API documentation for the Rust `IoSlice` struct in crate `std`.
Keywords: rust, rustlang, rust-lang, IoSlice

# 1.36.0[−][src]Struct std::io::IoSlice

    #[repr(transparent)]
    pub struct IoSlice<'a>(_);

A buffer type used with `Write::write_vectored`.

It is semantically a wrapper around an `&[u8]`, but is guaranteed to be ABI compatible with the `iovec` type on Unix platforms and `WSABUF` on Windows.

## Methods

### `impl<'a> IoSlice<'a>`[src]

#### `pub fn new(buf: &'a [u8]) -> IoSlice<'a>`[src]

Creates a new `IoSlice` wrapping a byte slice.

# Panics

Panics on Windows if the slice is larger than 4GB.

####
ⓘImportant traits for &'_ [u8]

### Important traits for &'_ [u8]

`impl<'_> Read for &'_ [u8]impl<'_> Write for &'_ mut [u8]`
`pub fn advance<'b>(
bufs: &'b mut [IoSlice<'a>],
n: usize
) -> &'b mut [IoSlice<'a>]`[src]

🔬 This is a nightly-only experimental API. (`io_slice_advance` #62726)

Advance the internal cursor of the slice.

# Notes

Elements in the slice may be modified if the cursor is not advanced to the end of the slice. For example if we have a slice of buffers with 2 `IoSlice`s, both of length 8, and we advance the cursor by 10 bytes the first `IoSlice` will be untouched however the second will be modified to remove the first 2 bytes (10 - 8).

# Examples

    #![feature(io_slice_advance)]

    use std::io::IoSlice;
    use std::mem;
    use std::ops::Deref;

    let mut buf1 = [1; 8];
    let mut buf2 = [2; 16];
    let mut buf3 = [3; 8];
    let mut bufs = &mut [
        IoSlice::new(&mut buf1),
        IoSlice::new(&mut buf2),
        IoSlice::new(&mut buf3),
    ][..];

    // Mark 10 bytes as written.
    bufs = IoSlice::advance(mem::replace(&mut bufs, &mut []), 10);
    assert_eq!(bufs[0].deref(), [2; 14].as_ref());
    assert_eq!(bufs[1].deref(), [3; 8].as_ref());Run

## Methods from Deref<Target = [u8]>

#### `pub const fn len(&self) -> usize`1.0.0[src]

Returns the number of elements in the slice.

# Examples

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

#### `pub const fn is_empty(&self) -> bool`1.0.0[src]

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

# Examples

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

#### `pub fn first(&self) -> Option<&T>`1.0.0[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());Run

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

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]);
    }Run

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

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]);
    }Run

#### `pub fn last(&self) -> Option<&T>`1.0.0[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());Run

#### `pub fn get<I>(&self, index: I) -> Option<&<I as SliceIndex<[T]>>::Output> where
I: SliceIndex<[T]>,` 1.0.0[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));Run

#### `pub unsafe fn get_unchecked<I>(
&self,
index: I
) -> &<I as SliceIndex<[T]>>::Output where
I: SliceIndex<[T]>,` 1.0.0[src]

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

This is generally not recommended, use with caution! Calling this method with an out-of-bounds index is undefined behavior even if the resulting reference is not used. For a safe alternative see `get`.

# Examples

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

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

#### `pub const fn as_ptr(&self) -> *const T`1.0.0[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() {
            assert_eq!(x.get_unchecked(i), &*x_ptr.add(i));
        }
    }Run

####
ⓘImportant traits for Range<A>

### Important traits for Range<A>

`impl<A> Iterator for Range<A> where
A: Step, type Item = A;`
`pub fn as_ptr_range(&self) -> Range<*const T>`[src]

🔬 This is a nightly-only experimental API. (`slice_ptr_range` #65807)

Returns the two raw pointers spanning the slice.

The returned range is half-open, which means that the end pointer points one past the last element of the slice. This way, an empty slice is represented by two equal pointers, and the difference between the two pointers represents the size of the size.

See `as_ptr` for warnings on using these pointers. The end pointer requires extra caution, as it does not point to a valid element in the slice.

This function is useful for interacting with foreign interfaces which use two pointers to refer to a range of elements in memory, as is common in C++.

It can also be useful to check if a pointer to an element refers to an element of this slice:

    #![feature(slice_ptr_range)]

    let a = [1, 2, 3];
    let x = &a[1] as *const _;
    let y = &5 as *const _;

    assert!(a.as_ptr_range().contains(&x));
    assert!(!a.as_ptr_range().contains(&y));Run

####
ⓘImportant traits for Iter<'a, T>

### Important traits for Iter<'a, T>

`impl<'a, T> Iterator for Iter<'a, T> type Item = &'a T;`
`pub fn iter(&self) -> Iter<T>`1.0.0[src]

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);Run

####
ⓘImportant traits for Windows<'a, T>

### Important traits for Windows<'a, T>

`impl<'a, T> Iterator for Windows<'a, T> type Item = &'a [T];`
`pub fn windows(&self, size: usize) -> Windows<T>`1.0.0[src]

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());Run

If the slice is shorter than `size`:

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

####
ⓘImportant traits for Chunks<'a, T>

### Important traits for Chunks<'a, T>

`impl<'a, T> Iterator for Chunks<'a, T> type Item = &'a [T];`
`pub fn chunks(&self, chunk_size: usize) -> Chunks<T>`1.0.0[src]

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.

# 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());Run

####
ⓘImportant traits for ChunksExact<'a, T>

### Important traits for ChunksExact<'a, T>

`impl<'a, T> Iterator for ChunksExact<'a, T> type Item = &'a [T];`
`pub fn chunks_exact(&self, chunk_size: usize) -> ChunksExact<T>`1.31.0[src]

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']);Run

####
ⓘImportant traits for RChunks<'a, T>

### Important traits for RChunks<'a, T>

`impl<'a, T> Iterator for RChunks<'a, T> type Item = &'a [T];`
`pub fn rchunks(&self, chunk_size: usize) -> RChunks<T>`1.31.0[src]

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());Run

####
ⓘImportant traits for RChunksExact<'a, T>

### Important traits for RChunksExact<'a, T>

`impl<'a, T> Iterator for RChunksExact<'a, T> type Item = &'a [T];`
`pub fn rchunks_exact(&self, chunk_size: usize) -> RChunksExact<T>`1.31.0[src]

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']);Run

#### `pub fn split_at(&self, mid: usize) -> (&[T], &[T])`1.0.0[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 == []);
    }Run

####
ⓘImportant traits for Split<'a, T, P>

### 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];`
`pub fn split<F>(&self, pred: F) -> Split<T, F> where
F: FnMut(&T) -> bool,` 1.0.0[src]

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

# Examples

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

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

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());Run

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

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

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

####
ⓘImportant traits for RSplit<'a, T, P>

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

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);Run

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);Run

####
ⓘImportant traits for SplitN<'a, T, P>

### 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];`
`pub fn splitn<F>(&self, n: usize, pred: F) -> SplitN<T, F> where
F: FnMut(&T) -> bool,` 1.0.0[src]

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);
    }Run

####
ⓘImportant traits for RSplitN<'a, T, P>

### 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];`
`pub fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<T, F> where
F: FnMut(&T) -> bool,` 1.0.0[src]

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

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

# Examples

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

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

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

#### `pub fn contains(&self, x: &T) -> bool where
T: PartialEq<T>,` 1.0.0[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));Run

If you do not have an `&T`, but just an `&U` such that `T: Borrow<U>` (e.g. `String: Borrow<str>`), you can use `iter().any`:

    let v = [String::from("hello"), String::from("world")]; // slice of `String`
    assert!(v.iter().any(|e| e == "hello")); // search with `&str`
    assert!(!v.iter().any(|e| e == "hi"));Run

#### `pub fn starts_with(&self, needle: &[T]) -> bool where
T: PartialEq<T>,` 1.0.0[src]

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

# Examples

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

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(&[]));Run

#### `pub fn ends_with(&self, needle: &[T]) -> bool where
T: PartialEq<T>,` 1.0.0[src]

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

# Examples

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

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(&[]));Run

#### `pub fn binary_search(&self, x: &T) -> Result<usize, usize> where
T: Ord,` 1.0.0[src]

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, });Run

If you want to insert an item to a sorted vector, while maintaining sort order:

    let mut s = vec![0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];
    let num = 42;
    let idx = s.binary_search(&num).unwrap_or_else(|x| x);
    s.insert(idx, num);
    assert_eq!(s, [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 42, 55]);Run

#### `pub fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize> where
F: FnMut(&'a T) -> Ordering,` 1.0.0[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, });Run

#### `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,` 1.10.0[src]

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, });Run

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

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 may 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. It is permissible for all of the input data to be returned as the prefix or suffix slice.

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);
    }Run

#### `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!([0].is_sorted());
    assert!(empty.is_sorted());
    assert!(![0.0, 1.0, std::f32::NAN].is_sorted());Run

#### `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()));Run

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

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

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

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.

####
ⓘImportant traits for Vec<u8>

### Important traits for Vec<u8>

`impl Write for Vec<u8>`
`pub fn to_vec(&self) -> Vec<T> where
T: Clone,` 1.0.0[src]

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.Run

####
ⓘImportant traits for Vec<u8>

### Important traits for Vec<u8>

`impl Write for Vec<u8>`
`pub fn repeat(&self, n: usize) -> Vec<T> where
T: Copy,` 1.40.0[src]

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

# Panics

This function will panic if the capacity would overflow.

# Examples

Basic usage:

    assert_eq!([1, 2].repeat(3), vec![1, 2, 1, 2, 1, 2]);Run

A panic upon overflow:

    // this will panic at runtime
    b"0123456789abcdef".repeat(usize::max_value());Run

####
ⓘImportant traits for &'_ [u8]

### Important traits for &'_ [u8]

`impl<'_> Read for &'_ [u8]impl<'_> Write for &'_ mut [u8]`
`pub fn concat<Item>(&self) -> <[T] as Concat<Item>>::Output where
Item: ?Sized,
[T]: Concat<Item>,` 1.0.0[src]

Flattens a slice of `T` into a single value `Self::Output`.

# Examples

    assert_eq!(["hello", "world"].concat(), "helloworld");
    assert_eq!([[1, 2], [3, 4]].concat(), [1, 2, 3, 4]);Run

####
ⓘImportant traits for &'_ [u8]

### Important traits for &'_ [u8]

`impl<'_> Read for &'_ [u8]impl<'_> Write for &'_ mut [u8]`
`pub fn join<Separator>(
&self,
sep: Separator
) -> <[T] as Join<Separator>>::Output where
[T]: Join<Separator>,` 1.3.0[src]

Flattens a slice of `T` into a single value `Self::Output`, placing a given separator between each.

# Examples

    assert_eq!(["hello", "world"].join(" "), "hello world");
    assert_eq!([[1, 2], [3, 4]].join(&0), [1, 2, 0, 3, 4]);
    assert_eq!([[1, 2], [3, 4]].join(&[0, 0][..]), [1, 2, 0, 0, 3, 4]);Run

####
ⓘImportant traits for &'_ [u8]

### Important traits for &'_ [u8]

`impl<'_> Read for &'_ [u8]impl<'_> Write for &'_ mut [u8]`
`pub fn connect<Separator>(
&self,
sep: Separator
) -> <[T] as Join<Separator>>::Output where
[T]: Join<Separator>,` 1.0.0[src]

Deprecated since 1.3.0:

renamed to join

Flattens a slice of `T` into a single value `Self::Output`, placing a given separator between each.

# Examples

    assert_eq!(["hello", "world"].connect(" "), "hello world");
    assert_eq!([[1, 2], [3, 4]].connect(&0), [1, 2, 0, 3, 4]);Run

####
ⓘImportant traits for Vec<u8>

### Important traits for Vec<u8>

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

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`.

####
ⓘImportant traits for Vec<u8>

### Important traits for Vec<u8>

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

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<'a> Debug for IoSlice<'a>`[src]

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

Formats the value using the given formatter. Read more

### `impl<'a> Deref for IoSlice<'a>`[src]

#### `type Target = [u8]`

The resulting type after dereferencing.

####
ⓘImportant traits for &'_ [u8]

### Important traits for &'_ [u8]

`impl<'_> Read for &'_ [u8]impl<'_> Write for &'_ mut [u8]`
`fn deref(&self) -> &[u8]`[src]

Dereferences the value.

## Auto Trait Implementations

### `impl<'a> UnwindSafe for IoSlice<'a>`

### `impl<'a> RefUnwindSafe for IoSlice<'a>`

### `impl<'a> Unpin for IoSlice<'a>`

### `impl<'a> !Send for IoSlice<'a>`

### `impl<'a> !Sync for IoSlice<'a>`

## Blanket Implementations

### `impl<T> From<T> for T`[src]

#### `fn from(t: T) -> T`[src]

Performs the conversion.

### `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.

#### `fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>`[src]

Performs the conversion.

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

#### `fn into(self) -> U`[src]

Performs the conversion.

### `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.

#### `fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>`[src]

Performs the conversion.

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

####
ⓘImportant traits for &'_ mut I

### Important traits for &'_ mut I

`impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, R: Read + ?Sized> Read for &'_ mut Rimpl<'_, W: Write + ?Sized> Write for &'_ mut W`
`fn borrow(&self) -> &T`[src]

Immutably borrows from an owned value. Read more

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

####
ⓘImportant traits for &'_ mut I

### Important traits for &'_ mut I

`impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, R: Read + ?Sized> Read for &'_ mut Rimpl<'_, W: Write + ?Sized> Write for &'_ mut W`
`fn borrow_mut(&mut self) -> &mut T`[src]

Mutably borrows from an owned value. Read more

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `fn type_id(&self) -> TypeId`[src]

Gets the `TypeId` of `self`. Read more