Struct generic_array::GenericArray [−] [src]

pub struct GenericArray<T, U: ArrayLength<T>> { /* fields omitted */ }

Struct representing a generic array - GenericArray<T, N> works like [T; N]

Methods

impl<T, N> GenericArray<T, N> where N: ArrayLength<T>
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map a function over a slice to a GenericArray. The length of the slice must be equal to the length of the array

map a function over a GenericArray.

impl<T: Default, N> GenericArray<T, N> where N: ArrayLength<T>
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Function constructing an array filled with default values

impl<T: Clone, N> GenericArray<T, N> where N: ArrayLength<T>
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Function constructing an array from a slice; the length of the slice must be equal to the length of the array

Methods from Deref<Target=[T]>

Returns the number of elements in the slice.

Example

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

Returns true if the slice has a length of 0

Example

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

Returns the first element of a 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

Returns a mutable pointer to the first element of a 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]);Run

Returns the first and all the rest of the elements of a slice.

Examples

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

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

Returns the first and all the rest of the elements of a slice.

Examples

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

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

Returns the last and all the rest of the elements of a slice.

Examples

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

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

Returns the last and all the rest of the elements of a slice.

Examples

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

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

Returns the last element of a 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

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]);Run

Returns the element of a slice at the given index, or None if the index is out of bounds.

Examples

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

Returns a mutable reference to the element at the given index.

Examples

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

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

or None if the index is out of bounds

Returns a pointer to the element at the given index, without doing bounds checking. So use it very carefully!

Examples

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

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

Returns an unsafe mutable pointer to the element in index. So use it very carefully!

Examples

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

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

Returns an raw pointer to the slice's buffer

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

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

Examples

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

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

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 slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.

Examples

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

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

Swaps two elements in a 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"]);Run

Reverse the order of elements in a slice, in place.

Example

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

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

Returns an iterator that allows modifying each value.

Examples

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

    for elem in iterator {
        *elem += 2;
    }
}
assert_eq!(x, &[3, 4, 6]);Run

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.

Example

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

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

Panics

Panics if size is 0.

Example

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

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

Panics

Panics if chunk_size is 0.

Examples

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

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

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 = [10, 40, 30, 20, 50];
let (v1, v2) = v.split_at(2);
assert_eq!([10, 40], v1);
assert_eq!([30, 20, 50], v2);Run

Divides one &mut into two at an index.

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

Panics

Panics if mid > len.

Examples

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

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

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

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

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

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

Examples

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

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

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

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

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

Examples

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

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

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

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

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

Examples

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

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

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

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

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

Binary search a sorted slice for a given element.

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

Example

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

Binary search a sorted slice with a comparator function.

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

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

Example

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

Binary search a sorted slice with a key extraction function.

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

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

Examples

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

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

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

This is equivalent to self.sort_by(|a, b| a.cmp(b)).

This sort is stable and O(n log n) worst-case but allocates approximately 2 * n where n is the length of self.

Examples

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

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

Sorts the slice, in place, using key to extract a key by which to order the sort by.

This sort is stable and O(n log n) worst-case but allocates approximately 2 * n, where n is the length of self.

Examples

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

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

Sorts the slice, in place, using compare to compare elements.

This sort is stable and O(n log n) worst-case but allocates approximately 2 * n, where n is the length of self.

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]);Run

Copies the elements from src into self.

The length of src must be the same as self.

Panics

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

Example

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

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

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

The length of src must be the same as self.

Panics

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

Example

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

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

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

Converts self into a vector without clones or allocation.

Examples

let s: Box<[i32]> = Box::new([10, 40, 30]);
let x = s.into_vec();
// `s` cannot be used anymore because it has been converted into `x`.

assert_eq!(x, vec!(10, 40, 30));Run

Trait Implementations

impl<T, N> IntoIterator for GenericArray<T, N> where N: ArrayLength<T>
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The type of the elements being iterated over.

Which kind of iterator are we turning this into?

Creates an iterator from a value. Read more

impl<T, N> Deref for GenericArray<T, N> where N: ArrayLength<T>
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The resulting type after dereferencing

The method called to dereference a value

impl<T, N> DerefMut for GenericArray<T, N> where N: ArrayLength<T>
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The method called to mutably dereference a value

impl<T: Clone, N> Clone for GenericArray<T, N> where N: ArrayLength<T>
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Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

impl<T: Copy, N> Copy for GenericArray<T, N> where N: ArrayLength<T>, N::ArrayType: Copy
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impl<T: PartialEq, N> PartialEq for GenericArray<T, N> where N: ArrayLength<T>
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This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl<T: Eq, N> Eq for GenericArray<T, N> where N: ArrayLength<T>
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impl<T: Debug, N> Debug for GenericArray<T, N> where N: ArrayLength<T>
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Formats the value using the given formatter.