Generic Structure

ContiguousArray

A contiguously stored array.

Declaration

@frozen struct ContiguousArray<Element>

Overview

The ContiguousArray type is a specialized array that always stores its elements in a contiguous region of memory. This contrasts with Array, which can store its elements in either a contiguous region of memory or an NSArray instance if its Element type is a class or @objc protocol.

If your array’s Element type is a class or @objc protocol and you do not need to bridge the array to NSArray or pass the array to Objective-C APIs, using ContiguousArray may be more efficient and have more predictable performance than Array. If the array’s Element type is a struct or enumeration, Array and ContiguousArray should have similar efficiency.

For more information about using arrays, see Array and ArraySlice, with which ContiguousArray shares most properties and methods.

Topics

Type Aliases

typealias ContiguousArray.ArrayLiteralElement

The type of the elements of an array literal.

typealias ContiguousArray.Regions

Available when Element is UInt8.

typealias ContiguousArray.SubSequence

A sequence that represents a contiguous subrange of the collection’s elements.

typealias ContiguousArray.Index

The index type for arrays, Int.

typealias ContiguousArray.Indices

The type that represents the indices that are valid for subscripting an array, in ascending order.

typealias ContiguousArray.Iterator

The type that allows iteration over an array’s elements.

Initializers

init()

Creates a new, empty array.

init<S>(S)

Creates an array containing the elements of a sequence.

init(arrayLiteral: Element...)

Creates an array from the given array literal.

init(from: Decoder)

Creates a new contiguous array by decoding from the given decoder.

Available when Element conforms to Decodable.

init(repeating: Element, count: Int)

Creates a new array containing the specified number of a single, repeated value.

init(unsafeUninitializedCapacity: Int, initializingWith: (inout UnsafeMutableBufferPointer<Element>, inout Int) -> Void)

Creates an array with the specified capacity, then calls the given closure with a buffer covering the array’s uninitialized memory.

Instance Properties

var capacity: Int

The total number of elements that the array can contain without allocating new storage.

var count: Int

The number of elements in the array.

var customMirror: Mirror

A mirror that reflects the array.

var debugDescription: String

A textual representation of the array and its elements, suitable for debugging.

var description: String

A textual representation of the array and its elements.

var endIndex: Int

The array’s “past the end” position—that is, the position one greater than the last valid subscript argument.

var first: Element?

The first element of the collection.

var hashValue: Int

The hash value.

Available when Element conforms to Hashable.

var indices: Range<Int>

The indices that are valid for subscripting the collection, in ascending order.

var isEmpty: Bool

A Boolean value indicating whether the collection is empty.

var last: Element?

The last element of the collection.

var lazy: LazySequence<ContiguousArray<Element>>

A sequence containing the same elements as this sequence, but on which some operations, such as map and filter, are implemented lazily.

var regions: CollectionOfOne<ContiguousArray<UInt8>>

Available when Element is UInt8.

var startIndex: Int

The position of the first element in a nonempty array.

var underestimatedCount: Int

A value less than or equal to the number of elements in the collection.

Instance Methods

func allSatisfy((Element) -> Bool) -> Bool

Returns a Boolean value indicating whether every element of a sequence satisfies a given predicate.

func append(Element)

Adds a new element at the end of the array.

func append<S>(contentsOf: S)

Adds the elements of a sequence or collection to the end of this collection.

func append<S>(contentsOf: S)

Adds the elements of a sequence to the end of the array.

func applying(CollectionDifference<Element>) -> ContiguousArray<Element>?

Applies the given difference to this collection.

func compactMap<ElementOfResult>((Element) -> ElementOfResult?) -> [ElementOfResult]

Returns an array containing the non-nil results of calling the given transformation with each element of this sequence.

func contains(Element) -> Bool

Returns a Boolean value indicating whether the sequence contains the given element.

Available when Element conforms to Equatable.

func contains(where: (Element) -> Bool) -> Bool

Returns a Boolean value indicating whether the sequence contains an element that satisfies the given predicate.

func difference<C>(from: C) -> CollectionDifference<Element>

Returns the difference needed to produce this collection’s ordered elements from the given collection.

Available when Element conforms to Equatable.

func difference<C>(from: C, by: (C.Element, Element) -> Bool) -> CollectionDifference<Element>

Returns the difference needed to produce this collection’s ordered elements from the given collection, using the given predicate as an equivalence test.

func distance(from: Int, to: Int) -> Int

Returns the distance between two indices.

func drop(while: (Element) -> Bool) -> ArraySlice<Element>

Returns a subsequence by skipping elements while predicate returns true and returning the remaining elements.

func dropFirst(Int) -> ArraySlice<Element>

Returns a subsequence containing all but the given number of initial elements.

func dropLast(Int) -> ArraySlice<Element>

Returns a subsequence containing all but the specified number of final elements.

func elementsEqual<OtherSequence>(OtherSequence) -> Bool

Returns a Boolean value indicating whether this sequence and another sequence contain the same elements in the same order.

Available when Element conforms to Equatable.

func elementsEqual<OtherSequence>(OtherSequence, by: (Element, OtherSequence.Element) -> Bool) -> Bool

Returns a Boolean value indicating whether this sequence and another sequence contain equivalent elements in the same order, using the given predicate as the equivalence test.

func encode(to: Encoder)

Encodes the elements of this contiguous array into the given encoder in an unkeyed container.

Available when Element conforms to Encodable.

func enumerated() -> EnumeratedSequence<ContiguousArray<Element>>

Returns a sequence of pairs (n, x), where n represents a consecutive integer starting at zero and x represents an element of the sequence.

func filter((Element) -> Bool) -> [Element]

func first(where: (Element) -> Bool) -> Element?

Returns the first element of the sequence that satisfies the given predicate.

func firstIndex(of: Element) -> Int?

Returns the first index where the specified value appears in the collection.

Available when Element conforms to Equatable.

func firstIndex(where: (Element) -> Bool) -> Int?

Returns the first index in which an element of the collection satisfies the given predicate.

func flatMap<SegmentOfResult>((Element) -> SegmentOfResult) -> [SegmentOfResult.Element]

Returns an array containing the concatenated results of calling the given transformation with each element of this sequence.

func flatMap<ElementOfResult>((Element) -> ElementOfResult?) -> [ElementOfResult]Deprecated

func forEach((Element) -> Void)

Calls the given closure on each element in the sequence in the same order as a for-in loop.

func formIndex(inout Int, offsetBy: Int)

Offsets the given index by the specified distance.

func formIndex(inout Int, offsetBy: Int, limitedBy: Int) -> Bool

Offsets the given index by the specified distance, or so that it equals the given limiting index.

func formIndex(after: inout Int)

Replaces the given index with its successor.

func formIndex(before: inout Int)

Replaces the given index with its predecessor.

func hash(into: inout Hasher)

Hashes the essential components of this value by feeding them into the given hasher.

Available when Element conforms to Hashable.

func index(Int, offsetBy: Int) -> Int

Returns an index that is the specified distance from the given index.

func index(Int, offsetBy: Int, limitedBy: Int) -> Int?

Returns an index that is the specified distance from the given index, unless that distance is beyond a given limiting index.

func index(after: Int) -> Int

Returns the position immediately after the given index.

func index(before: Int) -> Int

Returns the position immediately before the given index.

func index(of: Element) -> Int?

Returns the first index where the specified value appears in the collection.

Available when Element conforms to Equatable.

Deprecated

func index(where: (Element) -> Bool) -> Int?

Returns the first index in which an element of the collection satisfies the given predicate.

Deprecated

func insert(Element, at: Int)

Inserts a new element at the specified position.

func insert<C>(contentsOf: C, at: Int)

Inserts the elements of a sequence into the collection at the specified position.

func joined() -> FlattenSequence<ContiguousArray<Element>>

Returns the elements of this sequence of sequences, concatenated.

Available when Element conforms to Sequence.

func joined<Separator>(separator: Separator) -> JoinedSequence<ContiguousArray<Element>>

Returns the concatenated elements of this sequence of sequences, inserting the given separator between each element.

Available when Element conforms to Sequence.

func joined(separator: String) -> String

Returns a new string by concatenating the elements of the sequence, adding the given separator between each element.

Available when Element is String.

func joined(separator: String) -> String

Returns a new string by concatenating the elements of the sequence, adding the given separator between each element.

Available when Element conforms to StringProtocol.

func last(where: (Element) -> Bool) -> Element?

Returns the last element of the sequence that satisfies the given predicate.

func lastIndex(of: Element) -> Int?

Returns the last index where the specified value appears in the collection.

Available when Element conforms to Equatable.

func lastIndex(where: (Element) -> Bool) -> Int?

Returns the index of the last element in the collection that matches the given predicate.

func lexicographicallyPrecedes<OtherSequence>(OtherSequence) -> Bool

Returns a Boolean value indicating whether the sequence precedes another sequence in a lexicographical (dictionary) ordering, using the less-than operator (<) to compare elements.

Available when Element conforms to Comparable.

func lexicographicallyPrecedes<OtherSequence>(OtherSequence, by: (Element, Element) -> Bool) -> Bool

Returns a Boolean value indicating whether the sequence precedes another sequence in a lexicographical (dictionary) ordering, using the given predicate to compare elements.

func makeIterator() -> IndexingIterator<ContiguousArray<Element>>

Returns an iterator over the elements of the collection.

func map<T>((Element) -> T) -> [T]

Returns an array containing the results of mapping the given closure over the sequence’s elements.

func max() -> Element?

Returns the maximum element in the sequence.

Available when Element conforms to Comparable.

func max(by: (Element, Element) -> Bool) -> Element?

Returns the maximum element in the sequence, using the given predicate as the comparison between elements.

func min() -> Element?

Returns the minimum element in the sequence.

Available when Element conforms to Comparable.

func min(by: (Element, Element) -> Bool) -> Element?

Returns the minimum element in the sequence, using the given predicate as the comparison between elements.

func partition(by: (Element) -> Bool) -> Int

Reorders the elements of the collection such that all the elements that match the given predicate are after all the elements that don’t match.

func popLast() -> Element?

Removes and returns the last element of the collection.

func prefix(Int) -> ArraySlice<Element>

Returns a subsequence, up to the specified maximum length, containing the initial elements of the collection.

func prefix(through: Int) -> ArraySlice<Element>

Returns a subsequence from the start of the collection through the specified position.

func prefix(upTo: Int) -> ArraySlice<Element>

Returns a subsequence from the start of the collection up to, but not including, the specified position.

func prefix(while: (Element) -> Bool) -> ArraySlice<Element>

Returns a subsequence containing the initial elements until predicate returns false and skipping the remaining elements.

func randomElement() -> Element?

Returns a random element of the collection.

func randomElement<T>(using: inout T) -> Element?

Returns a random element of the collection, using the given generator as a source for randomness.

func reduce<Result>(Result, (Result, Element) -> Result) -> Result

Returns the result of combining the elements of the sequence using the given closure.

func reduce<Result>(into: Result, (inout Result, Element) -> ()) -> Result

Returns the result of combining the elements of the sequence using the given closure.

func remove(at: Int) -> Element

Removes and returns the element at the specified position.

func removeAll(keepingCapacity: Bool)

Removes all elements from the array.

func removeAll(where: (Element) -> Bool)

Removes all the elements that satisfy the given predicate.

func removeFirst() -> Element

Removes and returns the first element of the collection.

func removeFirst(Int)

Removes the specified number of elements from the beginning of the collection.

func removeLast() -> Element

Removes and returns the last element of the collection.

func removeLast(Int)

Removes the specified number of elements from the end of the collection.

func removeSubrange(Range<Int>)

Removes the elements in the specified subrange from the collection.

func removeSubrange<R>(R)

Removes the elements in the specified subrange from the collection.

func replaceSubrange<C, R>(R, with: C)

Replaces the specified subrange of elements with the given collection.

func replaceSubrange<C>(Range<Int>, with: C)

Replaces a range of elements with the elements in the specified collection.

func reserveCapacity(Int)

Reserves enough space to store the specified number of elements.

func reverse()

Reverses the elements of the collection in place.

func reversed() -> ReversedCollection<ContiguousArray<Element>>

Returns a view presenting the elements of the collection in reverse order.

func shuffle()

Shuffles the collection in place.

func shuffle<T>(using: inout T)

Shuffles the collection in place, using the given generator as a source for randomness.

func shuffled() -> [Element]

Returns the elements of the sequence, shuffled.

func shuffled<T>(using: inout T) -> [Element]

Returns the elements of the sequence, shuffled using the given generator as a source for randomness.

func sort()

Sorts the collection in place.

Available when Element conforms to Comparable.

func sort(by: (Element, Element) -> Bool)

Sorts the collection in place, using the given predicate as the comparison between elements.

func sorted() -> [Element]

Returns the elements of the sequence, sorted.

Available when Element conforms to Comparable.

func sorted(by: (Element, Element) -> Bool) -> [Element]

Returns the elements of the sequence, sorted using the given predicate as the comparison between elements.

func split(maxSplits: Int, omittingEmptySubsequences: Bool, whereSeparator: (Element) -> Bool) -> [ArraySlice<Element>]

Returns the longest possible subsequences of the collection, in order, that don’t contain elements satisfying the given predicate.

func split(separator: Element, maxSplits: Int, omittingEmptySubsequences: Bool) -> [ArraySlice<Element>]

Returns the longest possible subsequences of the collection, in order, around elements equal to the given element.

Available when Element conforms to Equatable.

func starts<PossiblePrefix>(with: PossiblePrefix) -> Bool

Returns a Boolean value indicating whether the initial elements of the sequence are the same as the elements in another sequence.

Available when Element conforms to Equatable.

func starts<PossiblePrefix>(with: PossiblePrefix, by: (Element, PossiblePrefix.Element) -> Bool) -> Bool

Returns a Boolean value indicating whether the initial elements of the sequence are equivalent to the elements in another sequence, using the given predicate as the equivalence test.

func suffix(Int) -> ArraySlice<Element>

Returns a subsequence, up to the given maximum length, containing the final elements of the collection.

func suffix(from: Int) -> ArraySlice<Element>

Returns a subsequence from the specified position to the end of the collection.

func swapAt(Int, Int)

Exchanges the values at the specified indices of the collection.

func withContiguousMutableStorageIfAvailable<R>((inout UnsafeMutableBufferPointer<Element>) -> R) -> R?

Call body(p), where p is a pointer to the collection’s mutable contiguous storage. If no such storage exists, it is first created. If the collection does not support an internal representation in a form of mutable contiguous storage, body is not called and nil is returned.

func withContiguousStorageIfAvailable<R>((UnsafeBufferPointer<Element>) -> R) -> R?

Call body(p), where p is a pointer to the collection’s contiguous storage. If no such storage exists, it is first created. If the collection does not support an internal representation in a form of contiguous storage, body is not called and nil is returned.