UnsafeMutableBufferPointer
A nonowning collection interface to a buffer of mutable elements stored contiguously in memory.
@frozen struct UnsafeMutableBufferPointer<Element>You can use an UnsafeMutableBufferPointer instance in low level operations to eliminate uniqueness checks and, in release mode, bounds checks. Bounds checks are always performed in debug mode.
UnsafeMutableBufferPointer Semantics
An UnsafeMutableBufferPointer instance is a view into memory and does not own the memory that it references. Copying a value of type UnsafeMutableBufferPointer does not copy the instances stored in the underlying memory. However, initializing another collection with an UnsafeMutableBufferPointer instance copies the instances out of the referenced memory and into the new collection.
Citizens in Swift
Conformances
protocol BidirectionalCollectionA collection that supports backward as well as forward traversal.
protocol CollectionA sequence whose elements can be traversed multiple times, nondestructively, and accessed by an indexed subscript.
protocol CustomDebugStringConvertibleA type with a customized textual representation suitable for debugging purposes.
protocol MutableCollectionA collection that supports subscript assignment.
protocol RandomAccessCollectionA collection that supports efficient random-access index traversal.
protocol SendableA type whose values can safely be passed across concurrency domains by copying.
protocol SequenceA type that provides sequential, iterated access to its elements.
Members
init(mutating: UnsafeBufferPointer<Element>) Creates a mutable typed buffer pointer referencing the same memory as the given immutable buffer pointer.
init(rebasing: Slice<UnsafeMutableBufferPointer<Element>>) Creates a buffer over the same memory as the given buffer slice.
init(start: UnsafeMutablePointer<Element>?, count: Int) Creates a new buffer pointer over the specified number of contiguous instances beginning at the given pointer.
static func allocate(capacity: Int) -> UnsafeMutableBufferPointer<Element> Allocates uninitialized memory for the specified number of instances of type
Element.var baseAddress: UnsafeMutablePointer<Element>?A pointer to the first element of the buffer.
let count: IntThe number of elements in the buffer.
var debugDescription: StringA textual representation of the buffer, suitable for debugging.
var endIndex: IntThe “past the end” position—that is, the position one greater than the last valid subscript argument.
var indices: UnsafeMutableBufferPointer<Element>.Indicesvar startIndex: IntThe index of the first element in a nonempty buffer.
subscript(Range<Int>) -> Slice<UnsafeMutableBufferPointer<Element>> Accesses a contiguous subrange of the buffer’s elements.
subscript(Int) -> Element Accesses the element at the specified position.
func deallocate() Deallocates the memory block previously allocated at this buffer pointer’s base address.
func deinitialize() -> UnsafeMutableRawBufferPointer Deinitializes every instance in this buffer.
func deinitializeElement(at: UnsafeMutableBufferPointer<Element>.Index) Deinitializes the memory underlying the element at
index.func distance(from: Int, to: Int) -> Int func formIndex(after: inout Int) func formIndex(before: inout Int) func index(Int, offsetBy: Int) -> Int func index(Int, offsetBy: Int, limitedBy: Int) -> Int? func index(after: Int) -> Int func index(before: Int) -> Int func initialize<S>(from: S) -> (unwritten: S.Iterator, index: UnsafeMutableBufferPointer<Element>.Index) Initializes the buffer’s memory with the given elements.
func initialize<C>(fromContentsOf: C) -> UnsafeMutableBufferPointer<Element>.Index Initializes the buffer’s memory with every element of the source.
func initialize(repeating: Element) Initializes every element in this buffer’s memory to a copy of the given value.
func initializeElement(at: UnsafeMutableBufferPointer<Element>.Index, to: Element) Initializes the element at
indexto the given value.func makeIterator() -> UnsafeMutableBufferPointer<Element>.Iterator Returns an iterator over the elements of this buffer.
func moveElement(from: UnsafeMutableBufferPointer<Element>.Index) -> Element Retrieves and returns the element at
index, leaving that element’s underlying memory uninitialized.func moveInitialize(fromContentsOf: UnsafeMutableBufferPointer<Element>) -> UnsafeMutableBufferPointer<Element>.Index Moves every element of an initialized source buffer into the uninitialized memory referenced by this buffer, leaving the source memory uninitialized and this buffer’s memory initialized.
func moveInitialize(fromContentsOf: Slice<UnsafeMutableBufferPointer<Element>>) -> UnsafeMutableBufferPointer<Element>.Index Moves every element of an initialized source buffer into the uninitialized memory referenced by this buffer, leaving the source memory uninitialized and this buffer’s memory initialized.
func moveUpdate(fromContentsOf: UnsafeMutableBufferPointer<Element>) -> UnsafeMutableBufferPointer<Element>.Index Updates this buffer’s initialized memory initialized memory by moving every element from the source buffer, leaving the source memory uninitialized.
func moveUpdate(fromContentsOf: Slice<UnsafeMutableBufferPointer<Element>>) -> UnsafeMutableBufferPointer<Element>.Index Updates this buffer’s initialized memory initialized memory by moving every element from the source buffer slice, leaving the source memory uninitialized.
func swapAt(Int, Int) Exchanges the values at the specified indices of the buffer.
func update<S>(from: S) -> (unwritten: S.Iterator, index: UnsafeMutableBufferPointer<Element>.Index) Updates the buffer’s initialized memory with the given elements.
func update<C>(fromContentsOf: C) -> UnsafeMutableBufferPointer<Element>.Index Updates the buffer’s initialized memory with every element of the source.
func update(repeating: Element) Updates every element of this buffer’s initialized memory.
func withContiguousMutableStorageIfAvailable<R>((inout UnsafeMutableBufferPointer<Element>) throws -> R) rethrows -> R? func withContiguousStorageIfAvailable<R>((UnsafeBufferPointer<Element>) throws -> R) rethrows -> R? func withMemoryRebound<T, Result>(to: T.Type, (UnsafeMutableBufferPointer<T>) throws -> Result) rethrows -> Result Executes the given closure while temporarily binding the memory referenced by this buffer to the given type.
typealias Indextypealias Indicestypealias Iteratorfunc assign(repeating: Element)
Features
var first: Self.Element?The first element of the collection.
var last: Self.Element?The last element of the collection.
var lazy: LazySequence<Self>A sequence containing the same elements as this sequence, but on which some operations, such as
mapandfilter, are implemented lazily.func allSatisfy((Self.Element) throws -> Bool) rethrows -> Bool Returns a Boolean value indicating whether every element of a sequence satisfies a given predicate.
func compactMap<ElementOfResult>((Self.Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult] Returns an array containing the non-
nilresults of calling the given transformation with each element of this sequence.func contains(Self.Element) -> Bool Returns a Boolean value indicating whether the sequence contains the given element.
func contains(where: (Self.Element) throws -> Bool) rethrows -> Bool Returns a Boolean value indicating whether the sequence contains an element that satisfies the given predicate.
func difference<C>(from: C) -> CollectionDifference<Self.Element> Returns the difference needed to produce this collection’s ordered elements from the given collection.
func difference<C>(from: C, by: (C.Element, Self.Element) -> Bool) -> CollectionDifference<Self.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 drop(while: (Self.Element) throws -> Bool) rethrows -> Self.SubSequence Returns a subsequence by skipping elements while
predicatereturnstrueand returning the remaining elements.func dropFirst(Int) -> Self.SubSequence Returns a subsequence containing all but the given number of initial elements.
func dropLast(Int) -> Self.SubSequence 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.
func elementsEqual<OtherSequence>(OtherSequence, by: (Self.Element, OtherSequence.Element) throws -> Bool) rethrows -> 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 enumerated() -> EnumeratedSequence<Self> 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((Self.Element) throws -> Bool) rethrows -> [Self.Element] Returns an array containing, in order, the elements of the sequence that satisfy the given predicate.
func first(where: (Self.Element) throws -> Bool) rethrows -> Self.Element? Returns the first element of the sequence that satisfies the given predicate.
func firstIndex(of: Self.Element) -> Self.Index? Returns the first index where the specified value appears in the collection.
func firstIndex(where: (Self.Element) throws -> Bool) rethrows -> Self.Index? Returns the first index in which an element of the collection satisfies the given predicate.
func flatMap<SegmentOfResult>((Self.Element) throws -> SegmentOfResult) rethrows -> [SegmentOfResult.Element] Returns an array containing the concatenated results of calling the given transformation with each element of this sequence.
func forEach((Self.Element) throws -> Void) rethrows Calls the given closure on each element in the sequence in the same order as a
for-inloop.func formIndex(inout Self.Index, offsetBy: Int) Offsets the given index by the specified distance.
func formIndex(inout Self.Index, offsetBy: Int, limitedBy: Self.Index) -> Bool Offsets the given index by the specified distance, or so that it equals the given limiting index.
func joined() -> FlattenSequence<Self> Returns the elements of this sequence of sequences, concatenated.
func joined(separator: String) -> String Returns a new string by concatenating the elements of the sequence, adding the given separator between each element.
func joined<Separator>(separator: Separator) -> JoinedSequence<Self> Returns the concatenated elements of this sequence of sequences, inserting the given separator between each element.
func joined(separator: String) -> String Returns a new string by concatenating the elements of the sequence, adding the given separator between each element.
func last(where: (Self.Element) throws -> Bool) rethrows -> Self.Element? Returns the last element of the sequence that satisfies the given predicate.
func lastIndex(of: Self.Element) -> Self.Index? Returns the last index where the specified value appears in the collection.
func lastIndex(where: (Self.Element) throws -> Bool) rethrows -> Self.Index? 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.func lexicographicallyPrecedes<OtherSequence>(OtherSequence, by: (Self.Element, Self.Element) throws -> Bool) rethrows -> 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 map<T>((Self.Element) throws -> T) rethrows -> [T] Returns an array containing the results of mapping the given closure over the sequence’s elements.
func map<T>((Self.Element) throws -> T) rethrows -> [T] Returns an array containing the results of mapping the given closure over the sequence’s elements.
func max() -> Self.Element? Returns the maximum element in the sequence.
func max(by: (Self.Element, Self.Element) throws -> Bool) rethrows -> Self.Element? Returns the maximum element in the sequence, using the given predicate as the comparison between elements.
func min() -> Self.Element? Returns the minimum element in the sequence.
func min(by: (Self.Element, Self.Element) throws -> Bool) rethrows -> Self.Element? Returns the minimum element in the sequence, using the given predicate as the comparison between elements.
func prefix(Int) -> Self.SubSequence Returns a subsequence, up to the specified maximum length, containing the initial elements of the collection.
func prefix(through: Self.Index) -> Self.SubSequence Returns a subsequence from the start of the collection through the specified position.
func prefix(upTo: Self.Index) -> Self.SubSequence Returns a subsequence from the start of the collection up to, but not including, the specified position.
func prefix(while: (Self.Element) throws -> Bool) rethrows -> Self.SubSequence Returns a subsequence containing the initial elements until
predicatereturnsfalseand skipping the remaining elements.func randomElement() -> Self.Element? Returns a random element of the collection.
func randomElement<T>(using: inout T) -> Self.Element? Returns a random element of the collection, using the given generator as a source for randomness.
func reduce<Result>(Result, (Result, Self.Element) throws -> Result) rethrows -> Result Returns the result of combining the elements of the sequence using the given closure.
func reduce<Result>(into: Result, (inout Result, Self.Element) throws -> ()) rethrows -> Result Returns the result of combining the elements of the sequence using the given closure.
func reverse() Reverses the elements of the collection in place.
func reversed() -> ReversedCollection<Self> 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() -> [Self.Element] Returns the elements of the sequence, shuffled.
func shuffled<T>(using: inout T) -> [Self.Element] Returns the elements of the sequence, shuffled using the given generator as a source for randomness.
func sort() Sorts the collection in place.
func sort(by: (Self.Element, Self.Element) throws -> Bool) rethrows Sorts the collection in place, using the given predicate as the comparison between elements.
func sorted() -> [Self.Element] Returns the elements of the sequence, sorted.
func sorted(by: (Self.Element, Self.Element) throws -> Bool) rethrows -> [Self.Element] Returns the elements of the sequence, sorted using the given predicate as the comparison between elements.
func split(maxSplits: Int, omittingEmptySubsequences: Bool, whereSeparator: (Self.Element) throws -> Bool) rethrows -> [Self.SubSequence] Returns the longest possible subsequences of the collection, in order, that don’t contain elements satisfying the given predicate.
func split(separator: Self.Element, maxSplits: Int, omittingEmptySubsequences: Bool) -> [ArraySlice<Self.Element>] Returns the longest possible subsequences of the sequence, in order, around elements equal to the given element.
func split(separator: Self.Element, maxSplits: Int, omittingEmptySubsequences: Bool) -> [Self.SubSequence] Returns the longest possible subsequences of the collection, in order, around elements equal to the given element.
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.
func starts<PossiblePrefix>(with: PossiblePrefix, by: (Self.Element, PossiblePrefix.Element) throws -> Bool) rethrows -> 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) -> Self.SubSequence Returns a subsequence, up to the given maximum length, containing the final elements of the collection.
func suffix(from: Self.Index) -> Self.SubSequence Returns a subsequence from the specified position to the end of the collection.
func flatMap<ElementOfResult>((Self.Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult] func index(of: Self.Element) -> Self.Index? Returns the first index where the specified value appears in the collection.
Available in Foundation
where Element == UInt8Conformances
protocol ContiguousBytesIndicates that the conforming type is a contiguous collection of raw bytes whose underlying storage is directly accessible by withUnsafeBytes.