StaticString

A string type designed to represent text that is known at compile time.

Instances of the StaticString type are immutable. StaticString provides limited, pointer-based access to its contents, unlike Swift's more commonly used String type. A static string can store its value as a pointer to an ASCII code unit sequence, as a pointer to a UTF-8 code unit sequence, or as a single Unicode scalar value.

Inheritance CustomDebugStringConvertible, CustomReflectable, CustomStringConvertible, ExpressibleByExtendedGraphemeClusterLiteral, ExpressibleByStringLiteral, ExpressibleByUnicodeScalarLiteral View Protocol Hierarchy →
Import
  • import Swift

Initializers

init()

Creates an empty static string.

Declaration

  • init()
init(extendedGraphemeClusterLiteral:)

Creates an instance initialized to a single character that is made up of one or more Unicode code points.

Do not call this initializer directly. It may be used by the compiler when you initialize a static string using an extended grapheme cluster.

Declaration

init(stringLiteral:)

Creates an instance initialized to the value of a string literal.

Do not call this initializer directly. It may be used by the compiler when you initialize a static string using a string literal.

Declaration

init(unicodeScalarLiteral:)

Creates an instance initialized to a single Unicode scalar.

Do not call this initializer directly. It may be used by the compiler when you initialize a static string with a Unicode scalar.

Declaration

Instance Variables

var customMirror: Mirror

The custom mirror for this instance.

If this type has value semantics, the mirror should be unaffected by subsequent mutations of the instance.

Declaration

  • var customMirror: Mirror { get }
var debugDescription: String

A textual representation of the static string, suitable for debugging.

Declaration

  • var debugDescription: String { get }
var description: String

A string representation of the static string.

Declaration

  • var description: String { get }
var hasPointerRepresentation: Bool

A Boolean value indicating whether the static string stores a pointer to ASCII or UTF-8 code units.

Declaration

  • var hasPointerRepresentation: Bool { get }
var isASCII: Bool

A Boolean value that is true if the static string stores a pointer to ASCII code units.

Use this property in conjunction with hasPointerRepresentation to determine whether a static string with pointer representation stores an ASCII or UTF-8 code unit sequence.

Warning: If the static string stores a single Unicode scalar value, the value of isASCII is unspecified.

Declaration

  • var isASCII: Bool { get }
var unicodeScalar: UnicodeScalar

The stored Unicode scalar value.

The static string must store a single Unicode scalar value. Accessing this property when hasPointerRepresentation is true triggers a runtime error.

Declaration

var utf8CodeUnitCount: Int

The length in bytes of the static string's ASCII or UTF-8 representation.

Warning: If the static string stores a single Unicode scalar value, the value of utf8CodeUnitCount is unspecified.

Declaration

  • var utf8CodeUnitCount: Int { get }
var utf8Start: UnsafePointer<UInt8>

A pointer to the beginning of the string's UTF-8 encoded representation.

The static string must store a pointer to either ASCII or UTF-8 code units. Accessing this property when hasPointerRepresentation is false triggers a runtime error.

Declaration

Instance Methods

func withUTF8Buffer(_:)

Invokes the given closure with a buffer containing the static string's UTF-8 code unit sequence.

This method works regardless of whether the static string stores a pointer or a single Unicode scalar value.

body: A closure that takes a buffer pointer to the static string's UTF-8 code unit sequence as its sole argument. If the closure has a return value, it is used as the return value of the withUTF8Buffer(invoke:) method. Returns: The return value of the body closure, if any.

Declaration