FixedWidthInteger

protocol FixedWidthInteger

An integer type that uses a fixed size for every instance.

The FixedWidthInteger protocol adds binary bitwise operations, bit shifts, and overflow handling to the operations supported by the BinaryInteger protocol.

Use the FixedWidthInteger protocol as a constraint or extension point when writing operations that depend on bit shifting, performing bitwise operations, catching overflows, or having access to the maximum or minimum representable value of a type. For example, the following code provides a binaryString property on every fixed-width integer that represents the number's binary representation, split into 8-bit chunks.

extension FixedWidthInteger {
    var binaryString: String {
        var result: [String] = []
        for i in 0..<(Self.bitWidth / 8) {
            let byte = UInt8(truncatingIfNeeded: self >> (i * 8))
            let byteString = String(byte, radix: 2)
            let padding = String(repeating: "0",
                                 count: 8 - byteString.count)
            result.append(padding + byteString)
        }
        return "0b" + result.reversed().joined(separator: "_")
    }
}

print(Int16.max.binaryString)
// Prints "0b01111111_11111111"
print((101 as UInt8).binaryString)
// Prints "0b11001001"

The binaryString implementation uses the static bitWidth property and the right shift operator (<<), both of which are available to any type that conforms to the FixedWidthInteger protocol.

The next example declares a generic squared function, which accepts an instance x of any fixed-width integer type. The function uses the multipliedReportingOverflow(by:) method to multiply x by itself and check whether the result is too large to represent in the same type.

func squared<T: FixedWidthInteger>(_ x: T) -> T? {
    let (result, overflow) = x.multipliedReportingOverflow(by: x)
    if overflow {
        return nil
    }
    return result
}

let (x, y): (Int8, Int8) = (9, 123)
print(squared(x))
// Prints "Optional(81)"
print(squared(y))
// Prints "nil"

Conforming to the FixedWidthInteger Protocol

To make your own custom type conform to the FixedWidthInteger protocol, declare the required initializers, properties, and methods. The required methods that are suffixed with ReportingOverflow serve as the customization points for arithmetic operations. When you provide just those methods, the standard library provides default implementations for all other arithmetic methods and operators.

Inheritance BinaryInteger, Comparable, CustomStringConvertible, Equatable, ExpressibleByIntegerLiteral, Hashable, LosslessStringConvertible, Numeric, Strideable, _BitwiseOperations View Protocol Hierarchy →
Associated Types
Words : Sequence

A type that represents the words of a binary integer.

The Words type must conform to the Collection protocol with an Element type of UInt.

IntegerLiteralType : _ExpressibleByBuiltinIntegerLiteral

A type that represents an integer literal.

The standard library integer and floating-point types are all valid types for IntegerLiteralType.

Magnitude : Comparable, Numeric

A type that can represent the absolute value of any possible value of the conforming type.

Stride : Comparable, SignedNumeric

A type that represents the distance between two values.

Import import Swift

Initializers

init(bigEndian:)

Creates an integer from its big-endian representation, changing the byte order if necessary.

value: A value to use as the big-endian representation of the new integer.

Declaration

init(bigEndian value: Self)
init(littleEndian:)

Creates an integer from its little-endian representation, changing the byte order if necessary.

value: A value to use as the little-endian representation of the new integer.

Declaration

init(littleEndian value: Self)
init<T>(_: T)

Creates an integer from the given floating-point value, rounding toward zero.

Any fractional part of the value passed as source is removed, rounding the value toward zero.

let x = Int(21.5)
// x == 21
let y = Int(-21.5)
// y == -21

If source is outside the bounds of this type after rounding toward zero, a runtime error may occur.

let z = UInt(-21.5)
// Error: ...the result would be less than UInt.min

source: A floating-point value to convert to an integer. source must be representable in this type after rounding toward zero.

Declaration

init<T>(_ source: T)

Declared In

BinaryInteger
init(clamping:)

Creates a new instance with the representable value that's closest to the given integer.

If the value passed as source is greater than the maximum representable value in this type, the result is the type's max value. If source is less than the smallest representable value in this type, the result is the type's min value.

In this example, x is initialized as an Int8 instance by clamping 500 to the range -128...127, and y is initialized as a UInt instance by clamping -500 to the range 0...UInt.max.

let x = Int8(clamping: 500)
// x == 127
// x == Int8.max

let y = UInt(clamping: -500)
// y == 0

source: An integer to convert to this type.

Declaration

init<T>(clamping source: T)

Declared In

BinaryInteger
init(truncatingIfNeeded:)

Creates a new instance from the bit pattern of the given instance by sign-extending or truncating to fit this type.

When the bit width of T (the type of source) is equal to or greater than this type's bit width, the result is the truncated least-significant bits of source. For example, when converting a 16-bit value to an 8-bit type, only the lower 8 bits of source are used.

let p: Int16 = -500
// 'p' has a binary representation of 11111110_00001100
let q = Int8(truncatingIfNeeded: p)
// q == 12
// 'q' has a binary representation of 00001100

When the bit width of T is less than this type's bit width, the result is sign-extended to fill the remaining bits. That is, if source is negative, the result is padded with ones; otherwise, the result is padded with zeros.

let u: Int8 = 21
// 'u' has a binary representation of 00010101
let v = Int16(truncatingIfNeeded: u)
// v == 21
// 'v' has a binary representation of 00000000_00010101

let w: Int8 = -21
// 'w' has a binary representation of 11101011
let x = Int16(truncatingIfNeeded: w)
// x == -21
// 'x' has a binary representation of 11111111_11101011
let y = UInt16(truncatingIfNeeded: w)
// y == 65515
// 'y' has a binary representation of 11111111_11101011

source: An integer to convert to this type.

Declaration

init<T>(truncatingIfNeeded source: T)

Declared In

BinaryInteger
init?(exactly:)

Creates an integer from the given floating-point value, if it can be represented exactly.

If the value passed as source is not representable exactly, the result is nil. In the following example, the constant x is successfully created from a value of 21.0, while the attempt to initialize the constant y from 21.5 fails:

let x = Int(exactly: 21.0)
// x == Optional(21)
let y = Int(exactly: 21.5)
// y == nil

source: A floating-point value to convert to an integer.

Declaration

init?<T>(exactly source: T)

Declared In

BinaryInteger , Numeric
init(integerLiteral:)

Creates an instance initialized to the specified integer value.

Do not call this initializer directly. Instead, initialize a variable or constant using an integer literal. For example:

let x = 23

In this example, the assignment to the x constant calls this integer literal initializer behind the scenes.

value: The value to create.

Declaration

init(integerLiteral value: Self.IntegerLiteralType)

Declared In

ExpressibleByIntegerLiteral
init?(_:)

Instantiates an instance of the conforming type from a string representation.

Declaration

init?(_ description: String)

Declared In

LosslessStringConvertible

Static Variables

static var bitWidth: Int Required

The number of bits used for the underlying binary representation of values of this type.

An unsigned, fixed-width integer type can represent values from 0 through (2 ** bitWidth) - 1, where ** is exponentiation. A signed, fixed-width integer type can represent values from -(2 ** (bitWidth - 1)) through (2 ** (bitWidth - 1)) - 1. For example, the Int8 type has a bitWidth value of 8 and can store any integer in the range -128...127.

Declaration

static var bitWidth: Int { get }
static var max: Self Required

The maximum representable integer in this type.

For unsigned integer types, this value is (2 ** bitWidth) - 1, where ** is exponentiation. For signed integer types, this value is (2 ** (bitWidth - 1)) - 1.

Declaration

static var max: Self { get }
static var min: Self Required

The minimum representable integer in this type.

For unsigned integer types, this value is always 0. For signed integer types, this value is -(2 ** (bitWidth - 1)), where ** is exponentiation.

Declaration

static var min: Self { get }
static var isSigned: Bool Required

A Boolean value indicating whether this type is a signed integer type.

Signed integer types can represent both positive and negative values. Unsigned integer types can represent only nonnegative values.

Declaration

static var isSigned: Bool { get }

Declared In

BinaryInteger

Instance Variables

var bigEndian: Self

The big-endian representation of this integer.

If necessary, the byte order of this value is reversed from the typical byte order of this integer type. On a big-endian platform, for any integer x, x == x.bigEndian.

Declaration

var bigEndian: Self { get }
var byteSwapped: Self Required

A representation of this integer with the byte order swapped.

Declaration

var byteSwapped: Self { get }
var leadingZeroBitCount: Int Required

The number of leading zeros in this value's binary representation.

For example, in a fixed-width integer type with a bitWidth value of 8, the number 31 has three leading zeros.

let x: Int8 = 0b0001_1111
// x == 31
// x.leadingZeroBitCount == 3

Declaration

var leadingZeroBitCount: Int { get }
var littleEndian: Self

The little-endian representation of this integer.

If necessary, the byte order of this value is reversed from the typical byte order of this integer type. On a little-endian platform, for any integer x, x == x.littleEndian.

Declaration

var littleEndian: Self { get }
var nonzeroBitCount: Int Required

The number of bits equal to 1 in this value's binary representation.

For example, in a fixed-width integer type with a bitWidth value of 8, the number 31 has five bits equal to 1.

let x: Int8 = 0b0001_1111
// x == 31
// x.nonzeroBitCount == 5

Declaration

var nonzeroBitCount: Int { get }
var trailingZeroBitCount: Int Required

The number of trailing zeros in this value's binary representation.

For example, in a fixed-width integer type with a bitWidth value of 8, the number -8 has three trailing zeros.

let x = Int8(bitPattern: 0b1111_1000)
// x == -8
// x.trailingZeroBitCount == 3

Declaration

var trailingZeroBitCount: Int { get }

Declared In

BinaryInteger
var words: Self.Words Required

A collection containing the words of this value's binary representation, in order from the least significant to most significant.

Negative values are returned in two's complement representation, regardless of the type's underlying implementation.

Declaration

var words: Self.Words { get }

Declared In

BinaryInteger
var description: String

A textual representation of this instance.

Calling this property directly is discouraged. Instead, convert an instance of any type to a string by using the String(describing:) initializer. This initializer works with any type, and uses the custom description property for types that conform to CustomStringConvertible:

struct Point: CustomStringConvertible {
    let x: Int, y: Int

    var description: String {
        return "(\(x), \(y))"
    }
}

let p = Point(x: 21, y: 30)
let s = String(describing: p)
print(s)
// Prints "(21, 30)"

The conversion of p to a string in the assignment to s uses the Point type's description property.

Declaration

var description: String { get }

Declared In

CustomStringConvertible
var hashValue: Int Required

The hash value.

Hash values are not guaranteed to be equal across different executions of your program. Do not save hash values to use during a future execution.

Declaration

var hashValue: Int { get }

Declared In

Hashable
var magnitude: Self.Magnitude Required

The magnitude of this value.

For any numeric value x, x.magnitude is the absolute value of x. You can use the magnitude property in operations that are simpler to implement in terms of unsigned values, such as printing the value of an integer, which is just printing a '-' character in front of an absolute value.

let x = -200
// x.magnitude == 200

The global abs(_:) function provides more familiar syntax when you need to find an absolute value. In addition, because abs(_:) always returns a value of the same type, even in a generic context, using the function instead of the magnitude property is encouraged.

Declaration

var magnitude: Self.Magnitude { get }

Declared In

Numeric

Instance Methods

func %(_:rhs:) Required

Returns the remainder of dividing the first value by the second.

The result of the modulo operator (%) has the same sign as lhs and is less than rhs.magnitude.

let x = 22 % 5
// x == 2
let y = 22 % -5
// y == 2
let z = -22 % -5
// z == -2

For any two integers a and b, their quotient q, and their remainder r, a == b * q + r.

Parameters: lhs: The value to divide. rhs: The value to divide lhs by. rhs must not be zero.

Declaration

func %(lhs: Self, rhs: Self) -> Self

Declared In

BinaryInteger
func %=(_:rhs:) Required

Divides the first value by the second and stores the remainder in the left-hand-side variable.

The result has the same sign as lhs and is less than rhs.magnitude.

var x = 22
x %= 5
// x == 2

var y = 22
y %= -5
// y == 2

var z = -22
z %= -5
// z == -2

Parameters: lhs: The value to divide. rhs: The value to divide lhs by. rhs must not be zero.

Declaration

func %=(lhs: inout Self, rhs: Self)

Declared In

BinaryInteger
func &(_:rhs:)

Returns the result of performing a bitwise AND operation on the two given values.

A bitwise AND operation results in a value that has each bit set to 1 where both of its arguments have that bit set to 1. For example:

let x: UInt8 = 5          // 0b00000101
let y: UInt8 = 14         // 0b00001110
let z = x & y             // 0b00000100
// z == 4

Parameters: lhs: An integer value. rhs: Another integer value.

Declaration

func &(lhs: Self, rhs: Self) -> Self

Declared In

BinaryInteger
func &<<(_:rhs:)

Returns the result of shifting a value's binary representation the specified number of digits to the left, masking the shift amount to the type's bit width.

Use the masking left shift operator (&<<) when you need to perform a shift and are sure that the shift amount is in the range 0..<lhs.bitWidth. Before shifting, the masking left shift operator masks the shift to this range. The shift is performed using this masked value.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the shift amount requires no masking.

let x: UInt8 = 30                 // 0b00011110
let y = x &<< 2
// y == 120                       // 0b01111000

However, if you use 8 as the shift amount, the method first masks the shift amount to zero, and then performs the shift, resulting in no change to the original value.

let z = x &<< 8
// z == 30                        // 0b00011110

If the bit width of the shifted integer type is a power of two, masking is performed using a bitmask; otherwise, masking is performed using a modulo operation.

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the left. If rhs is outside the range 0..<lhs.bitWidth, it is masked to produce a value within that range.

Declaration

func &<<(lhs: Self, rhs: Self) -> Self
func &<<=(_:rhs:)

Returns the result of shifting a value's binary representation the specified number of digits to the left, masking the shift amount to the type's bit width, and stores the result in the left-hand-side variable.

The &<<= operator performs a masking shift, where the value used as rhs is masked to produce a value in the range 0..<lhs.bitWidth. The shift is performed using this masked value.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the shift amount requires no masking.

var x: UInt8 = 30                 // 0b00011110
x &<<= 2
// x == 120                       // 0b01111000

However, if you pass 19 as rhs, the method first bitmasks rhs to 3, and then uses that masked value as the number of bits to shift lhs.

var y: UInt8 = 30                 // 0b00011110
y &<<= 19
// y == 240                       // 0b11110000

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the left. If rhs is outside the range 0..<lhs.bitWidth, it is masked to produce a value within that range.

Declaration

func &<<=(lhs: inout Self, rhs: Self)
func &=(_:rhs:) Required

Stores the result of performing a bitwise AND operation on the two given values in the left-hand-side variable.

A bitwise AND operation results in a value that has each bit set to 1 where both of its arguments have that bit set to 1. For example:

var x: UInt8 = 5          // 0b00000101
let y: UInt8 = 14         // 0b00001110
x &= y                    // 0b00000100

Parameters: lhs: An integer value. rhs: Another integer value.

Declaration

func &=(lhs: inout Self, rhs: Self)

Declared In

BinaryInteger
func &>>(_:rhs:)

Returns the result of shifting a value's binary representation the specified number of digits to the right, masking the shift amount to the type's bit width.

Use the masking right shift operator (&>>) when you need to perform a shift and are sure that the shift amount is in the range 0..<lhs.bitWidth. Before shifting, the masking right shift operator masks the shift to this range. The shift is performed using this masked value.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the shift amount requires no masking.

let x: UInt8 = 30                 // 0b00011110
let y = x &>> 2
// y == 7                         // 0b00000111

However, if you use 8 as the shift amount, the method first masks the shift amount to zero, and then performs the shift, resulting in no change to the original value.

let z = x &>> 8
// z == 30                        // 0b00011110

If the bit width of the shifted integer type is a power of two, masking is performed using a bitmask; otherwise, masking is performed using a modulo operation.

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the right. If rhs is outside the range 0..<lhs.bitWidth, it is masked to produce a value within that range.

Declaration

func &>>(lhs: Self, rhs: Self) -> Self
func &>>=(_:rhs:)

Calculates the result of shifting a value's binary representation the specified number of digits to the right, masking the shift amount to the type's bit width, and stores the result in the left-hand-side variable.

The &>>= operator performs a masking shift, where the value passed as rhs is masked to produce a value in the range 0..<lhs.bitWidth. The shift is performed using this masked value.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the shift amount requires no masking.

var x: UInt8 = 30                 // 0b00011110
x &>>= 2
// x == 7                         // 0b00000111

However, if you use 19 as rhs, the operation first bitmasks rhs to 3, and then uses that masked value as the number of bits to shift lhs.

var y: UInt8 = 30                 // 0b00011110
y &>>= 19
// y == 3                         // 0b00000011

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the right. If rhs is outside the range 0..<lhs.bitWidth, it is masked to produce a value within that range.

Declaration

func &>>=(lhs: inout Self, rhs: Self)
func *(_:rhs:) Required

Multiplies two values and produces their product.

The multiplication operator (*) calculates the product of its two arguments. For example:

2 * 3                   // 6
100 * 21                // 2100
-10 * 15                // -150
3.5 * 2.25              // 7.875

You cannot use * with arguments of different types. To multiply values of different types, convert one of the values to the other value's type.

let x: Int8 = 21
let y: Int = 1000000
Int(x) * y              // 21000000

Parameters: lhs: The first value to multiply. rhs: The second value to multiply.

Declaration

func *(lhs: Self, rhs: Self) -> Self

Declared In

BinaryInteger, Numeric
func *=(_:rhs:) Required

Multiplies two values and stores the result in the left-hand-side variable.

Parameters: lhs: The first value to multiply. rhs: The second value to multiply.

Declaration

func *=(lhs: inout Self, rhs: Self)

Declared In

BinaryInteger, Numeric
func +(_:rhs:)

Adds two values and produces their sum.

The addition operator (+) calculates the sum of its two arguments. For example:

1 + 2                   // 3
-10 + 15                // 5
-15 + -5                // -20
21.5 + 3.25             // 24.75

You cannot use + with arguments of different types. To add values of different types, convert one of the values to the other value's type.

let x: Int8 = 21
let y: Int = 1000000
Int(x) + y              // 1000021

Parameters: lhs: The first value to add. rhs: The second value to add.

Declaration

func +(lhs: Self, rhs: Self) -> Self

Declared In

BinaryInteger, Numeric
func +=(_:rhs:)

Adds two values and stores the result in the left-hand-side variable.

Parameters: lhs: The first value to add. rhs: The second value to add.

Declaration

func +=(lhs: inout Self, rhs: Self)

Declared In

BinaryInteger, Numeric
func /(_:rhs:) Required

Returns the quotient of dividing the first value by the second.

For integer types, any remainder of the division is discarded.

let x = 21 / 5
// x == 4

Parameters: lhs: The value to divide. rhs: The value to divide lhs by. rhs must not be zero.

Declaration

func /(lhs: Self, rhs: Self) -> Self

Declared In

BinaryInteger
func /=(_:rhs:) Required

Divides the first value by the second and stores the quotient in the left-hand-side variable.

For integer types, any remainder of the division is discarded.

var x = 21
x /= 5
// x == 4

Parameters: lhs: The value to divide. rhs: The value to divide lhs by. rhs must not be zero.

Declaration

func /=(lhs: inout Self, rhs: Self)

Declared In

BinaryInteger
func <(_:rhs:)

Returns a Boolean value indicating whether the value of the first argument is less than that of the second argument.

This function is the only requirement of the Comparable protocol. The remainder of the relational operator functions are implemented by the standard library for any type that conforms to Comparable.

Parameters: lhs: A value to compare. rhs: Another value to compare.

Declaration

func <(lhs: Self, rhs: Self) -> Bool

Declared In

Comparable
func <<(_:rhs:)

Returns the result of shifting a value's binary representation the specified number of digits to the left.

The << operator performs a smart shift, which defines a result for a shift of any value.

  • Using a negative value for rhs performs a right shift using abs(rhs).
  • Using a value for rhs that is greater than or equal to the bit width of lhs is an overshift, resulting in zero.
  • Using any other value for rhs performs a left shift on lhs by that amount.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the value is shifted left by two bits.

let x: UInt8 = 30                 // 0b00011110
let y = x << 2
// y == 120                       // 0b01111000

If you use 11 as rhs, x is overshifted such that all of its bits are set to zero.

let z = x << 11
// z == 0                         // 0b00000000

Using a negative value as rhs is the same as performing a right shift with abs(rhs).

let a = x << -3
// a == 3                         // 0b00000011
let b = x >> 3
// b == 3                         // 0b00000011

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the left.

Declaration

func <<<RHS>(lhs: Self, rhs: RHS) -> Self where RHS : BinaryInteger

Declared In

BinaryInteger
func <<=(_:rhs:)

Stores the result of shifting a value's binary representation the specified number of digits to the left in the left-hand-side variable.

The << operator performs a smart shift, which defines a result for a shift of any value.

  • Using a negative value for rhs performs a right shift using abs(rhs).
  • Using a value for rhs that is greater than or equal to the bit width of lhs is an overshift, resulting in zero.
  • Using any other value for rhs performs a left shift on lhs by that amount.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the value is shifted left by two bits.

var x: UInt8 = 30                 // 0b00011110
x <<= 2
// x == 120                       // 0b01111000

If you use 11 as rhs, x is overshifted such that all of its bits are set to zero.

var y: UInt8 = 30                 // 0b00011110
y <<= 11
// y == 0                         // 0b00000000

Using a negative value as rhs is the same as performing a right shift with abs(rhs).

var a: UInt8 = 30                 // 0b00011110
a <<= -3
// a == 3                         // 0b00000011

var b: UInt8 = 30                 // 0b00011110
b >>= 3
// b == 3                         // 0b00000011

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the left.

Declaration

func <<=<RHS>(lhs: inout Self, rhs: RHS)

Declared In

BinaryInteger
func <=(_:rhs:)

Returns a Boolean value indicating whether the value of the first argument is less than or equal to that of the second argument.

Parameters: lhs: A value to compare. rhs: Another value to compare.

Declaration

func <=(lhs: Self, rhs: Self) -> Bool

Declared In

Comparable
func ==(_:rhs:)

Returns a Boolean value indicating whether two values are equal.

Equality is the inverse of inequality. For any values a and b, a == b implies that a != b is false.

Parameters: lhs: A value to compare. rhs: Another value to compare.

Declaration

func ==(lhs: Self, rhs: Self) -> Bool

Declared In

Equatable
func >(_:rhs:)

Returns a Boolean value indicating whether the value of the first argument is greater than that of the second argument.

Parameters: lhs: A value to compare. rhs: Another value to compare.

Declaration

func >(lhs: Self, rhs: Self) -> Bool

Declared In

Comparable
func >=(_:rhs:)

Returns a Boolean value indicating whether the value of the first argument is greater than or equal to that of the second argument.

Parameters: lhs: A value to compare. rhs: Another value to compare.

Declaration

func >=(lhs: Self, rhs: Self) -> Bool

Declared In

Comparable
func >>(_:rhs:)

Returns the result of shifting a value's binary representation the specified number of digits to the right.

The >> operator performs a smart shift, which defines a result for a shift of any value.

  • Using a negative value for rhs performs a left shift using abs(rhs).
  • Using a value for rhs that is greater than or equal to the bit width of lhs is an overshift. An overshift results in -1 for a negative value of lhs or 0 for a nonnegative value.
  • Using any other value for rhs performs a right shift on lhs by that amount.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the value is shifted right by two bits.

let x: UInt8 = 30                 // 0b00011110
let y = x >> 2
// y == 7                         // 0b00000111

If you use 11 as rhs, x is overshifted such that all of its bits are set to zero.

let z = x >> 11
// z == 0                         // 0b00000000

Using a negative value as rhs is the same as performing a left shift using abs(rhs).

let a = x >> -3
// a == 240                       // 0b11110000
let b = x << 3
// b == 240                       // 0b11110000

Right shift operations on negative values "fill in" the high bits with ones instead of zeros.

let q: Int8 = -30                 // 0b11100010
let r = q >> 2
// r == -8                        // 0b11111000

let s = q >> 11
// s == -1                        // 0b11111111

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the right.

Declaration

func >><RHS>(lhs: Self, rhs: RHS) -> Self where RHS : BinaryInteger

Declared In

BinaryInteger
func >>=(_:rhs:)

Stores the result of shifting a value's binary representation the specified number of digits to the right in the left-hand-side variable.

The >>= operator performs a smart shift, which defines a result for a shift of any value.

  • Using a negative value for rhs performs a left shift using abs(rhs).
  • Using a value for rhs that is greater than or equal to the bit width of lhs is an overshift. An overshift results in -1 for a negative value of lhs or 0 for a nonnegative value.
  • Using any other value for rhs performs a right shift on lhs by that amount.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the value is shifted right by two bits.

var x: UInt8 = 30                 // 0b00011110
x >>= 2
// x == 7                         // 0b00000111

If you use 11 as rhs, x is overshifted such that all of its bits are set to zero.

var y: UInt8 = 30                 // 0b00011110
y >>= 11
// y == 0                         // 0b00000000

Using a negative value as rhs is the same as performing a left shift using abs(rhs).

var a: UInt8 = 30                 // 0b00011110
a >>= -3
// a == 240                       // 0b11110000

var b: UInt8 = 30                 // 0b00011110
b <<= 3
// b == 240                       // 0b11110000

Right shift operations on negative values "fill in" the high bits with ones instead of zeros.

var q: Int8 = -30                 // 0b11100010
q >>= 2
// q == -8                        // 0b11111000

var r: Int8 = -30                 // 0b11100010
r >>= 11
// r == -1                        // 0b11111111

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the right.

Declaration

func >>=<RHS>(lhs: inout Self, rhs: RHS)

Declared In

BinaryInteger
func ^(_:rhs:)

Returns the result of performing a bitwise XOR operation on the two given values.

A bitwise XOR operation, also known as an exclusive OR operation, results in a value that has each bit set to 1 where one or the other but not both of its arguments had that bit set to 1. For example:

let x: UInt8 = 5          // 0b00000101
let y: UInt8 = 14         // 0b00001110
let z = x ^ y             // 0b00001011
// z == 11

Parameters: lhs: An integer value. rhs: Another integer value.

Declaration

func ^(lhs: Self, rhs: Self) -> Self

Declared In

BinaryInteger
func ^=(_:rhs:) Required

Stores the result of performing a bitwise XOR operation on the two given values in the left-hand-side variable.

A bitwise XOR operation, also known as an exclusive OR operation, results in a value that has each bit set to 1 where one or the other but not both of its arguments had that bit set to 1. For example:

var x: UInt8 = 5          // 0b00000101
let y: UInt8 = 14         // 0b00001110
x ^= y                    // 0b00001011

Parameters: lhs: An integer value. rhs: Another integer value.

Declaration

func ^=(lhs: inout Self, rhs: Self)

Declared In

BinaryInteger
func |(_:rhs:)

Returns the result of performing a bitwise OR operation on the two given values.

A bitwise OR operation results in a value that has each bit set to 1 where one or both of its arguments have that bit set to 1. For example:

let x: UInt8 = 5          // 0b00000101
let y: UInt8 = 14         // 0b00001110
let z = x | y             // 0b00001111
// z == 15

Parameters: lhs: An integer value. rhs: Another integer value.

Declaration

func |(lhs: Self, rhs: Self) -> Self

Declared In

BinaryInteger
func |=(_:rhs:) Required

Stores the result of performing a bitwise OR operation on the two given values in the left-hand-side variable.

A bitwise OR operation results in a value that has each bit set to 1 where one or both of its arguments have that bit set to 1. For example:

var x: UInt8 = 5          // 0b00000101
let y: UInt8 = 14         // 0b00001110
x |= y                    // 0b00001111

Parameters: lhs: An integer value. rhs: Another integer value.

Declaration

func |=(lhs: inout Self, rhs: Self)

Declared In

BinaryInteger
prefix func ~(_:)

Returns the inverse of the bits set in the argument.

The bitwise NOT operator (~) is a prefix operator that returns a value in which all the bits of its argument are flipped: Bits that are 1 in the argument are 0 in the result, and bits that are 0 in the argument are 1 in the result. This is equivalent to the inverse of a set. For example:

let x: UInt8 = 5        // 0b00000101
let notX = ~x           // 0b11111010

Performing a bitwise NOT operation on 0 returns a value with every bit set to 1.

let allOnes = ~UInt8.min   // 0b11111111

Complexity: O(1).

Declaration

prefix func ~(x: Self) -> Self

Declared In

BinaryInteger
func -(_:rhs:)

Subtracts one value from another and produces their difference.

The subtraction operator (-) calculates the difference of its two arguments. For example:

8 - 3                   // 5
-10 - 5                 // -15
100 - -5                // 105
10.5 - 100.0            // -89.5

You cannot use - with arguments of different types. To subtract values of different types, convert one of the values to the other value's type.

let x: UInt8 = 21
let y: UInt = 1000000
y - UInt(x)             // 999979

Parameters: lhs: A numeric value. rhs: The value to subtract from lhs.

Declaration

func -(lhs: Self, rhs: Self) -> Self

Declared In

BinaryInteger, Numeric
func -=(_:rhs:)

Subtracts the second value from the first and stores the difference in the left-hand-side variable.

Parameters: lhs: A numeric value. rhs: The value to subtract from lhs.

Declaration

func -=(lhs: inout Self, rhs: Self)

Declared In

BinaryInteger, Numeric
func addingReportingOverflow(_:) Required

Returns the sum of this value and the given value, along with a Boolean value indicating whether overflow occurred in the operation.

rhs: The value to add to this value. Returns: A tuple containing the result of the addition along with a Boolean value indicating whether overflow occurred. If the overflow component is false, the partialValue component contains the entire sum. If the overflow component is true, an overflow occurred and the partialValue component contains the truncated sum of this value and rhs.

Declaration

func addingReportingOverflow(_ rhs: Self) -> (partialValue: Self, overflow: Bool)
func advanced(by:)

Returns a value that is offset the specified distance from this value.

Use the advanced(by:) method in generic code to offset a value by a specified distance. If you're working directly with numeric values, use the addition operator (+) instead of this method.

func addOne<T: Strideable>(to x: T) -> T
    where T.Stride : ExpressibleByIntegerLiteral
{
    return x.advanced(by: 1)
}

let x = addOne(to: 5)
// x == 6
let y = addOne(to: 3.5)
// y = 4.5

If this type's Stride type conforms to BinaryInteger, then for a value x, a distance n, and a value y = x.advanced(by: n), x.distance(to: y) == n. Using this method with types that have a noninteger Stride may result in an approximation.

n: The distance to advance this value. Returns: A value that is offset from this value by n.

Complexity: O(1)

Declaration

func advanced(by n: Self.Stride) -> Self

Declared In

Strideable
func distance(to:)

Returns the distance from this value to the given value, expressed as a stride.

If this type's Stride type conforms to BinaryInteger, then for two values x and y, and a distance n = x.distance(to: y), x.advanced(by: n) == y. Using this method with types that have a noninteger Stride may result in an approximation.

other: The value to calculate the distance to. Returns: The distance from this value to other.

Complexity: O(1)

Declaration

func distance(to other: Self) -> Self.Stride

Declared In

Strideable
func dividedReportingOverflow(by:) Required

Returns the quotient obtained by dividing this value by the given value, along with a Boolean value indicating whether overflow occurred in the operation.

Dividing by zero is not an error when using this method. For a value x, the result of x.dividedReportingOverflow(by: 0) is (x, true).

rhs: The value to divide this value by. Returns: A tuple containing the result of the division along with a Boolean value indicating whether overflow occurred. If the overflow component is false, the partialValue component contains the entire quotient. If the overflow component is true, an overflow occurred and the partialValue component contains either the truncated quotient or, if the quotient is undefined, the dividend.

Declaration

func dividedReportingOverflow(by rhs: Self) -> (partialValue: Self, overflow: Bool)
func dividingFullWidth(_ dividend: (high: Self,:) Required

Returns a tuple containing the quotient and remainder obtained by dividing the given value by this value.

The resulting quotient must be representable within the bounds of the type. If the quotient is too large to represent in the type, a runtime error may occur.

The following example divides a value that is too large to be represented using a single Int instance by another Int value. Because the quotient is representable as an Int, the division succeeds.

// 'dividend' represents the value 0x506f70652053616e74612049494949
let dividend = (22640526660490081, 7959093232766896457 as UInt)
let divisor = 2241543570477705381

let (quotient, remainder) = divisor.dividingFullWidth(dividend)
// quotient == 186319822866995413
// remainder == 0

dividend: A tuple containing the high and low parts of a double-width integer. Returns: A tuple containing the quotient and remainder obtained by dividing dividend by this value.

Declaration

func dividingFullWidth(_ dividend: (high: Self, low: Self.Magnitude)) -> (quotient: Self, remainder: Self)
func hash(into:) Required

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

Implement this method to conform to the Hashable protocol. The components used for hashing must be the same as the components compared in your type's == operator implementation. Call hasher.combine(_:) with each of these components.

Important: Never call finalize() on hasher. Doing so may become a compile-time error in the future.

hasher: The hasher to use when combining the components of this instance.

Declaration

func hash(into hasher: inout Hasher)

Declared In

Hashable
func multipliedFullWidth(by:) Required

Returns a tuple containing the high and low parts of the result of multiplying this value by the given value.

Use this method to calculate the full result of a product that would otherwise overflow. Unlike traditional truncating multiplication, the multipliedFullWidth(by:) method returns a tuple containing both the high and low parts of the product of this value and other. The following example uses this method to multiply two Int8 values that normally overflow when multiplied:

let x: Int8 = 48
let y: Int8 = -40
let result = x.multipliedFullWidth(by: y)
// result.high == -8
// result.low  == 128

The product of x and y is -1920, which is too large to represent in an Int8 instance. The high and low compnents of the result value represent -1920 when concatenated to form a double-width integer; that is, using result.high as the high byte and result.low as the low byte of an Int16 instance.

let z = Int16(result.high) << 8 | Int16(result.low)
// z == -1920

other: The value to multiply this value by. Returns: A tuple containing the high and low parts of the result of multiplying this value and other.

Declaration

func multipliedFullWidth(by other: Self) -> (high: Self, low: Self.Magnitude)
func multipliedReportingOverflow(by:) Required

Returns the product of this value and the given value, along with a Boolean value indicating whether overflow occurred in the operation.

rhs: The value to multiply by this value. Returns: A tuple containing the result of the multiplication along with a Boolean value indicating whether overflow occurred. If the overflow component is false, the partialValue component contains the entire product. If the overflow component is true, an overflow occurred and the partialValue component contains the truncated product of this value and rhs.

Declaration

func multipliedReportingOverflow(by rhs: Self) -> (partialValue: Self, overflow: Bool)
func quotientAndRemainder(dividingBy:)

Returns the quotient and remainder of this value divided by the given value.

Use this method to calculate the quotient and remainder of a division at the same time.

let x = 1_000_000
let (q, r) = x.quotientAndRemainder(dividingBy: 933)
// q == 1071
// r == 757

rhs: The value to divide this value by. Returns: A tuple containing the quotient and remainder of this value divided by rhs.

Declaration

func quotientAndRemainder(dividingBy rhs: Self) -> (quotient: Self, remainder: Self)

Declared In

BinaryInteger
func remainderReportingOverflow(dividingBy:) Required

Returns the remainder after dividing this value by the given value, along with a Boolean value indicating whether overflow occurred during division.

Dividing by zero is not an error when using this method. For a value x, the result of x.remainderReportingOverflow(dividingBy: 0) is (x, true).

rhs: The value to divide this value by. Returns: A tuple containing the result of the operation along with a Boolean value indicating whether overflow occurred. If the overflow component is false, the partialValue component contains the entire remainder. If the overflow component is true, an overflow occurred during division and the partialValue component contains either the entire remainder or, if the remainder is undefined, the dividend.

Declaration

func remainderReportingOverflow(dividingBy rhs: Self) -> (partialValue: Self, overflow: Bool)
func signum()

Returns -1 if this value is negative and 1 if it's positive; otherwise, 0.

Returns: The sign of this number, expressed as an integer of the same type.

Declaration

func signum() -> Self

Declared In

BinaryInteger
func subtractingReportingOverflow(_:) Required

Returns the difference obtained by subtracting the given value from this value, along with a Boolean value indicating whether overflow occurred in the operation.

rhs: The value to subtract from this value. Returns: A tuple containing the result of the subtraction along with a Boolean value indicating whether overflow occurred. If the overflow component is false, the partialValue component contains the entire difference. If the overflow component is true, an overflow occurred and the partialValue component contains the truncated result of rhs subtracted from this value.

Declaration

func subtractingReportingOverflow(_ rhs: Self) -> (partialValue: Self, overflow: Bool)

Default Implementations

init()

Creates a new value equal to zero.

Declaration

init()

Declared In

BinaryInteger
init(_:)

Creates an integer from the given floating-point value, rounding toward zero. Any fractional part of the value passed as source is removed.

let x = Int(21.5)
// x == 21
let y = Int(-21.5)
// y == -21

If source is outside the bounds of this type after rounding toward zero, a runtime error may occur.

let z = UInt(-21.5)
// Error: ...outside the representable range

source: A floating-point value to convert to an integer. source must be representable in this type after rounding toward zero.

Declaration

init<T>(_ source: T)
init(bigEndian:)

Creates an integer from its big-endian representation, changing the byte order if necessary.

value: A value to use as the big-endian representation of the new integer.

Declaration

init(bigEndian value: Self)
init(clamping:)

Creates a new instance with the representable value that's closest to the given integer.

If the value passed as source is greater than the maximum representable value in this type, the result is the type's max value. If source is less than the smallest representable value in this type, the result is the type's min value.

In this example, x is initialized as an Int8 instance by clamping 500 to the range -128...127, and y is initialized as a UInt instance by clamping -500 to the range 0...UInt.max.

let x = Int8(clamping: 500)
// x == 127
// x == Int8.max

let y = UInt(clamping: -500)
// y == 0

source: An integer to convert to this type.

Declaration

init<Other>(clamping source: Other)
init(integerLiteral:)

Creates an instance initialized to the specified integer value.

Do not call this initializer directly. Instead, initialize a variable or constant using an integer literal. For example:

let x = 23

In this example, the assignment to the x constant calls this integer literal initializer behind the scenes.

value: The value to create.

Declaration

init(integerLiteral value: Self)

Declared In

BinaryInteger
init(littleEndian:)

Creates an integer from its little-endian representation, changing the byte order if necessary.

value: A value to use as the little-endian representation of the new integer.

Declaration

init(littleEndian value: Self)
init(truncatingIfNeeded:)

Creates a new instance from the bit pattern of the given instance by truncating or sign-extending if needed to fit this type.

When the bit width of T (the type of source) is equal to or greater than this type's bit width, the result is the truncated least-significant bits of source. For example, when converting a 16-bit value to an 8-bit type, only the lower 8 bits of source are used.

let p: Int16 = -500
// 'p' has a binary representation of 11111110_00001100
let q = Int8(truncatingIfNeeded: p)
// q == 12
// 'q' has a binary representation of 00001100

When the bit width of T is less than this type's bit width, the result is sign-extended to fill the remaining bits. That is, if source is negative, the result is padded with ones; otherwise, the result is padded with zeros.

let u: Int8 = 21
// 'u' has a binary representation of 00010101
let v = Int16(truncatingIfNeeded: u)
// v == 21
// 'v' has a binary representation of 00000000_00010101

let w: Int8 = -21
// 'w' has a binary representation of 11101011
let x = Int16(truncatingIfNeeded: w)
// x == -21
// 'x' has a binary representation of 11111111_11101011
let y = UInt16(truncatingIfNeeded: w)
// y == 65515
// 'y' has a binary representation of 11111111_11101011

source: An integer to convert to this type.

Declaration

init<T>(truncatingIfNeeded source: T)
init?(_:)

Creates a new integer value from the given string.

The string passed as description may begin with a plus or minus sign character (+ or -), followed by one or more numeric digits (0-9).

let x = Int("123")
// x == 123

If description is in an invalid format, or if the value it denotes in base 10 is not representable, the result is nil. For example, the following conversions result in nil:

Int(" 100")                       // Includes whitespace
Int("21-50")                      // Invalid format
Int("ff6600")                     // Characters out of bounds
Int("10000000000000000000000000") // Out of range

description: The ASCII representation of a number.

Declaration

init?(_ description: String)
init?(_:radix:)

Creates a new integer value from the given string and radix.

The string passed as text may begin with a plus or minus sign character (+ or -), followed by one or more numeric digits (0-9) or letters (a-z or A-Z). Parsing of the string is case insensitive.

let x = Int("123")
// x == 123

let y = Int("-123", radix: 8)
// y == -83
let y = Int("+123", radix: 8)
// y == +83

let z = Int("07b", radix: 16)
// z == 123

If text is in an invalid format or contains characters that are out of bounds for the given radix, or if the value it denotes in the given radix is not representable, the result is nil. For example, the following conversions result in nil:

Int(" 100")                       // Includes whitespace
Int("21-50")                      // Invalid format
Int("ff6600")                     // Characters out of bounds
Int("zzzzzzzzzzzzz", radix: 36)   // Out of range

Parameters: text: The ASCII representation of a number in the radix passed as radix. radix: The radix, or base, to use for converting text to an integer value. radix must be in the range 2...36. The default is 10.

Declaration

init?<S>(_ text: S, radix: Int = default)
init?(exactly:)

Creates an integer from the given floating-point value, if it can be represented exactly.

If the value passed as source is not representable exactly, the result is nil. In the following example, the constant x is successfully created from a value of 21.0, while the attempt to initialize the constant y from 21.5 fails:

let x = Int(exactly: 21.0)
// x == Optional(21)
let y = Int(exactly: 21.5)
// y == nil

source: A floating-point value to convert to an integer.

Declaration

init?<T>(exactly source: T)
var bigEndian: Self

The big-endian representation of this integer.

If necessary, the byte order of this value is reversed from the typical byte order of this integer type. On a big-endian platform, for any integer x, x == x.bigEndian.

Declaration

var bigEndian: Self { get }
var bitWidth: Int

The number of bits in the binary representation of this value.

Declaration

var bitWidth: Int { get }
var description: String

A textual representation of this value.

Declaration

var description: String { get }

Declared In

BinaryInteger
var littleEndian: Self

The little-endian representation of this integer.

If necessary, the byte order of this value is reversed from the typical byte order of this integer type. On a little-endian platform, for any integer x, x == x.littleEndian.

Declaration

var littleEndian: Self { get }
func !=(_: Self, rhs: Self)

Declaration

func !=(lhs: Self, rhs: Self) -> Bool

Declared In

BinaryInteger
func !=(_:rhs:)

Returns a Boolean value indicating whether two values are not equal.

Inequality is the inverse of equality. For any values a and b, a != b implies that a == b is false.

This is the default implementation of the not-equal-to operator (!=) for any type that conforms to Equatable.

Parameters: lhs: A value to compare. rhs: Another value to compare.

Declaration

func !=(lhs: Self, rhs: Self) -> Bool

Declared In

BinaryInteger
func != <Other>(_: Self, rhs: Other)

Returns a Boolean value indicating whether the two given values are not equal.

You can check the inequality of instances of any BinaryInteger types using the not-equal-to operator (!=). For example, you can test whether the first UInt8 value in a string's UTF-8 encoding is not equal to the first UInt32 value in its Unicode scalar view:

let gameName = "Red Light, Green Light"
if let firstUTF8 = gameName.utf8.first,
    let firstScalar = gameName.unicodeScalars.first?.value {
    print("First code values are different: \(firstUTF8 != firstScalar)")
}
// Prints "First code values are different: false"

Parameters: lhs: An integer to compare. rhs: Another integer to compare.

Declaration

func !=<Other>(lhs: Self, rhs: Other) -> Bool where Other : BinaryInteger

Declared In

BinaryInteger
func &(_:rhs:)

Returns the result of performing a bitwise AND operation on the two given values.

A bitwise AND operation results in a value that has each bit set to 1 where both of its arguments have that bit set to 1. For example:

let x: UInt8 = 5          // 0b00000101
let y: UInt8 = 14         // 0b00001110
let z = x & y             // 0b00000100
// z == 4

Parameters: lhs: An integer value. rhs: Another integer value.

Declaration

func &(lhs: Self, rhs: Self) -> Self

Declared In

BinaryInteger
func &*(_:rhs:)

Returns the product of the two given values, discarding any overflow.

The masking multiplication operator (&*) silently discards any overflow that occurs during the operation. In the following example, the product of 10 and 50 is greater than the maximum representable Int8 value, so the result is the overflowed value:

let x: Int8 = 10 &* 5
// x == 50
let y: Int8 = 10 &* 50
// y == -12 (after overflow)

Parameters: lhs: The first value to multiply. rhs: The second value to multiply.

Declaration

func &*(lhs: Self, rhs: Self) -> Self
func &*=(_:rhs:)

Multiplies two values and stores the result in the left-hand-side variable, discarding any overflow.

The masking multiplication assignment operator (&*=) silently discards any overflow that occurs during the operation. In the following example, the product of 10 and 50 is greater than the maximum representable Int8 value, so the result is the overflowed value:

var x: Int8 = 10
x &*= 5
// x == 50
var y: Int8 = 10
y &*= 50
// y == -12 (after overflow)

Parameters: lhs: The first value to multiply. rhs: The second value to multiply.

Declaration

func &*=(lhs: inout Self, rhs: Self)
func &+(_:rhs:)

Returns the sum of the two given values, discarding any overflow.

The masking addition operator (&+) silently discards any overflow that occurs during the operation. In the following example, the sum of 100 and 121 is greater than the maximum representable Int8 value, so the result is the overflowed value:

let x: Int8 = 10 &+ 21
// x == 31
let y: Int8 = 100 &+ 121
// y == -35 (after overflow)

Parameters: lhs: The first value to add. rhs: The second value to add.

Declaration

func &+(lhs: Self, rhs: Self) -> Self
func &+=(_:rhs:)

Adds two values and stores the result in the left-hand-side variable, discarding any overflow.

The masking addition assignment operator (&+=) silently discards any overflow that occurs during the operation. In the following example, the sum of 100 and 121 is greater than the maximum representable Int8 value, so the result is the overflowed value:

var x: Int8 = 10
x &+= 21
// x == 31
var y: Int8 = 100
y &+= 121
// y == -35 (after overflow)

Parameters: lhs: The first value to add. rhs: The second value to add.

Declaration

func &+=(lhs: inout Self, rhs: Self)
func &<<(_: Self, rhs: Self)

Returns the result of shifting a value's binary representation the specified number of digits to the left, masking the shift amount to the type's bit width.

Use the masking left shift operator (&<<) when you need to perform a shift and are sure that the shift amount is in the range 0..<lhs.bitWidth. Before shifting, the masking left shift operator masks the shift to this range. The shift is performed using this masked value.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the shift amount requires no masking.

let x: UInt8 = 30                 // 0b00011110
let y = x &<< 2
// y == 120                       // 0b01111000

However, if you use 8 as the shift amount, the method first masks the shift amount to zero, and then performs the shift, resulting in no change to the original value.

let z = x &<< 8
// z == 30                        // 0b00011110

If the bit width of the shifted integer type is a power of two, masking is performed using a bitmask; otherwise, masking is performed using a modulo operation.

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the left. If rhs is outside the range 0..<lhs.bitWidth, it is masked to produce a value within that range.

Declaration

func &<<(lhs: Self, rhs: Self) -> Self
func &<< <Other>(_: Self, rhs: Other)

Returns the result of shifting a value's binary representation the specified number of digits to the left, masking the shift amount to the type's bit width.

Use the masking left shift operator (&<<) when you need to perform a shift and are sure that the shift amount is in the range 0..<lhs.bitWidth. Before shifting, the masking left shift operator masks the shift to this range. The shift is performed using this masked value.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the shift amount requires no masking.

let x: UInt8 = 30                 // 0b00011110
let y = x &<< 2
// y == 120                       // 0b01111000

However, if you use 8 as the shift amount, the method first masks the shift amount to zero, and then performs the shift, resulting in no change to the original value.

let z = x &<< 8
// z == 30                        // 0b00011110

If the bit width of the shifted integer type is a power of two, masking is performed using a bitmask; otherwise, masking is performed using a modulo operation.

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the left. If rhs is outside the range 0..<lhs.bitWidth, it is masked to produce a value within that range.

Declaration

func &<<<Other>(lhs: Self, rhs: Other) -> Self where Other : BinaryInteger
func &<<=(_:rhs:)

Returns the result of shifting a value's binary representation the specified number of digits to the left, masking the shift amount to the type's bit width, and stores the result in the left-hand-side variable.

The &<<= operator performs a masking shift, where the value used as rhs is masked to produce a value in the range 0..<lhs.bitWidth. The shift is performed using this masked value.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the shift amount requires no masking.

var x: UInt8 = 30                 // 0b00011110
x &<<= 2
// x == 120                       // 0b01111000

However, if you pass 19 as rhs, the method first bitmasks rhs to 3, and then uses that masked value as the number of bits to shift lhs.

var y: UInt8 = 30                 // 0b00011110
y &<<= 19
// y == 240                       // 0b11110000

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the left. If rhs is outside the range 0..<lhs.bitWidth, it is masked to produce a value within that range.

Declaration

func &<<=<Other>(lhs: inout Self, rhs: Other)
func &>>(_: Self, rhs: Self)

Returns the result of shifting a value's binary representation the specified number of digits to the right, masking the shift amount to the type's bit width.

Use the masking right shift operator (&>>) when you need to perform a shift and are sure that the shift amount is in the range 0..<lhs.bitWidth. Before shifting, the masking right shift operator masks the shift to this range. The shift is performed using this masked value.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the shift amount requires no masking.

let x: UInt8 = 30                 // 0b00011110
let y = x &>> 2
// y == 7                         // 0b00000111

However, if you use 8 as the shift amount, the method first masks the shift amount to zero, and then performs the shift, resulting in no change to the original value.

let z = x &>> 8
// z == 30                        // 0b00011110

If the bit width of the shifted integer type is a power of two, masking is performed using a bitmask; otherwise, masking is performed using a modulo operation.

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the right. If rhs is outside the range 0..<lhs.bitWidth, it is masked to produce a value within that range.

Declaration

func &>>(lhs: Self, rhs: Self) -> Self
func &>> <Other>(_: Self, rhs: Other)

Returns the result of shifting a value's binary representation the specified number of digits to the right, masking the shift amount to the type's bit width.

Use the masking right shift operator (&>>) when you need to perform a shift and are sure that the shift amount is in the range 0..<lhs.bitWidth. Before shifting, the masking right shift operator masks the shift to this range. The shift is performed using this masked value.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the shift amount requires no masking.

let x: UInt8 = 30                 // 0b00011110
let y = x &>> 2
// y == 7                         // 0b00000111

However, if you use 8 as the shift amount, the method first masks the shift amount to zero, and then performs the shift, resulting in no change to the original value.

let z = x &>> 8
// z == 30                        // 0b00011110

If the bit width of the shifted integer type is a power of two, masking is performed using a bitmask; otherwise, masking is performed using a modulo operation.

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the right. If rhs is outside the range 0..<lhs.bitWidth, it is masked to produce a value within that range.

Declaration

func &>><Other>(lhs: Self, rhs: Other) -> Self where Other : BinaryInteger
func &>>=(_:rhs:)

Calculates the result of shifting a value's binary representation the specified number of digits to the right, masking the shift amount to the type's bit width, and stores the result in the left-hand-side variable.

The &>>= operator performs a masking shift, where the value passed as rhs is masked to produce a value in the range 0..<lhs.bitWidth. The shift is performed using this masked value.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the shift amount requires no masking.

var x: UInt8 = 30                 // 0b00011110
x &>>= 2
// x == 7                         // 0b00000111

However, if you use 19 as rhs, the operation first bitmasks rhs to 3, and then uses that masked value as the number of bits to shift lhs.

var y: UInt8 = 30                 // 0b00011110
y &>>= 19
// y == 3                         // 0b00000011

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the right. If rhs is outside the range 0..<lhs.bitWidth, it is masked to produce a value within that range.

Declaration

func &>>=<Other>(lhs: inout Self, rhs: Other)
func &-(_:rhs:)

Returns the difference of the two given values, discarding any overflow.

The masking subtraction operator (&-) silently discards any overflow that occurs during the operation. In the following example, the difference of 10 and 21 is less than zero, the minimum representable UInt value, so the result is the overflowed value:

let x: UInt8 = 21 &- 10
// x == 11
let y: UInt8 = 10 &- 21
// y == 245 (after overflow)

Parameters: lhs: A numeric value. rhs: The value to subtract from lhs.

Declaration

func &-(lhs: Self, rhs: Self) -> Self
func &-=(_:rhs:)

Subtracts the second value from the first and stores the difference in the left-hand-side variable, discarding any overflow.

The masking subtraction assignment operator (&-=) silently discards any overflow that occurs during the operation. In the following example, the difference of 10 and 21 is less than zero, the minimum representable UInt value, so the result is the overflowed value:

var x: Int8 = 21
x &-= 10
// x == 11
var y: UInt8 = 10
y &-= 21
// y == 245 (after overflow)

Parameters: lhs: A numeric value. rhs: The value to subtract from lhs.

Declaration

func &-=(lhs: inout Self, rhs: Self)
prefix func +(_:)

Returns the given number unchanged.

You can use the unary plus operator (+) to provide symmetry in your code for positive numbers when also using the unary minus operator.

let x = -21
let y = +21
// x == -21
// y == 21

Returns: The given argument without any changes.

Declaration

prefix func +(x: Self) -> Self

Declared In

BinaryInteger
func +(_: Self, rhs: Self.Stride)

Adds two values and produces their sum.

The addition operator (+) calculates the sum of its two arguments. For example:

1 + 2                   // 3
-10 + 15                // 5
-15 + -5                // -20
21.5 + 3.25             // 24.75

You cannot use + with arguments of different types. To add values of different types, convert one of the values to the other value's type.

let x: Int8 = 21
let y: Int = 1000000
Int(x) + y              // 1000021

Parameters: lhs: The first value to add. rhs: The second value to add.

Declaration

func +(lhs: Self, rhs: Self.Stride) -> Self

Declared In

BinaryInteger
func +(_: Self.Stride, rhs: Self)

Adds two values and produces their sum.

The addition operator (+) calculates the sum of its two arguments. For example:

1 + 2                   // 3
-10 + 15                // 5
-15 + -5                // -20
21.5 + 3.25             // 24.75

You cannot use + with arguments of different types. To add values of different types, convert one of the values to the other value's type.

let x: Int8 = 21
let y: Int = 1000000
Int(x) + y              // 1000021

Parameters: lhs: The first value to add. rhs: The second value to add.

Declaration

func +(lhs: Self.Stride, rhs: Self) -> Self

Declared In

BinaryInteger
func +=(_:rhs:)

Adds two values and stores the result in the left-hand-side variable.

Parameters: lhs: The first value to add. rhs: The second value to add.

Declaration

func +=(lhs: inout Self, rhs: Self.Stride)

Declared In

BinaryInteger
prefix func ...(_: Self)

Returns a partial range up to, and including, its upper bound.

Use the prefix closed range operator (prefix ...) to create a partial range of any type that conforms to the Comparable protocol. This example creates a PartialRangeThrough<Double> instance that includes any value less than or equal to 5.0.

let throughFive = ...5.0

throughFive.contains(4.0)     // true
throughFive.contains(5.0)     // true
throughFive.contains(6.0)     // false

You can use this type of partial range of a collection's indices to represent the range from the start of the collection up to, and including, the partial range's upper bound.

let numbers = [10, 20, 30, 40, 50, 60, 70]
print(numbers[...3])
// Prints "[10, 20, 30, 40]"

maximum: The upper bound for the range.

Declaration

prefix func ...(maximum: Self) -> PartialRangeThrough<Self>

Declared In

BinaryInteger
func ...(_:maximum:)

Returns a closed range that contains both of its bounds.

Use the closed range operator (...) to create a closed range of any type that conforms to the Comparable protocol. This example creates a ClosedRange<Character> from "a" up to, and including, "z".

let lowercase = "a"..."z"
print(lowercase.contains("z"))
// Prints "true"

Parameters: minimum: The lower bound for the range. maximum: The upper bound for the range.

Declaration

func ...(minimum: Self, maximum: Self) -> ClosedRange<Self>

Declared In

BinaryInteger
prefix func ..<(_:)

Returns a partial range up to, but not including, its upper bound.

Use the prefix half-open range operator (prefix ..<) to create a partial range of any type that conforms to the Comparable protocol. This example creates a PartialRangeUpTo<Double> instance that includes any value less than 5.0.

let upToFive = ..<5.0

upToFive.contains(3.14)       // true
upToFive.contains(6.28)       // false
upToFive.contains(5.0)        // false

You can use this type of partial range of a collection's indices to represent the range from the start of the collection up to, but not including, the partial range's upper bound.

let numbers = [10, 20, 30, 40, 50, 60, 70]
print(numbers[..<3])
// Prints "[10, 20, 30]"

maximum: The upper bound for the range.

Declaration

prefix func ..<(maximum: Self) -> PartialRangeUpTo<Self>

Declared In

BinaryInteger
func ..<(_:maximum:)

Returns a half-open range that contains its lower bound but not its upper bound.

Use the half-open range operator (..<) to create a range of any type that conforms to the Comparable protocol. This example creates a Range<Double> from zero up to, but not including, 5.0.

let lessThanFive = 0.0..<5.0
print(lessThanFive.contains(3.14))  // Prints "true"
print(lessThanFive.contains(5.0))   // Prints "false"

Parameters: minimum: The lower bound for the range. maximum: The upper bound for the range.

Declaration

func ..<(minimum: Self, maximum: Self) -> Range<Self>

Declared In

BinaryInteger
func <(_:rhs:)

Returns a Boolean value indicating whether the value of the first argument is less than that of the second argument.

You can compare instances of any BinaryInteger types using the less-than operator (<), even if the two instances are of different types.

Parameters: lhs: An integer to compare. rhs: Another integer to compare.

Declaration

func <<Other>(lhs: Self, rhs: Other) -> Bool where Other : BinaryInteger

Declared In

BinaryInteger
func <(_:y:)

Declaration

func <(x: Self, y: Self) -> Bool

Declared In

BinaryInteger
func <<(_:rhs:)

Returns the result of shifting a value's binary representation the specified number of digits to the left.

The << operator performs a smart shift, which defines a result for a shift of any value.

  • Using a negative value for rhs performs a right shift using abs(rhs).
  • Using a value for rhs that is greater than or equal to the bit width of lhs is an overshift, resulting in zero.
  • Using any other value for rhs performs a left shift on lhs by that amount.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the value is shifted left by two bits.

let x: UInt8 = 30                 // 0b00011110
let y = x << 2
// y == 120                       // 0b01111000

If you use 11 as rhs, x is overshifted such that all of its bits are set to zero.

let z = x << 11
// z == 0                         // 0b00000000

Using a negative value as rhs is the same as performing a right shift with abs(rhs).

let a = x << -3
// a == 3                         // 0b00000011
let b = x >> 3
// b == 3                         // 0b00000011

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the left.

Declaration

func <<<Other>(lhs: Self, rhs: Other) -> Self where Other : BinaryInteger

Declared In

FixedWidthInteger, BinaryInteger
func <<=(_:rhs:)

Declaration

func <<=<Other>(lhs: inout Self, rhs: Other)
func <=(_: Self, rhs: Self)

Returns a Boolean value indicating whether the value of the first argument is less than or equal to that of the second argument.

Parameters: lhs: A value to compare. rhs: Another value to compare.

Declaration

func <=(lhs: Self, rhs: Self) -> Bool

Declared In

BinaryInteger
func <=(_:rhs:)

Returns a Boolean value indicating whether the value of the first argument is less than or equal to that of the second argument.

This is the default implementation of the less-than-or-equal-to operator (<=) for any type that conforms to Comparable.

Parameters: lhs: A value to compare. rhs: Another value to compare.

Declaration

func <=(lhs: Self, rhs: Self) -> Bool

Declared In

BinaryInteger
func <= <Other>(_: Self, rhs: Other)

Returns a Boolean value indicating whether the value of the first argument is less than or equal to that of the second argument.

You can compare instances of any BinaryInteger types using the less-than-or-equal-to operator (<=), even if the two instances are of different types.

Parameters: lhs: An integer to compare. rhs: Another integer to compare.

Declaration

func <=<Other>(lhs: Self, rhs: Other) -> Bool where Other : BinaryInteger

Declared In

BinaryInteger
func ==(_:rhs:)

Returns a Boolean value indicating whether the two given values are equal.

You can check the equality of instances of any BinaryInteger types using the equal-to operator (==). For example, you can test whether the first UInt8 value in a string's UTF-8 encoding is equal to the first UInt32 value in its Unicode scalar view:

let gameName = "Red Light, Green Light"
if let firstUTF8 = gameName.utf8.first,
    let firstScalar = gameName.unicodeScalars.first?.value {
    print("First code values are equal: \(firstUTF8 == firstScalar)")
}
// Prints "First code values are equal: true"

Parameters: lhs: An integer to compare. rhs: Another integer to compare.

Declaration

func ==<Other>(lhs: Self, rhs: Other) -> Bool where Other : BinaryInteger

Declared In

BinaryInteger
func ==(_:y:)

Declaration

func ==(x: Self, y: Self) -> Bool

Declared In

BinaryInteger
func >(_: Self, rhs: Self)

Returns a Boolean value indicating whether the value of the first argument is greater than that of the second argument.

Parameters: lhs: A value to compare. rhs: Another value to compare.

Declaration

func >(lhs: Self, rhs: Self) -> Bool

Declared In

BinaryInteger
func >(_:rhs:)

Returns a Boolean value indicating whether the value of the first argument is greater than that of the second argument.

This is the default implementation of the greater-than operator (>) for any type that conforms to Comparable.

Parameters: lhs: A value to compare. rhs: Another value to compare.

Declaration

func >(lhs: Self, rhs: Self) -> Bool

Declared In

BinaryInteger
func > <Other>(_: Self, rhs: Other)

Returns a Boolean value indicating whether the value of the first argument is greater than that of the second argument.

You can compare instances of any BinaryInteger types using the greater-than operator (>), even if the two instances are of different types.

Parameters: lhs: An integer to compare. rhs: Another integer to compare.

Declaration

func ><Other>(lhs: Self, rhs: Other) -> Bool where Other : BinaryInteger

Declared In

BinaryInteger
func >=(_: Self, rhs: Self)

Returns a Boolean value indicating whether the value of the first argument is greater than or equal to that of the second argument.

Parameters: lhs: A value to compare. rhs: Another value to compare.

Declaration

func >=(lhs: Self, rhs: Self) -> Bool

Declared In

BinaryInteger
func >=(_:rhs:)

Returns a Boolean value indicating whether the value of the first argument is greater than or equal to that of the second argument.

This is the default implementation of the greater-than-or-equal-to operator (>=) for any type that conforms to Comparable.

Parameters: lhs: A value to compare. rhs: Another value to compare. Returns: true if lhs is greater than or equal to rhs; otherwise, false.

Declaration

func >=(lhs: Self, rhs: Self) -> Bool

Declared In

BinaryInteger
func >= <Other>(_: Self, rhs: Other)

Returns a Boolean value indicating whether the value of the first argument is greater than or equal to that of the second argument.

You can compare instances of any BinaryInteger types using the greater-than-or-equal-to operator (>=), even if the two instances are of different types.

Parameters: lhs: An integer to compare. rhs: Another integer to compare.

Declaration

func >=<Other>(lhs: Self, rhs: Other) -> Bool where Other : BinaryInteger

Declared In

BinaryInteger
func >>(_:rhs:)

Returns the result of shifting a value's binary representation the specified number of digits to the right.

The >> operator performs a smart shift, which defines a result for a shift of any value.

  • Using a negative value for rhs performs a left shift using abs(rhs).
  • Using a value for rhs that is greater than or equal to the bit width of lhs is an overshift. An overshift results in -1 for a negative value of lhs or 0 for a nonnegative value.
  • Using any other value for rhs performs a right shift on lhs by that amount.

The following example defines x as an instance of UInt8, an 8-bit, unsigned integer type. If you use 2 as the right-hand-side value in an operation on x, the value is shifted right by two bits.

let x: UInt8 = 30                 // 0b00011110
let y = x >> 2
// y == 7                         // 0b00000111

If you use 11 as rhs, x is overshifted such that all of its bits are set to zero.

let z = x >> 11
// z == 0                         // 0b00000000

Using a negative value as rhs is the same as performing a left shift using abs(rhs).

let a = x >> -3
// a == 240                       // 0b11110000
let b = x << 3
// b == 240                       // 0b11110000

Right shift operations on negative values "fill in" the high bits with ones instead of zeros.

let q: Int8 = -30                 // 0b11100010
let r = q >> 2
// r == -8                        // 0b11111000

let s = q >> 11
// s == -1                        // 0b11111111

Parameters: lhs: The value to shift. rhs: The number of bits to shift lhs to the right.

Declaration

func >><Other>(lhs: Self, rhs: Other) -> Self where Other : BinaryInteger

Declared In

FixedWidthInteger, BinaryInteger
func >>=(_:rhs:)

Declaration

func >>=<Other>(lhs: inout Self, rhs: Other)
func ^(_:rhs:)

Returns the result of performing a bitwise XOR operation on the two given values.

A bitwise XOR operation, also known as an exclusive OR operation, results in a value that has each bit set to 1 where one or the other but not both of its arguments had that bit set to 1. For example:

let x: UInt8 = 5          // 0b00000101
let y: UInt8 = 14         // 0b00001110
let z = x ^ y             // 0b00001011
// z == 11

Parameters: lhs: An integer value. rhs: Another integer value.

Declaration

func ^(lhs: Self, rhs: Self) -> Self

Declared In

BinaryInteger
func |(_:rhs:)

Returns the result of performing a bitwise OR operation on the two given values.

A bitwise OR operation results in a value that has each bit set to 1 where one or both of its arguments have that bit set to 1. For example:

let x: UInt8 = 5          // 0b00000101
let y: UInt8 = 14         // 0b00001110
let z = x | y             // 0b00001111
// z == 15

Parameters: lhs: An integer value. rhs: Another integer value.

Declaration

func |(lhs: Self, rhs: Self) -> Self

Declared In

BinaryInteger
prefix func ~(_:)

Returns the inverse of the bits set in the argument.

The bitwise NOT operator (~) is a prefix operator that returns a value in which all the bits of its argument are flipped: Bits that are 1 in the argument are 0 in the result, and bits that are 0 in the argument are 1 in the result. This is equivalent to the inverse of a set. For example:

let x: UInt8 = 5        // 0b00000101
let notX = ~x           // 0b11111010

Performing a bitwise NOT operation on 0 returns a value with every bit set to 1.

let allOnes = ~UInt8.min   // 0b11111111

Complexity: O(1).

Declaration

prefix func ~(x: Self) -> Self
func -(_: Self, rhs: Self)

Subtracts one value from another and produces their difference.

The subtraction operator (-) calculates the difference of its two arguments. For example:

8 - 3                   // 5
-10 - 5                 // -15
100 - -5                // 105
10.5 - 100.0            // -89.5

You cannot use - with arguments of different types. To subtract values of different types, convert one of the values to the other value's type.

let x: UInt8 = 21
let y: UInt = 1000000
y - UInt(x)             // 999979

Parameters: lhs: A numeric value. rhs: The value to subtract from lhs.

Declaration

func -(lhs: Self, rhs: Self) -> Self.Stride

Declared In

BinaryInteger
func -(_: Self, rhs: Self.Stride)

Subtracts one value from another and produces their difference.

The subtraction operator (-) calculates the difference of its two arguments. For example:

8 - 3                   // 5
-10 - 5                 // -15
100 - -5                // 105
10.5 - 100.0            // -89.5

You cannot use - with arguments of different types. To subtract values of different types, convert one of the values to the other value's type.

let x: UInt8 = 21
let y: UInt = 1000000
y - UInt(x)             // 999979

Parameters: lhs: A numeric value. rhs: The value to subtract from lhs.

Declaration

func -(lhs: Self, rhs: Self.Stride) -> Self

Declared In

BinaryInteger
func -=(_:rhs:)

Subtracts the second value from the first and stores the difference in the left-hand-side variable.

Parameters: lhs: A numeric value. rhs: The value to subtract from lhs.

Declaration

func -=(lhs: inout Self, rhs: Self.Stride)

Declared In

BinaryInteger
func advanced(by:)

Returns a value that is offset the specified distance from this value.

Use the advanced(by:) method in generic code to offset a value by a specified distance. If you're working directly with numeric values, use the addition operator (+) instead of this method.

For a value x, a distance n, and a value y = x.advanced(by: n), x.distance(to: y) == n.

n: The distance to advance this value. Returns: A value that is offset from this value by n.

Declaration

func advanced(by n: Int) -> Self

Declared In

BinaryInteger
func distance(to:)

Returns the distance from this value to the given value, expressed as a stride.

For two values x and y, and a distance n = x.distance(to: y), x.advanced(by: n) == y.

other: The value to calculate the distance to. Returns: The distance from this value to other.

Declaration

func distance(to other: Self) -> Int

Declared In

BinaryInteger
func quotientAndRemainder(dividingBy:)

Returns the quotient and remainder of this value divided by the given value.

Use this method to calculate the quotient and remainder of a division at the same time.

let x = 1_000_000
let (q, r) = x.quotientAndRemainder(dividingBy: 933)
// q == 1071
// r == 757

rhs: The value to divide this value by. Returns: A tuple containing the quotient and remainder of this value divided by rhs.

Declaration

func quotientAndRemainder(dividingBy rhs: Self) -> (quotient: Self, remainder: Self)

Declared In

BinaryInteger
func signum()

Returns -1 if this value is negative and 1 if it's positive; otherwise, 0.

Returns: The sign of this number, expressed as an integer of the same type.

Declaration

func signum() -> Self

Declared In

BinaryInteger
func unsafeAdding(_:)

Returns the sum of this value and the given value without checking for arithmetic overflow.

Use this function only to avoid the cost of overflow checking when you are certain that the operation won't overflow. In optimized builds (-O) the compiler is free to assume that overflow won't occur. Failure to satisfy that assumption is a serious programming error and could lead to statements being unexpectedly executed or skipped.

In debug builds (-Onone) a runtime error is still triggered if the operation overflows.

rhs: The value to add to this value. Returns: The sum of this value and rhs.

Declaration

func unsafeAdding(_ other: Self) -> Self
func unsafeDivided(by:)

Returns the quotient obtained by dividing this value by the given value without checking for arithmetic overflow.

Use this function only to avoid the cost of overflow checking when you are certain that the operation won't overflow. In optimized builds (-O) the compiler is free to assume that overflow won't occur. Failure to satisfy that assumption is a serious programming error and could lead to statements being unexpectedly executed or skipped.

In debug builds (-Onone) a runtime error is still triggered if the operation overflows.

rhs: The value to divide this value by. Returns: The result of dividing this value by rhs.

Declaration

func unsafeDivided(by other: Self) -> Self
func unsafeMultiplied(by:)

Returns the product of this value and the given value without checking for arithmetic overflow.

Use this function only to avoid the cost of overflow checking when you are certain that the operation won't overflow. In optimized builds (-O) the compiler is free to assume that overflow won't occur. Failure to satisfy that assumption is a serious programming error and could lead to statements being unexpectedly executed or skipped.

In debug builds (-Onone) a runtime error is still triggered if the operation overflows.

rhs: The value to multiply by this value. Returns: The product of this value and rhs.

Declaration

func unsafeMultiplied(by other: Self) -> Self
func unsafeSubtracting(_:)

Returns the difference obtained by subtracting the given value from this value without checking for arithmetic overflow.

Use this function only to avoid the cost of overflow checking when you are certain that the operation won't overflow. In optimized builds (-O) the compiler is free to assume that overflow won't occur. Failure to satisfy that assumption is a serious programming error and could lead to statements being unexpectedly executed or skipped.

In debug builds (-Onone) a runtime error is still triggered if the operation overflows.

rhs: The value to subtract from this value. Returns: The result of subtracting rhs from this value.

Declaration

func unsafeSubtracting(_ other: Self) -> Self

Where Magnitude : UnsignedInteger, Stride : SignedInteger

static func random(in: ClosedRange<Self>)

Returns a random value within the specified range.

Use this method to generate an integer within a specific range. This example creates three new values in the range 1...100.

for _ in 1...3 {
    print(Int.random(in: 1...100))
}
// Prints "53"
// Prints "64"
// Prints "5"

This method uses the default random generator, Random.default. The call to Int.random(in: 1...100) above is equivalent to calling Int.random(in: 1...100, using: &Random.default).

range: The range in which to create a random value. Returns: A random value within the bounds of range.

Declaration

static func random(in range: ClosedRange<Self>) -> Self
static func random(in: Range<Self>)

Returns a random value within the specified range.

Use this method to generate an integer within a specific range. This example creates three new values in the range 1..<100.

for _ in 1...3 {
    print(Int.random(in: 1..<100))
}
// Prints "53"
// Prints "64"
// Prints "5"

This method uses the default random generator, Random.default. The call to Int.random(in: 1..<100) above is equivalent to calling Int.random(in: 1..<100, using: &Random.default).

range: The range in which to create a random value. range must not be empty. Returns: A random value within the bounds of range.

Declaration

static func random(in range: Range<Self>) -> Self
static func random<T>(in: ClosedRange<Self>, using: inout T)

Returns a random value within the specified range, using the given generator as a source for randomness.

Use this method to generate an integer within a specific range when you are using a custom random number generator. This example creates three new values in the range 1...100.

for _ in 1...3 {
    print(Int.random(in: 1...100, using: &myGenerator))
}
// Prints "7"
// Prints "44"
// Prints "21"

Parameters: range: The range in which to create a random value. generator: The random number generator to use when creating the new random value. Returns: A random value within the bounds of range.

Declaration

static func random<T>(in range: ClosedRange<Self>, using generator: inout T) -> Self where T : RandomNumberGenerator
static func random<T>(in: Range<Self>, using: inout T)

Returns a random value within the specified range, using the given generator as a source for randomness.

Use this method to generate an integer within a specific range when you are using a custom random number generator. This example creates three new values in the range 1..<100.

for _ in 1...3 {
    print(Int.random(in: 1..<100, using: &myGenerator))
}
// Prints "7"
// Prints "44"
// Prints "21"

Parameters: range: The range in which to create a random value. range must not be empty. generator: The random number generator to use when creating the new random value. Returns: A random value within the bounds of range.

Declaration

static func random<T>(in range: Range<Self>, using generator: inout T) -> Self where T : RandomNumberGenerator

Where Stride : SignedInteger

func ...(_:maximum:)

Returns a countable closed range that contains both of its bounds.

Use the closed range operator (...) to create a closed range of any type that conforms to the Strideable protocol with an associated signed integer Stride type, such as any of the standard library's integer types. This example creates a ClosedRange<Int> from zero up to, and including, nine.

let singleDigits = 0...9
print(singleDigits.contains(9))
// Prints "true"

You can use sequence or collection methods on the singleDigits range.

print(singleDigits.count)
// Prints "10"
print(singleDigits.last)
// Prints "9"

Parameters:)`. minimum: The lower bound for the range. maximum: The upper bound for the range.

Declaration

func ...(minimum: Self, maximum: Self) -> ClosedRange<Self>

Declared In

BinaryInteger