version: 1.10

package bits

import "math/bits"

Overview

Package bits implements bit counting and manipulation functions for the predeclared unsigned integer types.

Index

Examples

Package files

bits.go bits_tables.go

Constants

  1. const UintSize = uintSize

UintSize is the size of a uint in bits.

func LeadingZeros 

  1. func LeadingZeros(x uint) int

LeadingZeros returns the number of leading zero bits in x; the result is UintSize for x == 0.

func LeadingZeros16 

  1. func LeadingZeros16(x uint16) int

LeadingZeros16 returns the number of leading zero bits in x; the result is 16 for x == 0.

Example:

  1. fmt.Printf("LeadingZeros16(%016b) = %d\n", 1, bits.LeadingZeros16(1))
  2. // Output:
  3. // LeadingZeros16(0000000000000001) = 15

func LeadingZeros32 

  1. func LeadingZeros32(x uint32) int

LeadingZeros32 returns the number of leading zero bits in x; the result is 32 for x == 0.

Example:

  1. fmt.Printf("LeadingZeros32(%032b) = %d\n", 1, bits.LeadingZeros32(1))
  2. // Output:
  3. // LeadingZeros32(00000000000000000000000000000001) = 31

func LeadingZeros64 

  1. func LeadingZeros64(x uint64) int

LeadingZeros64 returns the number of leading zero bits in x; the result is 64 for x == 0.

Example:

  1. fmt.Printf("LeadingZeros64(%064b) = %d\n", 1, bits.LeadingZeros64(1))
  2. // Output:
  3. // LeadingZeros64(0000000000000000000000000000000000000000000000000000000000000001) = 63

func LeadingZeros8 

  1. func LeadingZeros8(x uint8) int

LeadingZeros8 returns the number of leading zero bits in x; the result is 8 for x == 0.

Example:

  1. fmt.Printf("LeadingZeros8(%08b) = %d\n", 1, bits.LeadingZeros8(1))
  2. // Output:
  3. // LeadingZeros8(00000001) = 7

func Len 

  1. func Len(x uint) int

Len returns the minimum number of bits required to represent x; the result is 0 for x == 0.

func Len16 

  1. func Len16(x uint16) (n int)

Len16 returns the minimum number of bits required to represent x; the result is 0 for x == 0.

Example:

  1. fmt.Printf("Len16(%016b) = %d\n", 8, bits.Len16(8))
  2. // Output:
  3. // Len16(0000000000001000) = 4

func Len32 

  1. func Len32(x uint32) (n int)

Len32 returns the minimum number of bits required to represent x; the result is 0 for x == 0.

Example:

  1. fmt.Printf("Len32(%032b) = %d\n", 8, bits.Len32(8))
  2. // Output:
  3. // Len32(00000000000000000000000000001000) = 4

func Len64 

  1. func Len64(x uint64) (n int)

Len64 returns the minimum number of bits required to represent x; the result is 0 for x == 0.

Example:

  1. fmt.Printf("Len64(%064b) = %d\n", 8, bits.Len64(8))
  2. // Output:
  3. // Len64(0000000000000000000000000000000000000000000000000000000000001000) = 4

func Len8 

  1. func Len8(x uint8) int

Len8 returns the minimum number of bits required to represent x; the result is 0 for x == 0.

Example:

  1. fmt.Printf("Len8(%08b) = %d\n", 8, bits.Len8(8))
  2. // Output:
  3. // Len8(00001000) = 4

func OnesCount 

  1. func OnesCount(x uint) int

OnesCount returns the number of one bits (“population count”) in x.

func OnesCount16 

  1. func OnesCount16(x uint16) int

OnesCount16 returns the number of one bits (“population count”) in x.

Example:

  1. fmt.Printf("OnesCount16(%016b) = %d\n", 14, bits.OnesCount16(14))
  2. // Output:
  3. // OnesCount16(0000000000001110) = 3

func OnesCount32 

  1. func OnesCount32(x uint32) int

OnesCount32 returns the number of one bits (“population count”) in x.

Example:

  1. fmt.Printf("OnesCount32(%032b) = %d\n", 14, bits.OnesCount32(14))
  2. // Output:
  3. // OnesCount32(00000000000000000000000000001110) = 3

func OnesCount64 

  1. func OnesCount64(x uint64) int

OnesCount64 returns the number of one bits (“population count”) in x.

Example:

  1. fmt.Printf("OnesCount64(%064b) = %d\n", 14, bits.OnesCount64(14))
  2. // Output:
  3. // OnesCount64(0000000000000000000000000000000000000000000000000000000000001110) = 3

func OnesCount8 

  1. func OnesCount8(x uint8) int

OnesCount8 returns the number of one bits (“population count”) in x.

Example:

  1. fmt.Printf("OnesCount8(%08b) = %d\n", 14, bits.OnesCount8(14))
  2. // Output:
  3. // OnesCount8(00001110) = 3

func Reverse 

  1. func Reverse(x uint) uint

Reverse returns the value of x with its bits in reversed order.

func Reverse16 

  1. func Reverse16(x uint16) uint16

Reverse16 returns the value of x with its bits in reversed order.

Example:

  1. fmt.Printf("%016b\n", 19)
  2. fmt.Printf("%016b\n", bits.Reverse16(19))
  3. // Output:
  4. // 0000000000010011
  5. // 1100100000000000

func Reverse32 

  1. func Reverse32(x uint32) uint32

Reverse32 returns the value of x with its bits in reversed order.

Example:

  1. fmt.Printf("%032b\n", 19)
  2. fmt.Printf("%032b\n", bits.Reverse32(19))
  3. // Output:
  4. // 00000000000000000000000000010011
  5. // 11001000000000000000000000000000

func Reverse64 

  1. func Reverse64(x uint64) uint64

Reverse64 returns the value of x with its bits in reversed order.

Example:

  1. fmt.Printf("%064b\n", 19)
  2. fmt.Printf("%064b\n", bits.Reverse64(19))
  3. // Output:
  4. // 0000000000000000000000000000000000000000000000000000000000010011
  5. // 1100100000000000000000000000000000000000000000000000000000000000

func Reverse8 

  1. func Reverse8(x uint8) uint8

Reverse8 returns the value of x with its bits in reversed order.

Example:

  1. fmt.Printf("%08b\n", 19)
  2. fmt.Printf("%08b\n", bits.Reverse8(19))
  3. // Output:
  4. // 00010011
  5. // 11001000

func ReverseBytes 

  1. func ReverseBytes(x uint) uint

ReverseBytes returns the value of x with its bytes in reversed order.

func ReverseBytes16 

  1. func ReverseBytes16(x uint16) uint16

ReverseBytes16 returns the value of x with its bytes in reversed order.

Example:

  1. fmt.Printf("%016b\n", 15)
  2. fmt.Printf("%016b\n", bits.ReverseBytes16(15))
  3. // Output:
  4. // 0000000000001111
  5. // 0000111100000000

func ReverseBytes32 

  1. func ReverseBytes32(x uint32) uint32

ReverseBytes32 returns the value of x with its bytes in reversed order.

Example:

  1. fmt.Printf("%032b\n", 15)
  2. fmt.Printf("%032b\n", bits.ReverseBytes32(15))
  3. // Output:
  4. // 00000000000000000000000000001111
  5. // 00001111000000000000000000000000

func ReverseBytes64 

  1. func ReverseBytes64(x uint64) uint64

ReverseBytes64 returns the value of x with its bytes in reversed order.

Example:

  1. fmt.Printf("%064b\n", 15)
  2. fmt.Printf("%064b\n", bits.ReverseBytes64(15))
  3. // Output:
  4. // 0000000000000000000000000000000000000000000000000000000000001111
  5. // 0000111100000000000000000000000000000000000000000000000000000000

func RotateLeft 

  1. func RotateLeft(x uint, k int) uint

RotateLeft returns the value of x rotated left by (k mod UintSize) bits. To rotate x right by k bits, call RotateLeft(x, -k).

func RotateLeft16 

  1. func RotateLeft16(x uint16, k int) uint16

RotateLeft16 returns the value of x rotated left by (k mod 16) bits. To rotate x right by k bits, call RotateLeft16(x, -k).

Example:

  1. fmt.Printf("%016b\n", 15)
  2. fmt.Printf("%016b\n", bits.RotateLeft16(15, 2))
  3. fmt.Printf("%016b\n", bits.RotateLeft16(15, -2))
  4. // Output:
  5. // 0000000000001111
  6. // 0000000000111100
  7. // 1100000000000011

func RotateLeft32 

  1. func RotateLeft32(x uint32, k int) uint32

RotateLeft32 returns the value of x rotated left by (k mod 32) bits. To rotate x right by k bits, call RotateLeft32(x, -k).

Example:

  1. fmt.Printf("%032b\n", 15)
  2. fmt.Printf("%032b\n", bits.RotateLeft32(15, 2))
  3. fmt.Printf("%032b\n", bits.RotateLeft32(15, -2))
  4. // Output:
  5. // 00000000000000000000000000001111
  6. // 00000000000000000000000000111100
  7. // 11000000000000000000000000000011

func RotateLeft64 

  1. func RotateLeft64(x uint64, k int) uint64

RotateLeft64 returns the value of x rotated left by (k mod 64) bits. To rotate x right by k bits, call RotateLeft64(x, -k).

Example:

  1. fmt.Printf("%064b\n", 15)
  2. fmt.Printf("%064b\n", bits.RotateLeft64(15, 2))
  3. fmt.Printf("%064b\n", bits.RotateLeft64(15, -2))
  4. // Output:
  5. // 0000000000000000000000000000000000000000000000000000000000001111
  6. // 0000000000000000000000000000000000000000000000000000000000111100
  7. // 1100000000000000000000000000000000000000000000000000000000000011

func RotateLeft8 

  1. func RotateLeft8(x uint8, k int) uint8

RotateLeft8 returns the value of x rotated left by (k mod 8) bits. To rotate x right by k bits, call RotateLeft8(x, -k).

Example:

  1. fmt.Printf("%08b\n", 15)
  2. fmt.Printf("%08b\n", bits.RotateLeft8(15, 2))
  3. fmt.Printf("%08b\n", bits.RotateLeft8(15, -2))
  4. // Output:
  5. // 00001111
  6. // 00111100
  7. // 11000011

func TrailingZeros 

  1. func TrailingZeros(x uint) int

TrailingZeros returns the number of trailing zero bits in x; the result is UintSize for x == 0.

func TrailingZeros16 

  1. func TrailingZeros16(x uint16) (n int)

TrailingZeros16 returns the number of trailing zero bits in x; the result is 16 for x == 0.

Example:

  1. fmt.Printf("TrailingZeros16(%016b) = %d\n", 14, bits.TrailingZeros16(14))
  2. // Output:
  3. // TrailingZeros16(0000000000001110) = 1

func TrailingZeros32 

  1. func TrailingZeros32(x uint32) int

TrailingZeros32 returns the number of trailing zero bits in x; the result is 32 for x == 0.

Example:

  1. fmt.Printf("TrailingZeros32(%032b) = %d\n", 14, bits.TrailingZeros32(14))
  2. // Output:
  3. // TrailingZeros32(00000000000000000000000000001110) = 1

func TrailingZeros64 

  1. func TrailingZeros64(x uint64) int

TrailingZeros64 returns the number of trailing zero bits in x; the result is 64 for x == 0.

Example:

  1. fmt.Printf("TrailingZeros64(%064b) = %d\n", 14, bits.TrailingZeros64(14))
  2. // Output:
  3. // TrailingZeros64(0000000000000000000000000000000000000000000000000000000000001110) = 1

func TrailingZeros8 

  1. func TrailingZeros8(x uint8) int

TrailingZeros8 returns the number of trailing zero bits in x; the result is 8 for x == 0.

Example:

  1. fmt.Printf("TrailingZeros8(%08b) = %d\n", 14, bits.TrailingZeros8(14))
  2. // Output:
  3. // TrailingZeros8(00001110) = 1