Bitwise math. More...

Functions
template<class T >
constexpr T	compress (T x) noexcept
	Compresses the even bits of a value into the lower half, then clears the upper half. More...

template<class T >
constexpr int	count (T x) noexcept
	Returns the number of set bits in a value, known as a population count or Hamming weight. More...

template<class T >
constexpr T	crossover (T a, T b, int i) noexcept
	Performs a single-point crossover between two values. More...

template<class T >
constexpr T	crossover_n (T a, T b, T mask) noexcept
	Performs an n-point crossover between two values. More...

template<class T >
constexpr T	deposit (T x, T mask) noexcept
	Reads bits from the least significant bits of a value and returns them in the positions marked by a mask. More...

template<class T >
constexpr T	desegregate (T x) noexcept
	Interleaves bits of the lower and upper halves of a value. More...

template<class T >
constexpr int	difference (T x, T y) noexcept
	Returns the number of differing bits between two values, known as Hamming distance. More...

template<class T >
constexpr T	expand (T x) noexcept
	Moves bits from the lower half of a value to occupy all even bits, and clears all odd bits. More...

template<class T >
constexpr T	extract (T x, T mask) noexcept
	Reads bits from a value in the positions marked by a mask and returns them in the least significant bits. More...

template<class T >
constexpr T	flip (T x, int i) noexcept
	Flips a single bit in a value. More...

template<class T , class U = T>
constexpr U	interleave (T a, T b) noexcept
	Returns a value with even bits containing the first value's lower half, and odd bits containing the second value's lower half. More...

template<class T >
constexpr T	merge (T a, T b, T mask) noexcept
	Merges the bits of two values using a bit mask. More...

template<class T >
constexpr T	parity (T x) noexcept
	Returns the parity of a value. More...

template<class T >
constexpr T	segregate (T x) noexcept
	Segregates the odd and even bits of a value. More...

template<class T >
constexpr T	swap_adjacent (T x) noexcept
	Swaps the each odd bit with its following even bit. More...

std::uint16_t	swap16 (std::uint16_t x) noexcept
	Swaps the byte order of an unsigned 16-bit number. More...

std::int16_t	swap16 (std::int16_t x) noexcept
	Swaps the byte order of a signed 16-bit number. More...

std::uint32_t	swap32 (std::uint32_t x) noexcept
	Swaps the byte order of an unsigned 32-bit number. More...

std::int32_t	swap32 (std::int32_t x) noexcept
	Swaps the byte order of a signed 32-bit number. More...

std::uint64_t	swap64 (std::uint64_t x) noexcept
	Swaps the byte order of an unsigned 64-bit number. More...

std::int64_t	swap64 (std::int64_t x) noexcept
	Swaps the byte order of a signed 64-bit number. More...

Detailed Description

Bitwise math.

Function Documentation

◆ compress()

template<class T >

constexpr T bit::compress ( T x )

constexprnoexcept

Compresses the even bits of a value into the lower half, then clears the upper half.

Parameters

x	Value to compress.

Returns: Compressed value.

Definition at line 193 of file bit-math.hpp.

◆ count()

template<class T >

constexpr int bit::count ( T x )

constexprnoexcept

Returns the number of set bits in a value, known as a population count or Hamming weight.

Parameters

x	Value to count.

Returns: Number of set bits in x.

Definition at line 211 of file bit-math.hpp.

◆ crossover()

template<class T >

constexpr T bit::crossover	(	T	a,
		T	b,
		int	i
	)

inlineconstexprnoexcept

Performs a single-point crossover between two values.

Parameters

a	First value.
b	Second value.
i	Index of the crossover point.

Returns: Crossed over value.

Definition at line 220 of file bit-math.hpp.

◆ crossover_n()

template<class T >

constexpr T bit::crossover_n	(	T	a,
		T	b,
		T	mask
	)

constexprnoexcept

Performs an n-point crossover between two values.

Parameters

a	First value.
b	Second value.
mask	Bit mask with set bits marking crossover points.

Returns: Crossed over value.

Definition at line 227 of file bit-math.hpp.

◆ deposit()

template<class T >

constexpr T bit::deposit	(	T	x,
		T	mask
	)

constexprnoexcept

Reads bits from the least significant bits of a value and returns them in the positions marked by a mask.

Parameters

x	Value from which bits should be read.
mask	Bit mask indicating where bits should be deposited.

Returns: Bits from the least significant bits of x in the positions marked by mask.

Definition at line 265 of file bit-math.hpp.

◆ desegregate()

template<class T >

constexpr T bit::desegregate ( T x )

inlineconstexprnoexcept

Interleaves bits of the lower and upper halves of a value.

Parameters

x	Value to desegregate.

Returns: Value with bits from the upper half of x interleaved with bits from the lower half.

Definition at line 241 of file bit-math.hpp.

◆ difference()

template<class T >

constexpr int bit::difference	(	T	x,
		T	y
	)

inlineconstexprnoexcept

Returns the number of differing bits between two values, known as Hamming distance.

Parameters

x	First value.
y	Second value.

Returns: Hamming distance between @px and y.

Definition at line 280 of file bit-math.hpp.

◆ expand()

template<class T >

constexpr T bit::expand ( T x )

constexprnoexcept

Moves bits from the lower half of a value to occupy all even bits, and clears all odd bits.

Parameters

x	Value to expand.

Returns: Expanded value.

Definition at line 247 of file bit-math.hpp.

◆ extract()

template<class T >

constexpr T bit::extract	(	T	x,
		T	mask
	)

constexprnoexcept

Reads bits from a value in the positions marked by a mask and returns them in the least significant bits.

Parameters

x	Value from which bits should be read.
mask	Bit mask indicating which bits to extract.

Returns: Bits of x from the positions marked by mask in the least significant bits.

Definition at line 286 of file bit-math.hpp.

◆ flip()

template<class T >

constexpr T bit::flip	(	T	x,
		int	i
	)

inlineconstexprnoexcept

Flips a single bit in a value.

Parameters

x	Value to modify.
i	Index of the bit to flip.

Returns: Copy of x with one bit flipped.

Definition at line 301 of file bit-math.hpp.

◆ interleave()

template<class T , class U = T>

constexpr U bit::interleave	(	T	a,
		T	b
	)

inlineconstexprnoexcept

Returns a value with even bits containing the first value's lower half, and odd bits containing the second value's lower half.

Parameters

a	First value.
b	Second value.

Returns: Value with bits from the lower halves of a and b interleaved.

Definition at line 307 of file bit-math.hpp.

◆ merge()

template<class T >

constexpr T bit::merge	(	T	a,
		T	b,
		T	mask
	)

inlineconstexprnoexcept

Merges the bits of two values using a bit mask.

Parameters

a	First value.
b	Second value.
mask	Bit mask with zeros where bits from `a` should be used, and ones where bits from `b` should be used.

Returns: Merged value.

Definition at line 313 of file bit-math.hpp.

◆ parity()

template<class T >

constexpr T bit::parity ( T x )

constexprnoexcept

Returns the parity of a value.

Parameters

x	Value to test.

Returns: 1 if an odd number of bits are set, 0 otherwise.

Definition at line 319 of file bit-math.hpp.

◆ segregate()

template<class T >

constexpr T bit::segregate ( T x )

constexprnoexcept

Segregates the odd and even bits of a value.

Parameters

x	Value to segregate.

Returns: Value with even bits of x in the lower half, and odd bits in the upper half.

Definition at line 334 of file bit-math.hpp.

◆ swap16() [1/2]

std::int16_t bit::swap16 ( std::int16_t x )

noexcept

Swaps the byte order of a signed 16-bit number.

Definition at line 353 of file bit-math.hpp.

◆ swap16() [2/2]

std::uint16_t bit::swap16 ( std::uint16_t x )

noexcept

Swaps the byte order of an unsigned 16-bit number.

Definition at line 348 of file bit-math.hpp.

◆ swap32() [1/2]

std::int32_t bit::swap32 ( std::int32_t x )

noexcept

Swaps the byte order of a signed 32-bit number.

Definition at line 364 of file bit-math.hpp.

◆ swap32() [2/2]

std::uint32_t bit::swap32 ( std::uint32_t x )

noexcept

Swaps the byte order of an unsigned 32-bit number.

Definition at line 358 of file bit-math.hpp.

◆ swap64() [1/2]

std::int64_t bit::swap64 ( std::int64_t x )

noexcept

Swaps the byte order of a signed 64-bit number.

Definition at line 377 of file bit-math.hpp.

◆ swap64() [2/2]

std::uint64_t bit::swap64 ( std::uint64_t x )

noexcept

Swaps the byte order of an unsigned 64-bit number.

Definition at line 370 of file bit-math.hpp.

◆ swap_adjacent()

template<class T >

constexpr T bit::swap_adjacent ( T x )

constexprnoexcept

Swaps the each odd bit with its following even bit.

Parameters

x	Value in which adjacent bits should be swap.

Returns: Copy of x with adjacent bits swapped.

Definition at line 343 of file bit-math.hpp.

Functions

Detailed Description

Function Documentation

◆ compress()

◆ count()

◆ crossover()

◆ crossover_n()

◆ deposit()

◆ desegregate()

◆ difference()

◆ expand()

◆ extract()

◆ flip()

◆ interleave()

◆ merge()

◆ parity()

◆ segregate()

◆ swap16() [1/2]

◆ swap16() [2/2]

◆ swap32() [1/2]

◆ swap32() [2/2]

◆ swap64() [1/2]

◆ swap64() [2/2]

◆ swap_adjacent()