Detailed Description

Bit manipulation and testing, endianness.

Typedefs
template<typename T >
using	gul14::BitFunctionReturnType = std::enable_if_t< std::is_integral< T >::value and not std::is_same< std::decay_t< T >, bool >::value, std::decay_t< T > >
	Return type of the bit manipulation functions. More...

Enumerations
enum class	gul14::endian { gul14::little , gul14::big , gul14::native }
	An enum to determine the endianness of multi-byte scalars on the current platform. More...

Functions
template<typename T = unsigned, typename ReturnT = BitFunctionReturnType<T>>
constexpr auto	gul14::bit_set (unsigned bit) noexcept -> ReturnT
	Set a bit in an integral type. More...

template<typename T , typename ReturnT = BitFunctionReturnType<T>>
constexpr auto	gul14::bit_set (T previous, unsigned bit) noexcept -> ReturnT
	Set a bit in an integral value. More...

template<typename T , typename ReturnT = BitFunctionReturnType<T>>
constexpr auto	gul14::bit_reset (T previous, unsigned bit) noexcept -> ReturnT
	Reset a bit in an integral value. More...

template<typename T , typename ReturnT = BitFunctionReturnType<T>>
constexpr auto	gul14::bit_flip (T previous, unsigned bit) noexcept -> ReturnT
	Flip a bit in an integral value. More...

template<typename T >
constexpr bool	gul14::bit_test (T bits, unsigned bit) noexcept
	Test a bit in an integral value. More...

constexpr bool	gul14::is_big_endian ()
	Determine whether this platform uses big-endian (Motorola) order for storing multi-byte quantities in memory. More...

constexpr bool	gul14::is_little_endian ()
	Determine whether this platform uses little-endian (Intel) order for storing multi-byte quantities in memory. More...

Typedef Documentation

◆ BitFunctionReturnType

template<typename T >

using gul14::BitFunctionReturnType = typedef std::enable_if_t< std::is_integral<T>::value and not std::is_same<std::decay_t<T>, bool>::value, std::decay_t<T> >

Return type of the bit manipulation functions.

We want to SFINAE out of all types except integers. Because bools counts as integer type and we don't want that we specifically exclude it here.

The type is then simply the decayed input type, to get rid of const or volatile specifiers.

Template Parameters

T	Type specified/deduced by bit_*() user

Enumeration Type Documentation

◆ endian

enum gul14::endian

strong

An enum to determine the endianness of multi-byte scalars on the current platform.

In big-endian (Motorola) order, the most significant byte is stored first, followed by the other bytes in order of decreasing significance. Little-endian platforms (e.g. Intel) store the bytes in the opposite order. There are also (historical) platforms which do not conform to either of these conventions.

if constexpr (gul14::endian::native == gul14::endian::big)

std::cout << "This is a big-endian machine!\n";

gul14::endian::native

@ native

Native endianness.

gul14::endian::big

@ big

Big-endian (e.g. Motorola)

This is a backport of std::endian from C++20.

See also: is_big_endian(), is_little_endian()

Since: GUL version 2.10

Enumerator
little	Little-endian (e.g. Intel)
big	Big-endian (e.g. Motorola)
native	Native endianness.

Function Documentation

◆ bit_flip()

template<typename T , typename ReturnT = BitFunctionReturnType<T>>

constexpr auto gul14::bit_flip	(	T	previous,
		unsigned	bit
	)		-> ReturnT

inlineconstexprnoexcept

Flip a bit in an integral value.

Flips the bit number bit in the existing value previous. This inverts the state of the bit: setting the bit if it was previously not set and resetting the bit if it was previously set.

When bit is greater or equal to the number of bits in type T, std::abort() is called (via assert()).

Parameters

previous	Existing integral value where the bit shall be modified
bit	Number of the bit that is to be modified (LSB == 0)

Returns: New integral value with the bit modified.

Template Parameters

T	Type of the bit-holding integral value.

Since: GUL version 1.8

See also: bit_set(bit), bit_set(previous, bit), bit_reset(previous, bit), bit_test(bits, bit)

◆ bit_reset()

template<typename T , typename ReturnT = BitFunctionReturnType<T>>

constexpr auto gul14::bit_reset	(	T	previous,
		unsigned	bit
	)		-> ReturnT

inlineconstexprnoexcept

Reset a bit in an integral value.

Reset (clear) the bit number bit in the existing value previous.

When bit is greater or equal to the number of bits in type T, std::abort() is called (via assert()).

Parameters

previous	Existing integral value where the bit shall be modified
bit	Number of the bit that is to be modified (LSB == 0)

Returns: New integral value with the bit modified.

Template Parameters

T	Type of the bit-holding integral value.

Since: GUL version 1.8

See also: bit_set(bit), bit_set(previous, bit), bit_flip(previous, bit), bit_test(bits, bit)

◆ bit_set() [1/2]

template<typename T , typename ReturnT = BitFunctionReturnType<T>>

constexpr auto gul14::bit_set	(	T	previous,
		unsigned	bit
	)		-> ReturnT

inlineconstexprnoexcept

Set a bit in an integral value.

Set the bit number bit in the existing value previous.

When bit is greater or equal to the number of bits in type T, std::abort() is called (via assert()).

Parameters

previous	Existing integral value where the bit shall be modified
bit	Number of the bit that is to be modified (LSB == 0)

Returns: New integral value with the bit modified.

Template Parameters

T	Type of the bit-holding integral value.

Since: GUL version 1.8

See also: bit_set(bit), bit_reset(previous, bit), bit_flip(previous, bit), bit_test(bits, bit)

◆ bit_set() [2/2]

template<typename T = unsigned, typename ReturnT = BitFunctionReturnType<T>>

constexpr auto gul14::bit_set ( unsigned bit ) -> ReturnT

inlineconstexprnoexcept

Set a bit in an integral type.

Return an integral value of type T where the bit number bit and only that bit is set.

When bit is greater or equal to the number of bits in type T, std::abort() is called (via assert()).

Parameters

bit	Number of the bit that is to be set (LSB == 0)

Returns: Integral value with the bit set.

Template Parameters

T	Type of the bit-holding integral value.

Note: If no type T is specified an unsigned int will be returned.

Since: GUL version 1.8

See also: bit_set(previous, bit), bit_reset(previous, bit), bit_flip(previous, bit), bit_test(bits, bit)

◆ bit_test()

template<typename T >

constexpr bool gul14::bit_test	(	T	bits,
		unsigned	bit
	)

inlineconstexprnoexcept

Test a bit in an integral value.

Test the bit number bit in the existing value bits.

When bit is greater or equal to the number of bits in type T, std::abort() is called (via assert()).

Parameters

bits	Integral value where the bit shall be tested
bit	Number of the bit that is to be modified (LSB == 0)

Returns: True or false

Template Parameters

T	Type of the bit-holding integral value.

Since: GUL version 1.8

See also: bit_set(bit), bit_set(previous, bit), bit_reset(previous, bit), bit_flip(previous, bit)

◆ is_big_endian()

constexpr bool gul14::is_big_endian ( )

constexpr

Determine whether this platform uses big-endian (Motorola) order for storing multi-byte quantities in memory.

In big-endian order, the most significant byte is stored first, followed by the other bytes in order of decreasing significance.

See also: is_little_endian(), gul14::endian

Since: GUL version 2.10

References gul14::big, and gul14::native.

◆ is_little_endian()

constexpr bool gul14::is_little_endian ( )

constexpr

Determine whether this platform uses little-endian (Intel) order for storing multi-byte quantities in memory.

In little-endian order, the least significant byte is stored first, followed by the other bytes in order of increasing significance.

See also: is_big_endian(), gul14::endian

Since: GUL version 2.10

References gul14::little, and gul14::native.

Detailed Description

Typedefs

Enumerations

Functions

Typedef Documentation

◆ BitFunctionReturnType

Enumeration Type Documentation

◆ endian

Function Documentation

◆ bit_flip()

◆ bit_reset()

◆ bit_set() [1/2]

◆ bit_set() [2/2]

◆ bit_test()

◆ is_big_endian()

◆ is_little_endian()