Integral integer types and arithmetic. More...

Namespaces
namespace	jau::int_literals

Classes
class	jau::mp::BigInt
	Arbitrary precision integer type. More...

struct	jau::float_bytes< bytesize >

struct	jau::float_bytes< sizeof(double)>

struct	jau::float_bytes< sizeof(float)>

struct	jau::float_bytes< sizeof(long double)>

class	jau::int_ctti

struct	jau::sint_bytes< bytesize >

struct	jau::sint_bytes< 4 >

struct	jau::sint_bytes< 8 >

struct	jau::uint128dp_t
	A 128-bit packed uint8_t data array. More...

struct	jau::uint192dp_t
	A 196-bit packed uint8_t data array. More...

struct	jau::uint256dp_t
	A 256-bit packed uint8_t data array. More...

struct	jau::uint_bytes< bytesize >

struct	jau::uint_bytes< 4 >

struct	jau::uint_bytes< 8 >

Typedefs
template<int bytesize>
using	jau::float_bytes_t = typename float_bytes<bytesize>::type
	Alias template for float_bytes.

typedef uint_fast32_t	jau::nsize_t
	Natural 'size_t' alternative using `uint_fast32_t` as its natural sized type.

template<int bytesize>
using	jau::sint_bytes_t = typename sint_bytes<bytesize>::type
	Alias template for sint_bytes.

typedef int_fast32_t	jau::snsize_t
	Natural 'ssize_t' alternative using `int_fast32_t` as its natural sized type.

template<int bytesize>
using	jau::uint_bytes_t = typename uint_bytes<bytesize>::type
	Alias template for uint_bytes.

Functions
mp::BigInt	jau::abs (const mp::BigInt &x) noexcept

template<typename T, std::enable_if_t< std::is_arithmetic_v< T > &&!std::is_unsigned_v< T >, bool > = true>
constexpr T	jau::abs (const T x) noexcept
	Returns the absolute value of an arithmetic number (w/ branching) in O(1)

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>
constexpr bool	jau::add_overflow (const T a, const T b, T &res) noexcept
	Integer overflow aware addition returning true if overflow occurred, otherwise false having the result stored in res.

const mp::BigInt &	jau::clamp (const mp::BigInt &x, const mp::BigInt &min_val, const mp::BigInt &max_val) noexcept

template<typename T, std::enable_if_t< std::is_arithmetic_v< T >, bool > = true>
constexpr T	jau::clamp (const T x, const T min_val, const T max_val) noexcept
	Returns constrained integral value to lie between given min- and maximum value (w/ branching) in O(1).

mp::BigInt &	jau::clamp (mp::BigInt &x, mp::BigInt &min_val, mp::BigInt &max_val) noexcept

void	jau::clear_bit_uint32 (const uint8_t nr, uint32_t &mask)

void	jau::clear_bit_uint64 (const uint8_t nr, uint64_t &mask)

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>
constexpr nsize_t	jau::digits10 (const T x, const bool sign_is_digit=true) noexcept
	Returns the number of decimal digits of the given integral value number using std::log10<T>().

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>
constexpr nsize_t	jau::digits10 (const T x, const snsize_t x_sign, const bool sign_is_digit=true) noexcept
	Returns the number of decimal digits of the given integral value number using std::log10<T>().

template<class T>
std::enable_if_t< std::is_integral_v< T >, bool > constexpr	jau::equals (const T &a, const T &b) noexcept
	Returns true if both values are equal.

template<class T>
std::enable_if_t< std::is_integral_v< T >, bool > constexpr	jau::equals (const T &a, const T &b, const T &allowed_deviation) noexcept
	Returns true if both values are equal, i.e.

mp::BigInt	jau::gcd (const mp::BigInt &a, const mp::BigInt &b) noexcept

template<typename T, std::enable_if_t< std::is_integral_v< T > &&!std::is_unsigned_v< T >, bool > = true>
constexpr T	jau::gcd (T a, T b) noexcept
	Returns the greatest common divisor (GCD) of the two given integer values following Euclid's algorithm from Euclid's Elements ~300 BC, using the absolute positive value of given integers.

consteval_cxx20 bool	jau::has_builtin_add_overflow () noexcept
	Query whether `__builtin_add_overflow` is available via `__has_builtin(__builtin_add_overflow)`.

consteval_cxx20 bool	jau::has_builtin_mul_overflow () noexcept
	Query whether `__builtin_mul_overflow` is available via `__has_builtin(__builtin_mul_overflow)`.

consteval_cxx20 bool	jau::has_builtin_sub_overflow () noexcept
	Query whether `__builtin_sub_overflow` is available via `__has_builtin(__builtin_sub_overflow)`.

template<typename T, std::enable_if_t< std::is_integral_v< T > &&std::is_unsigned_v< T >, bool > = true>
constexpr nsize_t	jau::high_bit (T x)
	Return the index of the highest set bit w/ branching (loop) in O(n), actually O(n/2).

template<class T, std::enable_if_t< std::is_arithmetic_v< T >, bool > = true>
bool	jau::in_range (const T &a, const T &b, const T &range)
	base_math: arithmetic types, i.e.

template<typename T, std::enable_if_t< std::is_arithmetic_v< T > &&!std::is_unsigned_v< T >, bool > = true>
constexpr T	jau::invert_sign (const T x) noexcept
	Safely inverts the sign of an arithmetic number w/ branching in O(1)

template<typename T, std::enable_if_t< std::is_integral_v< T > &&std::is_unsigned_v< T >, bool > = true>
constexpr bool	jau::is_power_of_2 (const T x) noexcept
	Power of 2 test (w/o branching ?) in O(1)

template<class T>
std::enable_if_t< std::is_integral_v< T >, bool > constexpr	jau::is_zero (const T &a) noexcept
	base_math: arithmetic types, i.e.

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>
constexpr bool	jau::lcm_overflow (const T a, const T b, T &result) noexcept
	Integer overflow aware calculation of least common multiple (LCM) following Euclid's algorithm from Euclid's Elements ~300 BC.

const mp::BigInt &	jau::max (const mp::BigInt &x, const mp::BigInt &y) noexcept

template<typename T, std::enable_if_t< std::is_arithmetic_v< T >, bool > = true>
constexpr T	jau::max (const T x, const T y) noexcept
	Returns the maximum of two integrals (w/ branching) in O(1)

mp::BigInt &	jau::max (mp::BigInt &x, mp::BigInt &y) noexcept

uint128dp_t	jau::merge_uint128 (uint16_t const uuid16, uint128dp_t const &base_uuid, nsize_t const uuid16_le_octet_index)
	Merge the given 'uuid16' into a 'base_uuid' copy at the given little endian 'uuid16_le_octet_index' position.

uint128dp_t	jau::merge_uint128 (uint32_t const uuid32, uint128dp_t const &base_uuid, nsize_t const uuid32_le_octet_index)
	Merge the given 'uuid32' into a 'base_uuid' copy at the given little endian 'uuid32_le_octet_index' position.

const mp::BigInt &	jau::min (const mp::BigInt &x, const mp::BigInt &y) noexcept

template<typename T, std::enable_if_t< std::is_arithmetic_v< T >, bool > = true>
constexpr T	jau::min (const T x, const T y) noexcept
	Returns the minimum of two integrals (w/ branching) in O(1)

mp::BigInt &	jau::min (mp::BigInt &x, mp::BigInt &y) noexcept

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>
constexpr bool	jau::mul_overflow (const T a, const T b, T &res) noexcept
	Integer overflow aware multiplication returning true if overflow occurred, otherwise false having the result stored in res.

mp::BigInt	jau::pow (mp::BigInt b, const mp::BigInt &e)

template<typename T, typename U, std::enable_if_t< std::is_integral_v< T > &&std::is_unsigned_v< T > &&std::is_integral_v< U > &&std::is_unsigned_v< U >, bool > = true>
constexpr T	jau::round_down (T n, U align_to)
	Round down w/ branching in O(1)

constexpr uint32_t	jau::round_to_power_of_2 (const uint32_t n)
	If the given `n` is not is_power_of_2() return next_power_of_2(), otherwise return `n` unchanged.

template<typename T, typename U, std::enable_if_t< std::is_integral_v< T > &&std::is_unsigned_v< T > &&std::is_integral_v< U > &&std::is_unsigned_v< U >, bool > = true>
constexpr T	jau::round_up (const T n, const U align_to)
	Round up w/ branching in O(1)

void	jau::set_bit_uint32 (const uint8_t nr, uint32_t &mask)

void	jau::set_bit_uint64 (const uint8_t nr, uint64_t &mask)

template<typename T, std::enable_if_t< std::is_arithmetic_v< T > &&!std::is_unsigned_v< T >, bool > = true>
constexpr int	jau::sign (const T x) noexcept
	Returns the value of the sign function (w/o branching ?) in O(1).

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>
constexpr bool	jau::sub_overflow (const T a, const T b, T &res) noexcept
	Integer overflow aware subtraction returning true if overflow occurred, otherwise false having the result stored in res.

uint32_t	jau::test_bit_uint32 (const uint8_t nr, const uint32_t mask)

uint64_t	jau::test_bit_uint64 (const uint8_t nr, const uint64_t mask)

Detailed Description

Integral integer types and arithmetic.

Further support is coming from Byte Utilities and meta-group Math Support

Typedef Documentation

◆ nsize_t

typedef uint_fast32_t jau::nsize_t

Natural 'size_t' alternative using uint_fast32_t as its natural sized type.

The leading 'n' stands for natural.

This is a compromise to indicate intend, but to avoid handling a multiple sized size_t footprint where not desired.

Examples: test_lfringbuffer11.cpp.

Definition at line 55 of file int_types.hpp.

◆ snsize_t

typedef int_fast32_t jau::snsize_t

Natural 'ssize_t' alternative using int_fast32_t as its natural sized type.

The leading 'n' stands for natural.

This is a compromise to indicate intend, but to avoid handling a multiple sized ssize_t footprint where not desired.

Definition at line 67 of file int_types.hpp.

◆ uint_bytes_t

template<int bytesize>

using jau::uint_bytes_t = typename uint_bytes<bytesize>::type

Alias template for uint_bytes.

Definition at line 79 of file int_types.hpp.

◆ sint_bytes_t

template<int bytesize>

using jau::sint_bytes_t = typename sint_bytes<bytesize>::type

Alias template for sint_bytes.

Definition at line 89 of file int_types.hpp.

◆ float_bytes_t

template<int bytesize>

using jau::float_bytes_t = typename float_bytes<bytesize>::type

Alias template for float_bytes.

Definition at line 97 of file int_types.hpp.

Function Documentation

◆ in_range()

template<class T, std::enable_if_t< std::is_arithmetic_v< T >, bool > = true>

bool jau::in_range	(	const T &	a,
		const T &	b,
		const T &	range )

base_math: arithmetic types, i.e.

integral + floating point types int_math: integral types float_math: floating point types Returns true, if both integer point values differ less than the given range.

Template Parameters

T	an arithmetic type

Parameters

a	value to compare
b	value to compare
range	the maximum difference both values may differ

Definition at line 62 of file base_math.hpp.

◆ sign()

template<typename T, std::enable_if_t< std::is_arithmetic_v< T > &&!std::is_unsigned_v< T >, bool > = true>

int jau::sign ( const T x )

constexprnoexcept

Returns the value of the sign function (w/o branching ?) in O(1).

-1 for x < 0
 0 for x = 0
 1 for x > 0

Implementation is type safe.

Branching may occur due to relational operator.

Template Parameters

T	an arithmetic number type

Parameters

x	the arithmetic number

Returns: function result

Definition at line 84 of file base_math.hpp.

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◆ invert_sign()

template<typename T, std::enable_if_t< std::is_arithmetic_v< T > &&!std::is_unsigned_v< T >, bool > = true>

T jau::invert_sign ( const T x )

constexprnoexcept

Safely inverts the sign of an arithmetic number w/ branching in O(1)

Implementation takes special care to have T_MIN, i.e. std::numeric_limits<T>::min(), converted to T_MAX, i.e. std::numeric_limits<T>::max().
This is necessary since T_MAX < | -T_MIN | and the result would not fit in the return type T otherwise.

Hence for the extreme minimum case:

jau::invert_sign<int32_t>(INT32_MIN) = | INT32_MIN | - 1 = INT32_MAX

Otherwise with x < 0:

jau::invert_sign<int32_t>(x) = | x | = -x

and x >= 0:

jau::invert_sign<int32_t>(x) = -x

Template Parameters

T	an unsigned arithmetic number type

Parameters

x	the number

Returns: function result

Definition at line 126 of file base_math.hpp.

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◆ abs() [1/2]

template<typename T, std::enable_if_t< std::is_arithmetic_v< T > &&!std::is_unsigned_v< T >, bool > = true>

T jau::abs ( const T x )

constexprnoexcept

Returns the absolute value of an arithmetic number (w/ branching) in O(1)

signed uses jau::invert_sign() to have a safe absolute value conversion
unsigned just returns the value
2-complement branch-less is not used due to lack of INT_MIN -> INT_MAX conversion, bithacks Integer-Abs

This implementation uses jau::invert_sign() to have a safe absolute value conversion, if required.

Template Parameters

T	an arithmetic number type

Parameters

x	the number

Returns: function result

Definition at line 155 of file base_math.hpp.

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◆ min() [1/3]

template<typename T, std::enable_if_t< std::is_arithmetic_v< T >, bool > = true>

T jau::min	(	const T	x,
		const T	y )

constexprnoexcept

Returns the minimum of two integrals (w/ branching) in O(1)

Template Parameters

T	an arithmetic number type

Parameters

x	one number
x	the other number

Definition at line 177 of file base_math.hpp.

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◆ max() [1/3]

template<typename T, std::enable_if_t< std::is_arithmetic_v< T >, bool > = true>

T jau::max	(	const T	x,
		const T	y )

constexprnoexcept

Returns the maximum of two integrals (w/ branching) in O(1)

Template Parameters

T	an arithmetic number type

Parameters

x	one number
x	the other number

Definition at line 191 of file base_math.hpp.

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◆ clamp() [1/3]

template<typename T, std::enable_if_t< std::is_arithmetic_v< T >, bool > = true>

T jau::clamp	(	const T	x,
		const T	min_val,
		const T	max_val )

constexprnoexcept

Returns constrained integral value to lie between given min- and maximum value (w/ branching) in O(1).

Implementation returns min(max(x, min_val), max_val), analog to GLSL's clamp()

Template Parameters

T	an arithmetic number type

Parameters

x	one number
min_val	the minimum limes, inclusive
max_val	the maximum limes, inclusive

Definition at line 208 of file base_math.hpp.

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◆ set_bit_uint32()

void jau::set_bit_uint32	(	const uint8_t	nr,
		uint32_t &	mask )

inline

Definition at line 559 of file basic_types.hpp.

◆ clear_bit_uint32()

void jau::clear_bit_uint32	(	const uint8_t	nr,
		uint32_t &	mask )

inline

Definition at line 566 of file basic_types.hpp.

◆ test_bit_uint32()

uint32_t jau::test_bit_uint32	(	const uint8_t	nr,
		const uint32_t	mask )

inline

Definition at line 573 of file basic_types.hpp.

◆ set_bit_uint64()

void jau::set_bit_uint64	(	const uint8_t	nr,
		uint64_t &	mask )

inline

Definition at line 580 of file basic_types.hpp.

◆ clear_bit_uint64()

void jau::clear_bit_uint64	(	const uint8_t	nr,
		uint64_t &	mask )

inline

Definition at line 587 of file basic_types.hpp.

◆ test_bit_uint64()

uint64_t jau::test_bit_uint64	(	const uint8_t	nr,
		const uint64_t	mask )

inline

Definition at line 594 of file basic_types.hpp.

◆ merge_uint128() [1/2]

uint128dp_t jau::merge_uint128	(	uint16_t const	uuid16,
		uint128dp_t const &	base_uuid,
		nsize_t const	uuid16_le_octet_index )

Merge the given 'uuid16' into a 'base_uuid' copy at the given little endian 'uuid16_le_octet_index' position.

The given 'uuid16' value will be added with the 'base_uuid' copy at the given position.

base_uuid: 00000000-0000-1000-8000-00805F9B34FB
   uuid16: DCBA
uuid16_le_octet_index: 12
   result: 0000DCBA-0000-1000-8000-00805F9B34FB

LE: low-mem - FB349B5F8000-0080-0010-0000-ABCD0000 - high-mem
                                          ^ index 12
LE: uuid16 -> value.data[12+13]

BE: low-mem - 0000DCBA-0000-1000-8000-00805F9B34FB - high-mem
                  ^ index 2
BE: uuid16 -> value.data[2+3]

Definition at line 528 of file basic_types.cpp.

◆ merge_uint128() [2/2]

uint128dp_t jau::merge_uint128	(	uint32_t const	uuid32,
		uint128dp_t const &	base_uuid,
		nsize_t const	uuid32_le_octet_index )

Merge the given 'uuid32' into a 'base_uuid' copy at the given little endian 'uuid32_le_octet_index' position.

The given 'uuid32' value will be added with the 'base_uuid' copy at the given position.

base_uuid: 00000000-0000-1000-8000-00805F9B34FB
   uuid32: 87654321
uuid32_le_octet_index: 12
   result: 87654321-0000-1000-8000-00805F9B34FB

LE: low-mem - FB349B5F8000-0080-0010-0000-12345678 - high-mem
                                          ^ index 12
LE: uuid32 -> value.data[12..15]

BE: low-mem - 87654321-0000-1000-8000-00805F9B34FB - high-mem
              ^ index 0
BE: uuid32 -> value.data[0..3]

Definition at line 563 of file basic_types.cpp.

◆ is_zero()

template<class T>

std::enable_if_t< std::is_integral_v< T >, bool > constexpr jau::is_zero ( const T & a )

constexprnoexcept

base_math: arithmetic types, i.e.

integral + floating point types int_math: integral types float_math: floating point types Returns true of the given integer value is zero.

Definition at line 56 of file int_math.hpp.

◆ equals() [1/2]

template<class T>

std::enable_if_t< std::is_integral_v< T >, bool > constexpr jau::equals	(	const T &	a,
		const T &	b )

constexprnoexcept

Returns true if both values are equal.

Template Parameters

T	an integral type

Parameters

a	value to compare
b	value to compare

Definition at line 69 of file int_math.hpp.

◆ equals() [2/2]

template<class T>

std::enable_if_t< std::is_integral_v< T >, bool > constexpr jau::equals	(	const T &	a,
		const T &	b,
		const T &	allowed_deviation )

constexprnoexcept

Returns true if both values are equal, i.e.

their absolute delta <= allowed_deviation.

Template Parameters

T	an integral type

Parameters

a	value to compare
b	value to compare
allowed_deviation	allowed deviation

Definition at line 83 of file int_math.hpp.

◆ round_up()

template<typename T, typename U, std::enable_if_t< std::is_integral_v< T > &&std::is_unsigned_v< T > &&std::is_integral_v< U > &&std::is_unsigned_v< U >, bool > = true>

T jau::round_up	(	const T	n,
		const U	align_to )

constexpr

Round up w/ branching in O(1)

Template Parameters

T	an unsigned integral number type
U	an unsigned integral number type

Parameters

n	to be aligned number
align_to	alignment boundary, must not be 0

Returns: n rounded up to a multiple of align_to

Definition at line 99 of file int_math.hpp.

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◆ round_down()

template<typename T, typename U, std::enable_if_t< std::is_integral_v< T > &&std::is_unsigned_v< T > &&std::is_integral_v< U > &&std::is_unsigned_v< U >, bool > = true>

T jau::round_down	(	T	n,
		U	align_to )

constexpr

Round down w/ branching in O(1)

Template Parameters

T	an unsigned integral number type
U	an unsigned integral number type

Parameters

n	to be aligned number
align_to	alignment boundary

Returns: n rounded down to a multiple of align_to

Definition at line 121 of file int_math.hpp.

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◆ is_power_of_2()

template<typename T, std::enable_if_t< std::is_integral_v< T > &&std::is_unsigned_v< T >, bool > = true>

bool jau::is_power_of_2 ( const T x )

constexprnoexcept

Power of 2 test (w/o branching ?) in O(1)

Source: bithacks Test PowerOf2

Branching may occur due to relational operator.

Template Parameters

T	an unsigned integral number type

Parameters

x	the unsigned integral number

Returns: true if arg is 2^n for some n > 0

Definition at line 138 of file int_math.hpp.

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◆ round_to_power_of_2()

uint32_t jau::round_to_power_of_2 ( const uint32_t n )

constexpr

If the given n is not is_power_of_2() return next_power_of_2(), otherwise return n unchanged.

return is_power_of_2(n) ? n : next_power_of_2(n);

Definition at line 150 of file int_math.hpp.

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◆ high_bit()

template<typename T, std::enable_if_t< std::is_integral_v< T > &&std::is_unsigned_v< T >, bool > = true>

nsize_t jau::high_bit ( T x )

constexpr

Return the index of the highest set bit w/ branching (loop) in O(n), actually O(n/2).

Template Parameters

T	an unsigned integral number type

Parameters

x value

Definition at line 162 of file int_math.hpp.

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◆ has_builtin_add_overflow()

consteval_cxx20 bool jau::has_builtin_add_overflow ( )

noexcept

Query whether __builtin_add_overflow is available via __has_builtin(__builtin_add_overflow).

Definition at line 177 of file int_math.hpp.

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◆ has_builtin_sub_overflow()

consteval_cxx20 bool jau::has_builtin_sub_overflow ( )

noexcept

Query whether __builtin_sub_overflow is available via __has_builtin(__builtin_sub_overflow).

Definition at line 188 of file int_math.hpp.

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◆ has_builtin_mul_overflow()

consteval_cxx20 bool jau::has_builtin_mul_overflow ( )

noexcept

Query whether __builtin_mul_overflow is available via __has_builtin(__builtin_mul_overflow).

Definition at line 199 of file int_math.hpp.

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◆ add_overflow()

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>

bool jau::add_overflow	(	const T	a,
		const T	b,
		T &	res )

constexprnoexcept

Integer overflow aware addition returning true if overflow occurred, otherwise false having the result stored in res.

Implementation uses Integer Overflow Builtins if available, otherwise its own implementation.

Template Parameters

T	an integral integer type

param a operand a

Parameters

b	operand b
res	storage for result

Returns: true if overflow, otherwise false

Definition at line 223 of file int_math.hpp.

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◆ sub_overflow()

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>

bool jau::sub_overflow	(	const T	a,
		const T	b,
		T &	res )

constexprnoexcept

Integer overflow aware subtraction returning true if overflow occurred, otherwise false having the result stored in res.

Implementation uses Integer Overflow Builtins if available, otherwise its own implementation.

Template Parameters

T	an integral integer type

param a operand a

Parameters

b	operand b
res	storage for result

Returns: true if overflow, otherwise false

Definition at line 257 of file int_math.hpp.

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◆ mul_overflow()

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>

bool jau::mul_overflow	(	const T	a,
		const T	b,
		T &	res )

constexprnoexcept

Integer overflow aware multiplication returning true if overflow occurred, otherwise false having the result stored in res.

Implementation uses Integer Overflow Builtins if available, otherwise its own implementation.

Template Parameters

T	an integral integer type

param a operand a

Parameters

b	operand b
res	storage for result

Returns: true if overflow, otherwise false

Definition at line 291 of file int_math.hpp.

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◆ gcd() [1/2]

template<typename T, std::enable_if_t< std::is_integral_v< T > &&!std::is_unsigned_v< T >, bool > = true>

T jau::gcd	(	T	a,
		T	b )

constexprnoexcept

Returns the greatest common divisor (GCD) of the two given integer values following Euclid's algorithm from Euclid's Elements ~300 BC, using the absolute positive value of given integers.

Returns zero if a and b is zero.

Note implementation uses modulo operator (a/b)*b + a % b = a, i.e. remainder of the integer division - hence implementation uses abs(a) % abs(b) in case the integral T is a signed type (dropped for unsigned).

Implementation is similar to std::gcd(), however, it uses a fixed common type T and a while loop instead of compile time evaluation via recursion.

Template Parameters

T	integral type

param a integral value a

Parameters

b	integral value b

Returns: zero if a and b are zero, otherwise the greatest common divisor (GCD) of a and b,

Definition at line 330 of file int_math.hpp.

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◆ lcm_overflow()

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>

bool jau::lcm_overflow	(	const T	a,
		const T	b,
		T &	result )

constexprnoexcept

Integer overflow aware calculation of least common multiple (LCM) following Euclid's algorithm from Euclid's Elements ~300 BC.

Template Parameters

T	integral type

param result storage for lcm result: zero if a and b are zero, otherwise lcm of a and b

Parameters

a	integral value a
b	integral value b

Returns: true if overflow, otherwise false for success

Definition at line 366 of file int_math.hpp.

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◆ digits10() [1/2]

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>

nsize_t jau::digits10	(	const T	x,
		const snsize_t	x_sign,
		const bool	sign_is_digit = true )

constexprnoexcept

Returns the number of decimal digits of the given integral value number using std::log10<T>().

If sign_is_digit == true (default), treats a potential negative sign as a digit.

x < 0: 1 + (int) ( log10( -x ) ) + ( sign_is_digit ? 1 : 0 )
x = 0: 1
x > 0: 1 + (int) ( log10(  x ) )

Implementation uses jau::invert_sign() to have a safe absolute value conversion, if required.

Convenience method, reusing precomputed sign of value to avoid redundant computations.

Template Parameters

T	an integral integer type

Parameters

x	the integral integer
x_sign	the pre-determined sign of the given value x
sign_is_digit	if true and value is negative, adds one to result for sign. Defaults to true.

Returns: digit count

Examples: test_intdecstring01.cpp.

Definition at line 403 of file int_math.hpp.

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◆ digits10() [2/2]

template<typename T, std::enable_if_t< std::is_integral_v< T >, bool > = true>

nsize_t jau::digits10	(	const T	x,
		const bool	sign_is_digit = true )

constexprnoexcept

Returns the number of decimal digits of the given integral value number using std::log10<T>().

If sign_is_digit == true (default), treats a potential negative sign as a digit.

x < 0: 1 + (int) ( log10( -x ) ) + ( sign_is_digit ? 1 : 0 )
x = 0: 1
x > 0: 1 + (int) ( log10(  x ) )

Implementation uses jau::invert_sign() to have a safe absolute value conversion, if required.

Template Parameters

T	an integral integer type

Parameters

x	the integral integer
sign_is_digit	if true and value is negative, adds one to result for sign. Defaults to true.

Returns: digit count

Definition at line 431 of file int_math.hpp.

◆ abs() [2/2]

mp::BigInt jau::abs ( const mp::BigInt & x )

inlinenoexcept

Definition at line 1559 of file big_int.hpp.

◆ pow()

mp::BigInt jau::pow	(	mp::BigInt	b,
		const mp::BigInt &	e )

inline

Definition at line 1560 of file big_int.hpp.

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◆ min() [2/3]

const mp::BigInt & jau::min	(	const mp::BigInt &	x,
		const mp::BigInt &	y )

inlinenoexcept

Definition at line 1562 of file big_int.hpp.

◆ max() [2/3]

const mp::BigInt & jau::max	(	const mp::BigInt &	x,
		const mp::BigInt &	y )

inlinenoexcept

Definition at line 1565 of file big_int.hpp.

◆ clamp() [2/3]

const mp::BigInt & jau::clamp	(	const mp::BigInt &	x,
		const mp::BigInt &	min_val,
		const mp::BigInt &	max_val )

inlinenoexcept

Definition at line 1568 of file big_int.hpp.

◆ min() [3/3]

mp::BigInt & jau::min	(	mp::BigInt &	x,
		mp::BigInt &	y )

inlinenoexcept

Definition at line 1572 of file big_int.hpp.

◆ max() [3/3]

mp::BigInt & jau::max	(	mp::BigInt &	x,
		mp::BigInt &	y )

inlinenoexcept

Definition at line 1575 of file big_int.hpp.

◆ clamp() [3/3]

mp::BigInt & jau::clamp	(	mp::BigInt &	x,
		mp::BigInt &	min_val,
		mp::BigInt &	max_val )

inlinenoexcept

Definition at line 1578 of file big_int.hpp.

◆ gcd() [2/2]

mp::BigInt jau::gcd	(	const mp::BigInt &	a,
		const mp::BigInt &	b )

inlinenoexcept

Definition at line 1582 of file big_int.hpp.

Namespaces

Classes

Typedefs

Functions

Detailed Description

Typedef Documentation

◆ nsize_t

◆ snsize_t

◆ uint_bytes_t

◆ sint_bytes_t

◆ float_bytes_t

Function Documentation

◆ in_range()

◆ sign()

◆ invert_sign()

◆ abs() [1/2]

◆ min() [1/3]

◆ max() [1/3]

◆ clamp() [1/3]

◆ set_bit_uint32()

◆ clear_bit_uint32()

◆ test_bit_uint32()

◆ set_bit_uint64()

◆ clear_bit_uint64()

◆ test_bit_uint64()

◆ merge_uint128() [1/2]

◆ merge_uint128() [2/2]

◆ is_zero()

◆ equals() [1/2]

◆ equals() [2/2]

◆ round_up()

◆ round_down()

◆ is_power_of_2()

◆ round_to_power_of_2()

◆ high_bit()

◆ has_builtin_add_overflow()

◆ has_builtin_sub_overflow()

◆ has_builtin_mul_overflow()

◆ add_overflow()

◆ sub_overflow()

◆ mul_overflow()

◆ gcd() [1/2]

◆ lcm_overflow()

◆ digits10() [1/2]

◆ digits10() [2/2]

◆ abs() [2/2]

◆ pow()

◆ min() [2/3]

◆ max() [2/3]

◆ clamp() [2/3]

◆ min() [3/3]

◆ max() [3/3]

◆ clamp() [3/3]

◆ gcd() [2/2]