Detailed Description

template<typename HighType>
class foxxll::uint_pair< HighType >

Construct an 40-bit or 48-bit unsigned integer stored in five or six bytes.

The purpose of this class is to provide integers with smaller data storage footprints when more than 32-bit, but less than 64-bit indexes are needed. This is commonly the case for storing file offsets and indexes. Here smaller types currently suffice for files < 1 TiB or < 16 TiB.

The class combines a 32-bit integer with a HighType (either 8-bit or 16-bit) to get a larger type. Only unsigned values are supported, which fits the general application of file offsets.

Calculation in uint_pair are generally done by transforming everything to 64-bit data type, so that 64-bit register arithmetic can be used. The exception here is increment and decrement, which is done directly on the lower/higher part. Not all arithmetic operations are supported, patches welcome if you really need the operations.

Definition at line 53 of file uint_types.hpp.

#include <uint_types.hpp>

Public Types
using	high_type = HighType
	higher part type, currently either 8-bit or 16-bit More...

using	low_type = uint32_t
	lower part type, always 32-bit More...

Public Member Functions
	uint_pair ()
	empty constructor, does not even initialize to zero! More...

	uint_pair (const low_type &l, const high_type &h)
	construct unit pair from lower and higher parts. More...

	uint_pair (const uint32_t &a)
	implicit conversion from a simple 32-bit unsigned integer More...

	uint_pair (const int32_t &a)
	implicit conversion from a simple 32-bit signed integer More...

	uint_pair (const uint64_t &a)
	implicit conversion from an uint64_t (unsigned long long) More...

	operator uint64_t () const
	implicit cast to an unsigned long long More...

bool	operator!= (const uint_pair &b) const
	inequality checking operator More...

uint_pair &	operator++ ()
	prefix increment operator (directly manipulates the integer parts) More...

uint_pair &	operator+= (const uint_pair &b)
	addition operator (uses 64-bit arithmetic) More...

uint_pair &	operator-- ()
	prefix decrement operator (directly manipulates the integer parts) More...

bool	operator< (const uint_pair &b) const
	less-than comparison operator More...

bool	operator<= (const uint_pair &b) const
	less-or-equal comparison operator More...

bool	operator== (const uint_pair &b) const
	equality checking operator More...

bool	operator> (const uint_pair &b) const
	greater comparison operator More...

bool	operator>= (const uint_pair &b) const
	greater-or-equal comparison operator More...

uint64_t	u64 () const
	return the number as a uint64_t More...

uint64_t	ull () const
	return the number as an uint64_t (unsigned long long) More...

Static Public Member Functions
static uint_pair	max ()
	return an uint_pair instance containing the largest value possible More...

static uint_pair	min ()
	return an uint_pair instance containing the smallest value possible More...

Static Public Attributes
static const size_t	bytes = sizeof(low_type) + sizeof(high_type)
	number of bytes in uint_pair More...

static const size_t	digits = low_bits + high_bits
	number of binary digits (bits) in uint_pair More...

Static Private Member Functions
static high_type	high_max ()
	return highest value storable in higher part, also used as a mask. More...

static low_type	low_max ()
	return highest value storable in lower part, also used as a mask. More...

Private Attributes
high_type	high
	member containing higher significant integer value More...

low_type	low
	member containing lower significant integer value More...

Static Private Attributes
static const size_t	high_bits = 8 * sizeof(high_type)
	number of bits in the higher integer part, used a bit shift value. More...

static const size_t	low_bits = 8 * sizeof(low_type)
	number of bits in the lower integer part, used a bit shift value. More...

Friends
std::ostream &	operator<< (std::ostream &os, const uint_pair &a)
	make a uint_pair outputtable via iostreams, using unsigned long long. More...

Member Typedef Documentation

◆ high_type

using high_type = HighType

higher part type, currently either 8-bit or 16-bit

Definition at line 59 of file uint_types.hpp.

◆ low_type

using low_type = uint32_t

lower part type, always 32-bit

Definition at line 57 of file uint_types.hpp.

Constructor & Destructor Documentation

◆ uint_pair() [1/5]

uint_pair ( )

inline

empty constructor, does not even initialize to zero!

Definition at line 93 of file uint_types.hpp.

Referenced by uint_pair< HighType >::max(), and uint_pair< HighType >::min().

◆ uint_pair() [2/5]

uint_pair	(	const low_type &	l,
		const high_type &	h
	)

inline

construct unit pair from lower and higher parts.

Definition at line 114 of file uint_types.hpp.

◆ uint_pair() [3/5]

uint_pair ( const uint32_t & a )

inline

implicit conversion from a simple 32-bit unsigned integer

Definition at line 119 of file uint_types.hpp.

◆ uint_pair() [4/5]

uint_pair ( const int32_t & a )

inline

implicit conversion from a simple 32-bit signed integer

Definition at line 124 of file uint_types.hpp.

◆ uint_pair() [5/5]

uint_pair ( const uint64_t & a )

inline

implicit conversion from an uint64_t (unsigned long long)

Definition at line 134 of file uint_types.hpp.

Member Function Documentation

◆ high_max()

static high_type high_max ( )

inlinestaticprivate

return highest value storable in higher part, also used as a mask.

Definition at line 77 of file uint_types.hpp.

Referenced by operator!=().

◆ low_max()

static low_type low_max ( )

inlinestaticprivate

return highest value storable in lower part, also used as a mask.

Definition at line 68 of file uint_types.hpp.

Referenced by operator!=(), uint_pair< HighType >::operator++(), and uint_pair< HighType >::operator--().

◆ max()

static uint_pair max ( )

inlinestatic

return an uint_pair instance containing the largest value possible

Definition at line 241 of file uint_types.hpp.

References foxxll::__attribute__(), max(), and uint_pair< HighType >::uint_pair().

Referenced by numeric_limits< foxxll::uint_pair< HighType > >::max().

◆ min()

static uint_pair min ( )

inlinestatic

return an uint_pair instance containing the smallest value possible

Definition at line 232 of file uint_types.hpp.

References min(), and uint_pair< HighType >::uint_pair().

Referenced by numeric_limits< foxxll::uint_pair< HighType > >::lowest(), and numeric_limits< foxxll::uint_pair< HighType > >::min().

◆ operator uint64_t()

operator uint64_t ( ) const

inline

implicit cast to an unsigned long long

Definition at line 149 of file uint_types.hpp.

References uint_pair< HighType >::ull().

◆ operator!=()

bool operator!= ( const uint_pair< HighType > & b ) const

inline

inequality checking operator

Definition at line 196 of file uint_types.hpp.

◆ operator++()

uint_pair& operator++ ( )

inline

prefix increment operator (directly manipulates the integer parts)

Definition at line 161 of file uint_types.hpp.

References uint_pair< HighType >::high, uint_pair< HighType >::low_max(), and TLX_UNLIKELY.

◆ operator+=()

uint_pair& operator+= ( const uint_pair< HighType > & b )

inline

addition operator (uses 64-bit arithmetic)

Definition at line 181 of file uint_types.hpp.

◆ operator--()

uint_pair& operator-- ( )

inline

prefix decrement operator (directly manipulates the integer parts)

Definition at line 171 of file uint_types.hpp.

References uint_pair< HighType >::high, uint_pair< HighType >::low_max(), and TLX_UNLIKELY.

◆ operator<()

bool operator< ( const uint_pair< HighType > & b ) const

inline

less-than comparison operator

Definition at line 202 of file uint_types.hpp.

◆ operator<=()

bool operator<= ( const uint_pair< HighType > & b ) const

inline

less-or-equal comparison operator

Definition at line 208 of file uint_types.hpp.

◆ operator==()

bool operator== ( const uint_pair< HighType > & b ) const

inline

equality checking operator

Definition at line 190 of file uint_types.hpp.

◆ operator>()

bool operator> ( const uint_pair< HighType > & b ) const

inline

greater comparison operator

Definition at line 214 of file uint_types.hpp.

◆ operator>=()

bool operator>= ( const uint_pair< HighType > & b ) const

inline

greater-or-equal comparison operator

Definition at line 220 of file uint_types.hpp.

◆ u64()

uint64_t u64 ( ) const

inline

return the number as a uint64_t

Definition at line 155 of file uint_types.hpp.

◆ ull()

uint64_t ull ( ) const

inline

return the number as an uint64_t (unsigned long long)

Definition at line 143 of file uint_types.hpp.

References uint_pair< HighType >::high.

Referenced by uint_pair< HighType >::operator uint64_t().

Friends And Related Function Documentation

◆ operator<<

std::ostream& operator<<	(	std::ostream &	os,
		const uint_pair< HighType > &	a
	)

friend

make a uint_pair outputtable via iostreams, using unsigned long long.

Definition at line 226 of file uint_types.hpp.

Member Data Documentation

◆ bytes

const size_t bytes = sizeof(low_type) + sizeof(high_type)

static

number of bytes in uint_pair

Definition at line 90 of file uint_types.hpp.

◆ digits

const size_t digits = low_bits + high_bits

static

number of binary digits (bits) in uint_pair

Definition at line 87 of file uint_types.hpp.

◆ high

high_type high

private

member containing higher significant integer value

Definition at line 65 of file uint_types.hpp.

Referenced by uint_pair< HighType >::operator++(), operator--(), uint_pair< HighType >::operator--(), and uint_pair< HighType >::ull().

◆ high_bits

const size_t high_bits = 8 * sizeof(high_type)

staticprivate

number of bits in the higher integer part, used a bit shift value.

Definition at line 83 of file uint_types.hpp.

◆ low

low_type low

private

member containing lower significant integer value

Definition at line 63 of file uint_types.hpp.

Referenced by operator!=().

◆ low_bits

const size_t low_bits = 8 * sizeof(low_type)

staticprivate

number of bits in the lower integer part, used a bit shift value.

Definition at line 74 of file uint_types.hpp.

Referenced by operator!=().

The documentation for this class was generated from the following file:

extlib/foxxll/foxxll/common/uint_types.hpp

Detailed Description

template<typename HighType> class foxxll::uint_pair< HighType >

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Static Private Member Functions

Private Attributes

Static Private Attributes

Friends

Member Typedef Documentation

◆ high_type

◆ low_type

Constructor & Destructor Documentation

◆ uint_pair() [1/5]

◆ uint_pair() [2/5]

◆ uint_pair() [3/5]

◆ uint_pair() [4/5]

◆ uint_pair() [5/5]

Member Function Documentation

◆ high_max()

◆ low_max()

◆ max()

◆ min()

◆ operator uint64_t()

◆ operator!=()

◆ operator++()

◆ operator+=()

◆ operator--()

◆ operator<()

◆ operator<=()

◆ operator==()

◆ operator>()

◆ operator>=()

◆ u64()

◆ ull()

Friends And Related Function Documentation

◆ operator<<

Member Data Documentation

◆ bytes

◆ digits

◆ high

◆ high_bits

◆ low

◆ low_bits

template<typename HighType>
class foxxll::uint_pair< HighType >