FBitMask Struct Reference

A memory-efficient bit mask. More...

#include <BitMask.h>

Classes
struct	ConstIterator
	The bit mask bit iterator. More...
struct	FBitAccessor
	A special adapter for setting individual bits. More...
struct	Iterator
	The bit mask bit iterator. More...

Public Types
enum	{   GroupSizeBits = sizeof(GroupType) * 8 , GroupShift = 6 , GroupBitIndexMask = GroupSizeBits - 1 , bitsCountLUTSize = 256 ,   InlineGroupsCount = 4 }
typedef uint64	GroupType
	The type of the bit group elements.

Public Member Functions
int32	GroupsNum () const
	Get the number of available bit groups.
int32	BitsNum () const
	Get the number of available (allocated) bits.
bool	At (const int32 Index) const
	Get the bit flag at the specified index.
bool	operator[] (const int32 Index) const
	Get a bit element by its index.
FBitAccessor	operator[] (const int32 Index)
	Get a bit element by its index.
void	SetAt (const int32 Index, const bool Value)
	Set a bit at a specific index.
bool	IsNonZero () const
	Check if there are any non-zero bits in the mask.
bool	operator== (const FBitMask &Other) const
	Compare two bit masks for equality.
bool	operator!= (const FBitMask &Other) const
	Compare two bit masks for inequality.
bool	Identical (const FBitMask *Other, uint32 PortFlags) const
	Compare two bit masks for equality.
EApparatusStatus	Trim (const bool bAllowShrinking=true) const
	Trim the meaningless high-order groups.
bool	IsAllZeroes () const
	Check if all of the bits in the mask are zeroes or none.
int32	CountNonZeroGroups () const
	Get the number of meaningful (non-zero) bit groups.
EApparatusStatus	Set (FBitMask &&InBitMask)
	Move the bit mask to this bit mask.
template<EParadigm Paradigm = EParadigm::Default>
TOutcome< Paradigm >	Set (const FBitMask &InBitMask)
	Set this bit mask equal to another bit mask.
FBitMask &	operator= (FBitMask &&InBitMask)
	Move the bit mask.
FBitMask &	operator= (const FBitMask &InBitMask)
	Set this bit mask equal to another bit mask.
int32	DifferencesCount (const FBitMask &BitMask) const
	Get the number of different bits in two masks.
int32	InclusionsCount (const FBitMask &BitMask) const
	Get the number of included bits in two masks.
bool	Includes (const FBitMask &BitMask) const
	Does the mask has all of the bits set in the supplied mask.
bool	IncludesPartially (const FBitMask &BitMask) const
	Check if the mask has any of the bits set in the supplied mask.
Iterator	begin ()
ConstIterator	begin () const
Iterator	end ()
ConstIterator	end () const
int32	IndexOf (const bool Bit, const int32 Offset=0) const
	Get the index of the first matching bit in the mask.
void	EnsureGroupsNum (const int32 InGroupsCount)
	Ensure a bit group count.
void	EnsureGroupsForBitAt (const int32 BitIndex)
	Ensure that there is enough bit groups for an index.
int32	GroupsMax () const
	Get the current maximum number of bit groups that can be stored without any additional allocations.
int32	BitsMax () const
	Get the current maximum number of bits that can be stored without any additional allocations.
void	Reserve (const int32 BitCapacity)
	Reserve space for a given number of bits.
void	Empty (const int32 Slack=0)
	Empties the array.
void	Reset (const int32 NewSize=0)
	Same as empty, but doesn't change memory allocations, unless the new size is larger than the current array.
void	SetMasked (const FBitMask &Mask, const bool State)
	Set the bits based on a mask.
void	Insert (const int32 Index, const bool Bit)
	Insert a bit at the specified index.
void	Remove (const bool Bit)
	Remove the first occurrence of the specified bit from the mask.
void	RemoveAt (const int32 Index)
	Remove the bit at the specified index.
void	Erase (const int32 Index)
	Remove an element at the specified index.
template<EParadigm Paradigm = EParadigm::Default>
TOutcome< Paradigm >	Intersect (const FBitMask &InMask)
	Logically-and the bitmask with a given mask.
FBitMask &	operator&= (const FBitMask &InMask)
	Conjunct the bitmask with a given mask.
template<EParadigm Paradigm = EParadigm::Default>
TOutcome< Paradigm >	Include (const FBitMask &InMask)
	Logical-or the bitmask with a an another mask.
FBitMask &	operator|= (const FBitMask &InMask)
	Disjunct the bitmask with a given mask.
FString	ToString () const
	Convert the bit mask to a string representation.
uint32	CalcHash () const
	Calculate the bit mask hash.
bool	Serialize (FArchive &Archive)
	Serialize the bit mask.
Initialization
	FBitMask ()
	Construct a new empty bit mask.
	FBitMask (const FBitMask &InBitMask)
	Copy-construct the bit mask.
	FBitMask (FBitMask &&InBitMask)
	Move-construct the bit mask.
	FBitMask (const int32 Capacity)
	Initialize a new instance of a mask with a certain bit capacity.
	FBitMask (std::initializer_list< bool > list)
	Construct a new bit mask with an initializer list.

Static Public Attributes
static const GroupType	ZeroGroup {0}
	A group of all one bits set.
static const GroupType	FirstOneGroup {1}
	A group with the first bit set.
static const GroupType	LastOneGroup {(((GroupType)1) << (GroupSizeBits - 1))}
	A group with the last bit set.
static const GroupType	AllOnesGroup {TNumericLimits<GroupType>::Max()}
	A group of all one bits set.

Friends
class	StaticConstructor
uint32	GetTypeHash (const FBitMask &bm)
FBitMask	operator& (const FBitMask &MaskA, const FBitMask &MaskB)
	Logically-conjunct the bits in masks.
FBitMask	operator| (const FBitMask &MaskA, const FBitMask &MaskB)
	Logically-disjunct the bits in masks.

Detailed Description

A memory-efficient bit mask.

Please, note that this is not a usual bit array and serves some different purposes.

Member Typedef Documentation

GroupType

typedef uint64 FBitMask::GroupType

The type of the bit group elements.

Member Enumeration Documentation

anonymous enum

anonymous enum

Enumerator
GroupSizeBits	The size of the group type in bits.
GroupShift	A number of bits to shift (right) for getting a group index from a bit index.
GroupBitIndexMask	A mask for the group to get an index of the bit from.
bitsCountLUTSize	The number of entries in the bits count LUT.
InlineGroupsCount	The number of inline-allocated groups.

Constructor & Destructor Documentation

FBitMask() [1/5]

FBitMask::FBitMask ( )

inline

Construct a new empty bit mask.

FBitMask() [2/5]

FBitMask::FBitMask ( const FBitMask &  InBitMask )

inline

Copy-construct the bit mask.

FBitMask() [3/5]

FBitMask::FBitMask ( FBitMask &&  InBitMask )

inline

Move-construct the bit mask.

FBitMask() [4/5]

FBitMask::FBitMask ( const int32  Capacity )

inline

Initialize a new instance of a mask with a certain bit capacity.

FBitMask() [5/5]

FBitMask::FBitMask ( std::initializer_list< bool >  list )

inline

Construct a new bit mask with an initializer list.

Member Function Documentation

At()

bool FBitMask::At ( const int32  Index ) const

inline

Get the bit flag at the specified index.

Parameters

Index

The index of the bit to get. If it's out of the number of elements, false is returned.

Returns

The state of the bit at the specified index.

begin() [1/2]

Iterator FBitMask::begin ( )

inline

begin() [2/2]

ConstIterator FBitMask::begin ( ) const

inline

BitsMax()

int32 FBitMask::BitsMax ( ) const

inline

Get the current maximum number of bits that can be stored without any additional allocations.

BitsNum()

int32 FBitMask::BitsNum ( ) const

inline

Get the number of available (allocated) bits.

CalcHash()

uint32 FBitMask::CalcHash ( ) const

inline

Calculate the bit mask hash.

CountNonZeroGroups()

int32 FBitMask::CountNonZeroGroups ( ) const

inline

Get the number of meaningful (non-zero) bit groups.

DifferencesCount()

int32 FBitMask::DifferencesCount

(

const FBitMask &

BitMask

)

const

Get the number of different bits in two masks.

Empty()

void FBitMask::Empty ( const int32  Slack = 0 )

inline

Empties the array.

It calls the destructors on held flags if needed.

Parameters

Slack

The expected usage size in bits after empty operation.

end() [1/2]

Iterator FBitMask::end ( )

inline

end() [2/2]

ConstIterator FBitMask::end ( ) const

inline

EnsureGroupsForBitAt()

void FBitMask::EnsureGroupsForBitAt ( const int32  BitIndex )

inline

Ensure that there is enough bit groups for an index.

EnsureGroupsNum()

void FBitMask::EnsureGroupsNum ( const int32  InGroupsCount )

inline

Ensure a bit group count.

Erase()

void FBitMask::Erase ( const int32  Index )

inline

Remove an element at the specified index.

Parameters

Index

An index of the element to erase.

GroupsMax()

int32 FBitMask::GroupsMax ( ) const

inline

Get the current maximum number of bit groups that can be stored without any additional allocations.

GroupsNum()

int32 FBitMask::GroupsNum ( ) const

inline

Get the number of available bit groups.

Identical()

bool FBitMask::Identical ( const FBitMask *  Other, uint32  PortFlags  ) const

inline

Compare two bit masks for equality.

Editor-friendly method.

Parameters

Other	The other bit mask to compare to.
PortFlags	The contextual port flags.

Returns

The state of examination.

Include()

template<EParadigm Paradigm = EParadigm::Default>

TOutcome< Paradigm > FBitMask::Include ( const FBitMask &  InMask )

inline

Logical-or the bitmask with a an another mask.

This can actually be slower than FBitMask::operator|= since it provides a status.

Template Parameters

Paradigm

The paradigm to work on.

Parameters

InMask

The mask to include.

Returns

The status of the operation.

Includes()

bool FBitMask::Includes ( const FBitMask &  BitMask ) const

inline

Does the mask has all of the bits set in the supplied mask.

The same as a bitwise A & B == B.

IncludesPartially()

bool FBitMask::IncludesPartially ( const FBitMask &  BitMask ) const

inline

Check if the mask has any of the bits set in the supplied mask.

The same as a bitwise A & B != 0.

InclusionsCount()

int32 FBitMask::InclusionsCount

(

const FBitMask &

BitMask

)

const

Get the number of included bits in two masks.

IndexOf()

int32 FBitMask::IndexOf	(	const bool	Bit,
		const int32	Offset = 0
	)		const

Get the index of the first matching bit in the mask.

The mask is considered to be zero-limitless, so a falsy bit is always found in the end.

Parameters

Bit	The bit state to find.
Offset	The offset index to start with.

Returns

The index of the bit in question or INDEX_NONE, if the bit couldn't be found.

Insert()

void FBitMask::Insert	(	const int32	Index,
		const bool	Bit
	)

Insert a bit at the specified index.

Intersect()

template<EParadigm Paradigm = EParadigm::Default>

TOutcome< Paradigm > FBitMask::Intersect ( const FBitMask &  InMask )

inline

Logically-and the bitmask with a given mask.

Template Parameters

Paradigm

The paradigm to work under.

Parameters

InMask

The mask to intersect with.

Returns

The status of the operation.

IsAllZeroes()

bool FBitMask::IsAllZeroes ( ) const

inline

Check if all of the bits in the mask are zeroes or none.

IsNonZero()

bool FBitMask::IsNonZero ( ) const

inline

Check if there are any non-zero bits in the mask.

operator!=()

bool FBitMask::operator!= ( const FBitMask &  Other ) const

inline

Compare two bit masks for inequality.

operator&=()

FBitMask & FBitMask::operator&= ( const FBitMask &  InMask )

inline

Conjunct the bitmask with a given mask.

operator=() [1/2]

FBitMask & FBitMask::operator= ( const FBitMask &  InBitMask )

inline

Set this bit mask equal to another bit mask.

operator=() [2/2]

FBitMask & FBitMask::operator= ( FBitMask &&  InBitMask )

inline

Move the bit mask.

operator==()

bool FBitMask::operator== ( const FBitMask &  Other ) const

inline

Compare two bit masks for equality.

operator[]() [1/2]

FBitAccessor FBitMask::operator[] ( const int32  Index )

inline

Get a bit element by its index.

operator[]() [2/2]

bool FBitMask::operator[] ( const int32  Index ) const

inline

Get a bit element by its index.

Constant version.

operator|=()

FBitMask & FBitMask::operator|= ( const FBitMask &  InMask )

inline

Disjunct the bitmask with a given mask.

Remove()

void FBitMask::Remove

(

const bool

Bit

)

Remove the first occurrence of the specified bit from the mask.

RemoveAt()

void FBitMask::RemoveAt

(

const int32

Index

)

Remove the bit at the specified index.

Parameters

Index

The index of the bit to remove.

Reserve()

void FBitMask::Reserve ( const int32  BitCapacity )

inline

Reserve space for a given number of bits.

Reset()

void FBitMask::Reset ( const int32  NewSize = 0 )

inline

Same as empty, but doesn't change memory allocations, unless the new size is larger than the current array.

Parameters

NewSize

The expected usage size in bits after calling this function.

Serialize()

bool FBitMask::Serialize ( FArchive &  Archive )

inline

Serialize the bit mask.

Set() [1/2]

template<EParadigm Paradigm = EParadigm::Default>

TOutcome< Paradigm > FBitMask::Set ( const FBitMask &  InBitMask )

inline

Set this bit mask equal to another bit mask.

Template Parameters

Paradigm

The paradigm to work under.

Parameters

InBitMask

The bit mask to set to.

Returns

The outcome of the operation.

Set() [2/2]

EApparatusStatus FBitMask::Set ( FBitMask &&  InBitMask )

inline

Move the bit mask to this bit mask.

SetAt()

void FBitMask::SetAt ( const int32  Index, const bool  Value  )

inline

Set a bit at a specific index.

SetMasked()

void FBitMask::SetMasked ( const FBitMask &  Mask, const bool  State  )

inline

Set the bits based on a mask.

Parameters

Mask	The mask to use while setting the bits.
State	The state to set.

ToString()

FString FBitMask::ToString ( ) const

inline

Convert the bit mask to a string representation.

Trim()

EApparatusStatus FBitMask::Trim ( const bool  bAllowShrinking = true ) const

inline

Trim the meaningless high-order groups.

Parameters

bAllowShrinking

Is physical array size allowed to shrunk?

Friends And Related Function Documentation

GetTypeHash

uint32 GetTypeHash ( const FBitMask &  bm )

friend

operator&

FBitMask operator& ( const FBitMask &  MaskA, const FBitMask &  MaskB  )

friend

Logically-conjunct the bits in masks.

Parameters

MaskA	The first mask to conjunct.
MaskB	The second mask to conjunct.

Returns

The resulting conjunct mask.

operator|

FBitMask operator| ( const FBitMask &  MaskA, const FBitMask &  MaskB  )

friend

Logically-disjunct the bits in masks.

Parameters

MaskA	The first mask to disjunct.
MaskB	The second mask to disjunct.

Returns

The resulting disjunct mask.

StaticConstructor

friend class StaticConstructor

friend

Member Data Documentation

AllOnesGroup

const GroupType FBitMask::AllOnesGroup {TNumericLimits<GroupType>::Max()}

static

A group of all one bits set.

FirstOneGroup

const GroupType FBitMask::FirstOneGroup {1}

static

A group with the first bit set.

LastOneGroup

const GroupType FBitMask::LastOneGroup {(((GroupType)1) << (GroupSizeBits - 1))}

static

A group with the last bit set.

ZeroGroup

const GroupType FBitMask::ZeroGroup {0}

static

A group of all one bits set.

---

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

• BitMask.h