DSC::BitsArray< N > Class Template Reference

Specialized class for handling arrays of bits. More...

#include <bits_array.hpp>

Classes
struct	__bit
	proxy bit access More...

Public Member Functions
	BitsArray (bool default_value=false)
	creates a new prefilled BitsArray instance More...
const bool &	operator[] (int index) const
	random access iterator in const contexts More...
__bit	operator[] (int index)
	random access iterator for both l-value and r-value contexts More...
bool	at (int index) const
	alternative to random access iterator More...
int	find_free_bit () const
	finds a position of the first unset bit in the array More...
int	size () const
void	clear ()
	clears all bits of the array (sets them all to 0)
void	set_all ()
	sets all bits of the array to 1
void	unset_all ()
	sets all bits of the array to 0

Static Public Member Functions
static BitsArray< N > *	take_over (void *offset)
	Makes the memory at a certain offset available as a bits array and provides direct bit access to it More...

Detailed Description

template<const int N>
class DSC::BitsArray< N >

Specialized class for handling arrays of bits.

Template Parameters

N	the size of the bits array

The bits are packed into full words in a contiguous memory zone, so the size of the structure BitsArray<N> is the size of the minimum number of 32-bit integers required to contain all the N bits.

Actually, sizeof(BitsArray<N>) == 4*((N+31) / 32).

Constructor & Destructor Documentation

BitsArray()

template<const int N>

DSC::BitsArray< N >::BitsArray

(

bool

default_value = false

)

creates a new prefilled BitsArray instance

Parameters

default_value

the initial value of all bits

Member Function Documentation

at()

template<const int N>

bool DSC::BitsArray< N >::at

(

int

index

)

const

alternative to random access iterator

Parameters

index

the position of the bit 0..N-1

Returns

the value of the bit at the specified index

find_free_bit()

template<const int N>

int DSC::BitsArray< N >::find_free_bit

finds a position of the first unset bit in the array

Returns

position of the unset bit (0..N-1), or -1 if no free bit was found

operator[]() [1/2]

template<const int N>

DSC::BitsArray< N >::__bit DSC::BitsArray< N >::operator[]

(

int

index

)

random access iterator for both l-value and r-value contexts

Parameters

index

the position of the bit 0..N-1

Returns

a reference to the value of the bit at the specified index

Warning

Do not use the reference as a substitute for the bit's value! The value of a bit is extracted from DSC::BitsArray::__bit by conversion to bool. This conversion is done implicitely wherever the compiler thinks it's necessary. However, if unsure whetehr the conversion takes place or not, use the explicit (bool)(...) conversion, or use DSC::BitsArray::at().

BitsArray<N> bits;
bits[0] = true;                       // ok
bool b = bits[0];                     // ok
if(bits[0]) {...}                     // ok
if(!bits[1]) {...}                    // ok
DSC::Debug::log("%i", bits[0]);       // wrong, will display the int constructed from the first 4 bytes of _the reference_ pushed to stack
DSC::Debug::log("%i", (bool)bits[0]); // ok, the actual bit value will be pushed onto stack

operator[]() [2/2]

template<const int N>

const bool & DSC::BitsArray< N >::operator[]

(

int

index

)

const

random access iterator in const contexts

Parameters

index

the position of the bit 0..N-1

Returns

the value of the bit at the specified index

size()

template<const int N>

int DSC::BitsArray< N >::size ( ) const

inline

Returns

the number of bits in the array

take_over()

template<const int N>

DSC::BitsArray< N > * DSC::BitsArray< N >::take_over ( void *  offset )

static

Makes the memory at a certain offset available as a bits array and provides direct bit access to it

Parameters

offset

the start of the bits array (must be word-aligned)

Template Parameters

N	the size of the bits array (must be multiple of 32)

Returns

pointer to BitsArray instance over the specified offset

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

• include/DSCEngine/types/bits_array.hpp