Represents a multi-index using a single integer. More...

#include <tiny_multi_index.hpp>

Classes
class	Entry

Public Member Functions
	TinyMultiIndex ()

	TinyMultiIndex (const TinyMultiIndex &that)

	TinyMultiIndex (const std::array< int, D > &that)

	TinyMultiIndex (std::initializer_list< int > list)

TinyMultiIndex &	operator= (const TinyMultiIndex &that)

int	operator[] (dim_t index) const

Entry	operator[] (dim_t index)

bool	operator== (const TinyMultiIndex &that) const

bool	operator!= (const TinyMultiIndex &that) const

	operator std::array< int, D > () const

Public Attributes
UINT	values_ = 0

Static Public Attributes
static const std::size_t	BITS_PER_ENTRY = (8*sizeof(UINT))/D

Static Private Member Functions
static int	limit (dim_t axis)

Friends
struct	std::less< waveblocks::wavepackets::shapes::TinyMultiIndex< UINT, D > >

struct	std::hash< waveblocks::wavepackets::shapes::TinyMultiIndex< UINT, D > >

struct	std::equal_to< waveblocks::wavepackets::shapes::TinyMultiIndex< UINT, D > >

Detailed Description

template<class UINT, dim_t D>
class waveblocks::wavepackets::shapes::TinyMultiIndex< UINT, D >

Represents a multi-index using a single integer.

This implementation splits an integer into same sized parts. For example, using a 64bit integer to represent a 10-dimensional multi-index: The largest index it can represent is 63 (6 bits). This means when using this class, special care must be taken to prevent overflows. Thus, code that uses multi-indices should ensure that a multi-index type is viable:

MultiIndex mindex;
for (dim_t d = 0; d < D; d++) {
   mindex[d] = largest_possible_index;
   if (mindex[d] != largest_possible_index)
      throw std::runtime_error("multi-index type is not compatible!");
}

If TinyMultiIndex is not enough for you. You will have to implement your own type. A custom implementation must possess the same semantics as std::array<int,D>. Furthermore it has to specialize std::less, that performs lexical index comparison beginning on the first index. And it has to specialize std::equal_to and std::hash to enable use of multi-indices as hashtable keys.

Template Parameters

UINT	Option to select, which integer type is used.
D	Dimensionality of multi-index i.e number of entries.