cub::ArgIndexInputIterator< InputIteratorT, OffsetT, OutputValueT > Class Template Reference

A random-access input wrapper for pairing dereferenced values with their corresponding indices (forming KeyValuePair tuples). More...

Detailed Description

template<typename InputIteratorT, typename OffsetT = ptrdiff_t, typename OutputValueT = typename std::iterator_traits<InputIteratorT>::value_type>
class cub::ArgIndexInputIterator< InputIteratorT, OffsetT, OutputValueT >

A random-access input wrapper for pairing dereferenced values with their corresponding indices (forming KeyValuePair tuples).

Overview

• ArgIndexInputIteratorTwraps a random access input iterator itr of type InputIteratorT. Dereferencing an ArgIndexInputIteratorTat offset i produces a KeyValuePair value whose key field is i and whose value field is itr[i].
• Can be used with any data type.
• Can be constructed, manipulated, and exchanged within and between host and device functions. Wrapped host memory can only be dereferenced on the host, and wrapped device memory can only be dereferenced on the device.
• Compatible with Thrust API v1.7 or newer.

Snippet

The code snippet below illustrates the use of ArgIndexInputIteratorTto dereference an array of doubles

#include <cub/cub.cuh>   // or equivalently <cub/iterator/arg_index_input_iterator.cuh>

// Declare, allocate, and initialize a device array
double *d_in;         // e.g., [8.0, 6.0, 7.0, 5.0, 3.0, 0.0, 9.0]

// Create an iterator wrapper
cub::ArgIndexInputIterator<double*> itr(d_in);

// Within device code:
typedef typename cub::ArgIndexInputIterator<double*>::value_type Tuple;
Tuple item_offset_pair.key = *itr;
printf("%f @ %d\n",
  item_offset_pair.value,
  item_offset_pair.key);   // 8.0 @ 0

itr = itr + 6;
item_offset_pair.key = *itr;
printf("%f @ %d\n",
  item_offset_pair.value,
  item_offset_pair.key);   // 9.0 @ 6

Template Parameters

InputIteratorT	The value type of the wrapped input iterator
OffsetT	The difference type of this iterator (Default: ptrdiff_t)
OutputValueT	The paired value type of the <offset,value> tuple (Default: value type of input iterator)

Definition at line 113 of file arg_index_input_iterator.cuh.

Public Types
typedef ArgIndexInputIterator	self_type
	My own type.
typedef OffsetT	difference_type
	Type to express the result of subtracting one iterator from another.
typedef KeyValuePair< difference_type, OutputValueT >	value_type
	The type of the element the iterator can point to.
typedef value_type *	pointer
	The type of a pointer to an element the iterator can point to.
typedef value_type	reference
	The type of a reference to an element the iterator can point to.
typedef std::random_access_iterator_tag	iterator_category
	The iterator category.

Public Member Functions
__host__ __device__ __forceinline__	ArgIndexInputIterator (InputIteratorT itr, difference_type offset=0)
	Constructor. More...
__host__ __device__ __forceinline__ self_type	operator++ (int)
	Postfix increment.
__host__ __device__ __forceinline__ self_type	operator++ ()
	Prefix increment.
__host__ __device__ __forceinline__ reference	operator * () const
	Indirection.
template<typename Distance >
__host__ __device__ __forceinline__ self_type	operator+ (Distance n) const
	Addition.
template<typename Distance >
__host__ __device__ __forceinline__ self_type &	operator+= (Distance n)
	Addition assignment.
template<typename Distance >
__host__ __device__ __forceinline__ self_type	operator- (Distance n) const
	Subtraction.
template<typename Distance >
__host__ __device__ __forceinline__ self_type &	operator-= (Distance n)
	Subtraction assignment.
__host__ __device__ __forceinline__ difference_type	operator- (self_type other) const
	Distance.
template<typename Distance >
__host__ __device__ __forceinline__ reference	operator[] (Distance n) const
	Array subscript.
__host__ __device__ __forceinline__ pointer	operator-> ()
	Structure dereference.
__host__ __device__ __forceinline__ bool	operator== (const self_type &rhs)
	Equal to.
__host__ __device__ __forceinline__ bool	operator!= (const self_type &rhs)
	Not equal to.
__host__ __device__ __forceinline__ void	normalize ()
	Normalize.

Private Attributes
InputIteratorT	itr
difference_type	offset

Friends
std::ostream &	operator<< (std::ostream &os, const self_type &)
	ostream operator

Constructor & Destructor Documentation

ArgIndexInputIterator()

template<typename InputIteratorT, typename OffsetT = ptrdiff_t, typename OutputValueT = typename std::iterator_traits<InputIteratorT>::value_type>

__host__ __device__ __forceinline__ cub::ArgIndexInputIterator< InputIteratorT, OffsetT, OutputValueT >::ArgIndexInputIterator ( InputIteratorT  itr, difference_type  offset = 0  )

inline

Constructor.

Parameters

itr	Input iterator to wrap
offset	OffsetT (in items) from itr denoting the position of the iterator

Definition at line 144 of file arg_index_input_iterator.cuh.

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

• openfpm_data/src/util/cuda/cub_old/iterator/arg_index_input_iterator.cuh