CUB
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Groups
Public Types | Public Methods | Friends | List of all members
cub::TransformInputIterator< ValueType, ConversionOp, InputIteratorT, OffsetT > Class Template Reference

Detailed description

template< typename ValueType, typename ConversionOp, typename InputIteratorT, typename OffsetT = ptrdiff_t>
class cub::TransformInputIterator< ValueType, ConversionOp, InputIteratorT, OffsetT >

A random-access input wrapper for transforming dereferenced values.

Overview
  • TransformInputIteratorTwraps a unary conversion functor of type ConversionOp and a random-access input iterator of type InputIteratorT, using the former to produce references of type ValueType from the latter.
  • 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 TransformInputIteratorTto dereference an array of integers, tripling the values and converting them to doubles.
#include <cub/cub.cuh> // or equivalently <cub/iterator/transform_input_iterator.cuh>
// Functor for tripling integer values and converting to doubles
struct TripleDoubler
{
__host__ __device__ __forceinline__
double operator()(const int &a) const {
return double(a * 3);
}
};
// Declare, allocate, and initialize a device array
int *d_in; // e.g., [8, 6, 7, 5, 3, 0, 9]
TripleDoubler conversion_op;
// Create an iterator wrapper
// Within device code:
printf("%f\n", itr[0]); // 24.0
printf("%f\n", itr[1]); // 18.0
printf("%f\n", itr[6]); // 27.0
Template Parameters
ValueTypeThe value type of this iterator
ConversionOpUnary functor type for mapping objects of type InputType to type ValueType. Must have member ValueType operator()(const InputType &datum).
InputIteratorTThe type of the wrapped input iterator
OffsetTThe difference type of this iterator (Default: ptrdiff_t)

Public Types

typedef TransformInputIterator self_type
 My own type.
 
typedef OffsetT difference_type
 Type to express the result of subtracting one iterator from another.
 
typedef ValueType value_type
 The type of the element the iterator can point to.
 
typedef ValueType * pointer
 The type of a pointer to an element the iterator can point to.
 
typedef ValueType 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 Methods

__host__ __device__ __forceinline__ TransformInputIterator (InputIteratorT input_itr, ConversionOp conversion_op)
 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.
 

Friends

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

Constructor & Destructor Documentation

template<typename ValueType, typename ConversionOp, typename InputIteratorT, typename OffsetT = ptrdiff_t>
__host__ __device__ __forceinline__ cub::TransformInputIterator< ValueType, ConversionOp, InputIteratorT, OffsetT >::TransformInputIterator ( InputIteratorT  input_itr,
ConversionOp  conversion_op 
)
inline

Constructor.

Parameters
input_itrInput iterator to wrap
conversion_opConversion functor to wrap

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