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/*
* Copyright 2008-2012 NVIDIA Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*! \file scatter.h
* \brief Irregular copying to a destination range
*/
#pragma once
#include <thrust/detail/config.h>
#include <thrust/detail/dispatchable.h>
namespace thrust
{
template<typename System,
typename InputIterator1,
typename InputIterator2,
typename RandomAccessIterator>
void scatter(thrust::detail::dispatchable_base<System> &system,
InputIterator1 first,
InputIterator1 last,
InputIterator2 map,
RandomAccessIterator output);
template<typename System,
typename InputIterator1,
typename InputIterator2,
typename InputIterator3,
typename RandomAccessIterator>
void scatter_if(thrust::detail::dispatchable_base<System> &system,
InputIterator1 first,
InputIterator1 last,
InputIterator2 map,
InputIterator3 stencil,
RandomAccessIterator output);
template<typename System,
typename InputIterator1,
typename InputIterator2,
typename InputIterator3,
typename RandomAccessIterator,
typename Predicate>
void scatter_if(thrust::detail::dispatchable_base<System> &system,
InputIterator1 first,
InputIterator1 last,
InputIterator2 map,
InputIterator3 stencil,
RandomAccessIterator output,
Predicate pred);
/*! \addtogroup scattering
* \ingroup copying
* \{
*/
/*! \p scatter copies elements from a source range into an output array
* according to a map. For each iterator \c i in the range [\p first, \p last),
* the value \c *i is assigned to <tt>output[*(map + (i - first))]</tt>. The
* output iterator must permit random access. If the same index
* appears more than once in the range <tt>[map, map + (last - first))</tt>,
* the result is undefined.
*
* \param first Beginning of the sequence of values to scatter.
* \param last End of the sequence of values to scatter.
* \param map Beginning of the sequence of output indices.
* \param output Destination of the source elements.
*
* \tparam InputIterator1 must be a model of <a href="http://www.sgi.com/tech/stl/InputIterator.html">Input Iterator</a> and \c InputIterator1's \c value_type must be convertible to \c RandomAccessIterator's \c value_type.
* \tparam InputIterator2 must be a model of <a href="http://www.sgi.com/tech/stl/InputIterator.html">Input Iterator</a> and \c InputIterator2's \c value_type must be convertible to \c RandomAccessIterator's \c difference_type.
* \tparam RandomAccessIterator must be a model of <a href="http://www.sgi.com/tech/stl/RandomAccessIterator.html">Random Access iterator</a>.
*
* The following code snippet demonstrates how to use \p scatter to
* reorder a range.
*
* \code
* #include <thrust/scatter.h>
* #include <thrust/device_vector.h>
* ...
* // mark even indices with a 1; odd indices with a 0
* int values[10] = {1, 0, 1, 0, 1, 0, 1, 0, 1, 0};
* thrust::device_vector<int> d_values(values, values + 10);
*
* // scatter all even indices into the first half of the
* // range, and odd indices vice versa
* int map[10] = {0, 5, 1, 6, 2, 7, 3, 8, 4, 9};
* thrust::device_vector<int> d_map(map, map + 10);
*
* thrust::device_vector<int> d_output(10);
* thrust::scatter(d_values.begin(), d_values.end(),
* d_map.begin(), d_output.begin());
* // d_output is now {1, 1, 1, 1, 1, 0, 0, 0, 0, 0}
* \endcode
*
* \note \p scatter is the inverse of thrust::gather.
*/
template<typename InputIterator1,
typename InputIterator2,
typename RandomAccessIterator>
void scatter(InputIterator1 first,
InputIterator1 last,
InputIterator2 map,
RandomAccessIterator output);
/*! \p scatter_if conditionally copies elements from a source range into an
* output array according to a map. For each iterator \c i in the
* range <tt>[first, last)</tt> such that <tt>*(stencil + (i - first))</tt> is
* true, the value \c *i is assigned to <tt>output[*(map + (i - first))]</tt>.
* The output iterator must permit random access. If the same index
* appears more than once in the range <tt>[map, map + (last - first))</tt>
* the result is undefined.
*
* \param first Beginning of the sequence of values to scatter.
* \param last End of the sequence of values to scatter.
* \param map Beginning of the sequence of output indices.
* \param stencil Beginning of the sequence of predicate values.
* \param output Beginning of the destination range.
*
* \tparam InputIterator1 must be a model of <a href="http://www.sgi.com/tech/stl/InputIterator.html">Input Iterator</a> and \c InputIterator1's \c value_type must be convertible to \c RandomAccessIterator's \c value_type.
* \tparam InputIterator2 must be a model of <a href="http://www.sgi.com/tech/stl/InputIterator.html">Input Iterator</a> and \c InputIterator2's \c value_type must be convertible to \c RandomAccessIterator's \c difference_type.
* \tparam InputIterator3 must be a model of <a href="http://www.sgi.com/tech/stl/InputIterator.html">Input Iterator</a> and \c InputIterator3's \c value_type must be convertible to \c bool.
* \tparam RandomAccessIterator must be a model of <a href="http://www.sgi.com/tech/stl/RandomAccessIterator.html">Random Access iterator</a>.
*
* \code
* #include <thrust/scatter.h>
* ...
* int V[8] = {10, 20, 30, 40, 50, 60, 70, 80};
* int M[8] = {0, 5, 1, 6, 2, 7, 3, 4};
* int S[8] = {1, 0, 1, 0, 1, 0, 1, 0};
* int D[8] = {0, 0, 0, 0, 0, 0, 0, 0};
*
* thrust::scatter_if(V, V + 8, M, S, D);
*
* // D contains [10, 30, 50, 70, 0, 0, 0, 0];
* \endcode
*
* \note \p scatter_if is the inverse of thrust::gather_if.
*/
template<typename InputIterator1,
typename InputIterator2,
typename InputIterator3,
typename RandomAccessIterator>
void scatter_if(InputIterator1 first,
InputIterator1 last,
InputIterator2 map,
InputIterator3 stencil,
RandomAccessIterator output);
/*! \p scatter_if conditionally copies elements from a source range into an
* output array according to a map. For each iterator \c i in the
* range <tt>[first, last)</tt> such that <tt>pred(*(stencil + (i - first)))</tt> is
* \c true, the value \c *i is assigned to <tt>output[*(map + (i - first))]</tt>.
* The output iterator must permit random access. If the same index
* appears more than once in the range <tt>[map, map + (last - first))</tt>
* the result is undefined.
*
* \param first Beginning of the sequence of values to scatter.
* \param last End of the sequence of values to scatter.
* \param map Beginning of the sequence of output indices.
* \param stencil Beginning of the sequence of predicate values.
* \param output Beginning of the destination range.
* \param pred Predicate to apply to the stencil values.
*
* \tparam InputIterator1 must be a model of <a href="http://www.sgi.com/tech/stl/InputIterator.html">Input Iterator</a> and \c InputIterator1's \c value_type must be convertible to \c RandomAccessIterator's \c value_type.
* \tparam InputIterator2 must be a model of <a href="http://www.sgi.com/tech/stl/InputIterator.html">Input Iterator</a> and \c InputIterator2's \c value_type must be convertible to \c RandomAccessIterator's \c difference_type.
* \tparam InputIterator3 must be a model of <a href="http://www.sgi.com/tech/stl/InputIterator.html">Input Iterator</a> and \c InputIterator3's \c value_type must be convertible to \c Predicate's \c argument_type.
* \tparam RandomAccessIterator must be a model of <a href="http://www.sgi.com/tech/stl/RandomAccessIterator.html">Random Access iterator</a>.
* \tparam Predicate must be a model of <a href="http://www.sgi.com/tech/stl/Predicate.html">Predicate</a>.
*
* \code
* #include <thrust/scatter.h>
*
* struct is_even
* {
* __host__ __device__
* bool operator()(int x)
* {
* return (x % 2) == 0;
* }
* };
*
* ...
*
* int V[8] = {10, 20, 30, 40, 50, 60, 70, 80};
* int M[8] = {0, 5, 1, 6, 2, 7, 3, 4};
* int S[8] = {2, 1, 2, 1, 2, 1, 2, 1};
* int D[8] = {0, 0, 0, 0, 0, 0, 0, 0};
*
* is_even pred;
* thrust::scatter_if(V, V + 8, M, S, D, pred);
*
* // D contains [10, 30, 50, 70, 0, 0, 0, 0];
* \endcode
*
* \note \p scatter_if is the inverse of thrust::gather_if.
*/
template<typename InputIterator1,
typename InputIterator2,
typename InputIterator3,
typename RandomAccessIterator,
typename Predicate>
void scatter_if(InputIterator1 first,
InputIterator1 last,
InputIterator2 map,
InputIterator3 stencil,
RandomAccessIterator output,
Predicate pred);
/*! \} // end scattering
*/
} // end namespace thrust
#include <thrust/detail/scatter.inl>
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