56fd68e7dd
CCCL (CUDA C++ Core Libraries) provides: - CUB: device/block/warp-level GPU primitives (reduce, scan, sort, topk) - Thrust: high-level parallel algorithms (transform_reduce, sort, scan) - libcudacxx: CUDA C++ standard library (atomics, barriers, memory) - cudax: experimental features (memory resources, allocators) - Tuning policies: per-SM hardware-specific algorithm parameters Competition optimization vectors mapped to CCCL: - Output TPS (83% weight): warp_reduce, block_reduce, device_topk - Input TPS (14% weight): device_scan, block_load, prefetch - Cache TPS (3% weight): prefix caching strategy patterns - Memory (0.9 util): pooled/cached/buddy allocators Source: https://github.com/NVIDIA/cccl (shallow clone, HEAD only) License: Apache-2.0
458 lines
21 KiB
C++
458 lines
21 KiB
C++
// SPDX-FileCopyrightText: Copyright (c) 2008-2013, NVIDIA Corporation. All rights reserved.
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// SPDX-License-Identifier: Apache-2.0
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/*! \file scatter.h
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* \brief Irregular copying to a destination range
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*/
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#pragma once
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#include <thrust/detail/config.h>
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#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
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# pragma GCC system_header
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#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
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# pragma clang system_header
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#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
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# pragma system_header
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#endif // no system header
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#include <thrust/detail/execution_policy.h>
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THRUST_NAMESPACE_BEGIN
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/*! \addtogroup scattering
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* \ingroup copying
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* \{
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*/
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/*! \p scatter copies elements from a source range into an output array
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* according to a map. For each iterator \c i in the range [\p first, \p last),
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* the value \c *i is assigned to <tt>output[*(map + (i - first))]</tt>. The
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* output iterator must permit random access. If the same index
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* appears more than once in the range <tt>[map, map + (last - first))</tt>,
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* the result is undefined.
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*
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* The algorithm's execution is parallelized as determined by \p exec.
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*
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* \param exec The execution policy to use for parallelization.
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* \param first Beginning of the sequence of values to scatter.
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* \param last End of the sequence of values to scatter.
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* \param map Beginning of the sequence of output indices.
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* \param result Destination of the source elements.
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*
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* \tparam DerivedPolicy The name of the derived execution policy.
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* \tparam InputIterator1 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator1's \c value_type must be convertible to \c RandomAccessIterator's \c value_type.
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* \tparam InputIterator2 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator2's \c value_type must be convertible to \c RandomAccessIterator's \c
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* difference_type. \tparam RandomAccessIterator must be a model of <a
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* href="https://en.cppreference.com/w/cpp/iterator/random_access_iterator">Random Access iterator</a>.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[first,last)` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[map, map + (last - first))` for all iterators `i` in the range `[map, map + (last - first))`.
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*
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* \pre The expression `result[*i]` shall be valid for all iterators in the range `[map, map + (last - first))`.
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*
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* The following code snippet demonstrates how to use \p scatter to reorder a range using
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* the \p thrust::device execution policy for parallelization:
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*
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* \code
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* #include <thrust/scatter.h>
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* #include <thrust/device_vector.h>
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* #include <thrust/execution_policy.h>
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* ...
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* // mark even indices with a 1; odd indices with a 0
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* int values[10] = {1, 0, 1, 0, 1, 0, 1, 0, 1, 0};
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* thrust::device_vector<int> d_values(values, values + 10);
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*
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* // scatter all even indices into the first half of the
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* // range, and odd indices vice versa
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* int map[10] = {0, 5, 1, 6, 2, 7, 3, 8, 4, 9};
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* thrust::device_vector<int> d_map(map, map + 10);
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*
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* thrust::device_vector<int> d_output(10);
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* thrust::scatter(thrust::device,
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* d_values.begin(), d_values.end(),
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* d_map.begin(), d_output.begin());
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* // d_output is now {1, 1, 1, 1, 1, 0, 0, 0, 0, 0}
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* \endcode
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*
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* \note \p scatter is the inverse of thrust::gather.
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*
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* \verbatim embed:rst:leading-asterisk
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* .. versionadded:: 2.2.0
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* \endverbatim
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*/
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template <typename DerivedPolicy, typename InputIterator1, typename InputIterator2, typename RandomAccessIterator>
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_CCCL_HOST_DEVICE void
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scatter(const thrust::detail::execution_policy_base<DerivedPolicy>& exec,
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InputIterator1 first,
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InputIterator1 last,
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InputIterator2 map,
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RandomAccessIterator result);
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/*! \p scatter copies elements from a source range into an output array
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* according to a map. For each iterator \c i in the range [\p first, \p last),
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* the value \c *i is assigned to <tt>output[*(map + (i - first))]</tt>. The
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* output iterator must permit random access. If the same index
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* appears more than once in the range <tt>[map, map + (last - first))</tt>,
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* the result is undefined.
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*
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* \param first Beginning of the sequence of values to scatter.
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* \param last End of the sequence of values to scatter.
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* \param map Beginning of the sequence of output indices.
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* \param result Destination of the source elements.
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*
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* \tparam InputIterator1 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator1's \c value_type must be convertible to \c RandomAccessIterator's \c value_type.
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* \tparam InputIterator2 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator2's \c value_type must be convertible to \c RandomAccessIterator's \c
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* difference_type. \tparam RandomAccessIterator must be a model of <a
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* href="https://en.cppreference.com/w/cpp/iterator/random_access_iterator">Random Access iterator</a>.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[first,last)` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[map,map + (last - first))` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The expression `result[*i]` shall be valid for all iterators in the range `[map,map + (last - first))`.
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*
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* The following code snippet demonstrates how to use \p scatter to reorder a range.
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*
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* \code
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* #include <thrust/scatter.h>
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* #include <thrust/device_vector.h>
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* ...
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* // mark even indices with a 1; odd indices with a 0
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* int values[10] = {1, 0, 1, 0, 1, 0, 1, 0, 1, 0};
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* thrust::device_vector<int> d_values(values, values + 10);
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*
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* // scatter all even indices into the first half of the
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* // range, and odd indices vice versa
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* int map[10] = {0, 5, 1, 6, 2, 7, 3, 8, 4, 9};
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* thrust::device_vector<int> d_map(map, map + 10);
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*
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* thrust::device_vector<int> d_output(10);
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* thrust::scatter(d_values.begin(), d_values.end(),
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* d_map.begin(), d_output.begin());
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* // d_output is now {1, 1, 1, 1, 1, 0, 0, 0, 0, 0}
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* \endcode
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*
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* \note \p scatter is the inverse of thrust::gather.
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*
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* \verbatim embed:rst:leading-asterisk
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* .. versionadded:: 2.2.0
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* \endverbatim
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*/
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template <typename InputIterator1, typename InputIterator2, typename RandomAccessIterator>
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void scatter(InputIterator1 first, InputIterator1 last, InputIterator2 map, RandomAccessIterator result);
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/*! \p scatter_if conditionally copies elements from a source range into an
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* output array according to a map. For each iterator \c i in the
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* range <tt>[first, last)</tt> such that <tt>*(stencil + (i - first))</tt> is
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* true, the value \c *i is assigned to <tt>output[*(map + (i - first))]</tt>.
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* The output iterator must permit random access. If the same index
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* appears more than once in the range <tt>[map, map + (last - first))</tt>
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* the result is undefined.
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*
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* The algorithm's execution is parallelized as determined by \p exec.
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*
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* \param exec The execution policy to use for parallelization.
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* \param first Beginning of the sequence of values to scatter.
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* \param last End of the sequence of values to scatter.
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* \param map Beginning of the sequence of output indices.
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* \param stencil Beginning of the sequence of predicate values.
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* \param output Beginning of the destination range.
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*
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* \tparam DerivedPolicy The name of the derived execution policy.
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* \tparam InputIterator1 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator1's \c value_type must be convertible to \c RandomAccessIterator's \c value_type.
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* \tparam InputIterator2 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator2's \c value_type must be convertible to \c RandomAccessIterator's \c
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* difference_type. \tparam InputIterator3 must be a model of <a
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* href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input Iterator</a> and \c InputIterator3's \c
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* value_type must be convertible to \c bool. \tparam RandomAccessIterator must be a model of <a
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* href="https://en.cppreference.com/w/cpp/iterator/random_access_iterator">Random Access iterator</a>.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[first,last)` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[map,map + (last - first))` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[stencil,stencil + (last - first))` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The expression `result[*i]` shall be valid for all iterators `i` in the range `[map,map + (last - first))` for
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* which the following condition holds: `*(stencil + i) != false`.
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*
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* \code
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* #include <thrust/scatter.h>
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* #include <thrust/execution_policy.h>
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* ...
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* int V[8] = {10, 20, 30, 40, 50, 60, 70, 80};
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* int M[8] = {0, 5, 1, 6, 2, 7, 3, 4};
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* int S[8] = {1, 0, 1, 0, 1, 0, 1, 0};
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* int D[8] = {0, 0, 0, 0, 0, 0, 0, 0};
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*
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* thrust::scatter_if(thrust::host, V, V + 8, M, S, D);
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*
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* // D contains [10, 30, 50, 70, 0, 0, 0, 0];
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* \endcode
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*
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* \note \p scatter_if is the inverse of thrust::gather_if.
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*
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* \verbatim embed:rst:leading-asterisk
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* .. versionadded:: 2.2.0
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* \endverbatim
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*/
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template <typename DerivedPolicy,
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typename InputIterator1,
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typename InputIterator2,
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typename InputIterator3,
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typename RandomAccessIterator>
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_CCCL_HOST_DEVICE void scatter_if(
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const thrust::detail::execution_policy_base<DerivedPolicy>& exec,
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InputIterator1 first,
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InputIterator1 last,
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InputIterator2 map,
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InputIterator3 stencil,
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RandomAccessIterator output);
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/*! \p scatter_if conditionally copies elements from a source range into an
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* output array according to a map. For each iterator \c i in the
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* range <tt>[first, last)</tt> such that <tt>*(stencil + (i - first))</tt> is
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* true, the value \c *i is assigned to <tt>output[*(map + (i - first))]</tt>.
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* The output iterator must permit random access. If the same index
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* appears more than once in the range <tt>[map, map + (last - first))</tt>
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* the result is undefined.
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*
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* \param first Beginning of the sequence of values to scatter.
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* \param last End of the sequence of values to scatter.
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* \param map Beginning of the sequence of output indices.
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* \param stencil Beginning of the sequence of predicate values.
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* \param output Beginning of the destination range.
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*
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* \tparam InputIterator1 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator1's \c value_type must be convertible to \c RandomAccessIterator's \c value_type.
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* \tparam InputIterator2 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator2's \c value_type must be convertible to \c RandomAccessIterator's \c
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* difference_type. \tparam InputIterator3 must be a model of <a
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* href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input Iterator</a> and \c InputIterator3's \c
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* value_type must be convertible to \c bool. \tparam RandomAccessIterator must be a model of <a
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* href="https://en.cppreference.com/w/cpp/iterator/random_access_iterator">Random Access iterator</a>.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[first,last)` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[map,map + (last - first))` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[stencil,stencil + (last - first))` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The expression `result[*i]` shall be valid for all iterators `i` in the range `[map,map + (last - first))` for
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* which the following condition holds: `*(stencil + i) != false`.
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*
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* \code
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* #include <thrust/scatter.h>
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* ...
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* int V[8] = {10, 20, 30, 40, 50, 60, 70, 80};
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* int M[8] = {0, 5, 1, 6, 2, 7, 3, 4};
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* int S[8] = {1, 0, 1, 0, 1, 0, 1, 0};
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* int D[8] = {0, 0, 0, 0, 0, 0, 0, 0};
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*
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* thrust::scatter_if(V, V + 8, M, S, D);
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*
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* // D contains [10, 30, 50, 70, 0, 0, 0, 0];
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* \endcode
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*
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* \note \p scatter_if is the inverse of thrust::gather_if.
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*
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* \verbatim embed:rst:leading-asterisk
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* .. versionadded:: 2.2.0
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* \endverbatim
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*/
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template <typename InputIterator1, typename InputIterator2, typename InputIterator3, typename RandomAccessIterator>
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void scatter_if(
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InputIterator1 first, InputIterator1 last, InputIterator2 map, InputIterator3 stencil, RandomAccessIterator output);
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/*! \p scatter_if conditionally copies elements from a source range into an
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* output array according to a map. For each iterator \c i in the
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* range <tt>[first, last)</tt> such that <tt>pred(*(stencil + (i - first)))</tt> is
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* \c true, the value \c *i is assigned to <tt>output[*(map + (i - first))]</tt>.
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* The output iterator must permit random access. If the same index
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* appears more than once in the range <tt>[map, map + (last - first))</tt>
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* the result is undefined.
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*
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* The algorithm's execution is parallelized as determined by \p exec.
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*
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* \param exec The execution policy to use for parallelization.
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* \param first Beginning of the sequence of values to scatter.
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* \param last End of the sequence of values to scatter.
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* \param map Beginning of the sequence of output indices.
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* \param stencil Beginning of the sequence of predicate values.
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* \param output Beginning of the destination range.
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* \param pred Predicate to apply to the stencil values.
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*
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* \tparam DerivedPolicy The name of the derived execution policy.
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* \tparam InputIterator1 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator1's \c value_type must be convertible to \c RandomAccessIterator's \c value_type.
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* \tparam InputIterator2 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator2's \c value_type must be convertible to \c RandomAccessIterator's \c
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* difference_type. \tparam InputIterator3 must be a model of <a
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* href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input Iterator</a> and \c InputIterator3's \c
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* value_type must be convertible to \c Predicate's argument type. \tparam RandomAccessIterator must be a model of <a
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* href="https://en.cppreference.com/w/cpp/iterator/random_access_iterator">Random Access iterator</a>. \tparam
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* Predicate must be a model of <a href="https://en.cppreference.com/w/cpp/concepts/predicate">Predicate</a>.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[first,last)` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[map,map + (last - first))` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[stencil,stencil + (last - first))` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The expression `result[*i]` shall be valid for all iterators `i` in the range `[map,map + (last - first))` for
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* which the following condition holds: `pred(*(stencil + i)) != false`.
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*
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* \code
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* #include <thrust/scatter.h>
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* #include <thrust/execution_policy.h>
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*
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* struct is_even
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* {
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* __host__ __device__
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* bool operator()(int x)
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* {
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* return (x % 2) == 0;
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* }
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* };
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*
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* ...
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*
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* int V[8] = {10, 20, 30, 40, 50, 60, 70, 80};
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* int M[8] = {0, 5, 1, 6, 2, 7, 3, 4};
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* int S[8] = {2, 1, 2, 1, 2, 1, 2, 1};
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* int D[8] = {0, 0, 0, 0, 0, 0, 0, 0};
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*
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* is_even pred;
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* thrust::scatter_if(thrust::host, V, V + 8, M, S, D, pred);
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*
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* // D contains [10, 30, 50, 70, 0, 0, 0, 0];
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* \endcode
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*
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* \note \p scatter_if is the inverse of thrust::gather_if.
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*
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* \verbatim embed:rst:leading-asterisk
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* .. versionadded:: 2.2.0
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* \endverbatim
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*/
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template <typename DerivedPolicy,
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typename InputIterator1,
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typename InputIterator2,
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typename InputIterator3,
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typename RandomAccessIterator,
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typename Predicate>
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_CCCL_HOST_DEVICE void scatter_if(
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const thrust::detail::execution_policy_base<DerivedPolicy>& exec,
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InputIterator1 first,
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InputIterator1 last,
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InputIterator2 map,
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InputIterator3 stencil,
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RandomAccessIterator output,
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Predicate pred);
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/*! \p scatter_if conditionally copies elements from a source range into an
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* output array according to a map. For each iterator \c i in the
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* range <tt>[first, last)</tt> such that <tt>pred(*(stencil + (i - first)))</tt> is
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* \c true, the value \c *i is assigned to <tt>output[*(map + (i - first))]</tt>.
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* The output iterator must permit random access. If the same index
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* appears more than once in the range <tt>[map, map + (last - first))</tt>
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* the result is undefined.
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*
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* \param first Beginning of the sequence of values to scatter.
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* \param last End of the sequence of values to scatter.
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* \param map Beginning of the sequence of output indices.
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* \param stencil Beginning of the sequence of predicate values.
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* \param output Beginning of the destination range.
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* \param pred Predicate to apply to the stencil values.
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*
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* \tparam InputIterator1 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator1's \c value_type must be convertible to \c RandomAccessIterator's \c value_type.
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* \tparam InputIterator2 must be a model of <a href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input
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* Iterator</a> and \c InputIterator2's \c value_type must be convertible to \c RandomAccessIterator's \c
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* difference_type. \tparam InputIterator3 must be a model of <a
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* href="https://en.cppreference.com/w/cpp/iterator/input_iterator">Input Iterator</a> and \c InputIterator3's \c
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* value_type must be convertible to \c Predicate's argument type. \tparam RandomAccessIterator must be a model of <a
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* href="https://en.cppreference.com/w/cpp/iterator/random_access_iterator">Random Access iterator</a>. \tparam
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* Predicate must be a model of <a href="https://en.cppreference.com/w/cpp/concepts/predicate">Predicate</a>.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[first,last)` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[map,map + (last - first))` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The iterator `result + i` shall not refer to any element referenced by any iterator `j` in the range
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* `[stencil,stencil + (last - first))` for all iterators `i` in the range `[map,map + (last - first))`.
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*
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* \pre The expression `result[*i]` shall be valid for all iterators `i` in the range `[map,map + (last - first))` for
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* which the following condition holds: `pred(*(stencil + i)) != false`.
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*
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* \code
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* #include <thrust/scatter.h>
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*
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* struct is_even
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* {
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* __host__ __device__
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* bool operator()(int x)
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* {
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* return (x % 2) == 0;
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* }
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* };
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*
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* ...
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*
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* int V[8] = {10, 20, 30, 40, 50, 60, 70, 80};
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* int M[8] = {0, 5, 1, 6, 2, 7, 3, 4};
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* int S[8] = {2, 1, 2, 1, 2, 1, 2, 1};
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* int D[8] = {0, 0, 0, 0, 0, 0, 0, 0};
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*
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* is_even pred;
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* thrust::scatter_if(V, V + 8, M, S, D, pred);
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*
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* // D contains [10, 30, 50, 70, 0, 0, 0, 0];
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* \endcode
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*
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* \note \p scatter_if is the inverse of thrust::gather_if.
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*
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* \verbatim embed:rst:leading-asterisk
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* .. versionadded:: 2.2.0
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* \endverbatim
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*/
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template <typename InputIterator1,
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typename InputIterator2,
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typename InputIterator3,
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typename RandomAccessIterator,
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typename Predicate>
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void scatter_if(InputIterator1 first,
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InputIterator1 last,
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InputIterator2 map,
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InputIterator3 stencil,
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RandomAccessIterator output,
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Predicate pred);
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/*! \} // end scattering
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*/
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THRUST_NAMESPACE_END
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#include <thrust/detail/scatter.inl>
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