text: /*
   *  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.
   */
  
  #include <thrust/detail/config.h>
  #include <thrust/system/detail/generic/gather.h>
  #include <thrust/iterator/iterator_traits.h>
  #include <thrust/functional.h>
  #include <thrust/transform.h>
  #include <thrust/iterator/permutation_iterator.h>
  
  namespace thrust
  {
  namespace system
  {
  namespace detail
  {
  namespace generic
  {
  
  template<typename InputIterator,
           typename RandomAccessIterator,
           typename OutputIterator>
    OutputIterator gather(tag,
                          InputIterator        map_first,
                          InputIterator        map_last,
                          RandomAccessIterator input_first,
                          OutputIterator       result)
  {
    return thrust::transform(thrust::make_permutation_iterator(input_first, map_first),
                             thrust::make_permutation_iterator(input_first, map_last),
                             result,
                             thrust::identity<typename thrust::iterator_value<RandomAccessIterator>::type>());
  } // end gather()
  
  
  template<typename InputIterator1,
           typename InputIterator2,
           typename RandomAccessIterator,
           typename OutputIterator>
    OutputIterator gather_if(tag,
                             InputIterator1       map_first,
                             InputIterator1       map_last,
                             InputIterator2       stencil,
                             RandomAccessIterator input_first,
                             OutputIterator       result)
  {
    typedef typename thrust::iterator_value<InputIterator2>::type StencilType;
    return thrust::gather_if(map_first,
                             map_last,
                             stencil,
                             input_first,
                             result,
                             thrust::identity<StencilType>());
  } // end gather_if()
  
  
  template<typename InputIterator1,
           typename InputIterator2,
           typename RandomAccessIterator,
           typename OutputIterator,
           typename Predicate>
    OutputIterator gather_if(tag,
                             InputIterator1       map_first,
                             InputIterator1       map_last,
                             InputIterator2       stencil,
                             RandomAccessIterator input_first,
                             OutputIterator       result,
                             Predicate            pred)
  {
    typedef typename thrust::iterator_value<RandomAccessIterator>::type InputType;
    return thrust::transform_if(thrust::make_permutation_iterator(input_first, map_first),
                                thrust::make_permutation_iterator(input_first, map_last),
                                stencil,
                                result,
                                thrust::identity<InputType>(),
                                pred);
  } // end gather_if()
  
  } // end namespace generic
  } // end namespace detail
  } // end namespace system
  } // end namespace thrust
  
  