text: /*
   *  Copyright 2008-2013 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/reverse.h>
  #include <thrust/advance.h>
  #include <thrust/distance.h>
  #include <thrust/detail/copy.h>
  #include <thrust/swap.h>
  #include <thrust/iterator/iterator_traits.h>
  #include <thrust/iterator/reverse_iterator.h>
  
  namespace thrust
  {
  namespace system
  {
  namespace detail
  {
  namespace generic
  {
  
  template<typename ExecutionPolicy, typename BidirectionalIterator>
    void reverse(thrust::execution_policy<ExecutionPolicy> &exec,
                 BidirectionalIterator first,
                 BidirectionalIterator last)
  {
    typedef typename thrust::iterator_difference<BidirectionalIterator>::type difference_type;
  
    // find the midpoint of [first,last)
    difference_type N = thrust::distance(first, last);
    BidirectionalIterator mid(first);
    thrust::advance(mid, N / 2);
  
    // swap elements of [first,mid) with [last - 1, mid)
    thrust::swap_ranges(exec, first, mid, thrust::make_reverse_iterator(last));
  } // end reverse()
  
  template<typename ExecutionPolicy,
           typename BidirectionalIterator,
           typename OutputIterator>
    OutputIterator reverse_copy(thrust::execution_policy<ExecutionPolicy> &exec,
                                BidirectionalIterator first,
                                BidirectionalIterator last,
                                OutputIterator result)
  {
    return thrust::copy(exec,
                        thrust::make_reverse_iterator(last),
                        thrust::make_reverse_iterator(first),
                        result);
  } // end reverse_copy()
  
  } // end namespace generic
  } // end namespace detail
  } // end namespace system
  } // end namespace thrust
  
  
  