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/*
* 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.
*/
#pragma once
#include <thrust/detail/config.h>
#include <thrust/iterator/iterator_facade.h>
#include <thrust/iterator/detail/minimum_system.h>
#include <thrust/iterator/counting_iterator.h>
#include <thrust/detail/type_traits.h>
THRUST_NAMESPACE_BEGIN
namespace detail
{
template<typename RandomAccessIterator1,
typename RandomAccessIterator2,
typename Difference,
typename Reference>
class join_iterator;
namespace join_iterator_detail
{
template<typename RandomAccessIterator1,
typename RandomAccessIterator2,
typename Difference,
typename Reference>
struct join_iterator_base
{
typedef typename thrust::detail::remove_reference<Reference>::type value_type;
typedef typename thrust::iterator_system<RandomAccessIterator1>::type system1;
typedef typename thrust::iterator_system<RandomAccessIterator2>::type system2;
typedef typename thrust::detail::minimum_system<system1,system2>::type system;
typedef thrust::iterator_adaptor<
join_iterator<RandomAccessIterator1,RandomAccessIterator2,Difference,Reference>,
thrust::counting_iterator<Difference>,
value_type,
system,
thrust::random_access_traversal_tag,
Reference,
Difference
> type;
}; // end join_iterator_base
} // end join_iterator_detail
template<typename RandomAccessIterator1,
typename RandomAccessIterator2,
typename Difference = typename thrust::iterator_difference<RandomAccessIterator1>::type,
typename Reference = typename thrust::iterator_value<RandomAccessIterator1>::type>
class join_iterator
: public join_iterator_detail::join_iterator_base<RandomAccessIterator1, RandomAccessIterator2, Difference, Reference>::type
{
private:
typedef typename join_iterator_detail::join_iterator_base<RandomAccessIterator1, RandomAccessIterator2, Difference, Reference>::type super_t;
typedef typename super_t::difference_type size_type;
public:
inline __host__ __device__
join_iterator(RandomAccessIterator1 first1, size_type n, RandomAccessIterator2 first2)
: super_t(thrust::counting_iterator<size_type>(0)),
m_n1(n),
m_iter1(first1),
m_iter2(first2 - m_n1)
{}
inline __host__ __device__
join_iterator(const join_iterator &other)
: super_t(other),
m_n1(other.m_n1),
m_iter1(other.m_iter1),
m_iter2(other.m_iter2)
{}
private:
friend class thrust::iterator_core_access;
// MSVC 2013 and 2015 incorrectly warning about returning a reference to
// a local/temporary here.
// See goo.gl/LELTNp
THRUST_DISABLE_MSVC_WARNING_BEGIN(4172)
__host__ __device__
typename super_t::reference dereference() const
{
size_type i = *super_t::base();
return (i < m_n1) ? m_iter1[i] : static_cast<typename super_t::reference>(m_iter2[i]);
} // end dereference()
THRUST_DISABLE_MSVC_WARNING_END(4172)
size_type m_n1;
RandomAccessIterator1 m_iter1;
RandomAccessIterator2 m_iter2;
}; // end join_iterator
template<typename RandomAccessIterator1, typename Size, typename RandomAccessIterator2>
__host__ __device__
join_iterator<RandomAccessIterator1,RandomAccessIterator2,Size> make_join_iterator(RandomAccessIterator1 first1, Size n1, RandomAccessIterator2 first2)
{
return join_iterator<RandomAccessIterator1,RandomAccessIterator2,Size>(first1, n1, first2);
} // end make_join_iterator()
} // end detail
THRUST_NAMESPACE_END
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