// Copyright (c) 2001-2011 Hartmut Kaiser
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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#ifndef BOOST_SPIRIT_KARMA_DETAIL_INDIRECT_ITERATOR_HPP
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#define BOOST_SPIRIT_KARMA_DETAIL_INDIRECT_ITERATOR_HPP
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#if defined(_MSC_VER)
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#pragma once
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#endif
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#include <boost/spirit/home/support/unused.hpp>
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#include <boost/iterator/iterator_facade.hpp>
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#include <iterator> // for std::iterator_traits
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///////////////////////////////////////////////////////////////////////////////
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namespace boost { namespace spirit { namespace karma { namespace detail
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{
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///////////////////////////////////////////////////////////////////////
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// This is a wrapper for any iterator allowing to pass a reference of it
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// to the components of the sequence
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template <typename Iterator>
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class indirect_iterator
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: public boost::iterator_facade<
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indirect_iterator<Iterator>
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, typename std::iterator_traits<Iterator>::value_type
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, boost::forward_traversal_tag
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, typename std::iterator_traits<Iterator>::reference>
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{
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typedef typename std::iterator_traits<Iterator>::value_type
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base_value_type;
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typedef typename std::iterator_traits<Iterator>::reference
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base_reference_type;
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typedef boost::iterator_facade<
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indirect_iterator<Iterator>, base_value_type
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, boost::forward_traversal_tag, base_reference_type
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> base_type;
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public:
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indirect_iterator(Iterator& iter)
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: iter_(&iter)
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{}
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indirect_iterator(indirect_iterator const& iter)
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: iter_(iter.iter_)
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{}
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private:
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friend class boost::iterator_core_access;
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void increment()
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{
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++*iter_;
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}
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bool equal(indirect_iterator const& other) const
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{
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return *iter_ == *other.iter_;
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}
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base_reference_type dereference() const
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{
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return **iter_;
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}
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private:
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Iterator* iter_;
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};
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}}}}
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///////////////////////////////////////////////////////////////////////////////
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namespace boost { namespace spirit { namespace traits
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{
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template <typename Iterator>
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struct make_indirect_iterator
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{
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typedef karma::detail::indirect_iterator<Iterator> type;
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};
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template <typename Iterator>
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struct make_indirect_iterator<karma::detail::indirect_iterator<Iterator> >
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{
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typedef karma::detail::indirect_iterator<Iterator> type;
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};
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template <>
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struct make_indirect_iterator<unused_type const*>
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{
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typedef unused_type const* type;
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};
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template <typename Iterator>
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struct make_indirect_iterator<Iterator const&>
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: make_indirect_iterator<Iterator const>
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{};
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}}}
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#endif
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