1 | /*=============================================================================
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2 | Copyright (c) 2003 Joel de Guzman
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3 | Copyright (c) 2004 Peder Holt
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4 |
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5 | Use, modification and distribution is subject to the Boost Software
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6 | License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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7 | http://www.boost.org/LICENSE_1_0.txt)
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8 | ==============================================================================*/
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9 | #if !defined(FUSION_ITERATOR_DETAIL_FILTER_VIEW_ITERATOR_NEXT_TRAITS_HPP)
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10 | #define FUSION_ITERATOR_DETAIL_FILTER_VIEW_ITERATOR_NEXT_TRAITS_HPP
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11 |
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12 | #include <boost/spirit/fusion/detail/config.hpp>
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13 | #include <boost/spirit/fusion/algorithm/detail/find_if.ipp>
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14 | #include <boost/spirit/fusion/iterator/next.hpp>
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15 | #include <boost/spirit/fusion/iterator/equal_to.hpp>
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16 | #include <boost/mpl/eval_if.hpp>
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17 | #include <boost/mpl/identity.hpp>
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18 |
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19 | namespace boost { namespace fusion
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20 | {
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21 | struct filter_view_iterator_tag;
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22 |
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23 | template <typename First, typename Last, typename Pred>
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24 | struct filter_iterator;
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25 |
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26 | namespace filter_view_detail {
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27 | template<typename Iterator>
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28 | struct next_traits_impl {
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29 | typedef typename Iterator::first_type first_type;
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30 | typedef typename Iterator::last_type last_type;
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31 | typedef typename Iterator::pred_type pred_type;
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32 |
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33 | typedef typename
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34 | mpl::eval_if<
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35 | meta::equal_to<first_type, last_type>
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36 | , mpl::identity<last_type>
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37 | , meta::next<first_type>
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38 | >::type
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39 | next_type;
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40 |
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41 | typedef typename detail::static_find_if<
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42 | next_type, last_type, pred_type>
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43 | filter;
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44 |
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45 | typedef filter_iterator<
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46 | typename filter::type, last_type, pred_type>
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47 | type;
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48 |
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49 | static type
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50 | call(Iterator const& i);
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51 | };
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52 | template<typename Iterator>
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53 | typename next_traits_impl<Iterator>::type
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54 | next_traits_impl<Iterator>::call(Iterator const& i)
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55 | {
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56 | return type(filter::call(i.first));
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57 | }
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58 | }
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59 |
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60 | namespace meta
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61 | {
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62 | template <typename Tag>
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63 | struct next_impl;
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64 |
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65 | template <>
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66 | struct next_impl<filter_view_iterator_tag>
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67 | {
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68 | template <typename Iterator>
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69 | struct apply : filter_view_detail::next_traits_impl<Iterator>
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70 | {};
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71 | };
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72 | }
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73 | }}
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74 |
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75 | #endif
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76 |
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77 |
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