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_SEQUENCE_AS_FUSION_ITERATOR_HPP)
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10 | #define FUSION_SEQUENCE_AS_FUSION_ITERATOR_HPP
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11 |
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12 | #include <boost/spirit/fusion/iterator/is_iterator.hpp>
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13 | #include <boost/spirit/fusion/iterator/type_sequence_iterator.hpp>
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14 | #include <boost/mpl/if.hpp>
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15 | #include <boost/mpl/bool.hpp>
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16 |
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17 | namespace boost { namespace fusion
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18 | {
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19 | // Test T. If it is a fusion iterator, return a reference to it.
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20 | // else, assume it is an mpl iterator.
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21 |
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22 | namespace as_fusion_iterator_detail {
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23 | template <typename T>
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24 | static T const&
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25 | convert(T const& x, mpl::true_)
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26 | {
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27 | return x;
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28 | }
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29 |
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30 | template <typename T>
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31 | static type_sequence_iterator<T>
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32 | convert(T const& x, mpl::false_)
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33 | {
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34 | return type_sequence_iterator<T>();
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35 | }
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36 | }
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37 |
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38 | template <typename T>
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39 | struct as_fusion_iterator
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40 | {
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41 | typedef typename
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42 | mpl::if_<
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43 | fusion::is_iterator<T>
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44 | , T
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45 | , type_sequence_iterator<T>
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46 | >::type
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47 | type;
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48 |
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49 | static typename
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50 | mpl::if_<
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51 | fusion::is_iterator<T>
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52 | , T const&
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53 | , type_sequence_iterator<T>
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54 | >::type
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55 | convert(T const& x);
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56 | };
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57 |
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58 | template <typename T>
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59 | typename
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60 | mpl::if_<
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61 | fusion::is_iterator<T>
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62 | , T const&
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63 | , type_sequence_iterator<T>
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64 | >::type
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65 | as_fusion_iterator<T>::convert(T const& x)
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66 | {
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67 | return as_fusion_iterator_detail::convert(x, fusion::is_iterator<T>());
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68 | }
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69 |
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70 | }}
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71 |
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72 | #endif
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