1 | |
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2 | #ifndef BOOST_MPL_SEQUENCE_TAG_HPP_INCLUDED |
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3 | #define BOOST_MPL_SEQUENCE_TAG_HPP_INCLUDED |
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4 | |
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5 | // Copyright Aleksey Gurtovoy 2000-2004 |
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6 | // |
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7 | // Distributed under the Boost Software License, Version 1.0. |
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8 | // (See accompanying file LICENSE_1_0.txt or copy at |
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9 | // http://www.boost.org/LICENSE_1_0.txt) |
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10 | // |
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11 | // See http://www.boost.org/libs/mpl for documentation. |
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12 | |
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13 | // $Id: sequence_tag.hpp 49267 2008-10-11 06:19:02Z agurtovoy $ |
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14 | // $Date: 2008-10-11 02:19:02 -0400 (Sat, 11 Oct 2008) $ |
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15 | // $Revision: 49267 $ |
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16 | |
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17 | #include <boost/mpl/sequence_tag_fwd.hpp> |
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18 | #include <boost/mpl/aux_/has_tag.hpp> |
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19 | #include <boost/mpl/aux_/has_begin.hpp> |
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20 | #include <boost/mpl/aux_/na_spec.hpp> |
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21 | #include <boost/mpl/aux_/is_msvc_eti_arg.hpp> |
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22 | #include <boost/mpl/aux_/config/eti.hpp> |
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23 | #include <boost/mpl/aux_/yes_no.hpp> |
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24 | #include <boost/mpl/aux_/config/workaround.hpp> |
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25 | |
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26 | namespace boost { namespace mpl { |
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27 | |
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28 | // agurt, 27/nov/02: have to use a simplistic 'sequence_tag' implementation |
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29 | // on MSVC to avoid dreadful "internal structure overflow" error |
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30 | #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) \ |
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31 | || defined(BOOST_MPL_CFG_NO_HAS_XXX) |
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32 | |
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33 | template< |
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34 | typename BOOST_MPL_AUX_NA_PARAM(Sequence) |
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35 | > |
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36 | struct sequence_tag |
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37 | { |
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38 | typedef typename Sequence::tag type; |
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39 | }; |
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40 | |
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41 | #elif BOOST_WORKAROUND(BOOST_MSVC, == 1300) |
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42 | |
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43 | // agurt, 07/feb/03: workaround for what seems to be MSVC 7.0-specific ETI issue |
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44 | |
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45 | namespace aux { |
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46 | |
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47 | template< bool > |
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48 | struct sequence_tag_impl |
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49 | { |
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50 | template< typename Sequence > struct result_ |
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51 | { |
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52 | typedef typename Sequence::tag type; |
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53 | }; |
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54 | }; |
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55 | |
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56 | template<> |
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57 | struct sequence_tag_impl<false> |
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58 | { |
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59 | template< typename Sequence > struct result_ |
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60 | { |
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61 | typedef int type; |
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62 | }; |
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63 | }; |
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64 | |
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65 | } // namespace aux |
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66 | |
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67 | template< |
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68 | typename BOOST_MPL_AUX_NA_PARAM(Sequence) |
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69 | > |
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70 | struct sequence_tag |
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71 | : aux::sequence_tag_impl< !aux::is_msvc_eti_arg<Sequence>::value > |
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72 | ::template result_<Sequence> |
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73 | { |
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74 | }; |
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75 | |
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76 | #else |
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77 | |
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78 | namespace aux { |
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79 | |
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80 | template< bool has_tag_, bool has_begin_ > |
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81 | struct sequence_tag_impl |
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82 | { |
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83 | // agurt 24/nov/02: MSVC 6.5 gets confused in 'sequence_tag_impl<true>' |
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84 | // specialization below, if we name it 'result_' here |
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85 | template< typename Sequence > struct result2_; |
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86 | }; |
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87 | |
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88 | # define AUX_CLASS_SEQUENCE_TAG_SPEC(has_tag, has_begin, result_type) \ |
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89 | template<> struct sequence_tag_impl<has_tag,has_begin> \ |
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90 | { \ |
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91 | template< typename Sequence > struct result2_ \ |
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92 | { \ |
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93 | typedef result_type type; \ |
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94 | }; \ |
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95 | }; \ |
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96 | /**/ |
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97 | |
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98 | AUX_CLASS_SEQUENCE_TAG_SPEC(true, true, typename Sequence::tag) |
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99 | AUX_CLASS_SEQUENCE_TAG_SPEC(true, false, typename Sequence::tag) |
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100 | AUX_CLASS_SEQUENCE_TAG_SPEC(false, true, nested_begin_end_tag) |
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101 | AUX_CLASS_SEQUENCE_TAG_SPEC(false, false, non_sequence_tag) |
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102 | |
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103 | # undef AUX_CLASS_SEQUENCE_TAG_SPEC |
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104 | |
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105 | } // namespace aux |
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106 | |
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107 | template< |
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108 | typename BOOST_MPL_AUX_NA_PARAM(Sequence) |
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109 | > |
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110 | struct sequence_tag |
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111 | : aux::sequence_tag_impl< |
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112 | ::boost::mpl::aux::has_tag<Sequence>::value |
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113 | , ::boost::mpl::aux::has_begin<Sequence>::value |
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114 | >::template result2_<Sequence> |
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115 | { |
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116 | }; |
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117 | |
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118 | #endif // BOOST_MSVC |
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119 | |
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120 | BOOST_MPL_AUX_NA_SPEC(1, sequence_tag) |
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121 | |
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122 | }} |
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123 | |
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124 | #endif // BOOST_MPL_SEQUENCE_TAG_HPP_INCLUDED |
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