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2 | #ifndef BOOST_MPL_INDEX_IF_HPP_INCLUDED |
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3 | #define BOOST_MPL_INDEX_IF_HPP_INCLUDED |
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4 | |
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5 | // Copyright Eric Friedman 2003 |
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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 | // $Source: /cvsroot/boost/boost/boost/mpl/index_if.hpp,v $ |
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14 | // $Date: 2004/09/02 15:40:41 $ |
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15 | // $Revision: 1.7 $ |
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16 | |
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17 | #include <boost/mpl/aux_/find_if_pred.hpp> |
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18 | #include <boost/mpl/begin_end.hpp> |
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19 | #include <boost/mpl/if.hpp> |
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20 | #include <boost/mpl/int.hpp> |
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21 | #include <boost/mpl/iter_fold_if.hpp> |
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22 | #include <boost/mpl/next.hpp> |
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23 | #include <boost/mpl/void.hpp> |
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24 | #include <boost/mpl/aux_/na_spec.hpp> |
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25 | #include <boost/mpl/aux_/lambda_support.hpp> |
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26 | #include <boost/type_traits/is_same.hpp> |
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27 | |
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28 | namespace boost { namespace mpl { |
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29 | |
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30 | template< |
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31 | typename BOOST_MPL_AUX_NA_PARAM(Sequence) |
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32 | , typename BOOST_MPL_AUX_NA_PARAM(Predicate) |
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33 | > |
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34 | struct index_if |
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35 | { |
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36 | typedef typename iter_fold_if< |
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37 | Sequence |
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38 | , int_<0> |
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39 | , next<> |
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40 | , aux::find_if_pred<Predicate> |
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41 | >::type result_; |
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42 | |
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43 | typedef typename end<Sequence>::type not_found_; |
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44 | typedef typename first<result_>::type result_index_; |
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45 | typedef typename second<result_>::type result_iterator_; |
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46 | |
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47 | typedef typename if_< |
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48 | is_same< result_iterator_,not_found_ > |
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49 | , void_ |
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50 | , result_index_ |
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51 | >::type type; |
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52 | |
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53 | BOOST_MPL_AUX_LAMBDA_SUPPORT(2,index_if,(Sequence,Predicate)) |
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54 | }; |
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55 | |
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56 | BOOST_MPL_AUX_NA_SPEC(2, index_if) |
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57 | |
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58 | }} |
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59 | |
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60 | #endif // BOOST_MPL_INDEX_IF_HPP_INCLUDED |
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