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1 |
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2 #ifndef BOOST_MPL_DISTANCE_HPP_INCLUDED |
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3 #define BOOST_MPL_DISTANCE_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: distance.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/distance_fwd.hpp> |
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18 #include <boost/mpl/iter_fold.hpp> |
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19 #include <boost/mpl/iterator_range.hpp> |
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20 #include <boost/mpl/long.hpp> |
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21 #include <boost/mpl/next.hpp> |
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22 #include <boost/mpl/tag.hpp> |
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23 #include <boost/mpl/apply_wrap.hpp> |
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24 #include <boost/mpl/aux_/msvc_eti_base.hpp> |
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25 #include <boost/mpl/aux_/value_wknd.hpp> |
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26 #include <boost/mpl/aux_/na_spec.hpp> |
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27 #include <boost/mpl/aux_/config/forwarding.hpp> |
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28 #include <boost/mpl/aux_/config/static_constant.hpp> |
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29 |
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30 |
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31 namespace boost { namespace mpl { |
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32 |
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33 // default implementation for forward/bidirectional iterators |
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34 template< typename Tag > struct distance_impl |
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35 { |
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36 template< typename First, typename Last > struct apply |
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37 #if !defined(BOOST_MPL_CFG_NO_NESTED_FORWARDING) |
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38 : aux::msvc_eti_base< typename iter_fold< |
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39 iterator_range<First,Last> |
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40 , mpl::long_<0> |
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41 , next<> |
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42 >::type > |
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43 { |
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44 #else |
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45 { |
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46 typedef typename iter_fold< |
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47 iterator_range<First,Last> |
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48 , mpl::long_<0> |
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49 , next<> |
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50 >::type type; |
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51 |
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52 BOOST_STATIC_CONSTANT(long, value = |
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53 (iter_fold< |
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54 iterator_range<First,Last> |
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55 , mpl::long_<0> |
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56 , next<> |
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57 >::type::value) |
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58 ); |
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59 #endif |
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60 }; |
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61 }; |
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62 |
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63 template< |
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64 typename BOOST_MPL_AUX_NA_PARAM(First) |
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65 , typename BOOST_MPL_AUX_NA_PARAM(Last) |
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66 > |
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67 struct distance |
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68 : distance_impl< typename tag<First>::type > |
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69 ::template apply<First, Last> |
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70 { |
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71 BOOST_MPL_AUX_LAMBDA_SUPPORT(2, distance, (First, Last)) |
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72 }; |
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73 |
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74 BOOST_MPL_AUX_NA_SPEC(2, distance) |
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75 |
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76 }} |
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77 |
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78 #endif // BOOST_MPL_DISTANCE_HPP_INCLUDED |