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64 lines
1.8 KiB
64 lines
1.8 KiB
/*============================================================================= |
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Copyright (c) 2001-2011 Joel de Guzman |
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Distributed under the Boost Software License, Version 1.0. (See accompanying |
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
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==============================================================================*/ |
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#if !defined(FUSION_DISTANCE_09172005_0730) |
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#define FUSION_DISTANCE_09172005_0730 |
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#include <boost/mpl/int.hpp> |
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#include <boost/mpl/if.hpp> |
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#include <boost/mpl/eval_if.hpp> |
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#include <boost/mpl/next.hpp> |
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#include <boost/mpl/identity.hpp> |
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#include <boost/fusion/iterator/next.hpp> |
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#include <boost/fusion/iterator/equal_to.hpp> |
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namespace boost { namespace fusion { namespace distance_detail |
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{ |
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// Default distance implementation, linear |
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// search for the Last iterator. |
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template <typename First, typename Last> |
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struct linear_distance; |
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template <typename First, typename Last> |
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struct next_distance |
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{ |
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typedef typename |
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mpl::next< |
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typename linear_distance< |
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typename result_of::next<First>::type |
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, Last |
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>::type |
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>::type |
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type; |
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}; |
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template <typename First, typename Last> |
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struct linear_distance |
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: mpl::eval_if< |
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result_of::equal_to<First, Last> |
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, mpl::identity<mpl::int_<0> > |
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, next_distance<First, Last> |
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>::type |
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{ |
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typedef typename |
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mpl::eval_if< |
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result_of::equal_to<First, Last> |
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, mpl::identity<mpl::int_<0> > |
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, next_distance<First, Last> |
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>::type |
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type; |
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static type |
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call(First const&, Last const&) |
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{ |
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return type(); |
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} |
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}; |
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}}} |
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#endif
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