67 lines
1.9 KiB
Plaintext
67 lines
1.9 KiB
Plaintext
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/*=============================================================================
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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/fusion/support/config.hpp>
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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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BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
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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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