77 lines
2.0 KiB
C++
77 lines
2.0 KiB
C++
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#ifndef BOOST_MPL_ADVANCE_HPP_INCLUDED
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#define BOOST_MPL_ADVANCE_HPP_INCLUDED
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// Copyright Aleksey Gurtovoy 2000-2004
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//
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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// See http://www.boost.org/libs/mpl for documentation.
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// $Id$
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// $Date$
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// $Revision$
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#include <boost/mpl/advance_fwd.hpp>
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#include <boost/mpl/less.hpp>
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#include <boost/mpl/negate.hpp>
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#include <boost/mpl/long.hpp>
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#include <boost/mpl/if.hpp>
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#include <boost/mpl/tag.hpp>
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#include <boost/mpl/apply_wrap.hpp>
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#include <boost/mpl/aux_/advance_forward.hpp>
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#include <boost/mpl/aux_/advance_backward.hpp>
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#include <boost/mpl/aux_/value_wknd.hpp>
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#include <boost/mpl/aux_/na_spec.hpp>
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#include <boost/mpl/aux_/nttp_decl.hpp>
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namespace boost { namespace mpl {
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// default implementation for forward/bidirectional iterators
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template< typename Tag >
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struct advance_impl
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{
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template< typename Iterator, typename N > struct apply
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{
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typedef typename less< N,long_<0> >::type backward_;
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typedef typename if_< backward_, negate<N>, N >::type offset_;
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typedef typename if_<
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backward_
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, aux::advance_backward< BOOST_MPL_AUX_VALUE_WKND(offset_)::value >
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, aux::advance_forward< BOOST_MPL_AUX_VALUE_WKND(offset_)::value >
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>::type f_;
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typedef typename apply_wrap1<f_,Iterator>::type type;
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};
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};
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template<
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typename BOOST_MPL_AUX_NA_PARAM(Iterator)
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, typename BOOST_MPL_AUX_NA_PARAM(N)
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>
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struct advance
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: advance_impl< typename tag<Iterator>::type >
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::template apply<Iterator,N>
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{
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};
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template<
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typename Iterator
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, BOOST_MPL_AUX_NTTP_DECL(long, N)
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>
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struct advance_c
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: advance_impl< typename tag<Iterator>::type >
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::template apply<Iterator,long_<N> >
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{
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};
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BOOST_MPL_AUX_NA_SPEC(2, advance)
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}}
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#endif // BOOST_MPL_ADVANCE_HPP_INCLUDED
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