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| 2 | #ifndef BOOST_MPL_ADVANCE_HPP_INCLUDED |
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| 3 | #define BOOST_MPL_ADVANCE_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 | // $Source: /cvsroot/boost/boost/boost/mpl/advance.hpp,v $ |
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| 14 | // $Date: 2004/09/02 15:40:41 $ |
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| 15 | // $Revision: 1.9 $ |
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| 16 | |
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| 17 | #include <boost/mpl/advance_fwd.hpp> |
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| 18 | #include <boost/mpl/less.hpp> |
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| 19 | #include <boost/mpl/negate.hpp> |
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| 20 | #include <boost/mpl/long.hpp> |
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| 21 | #include <boost/mpl/if.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_/advance_forward.hpp> |
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| 25 | #include <boost/mpl/aux_/advance_backward.hpp> |
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| 26 | #include <boost/mpl/aux_/value_wknd.hpp> |
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| 27 | #include <boost/mpl/aux_/na_spec.hpp> |
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| 28 | #include <boost/mpl/aux_/nttp_decl.hpp> |
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| 29 | |
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| 30 | namespace boost { namespace mpl { |
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| 31 | |
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| 32 | // default implementation for forward/bidirectional iterators |
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| 33 | template< typename Tag > |
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| 34 | struct advance_impl |
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| 35 | { |
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| 36 | template< typename Iterator, typename N > struct apply |
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| 37 | { |
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| 38 | typedef typename less< N,long_<0> >::type backward_; |
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| 39 | typedef typename if_< backward_, negate<N>, N >::type offset_; |
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| 40 | |
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| 41 | typedef typename if_< |
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| 42 | backward_ |
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| 43 | , aux::advance_backward< BOOST_MPL_AUX_VALUE_WKND(offset_)::value > |
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| 44 | , aux::advance_forward< BOOST_MPL_AUX_VALUE_WKND(offset_)::value > |
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| 45 | >::type f_; |
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| 46 | |
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| 47 | typedef typename apply_wrap1<f_,Iterator>::type type; |
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| 48 | }; |
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| 49 | }; |
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| 50 | |
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| 51 | |
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| 52 | template< |
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| 53 | typename BOOST_MPL_AUX_NA_PARAM(Iterator) |
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| 54 | , typename BOOST_MPL_AUX_NA_PARAM(N) |
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| 55 | > |
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| 56 | struct advance |
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| 57 | : advance_impl< typename tag<Iterator>::type > |
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| 58 | ::template apply<Iterator,N> |
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| 59 | { |
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| 60 | }; |
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| 61 | |
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| 62 | template< |
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| 63 | typename Iterator |
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| 64 | , BOOST_MPL_AUX_NTTP_DECL(long, N) |
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| 65 | > |
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| 66 | struct advance_c |
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| 67 | : advance_impl< typename tag<Iterator>::type > |
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| 68 | ::template apply<Iterator,long_<N> > |
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| 69 | { |
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| 70 | }; |
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| 71 | |
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| 72 | BOOST_MPL_AUX_NA_SPEC(2, advance) |
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| 73 | |
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| 74 | }} |
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| 75 | |
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| 76 | #endif // BOOST_MPL_ADVANCE_HPP_INCLUDED |
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