47 lines
1.3 KiB
C++
47 lines
1.3 KiB
C++
//-----------------------------------------------------------------------------
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// boost mpl/aux_/at_impl.hpp header file
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// See http://www.boost.org for updates, documentation, and revision history.
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//-----------------------------------------------------------------------------
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//
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// Copyright (c) 2000-02
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// Aleksey Gurtovoy
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//
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// Distributed under the Boost Software License, Version 1.0. (See
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// 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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#ifndef BOOST_MPL_AUX_AT_IMPL_HPP_INCLUDED
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#define BOOST_MPL_AUX_AT_IMPL_HPP_INCLUDED
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#include "boost/mpl/begin_end.hpp"
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#include "boost/mpl/advance.hpp"
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#include "boost/mpl/aux_/deref_wknd.hpp"
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#include "boost/mpl/aux_/traits_lambda_spec.hpp"
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namespace boost {
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namespace mpl {
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// default implementation; conrete sequences might override it by
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// specializing either the |at_traits| or the primary |at| template
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template< typename Tag >
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struct at_traits
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{
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template< typename Sequence, typename N > struct algorithm
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{
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typedef typename advance<
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typename begin<Sequence>::type
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, N
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>::type iter_;
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typedef typename BOOST_MPL_AUX_DEREF_WNKD(iter_) type;
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};
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};
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BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(2,at_traits)
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} // namespace mpl
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} // namespace boost
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#endif // BOOST_MPL_AUX_AT_IMPL_HPP_INCLUDED
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