forked from boostorg/fusion
64 lines
1.8 KiB
C++
64 lines
1.8 KiB
C++
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/*=============================================================================
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Copyright (c) 2001-2006 Joel de Guzman
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Copyright (c) 2005-2006 Dan Marsden
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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(BOOST_FUSION_AT_IMPL_24122005_1807)
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#define BOOST_FUSION_AT_IMPL_24122005_1807
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#include <boost/fusion/support/detail/access.hpp>
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#include <boost/mpl/assert.hpp>
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#include <boost/mpl/int.hpp>
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namespace boost { namespace fusion
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{
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struct struct_tag;
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namespace extension
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{
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template<typename T>
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struct at_impl;
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template <typename Struct, int N>
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struct struct_member;
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template <typename Struct>
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struct struct_size;
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template <>
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struct at_impl<struct_tag>
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{
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template <typename Sequence, typename N>
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struct apply
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{
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static int const n_value = N::value;
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BOOST_MPL_ASSERT_RELATION(
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n_value, <=, extension::struct_size<Sequence>::value);
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typedef typename
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extension::struct_member<Sequence, N::value>
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element;
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typedef typename
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mpl::eval_if<
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is_const<Sequence>
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, detail::cref_result<element>
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, detail::ref_result<element>
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>::type
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type;
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static type
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call(Sequence& seq)
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{
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return extension::
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struct_member<Sequence, N::value>::call(seq);
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}
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};
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};
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}
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}}
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#endif
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