forked from boostorg/mpl
89 lines
2.7 KiB
C++
89 lines
2.7 KiB
C++
//-----------------------------------------------------------------------------
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// boost mpl/aux_/begin_end_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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// Permission to use, copy, modify, distribute and sell this software
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// and its documentation for any purpose is hereby granted without fee,
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// provided that the above copyright notice appears in all copies and
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// that both the copyright notice and this permission notice appear in
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// supporting documentation. No representations are made about the
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// suitability of this software for any purpose. It is provided "as is"
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// without express or implied warranty.
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#ifndef BOOST_MPL_AUX_BEGIN_END_IMPL_HPP_INCLUDED
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#define BOOST_MPL_AUX_BEGIN_END_IMPL_HPP_INCLUDED
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#include "boost/mpl/begin_end_fwd.hpp"
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#include "boost/mpl/sequence_tag_fwd.hpp"
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#include "boost/mpl/void.hpp"
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#include "boost/mpl/aux_/traits_lambda_spec.hpp"
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#include "boost/mpl/aux_/config/eti.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 'begin_traits/end_traits' or the primary
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// 'begin/end' templates
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template< typename Tag >
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struct begin_traits
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{
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template< typename Sequence > struct algorithm
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{
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typedef typename Sequence::begin type;
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};
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};
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template< typename Tag >
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struct end_traits
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{
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template< typename Sequence > struct algorithm
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{
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typedef typename Sequence::end type;
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};
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};
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// specialize 'begin_trait/end_trait' for two pre-defined tags
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# define AUX_AGLORITM_TRAIT_SPEC(name, tag, result) \
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template<> \
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struct name##_traits<tag> \
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{ \
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template< typename Sequence > struct algorithm \
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{ \
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typedef result type; \
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}; \
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}; \
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/**/
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// a sequence with nested 'begin/end' typedefs; just query them
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AUX_AGLORITM_TRAIT_SPEC(begin, nested_begin_end_tag, typename Sequence::begin)
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AUX_AGLORITM_TRAIT_SPEC(end, nested_begin_end_tag, typename Sequence::end)
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// if a type 'T' does not contain 'begin/end' or 'tag' members
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// and doesn't specialize either 'begin/end' or 'begin_traits/end_traits'
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// templates, then we end up here
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AUX_AGLORITM_TRAIT_SPEC(begin, non_sequence_tag, void_)
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AUX_AGLORITM_TRAIT_SPEC(end, non_sequence_tag, void_)
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#if defined(BOOST_MPL_MSVC_ETI_BUG)
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AUX_AGLORITM_TRAIT_SPEC(begin, int, int)
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AUX_AGLORITM_TRAIT_SPEC(end, int, int)
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#endif
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# undef AUX_AGLORITM_TRAIT_SPEC
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BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(1,begin_traits)
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BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(1,end_traits)
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} // namespace mpl
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} // namespace boost
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#endif // BOOST_MPL_AUX_BEGIN_END_IMPL_HPP_INCLUDED
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