54 lines
1.4 KiB
C++
54 lines
1.4 KiB
C++
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// (C) Copyright Edward Diener 2015
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// Use, modification and distribution are subject to the Boost Software License,
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// Version 1.0. (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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#if !defined(BOOST_VMD_SEQ_PUSH_FRONT_HPP)
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#define BOOST_VMD_SEQ_PUSH_FRONT_HPP
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#include <boost/vmd/detail/setup.hpp>
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#if BOOST_PP_VARIADICS
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#include <boost/preprocessor/control/iif.hpp>
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#include <boost/preprocessor/seq/push_front.hpp>
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#include <boost/vmd/identity.hpp>
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#include <boost/vmd/is_empty.hpp>
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/*
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The succeeding comments in this file are in doxygen format.
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*/
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/** \file
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*/
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/** \def BOOST_VMD_SEQ_PUSH_FRONT(seq,elem)
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\brief inserts an element at the beginning of a seq.
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seq = seq to insert an element at.
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elem = element to insert.
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If the seq is an empty seq the result is a seq with the single element.
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Otherwise the result is a seq after inserting the element at the beginning.
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*/
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#define BOOST_VMD_SEQ_PUSH_FRONT(seq,elem) \
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BOOST_VMD_IDENTITY_RESULT \
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( \
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BOOST_PP_IIF \
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( \
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BOOST_VMD_IS_EMPTY(seq), \
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BOOST_VMD_IDENTITY((elem)), \
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BOOST_PP_SEQ_PUSH_FRONT \
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) \
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(seq,elem) \
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) \
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/**/
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#endif /* BOOST_PP_VARIADICS */
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#endif /* BOOST_VMD_SEQ_PUSH_FRONT_HPP */
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