2 // (C) Copyright Edward Diener 2015
3 // Use, modification and distribution are subject to the Boost Software License,
4 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
5 // http://www.boost.org/LICENSE_1_0.txt).
7 #if !defined(BOOST_VMD_SEQ_PUSH_FRONT_HPP)
8 #define BOOST_VMD_SEQ_PUSH_FRONT_HPP
10 #include <boost/vmd/detail/setup.hpp>
12 #if BOOST_PP_VARIADICS
14 #include <boost/preprocessor/control/iif.hpp>
15 #include <boost/preprocessor/seq/push_front.hpp>
16 #include <boost/vmd/identity.hpp>
17 #include <boost/vmd/is_empty.hpp>
21 The succeeding comments in this file are in doxygen format.
28 /** \def BOOST_VMD_SEQ_PUSH_FRONT(seq,elem)
30 \brief inserts an element at the beginning of a seq.
32 seq = seq to insert an element at.
33 elem = element to insert.
35 If the seq is an empty seq the result is a seq with the single element.
36 Otherwise the result is a seq after inserting the element at the beginning.
39 #define BOOST_VMD_SEQ_PUSH_FRONT(seq,elem) \
40 BOOST_VMD_IDENTITY_RESULT \
44 BOOST_VMD_IS_EMPTY(seq), \
45 BOOST_VMD_IDENTITY((elem)), \
46 BOOST_PP_SEQ_PUSH_FRONT \
52 #endif /* BOOST_PP_VARIADICS */
53 #endif /* BOOST_VMD_SEQ_PUSH_FRONT_HPP */