54 lines
1.4 KiB
C++
54 lines
1.4 KiB
C++
|
|
// (C) Copyright Edward Diener 2015
|
|
// Use, modification and distribution are subject to the Boost Software License,
|
|
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
|
|
// http://www.boost.org/LICENSE_1_0.txt).
|
|
|
|
#if !defined(BOOST_VMD_TUPLE_PUSH_FRONT_HPP)
|
|
#define BOOST_VMD_TUPLE_PUSH_FRONT_HPP
|
|
|
|
#include <boost/vmd/detail/setup.hpp>
|
|
|
|
#if BOOST_PP_VARIADICS
|
|
|
|
#include <boost/preprocessor/control/iif.hpp>
|
|
#include <boost/preprocessor/tuple/push_front.hpp>
|
|
#include <boost/vmd/identity.hpp>
|
|
#include <boost/vmd/is_empty.hpp>
|
|
|
|
/*
|
|
|
|
The succeeding comments in this file are in doxygen format.
|
|
|
|
*/
|
|
|
|
/** \file
|
|
*/
|
|
|
|
/** \def BOOST_VMD_TUPLE_PUSH_FRONT(tuple,elem)
|
|
|
|
\brief inserts an element at the beginning of a tuple.
|
|
|
|
tuple = tuple to insert an element at.
|
|
elem = element to insert.
|
|
|
|
If the tuple is an empty tuple the result is a tuple with the single element.
|
|
Otherwise the result is a tuple after inserting the element at the beginning.
|
|
*/
|
|
|
|
#define BOOST_VMD_TUPLE_PUSH_FRONT(tuple,elem) \
|
|
BOOST_VMD_IDENTITY_RESULT \
|
|
( \
|
|
BOOST_PP_IIF \
|
|
( \
|
|
BOOST_VMD_IS_EMPTY(tuple), \
|
|
BOOST_VMD_IDENTITY((elem)), \
|
|
BOOST_PP_TUPLE_PUSH_FRONT \
|
|
) \
|
|
(tuple,elem) \
|
|
) \
|
|
/**/
|
|
|
|
#endif /* BOOST_PP_VARIADICS */
|
|
#endif /* BOOST_VMD_TUPLE_PUSH_FRONT_HPP */
|