vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/vmd/seq/pop_back.hpp

52 lines
1.3 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_SEQ_POP_BACK_HPP)
#define BOOST_VMD_SEQ_POP_BACK_HPP
#include <boost/vmd/detail/setup.hpp>
#if BOOST_PP_VARIADICS
#include <boost/preprocessor/comparison/equal.hpp>
#include <boost/preprocessor/control/iif.hpp>
#include <boost/preprocessor/seq/pop_back.hpp>
#include <boost/preprocessor/seq/size.hpp>
#include <boost/vmd/empty.hpp>
/*
The succeeding comments in this file are in doxygen format.
*/
/** \file
*/
/** \def BOOST_VMD_SEQ_POP_BACK(seq)
\brief pops an element from the end of a seq.
seq = seq to pop an element from.
If the seq is an empty seq the result is undefined.
If the seq is a single element the result is an empty seq.
Otherwise the result is a seq after removing the last element.
*/
#define BOOST_VMD_SEQ_POP_BACK(seq) \
BOOST_PP_IIF \
( \
BOOST_PP_EQUAL(BOOST_PP_SEQ_SIZE(seq),1), \
BOOST_VMD_EMPTY, \
BOOST_PP_SEQ_POP_BACK \
) \
(seq) \
/**/
#endif /* BOOST_PP_VARIADICS */
#endif /* BOOST_VMD_SEQ_POP_BACK_HPP */