vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/vmd/tuple/pop_front.hpp

74 lines
2.0 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_POP_FRONT_HPP)
#define BOOST_VMD_TUPLE_POP_FRONT_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/tuple/pop_front.hpp>
#include <boost/preprocessor/tuple/size.hpp>
#include <boost/vmd/empty.hpp>
/*
The succeeding comments in this file are in doxygen format.
*/
/** \file
*/
/** \def BOOST_VMD_TUPLE_POP_FRONT(tuple)
\brief pops an element from the front of a tuple.
tuple = tuple to pop an element from.
If the tuple is an empty tuple the result is undefined.
If the tuple is a single element the result is an empty tuple.
Otherwise the result is a tuple after removing the first element.
*/
#define BOOST_VMD_TUPLE_POP_FRONT(tuple) \
BOOST_PP_IIF \
( \
BOOST_PP_EQUAL(BOOST_PP_TUPLE_SIZE(tuple),1), \
BOOST_VMD_EMPTY, \
BOOST_PP_TUPLE_POP_FRONT \
) \
(tuple) \
/**/
/** \def BOOST_VMD_TUPLE_POP_FRONT_Z(z,tuple)
\brief pops an element from the front of a tuple. It reenters BOOST_PP_REPEAT with maximum efficiency.
z = the next available BOOST_PP_REPEAT dimension.
tuple = tuple to pop an element from.
If the tuple is an empty tuple the result is undefined.
If the tuple is a single element the result is an empty tuple.
Otherwise the result is a tuple after removing the first element.
*/
#define BOOST_VMD_TUPLE_POP_FRONT_Z(z,tuple) \
BOOST_PP_IIF \
( \
BOOST_PP_EQUAL(BOOST_PP_TUPLE_SIZE(tuple),1), \
BOOST_VMD_EMPTY, \
BOOST_PP_TUPLE_POP_FRONT_Z \
) \
(z,tuple) \
/**/
#endif /* BOOST_PP_VARIADICS */
#endif /* BOOST_VMD_TUPLE_POP_FRONT_HPP */