boost/vmd/is_empty_list.hpp

//  (C) Copyright Edward Diener 2011-2015
//  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_IS_EMPTY_LIST_HPP)
#define BOOST_VMD_IS_EMPTY_LIST_HPP
#include <boost/vmd/detail/setup.hpp>
#if BOOST_PP_VARIADICS
#include <boost/vmd/detail/is_list.hpp>
/*
  The succeeding comments in this file are in doxygen format.
*/
/** \file
*/
/** \def BOOST_VMD_IS_EMPTY_LIST(sequence)
    \brief Tests whether a sequence is an empty Boost PP list.
    An empty Boost PP list consists of the single identifier 'BOOST_PP_NIL'.
    This identifier also serves as a list terminator for a non-empty list.
    
    sequence = a preprocessor parameter
    returns = 1 if the sequence is an empty Boost PP list
              0 if it is not.
              
    The macro will generate a preprocessing error if the input
    as an empty list marker, instead of being an identifier, is 
    a preprocessor token which VMD cannot parse, as in the 
    example '&BOOST_PP_NIL'.
    
*/
#define BOOST_VMD_IS_EMPTY_LIST(sequence) \
    BOOST_VMD_DETAIL_IS_LIST_IS_EMPTY_LIST_PROCESS(sequence) \
/**/
/** \def BOOST_VMD_IS_EMPTY_LIST_D(d,sequence)
    \brief Tests whether a sequence is an empty Boost PP list. Re-entrant version.
    An empty Boost PP list consists of the single identifier 'BOOST_PP_NIL'.
    This identifier also serves as a list terminator for a non-empty list.
    
    d        = The next available BOOST_PP_WHILE iteration
    sequence = a preprocessor parameter
    returns = 1 if the sequence is an empty Boost PP list
              0 if it is not.
              
    The macro will generate a preprocessing error if the input
    as an empty list marker, instead of being an identifier, is 
    a preprocessor token which VMD cannot parse, as in the 
    example '&BOOST_PP_NIL'.
    
*/
#define BOOST_VMD_IS_EMPTY_LIST_D(d,sequence) \
    BOOST_VMD_DETAIL_IS_LIST_IS_EMPTY_LIST_PROCESS_D(d,sequence) \
/**/
#endif /* BOOST_PP_VARIADICS */
#endif /* BOOST_VMD_IS_EMPTY_LIST_HPP */