Boost C++ Libraries

boost/vmd/seq/size.hpp

//  (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_SIZE_HPP)
#define BOOST_VMD_SEQ_SIZE_HPP

#include <boost/vmd/detail/setup.hpp>

#if BOOST_PP_VARIADICS

#include <boost/preprocessor/control/iif.hpp>
#include <boost/preprocessor/seq/size.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_SEQ_SIZE(seq)

    \brief  expands to the size of the seq passed to it. 

    seq = seq whose size is to be extracted. 
    
    If the seq is an empty seq its size is 0.
    Otherwise the result is the number of elements in the seq.
*/

#define BOOST_VMD_SEQ_SIZE(seq) \
    BOOST_VMD_IDENTITY_RESULT \
        ( \
        BOOST_PP_IIF \
            ( \
            BOOST_VMD_IS_EMPTY(seq), \
            BOOST_VMD_IDENTITY(0), \
            BOOST_PP_SEQ_SIZE \
            ) \
        (seq) \
        ) \
/**/

#endif /* BOOST_PP_VARIADICS */
#endif /* BOOST_VMD_SEQ_SIZE_HPP */