// (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_ARRAY_HPP) #define BOOST_VMD_IS_EMPTY_ARRAY_HPP #include #if BOOST_PP_VARIADICS #include #include #include #include /* The succeeding comments in this file are in doxygen format. */ /** \file */ /** \def BOOST_VMD_IS_EMPTY_ARRAY(sequence) \brief Tests whether a sequence is an empty Boost PP array. An empty Boost PP array is a two element tuple where the first size element is 0 and the second element is a tuple with a single empty element, ie. '(0,())'. sequence = a possible empty array returns = 1 if the sequence is an empty Boost PP array, 0 if it is not. The macro will generate a preprocessing error if the sequence is in the form of an array but its first tuple element, instead of being a number, is a preprocessor token which VMD cannot parse, as in the example '(&0,())' which is a valid tuple but an invalid array. */ #define BOOST_VMD_IS_EMPTY_ARRAY(sequence) \ BOOST_VMD_IDENTITY_RESULT \ ( \ BOOST_PP_IIF \ ( \ BOOST_VMD_IS_ARRAY(sequence), \ BOOST_VMD_DETAIL_IS_EMPTY_ARRAY_SIZE, \ BOOST_VMD_IDENTITY(0) \ ) \ (sequence) \ ) \ /**/ /** \def BOOST_VMD_IS_EMPTY_ARRAY_D(d,sequence) \brief Tests whether a sequence is an empty Boost PP array. Re-entrant version. An empty Boost PP array is a two element tuple where the first size element is 0 and the second element is a tuple with a single empty element, ie. '(0,())'. d = The next available BOOST_PP_WHILE iteration.
sequence = a possible empty array returns = 1 if the sequence is an empty Boost PP array, 0 if it is not. The macro will generate a preprocessing error if the sequence is in the form of an array but its first tuple element, instead of being a number, is a preprocessor token which VMD cannot parse, as in the example '(&0,())' which is a valid tuple but an invalid array. */ #define BOOST_VMD_IS_EMPTY_ARRAY_D(d,sequence) \ BOOST_VMD_IDENTITY_RESULT \ ( \ BOOST_PP_IIF \ ( \ BOOST_VMD_IS_ARRAY_D(d,sequence), \ BOOST_VMD_DETAIL_IS_EMPTY_ARRAY_SIZE, \ BOOST_VMD_IDENTITY(0) \ ) \ (sequence) \ ) \ /**/ #endif /* BOOST_PP_VARIADICS */ #endif /* BOOST_VMD_IS_EMPTY_ARRAY_HPP */