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+
+// (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 <boost/vmd/detail/setup.hpp>
+
+#if BOOST_PP_VARIADICS
+
+#include <boost/preprocessor/control/iif.hpp>
+#include <boost/vmd/is_array.hpp>
+#include <boost/vmd/identity.hpp>
+#include <boost/vmd/detail/is_empty_array.hpp>
+
+/*
+
+ 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 */