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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_HPP)
+#define BOOST_VMD_IS_EMPTY_HPP
+
+#include <boost/vmd/detail/setup.hpp>
+
+#if BOOST_PP_VARIADICS
+
+#include <boost/preprocessor/punctuation/is_begin_parens.hpp>
+#include <boost/vmd/detail/is_empty.hpp>
+
+/*
+
+ The succeeding comments in this file are in doxygen format.
+
+*/
+
+/** \file
+*/
+
+/** \def BOOST_VMD_IS_EMPTY(...)
+
+ \brief Tests whether its input is empty or not.
+
+ The macro checks to see if the input is empty or not.
+ It returns 1 if the input is empty, else returns 0.
+
+ The macro is a variadic macro taking any input.
+ For the VC++8 compiler (VS2005) the macro takes a single parameter of input to check.
+
+ The macro is not perfect, and can not be so. The problem
+ area is if the input to be checked is a function-like
+ macro name, in which case either a compiler error can result
+ or a false result can occur.
+
+ This macro is a replacement, using variadic macro support,
+ for the undocumented macro BOOST_PP_IS_EMPTY in the Boost
+ PP library. The code is taken from a posting by Paul Mensonides
+ of a variadic version for BOOST_PP_IS_EMPTY, and changed
+ in order to also support VC++.
+
+ .... = variadic input, for VC++8 this must be a single parameter
+
+ returns = 1 if the input is empty, 0 if it is not
+
+ It is recommended to append BOOST_PP_EMPTY() to whatever input
+ is being tested in order to avoid possible warning messages
+ from some compilers about no parameters being passed to the macro
+ when the input is truly empty.
+
+*/
+
+#if BOOST_VMD_MSVC_V8
+
+#define BOOST_VMD_IS_EMPTY(sequence) \
+ BOOST_VMD_DETAIL_IS_EMPTY_IIF \
+ ( \
+ BOOST_PP_IS_BEGIN_PARENS \
+ ( \
+ sequence \
+ ) \
+ ) \
+ ( \
+ BOOST_VMD_DETAIL_IS_EMPTY_GEN_ZERO, \
+ BOOST_VMD_DETAIL_IS_EMPTY_PROCESS \
+ ) \
+ (sequence) \
+/**/
+
+#else
+
+#define BOOST_VMD_IS_EMPTY(...) \
+ BOOST_VMD_DETAIL_IS_EMPTY_IIF \
+ ( \
+ BOOST_PP_IS_BEGIN_PARENS \
+ ( \
+ __VA_ARGS__ \
+ ) \
+ ) \
+ ( \
+ BOOST_VMD_DETAIL_IS_EMPTY_GEN_ZERO, \
+ BOOST_VMD_DETAIL_IS_EMPTY_PROCESS \
+ ) \
+ (__VA_ARGS__) \
+/**/
+
+#endif /* BOOST_VMD_MSVC_V8 */
+
+#endif /* BOOST_PP_VARIADICS */
+#endif /* BOOST_VMD_IS_EMPTY_HPP */