1 # /* ************************************************************************** 2 # * * 3 # * (C) Copyright Edward Diener 2014,2019. 4 # * Distributed under the Boost Software License, Version 1.0. (See 5 # * accompanying file LICENSE_1_0.txt or copy at 6 # * http://www.boost.org/LICENSE_1_0.txt) 7 # * * 8 # ************************************************************************** */ 9 # 10 # /* See http://www.boost.org for most recent version. */ 11 # 12 # ifndef BOOST_PREPROCESSOR_FACILITIES_IS_EMPTY_VARIADIC_HPP 13 # define BOOST_PREPROCESSOR_FACILITIES_IS_EMPTY_VARIADIC_HPP 14 # 15 # include <boost/preprocessor/config/config.hpp> 16 # 17 # if BOOST_PP_VARIADICS 18 # 19 # include <boost/preprocessor/punctuation/is_begin_parens.hpp> 20 # include <boost/preprocessor/facilities/detail/is_empty.hpp> 21 # 22 #if BOOST_PP_VARIADICS_MSVC && _MSC_VER <= 1400 23 # 24 #define BOOST_PP_IS_EMPTY(param) \ 25 BOOST_PP_DETAIL_IS_EMPTY_IIF \ 26 ( \ 27 BOOST_PP_IS_BEGIN_PARENS \ 28 ( \ 29 param \ 30 ) \ 31 ) \ 32 ( \ 33 BOOST_PP_IS_EMPTY_ZERO, \ 34 BOOST_PP_DETAIL_IS_EMPTY_PROCESS \ 35 ) \ 36 (param) \ 37 /**/ 38 #define BOOST_PP_IS_EMPTY_ZERO(param) 0 39 # else 40 # if defined(__cplusplus) && __cplusplus > 201703L 41 # include <boost/preprocessor/variadic/has_opt.hpp> 42 #define BOOST_PP_IS_EMPTY(...) \ 43 BOOST_PP_DETAIL_IS_EMPTY_IIF \ 44 ( \ 45 BOOST_PP_VARIADIC_HAS_OPT() \ 46 ) \ 47 ( \ 48 BOOST_PP_IS_EMPTY_OPT, \ 49 BOOST_PP_IS_EMPTY_NO_OPT \ 50 ) \ 51 (__VA_ARGS__) \ 52 /**/ 53 #define BOOST_PP_IS_EMPTY_FUNCTION2(...) \ 54 __VA_OPT__(0,) 1 \ 55 /**/ 56 #define BOOST_PP_IS_EMPTY_FUNCTION(...) \ 57 BOOST_PP_IS_EMPTY_FUNCTION2(__VA_ARGS__) \ 58 /**/ 59 #define BOOST_PP_IS_EMPTY_OPT(...) \ 60 BOOST_PP_VARIADIC_HAS_OPT_ELEM0(BOOST_PP_IS_EMPTY_FUNCTION(__VA_ARGS__),) \ 61 /**/ 62 # else 63 #define BOOST_PP_IS_EMPTY(...) \ 64 BOOST_PP_IS_EMPTY_NO_OPT(__VA_ARGS__) \ 65 /**/ 66 # endif /* defined(__cplusplus) && __cplusplus > 201703L */ 67 #define BOOST_PP_IS_EMPTY_NO_OPT(...) \ 68 BOOST_PP_DETAIL_IS_EMPTY_IIF \ 69 ( \ 70 BOOST_PP_IS_BEGIN_PARENS \ 71 ( \ 72 __VA_ARGS__ \ 73 ) \ 74 ) \ 75 ( \ 76 BOOST_PP_IS_EMPTY_ZERO, \ 77 BOOST_PP_DETAIL_IS_EMPTY_PROCESS \ 78 ) \ 79 (__VA_ARGS__) \ 80 /**/ 81 #define BOOST_PP_IS_EMPTY_ZERO(...) 0 82 # endif /* BOOST_PP_VARIADICS_MSVC && _MSC_VER <= 1400 */ 83 # endif /* BOOST_PP_VARIADICS */ 84 # endif /* BOOST_PREPROCESSOR_FACILITIES_IS_EMPTY_VARIADIC_HPP */ 85