detail/preprocessor/void_list.hpp

0001
0002 // Copyright (C) 2009-2012 Lorenzo Caminiti
0003 // Distributed under the Boost Software License, Version 1.0
0004 // (see accompanying file LICENSE_1_0.txt or a copy at
0005 // http://www.boost.org/LICENSE_1_0.txt)
0006 // Home at http://www.boost.org/libs/local_function
0007
0008 #ifndef BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_HPP_
0009 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_HPP_
0010
0011 #include <boost/local_function/detail/preprocessor/keyword/void.hpp>
0012 #include <boost/config.hpp>
0013 #include <boost/preprocessor/cat.hpp>
0014 #include <boost/preprocessor/control/iif.hpp>
0015 #include <boost/preprocessor/comparison/equal.hpp>
0016 #include <boost/preprocessor/tuple/to_list.hpp>
0017 #include <boost/preprocessor/seq/size.hpp>
0018 #include <boost/preprocessor/seq/to_tuple.hpp>
0019
0020 // PRIVATE //
0021
0022 // Argument: (token1)...
0023 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_FROM_SEQ_(unused, seq) \
0024     BOOST_PP_TUPLE_TO_LIST(BOOST_PP_SEQ_SIZE(seq), BOOST_PP_SEQ_TO_TUPLE(seq))
0025
0026 // Token: void | token1
0027 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_HANDLE_VOID_( \
0028         is_void_macro, token) \
0029     BOOST_PP_IIF(is_void_macro(token), \
0030         BOOST_PP_NIL \
0031     , \
0032         (token, BOOST_PP_NIL) \
0033     )
0034
0035 // Token: (a)(b)... | empty | void | token
0036 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_HANDLE_SEQ_( \
0037         is_void_macro, token) \
0038     BOOST_PP_IIF(BOOST_PP_IS_UNARY(token), /* unary paren (a)... */ \
0039         BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_FROM_SEQ_ \
0040     , \
0041         BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_HANDLE_VOID_ \
0042     )(is_void_macro, token)
0043
0044 #ifdef BOOST_NO_CXX11_VARIADIC_MACROS
0045
0046 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_(is_void_macro, seq) \
0047     BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_HANDLE_SEQ_(is_void_macro, seq)
0048
0049 #else // VARIADICS
0050
0051 // FUTURE: Replace this with BOOST_PP_VARIADIC_SIZE when and if
0052 // BOOST_PP_VARIAIDCS detection will match !BOOST_NO_CXX11_VARIADIC_MACROS (for now
0053 // Boost.Preprocessor and Boost.Config disagree on detecting compiler variadic
0054 // support while this VARIADIC_SIZE works on compilers not detected by PP).
0055 #if BOOST_MSVC
0056 #   define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_VARIADIC_SIZE_(...) \
0057         BOOST_PP_CAT(BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_VARIADIC_SIZE_I_(__VA_ARGS__, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1,),)
0058 #else // MSVC
0059 #   define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_VARIADIC_SIZE_(...) \
0060         BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_VARIADIC_SIZE_I_(__VA_ARGS__, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1,)
0061 #endif // MSVC
0062 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_VARIADIC_SIZE_I_(e0, e1, e2, e3, e4, e5, e6, e7, e8, e9, e10, e11, e12, e13, e14, e15, e16, e17, e18, e19, e20, e21, e22, e23, e24, e25, e26, e27, e28, e29, e30, e31, e32, e33, e34, e35, e36, e37, e38, e39, e40, e41, e42, e43, e44, e45, e46, e47, e48, e49, e50, e51, e52, e53, e54, e55, e56, e57, e58, e59, e60, e61, e62, e63, size, ...) size
0063
0064 // Argument: token1, ...
0065 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_FROM_VARIADIC_(unused, ...) \
0066     BOOST_PP_TUPLE_TO_LIST( \
0067             BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_VARIADIC_SIZE_( \
0068                     __VA_ARGS__), (__VA_ARGS__))
0069
0070 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_(is_void_macro, ...) \
0071     BOOST_PP_IIF(BOOST_PP_EQUAL( \
0072             BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_VARIADIC_SIZE_( \
0073                     __VA_ARGS__), 1), \
0074         BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_HANDLE_SEQ_ \
0075     , \
0076         BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_FROM_VARIADIC_ \
0077     )(is_void_macro, __VA_ARGS__)
0078
0079 #endif // VARIADICS
0080
0081 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_NEVER_(tokens) \
0082     0 /* void check always returns false */
0083
0084 // PUBLIC //
0085
0086 // NOTE: Empty list must always be represented is void (which is also a way to
0087 // specify no function parameter) and it can never be empty because (1)
0088 // IS_EMPTY(&var) fails (because of the leading non alphanumeric symbol) and
0089 // (2) some compilers (MSVC) fail to correctly pass empty macro parameters
0090 // even if they support variadic macros. Therefore, always using void to
0091 // represent is more portable.
0092
0093 #ifdef BOOST_NO_CXX11_VARIADIC_MACROS
0094
0095 // Expand `void | (a)(b)...` to pp-list `NIL | (a, (b, NIL))`.
0096 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST(sign) \
0097     BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_( \
0098             BOOST_LOCAL_FUNCTION_DETAIL_PP_KEYWORD_IS_VOID_BACK, sign)
0099
0100 // Expand `(a)(b)...` to pp-list `(a, (b, NIL))`.
0101 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_NON_VOID_LIST(seq) \
0102     BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_( \
0103             BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_NEVER_, seq)
0104
0105 #else // VARIADICS
0106
0107 // Expand `void | (a)(b)... | a, b, ...` to pp-list `NIL | (a, (b, NIL))`.
0108 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST(...) \
0109     BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_( \
0110             BOOST_LOCAL_FUNCTION_DETAIL_PP_KEYWORD_IS_VOID_BACK, __VA_ARGS__)
0111
0112 // Expand `(a)(b)... | a, b, ...` to pp-list `(a, (b, NIL))`.
0113 #define BOOST_LOCAL_FUNCTION_DETAIL_PP_NON_VOID_LIST(...) \
0114     BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_( \
0115             BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST_NEVER_, __VA_ARGS__)
0116
0117 #endif // VARIADICS
0118
0119 #endif // #include guard
0120