1 // Copyright 2008 Christophe Henry
2 // henry UNDERSCORE christophe AT hotmail DOT com
3 // This is an extended version of the state machine available in the boost::mpl library
4 // Distributed under the same license as the original.
5 // Copyright for the original version:
6 // Copyright 2005 David Abrahams and Aleksey Gurtovoy. Distributed
7 // under the Boost Software License, Version 1.0. (See accompanying
8 // file LICENSE_1_0.txt or copy at
9 // http://www.boost.org/LICENSE_1_0.txt)
10 
11 #ifndef BOOST_MSM_BACK_ARGS_H
12 #define BOOST_MSM_BACK_ARGS_H
13 
14 #include <boost/preprocessor/repetition/enum_params.hpp>
15 #include <boost/preprocessor/arithmetic/sub.hpp>
16 #include <boost/preprocessor/punctuation/comma_if.hpp>
17 #include <boost/preprocessor/control/expr_if.hpp>
18 #include <boost/preprocessor/punctuation/comma.hpp>
19 #include <boost/preprocessor/arithmetic/add.hpp>
20 #include <boost/preprocessor/cat.hpp>
21 #include <boost/preprocessor/comparison/less.hpp>
22 #include <boost/preprocessor/arithmetic/dec.hpp>
23 #include <boost/function.hpp>
24 
25 #ifndef BOOST_MSM_VISITOR_ARG_SIZE
26 #define BOOST_MSM_VISITOR_ARG_SIZE 2 // default max number of arguments
27 #endif
28 
29 namespace boost { namespace msm { namespace back
30 {
31 struct no_args {};
32 #define MSM_ARGS_TYPEDEF_SUB(z, n, unused) typedef ARG ## n argument ## n ;
33 #define MSM_ARGS_PRINT(z, n, data) data
34 #define MSM_ARGS_NONE_PRINT(z, n, data) class data ## n = no_args                          \
35     BOOST_PP_COMMA_IF( BOOST_PP_LESS(n, BOOST_PP_DEC(BOOST_MSM_VISITOR_ARG_SIZE) ) )
36 
37 #define MSM_VISITOR_MAIN_ARGS(n)                                                        \
38     template <class RES,                                                                \
39               BOOST_PP_REPEAT(BOOST_MSM_VISITOR_ARG_SIZE, MSM_ARGS_NONE_PRINT, ARG)>    \
40     struct args                                                                         \
41     {                                                                                   \
42         typedef ::boost::function<RES(BOOST_PP_ENUM_PARAMS(n, ARG))> type;              \
43         enum {args_number=n};                                                           \
44         BOOST_PP_REPEAT(n, MSM_ARGS_TYPEDEF_SUB, ~ )                                    \
45     };
46 
47 #define MSM_VISITOR_ARGS(z, n, unused)                                                              \
48     template <class RES BOOST_PP_COMMA_IF(n) BOOST_PP_ENUM_PARAMS(n, class ARG)>                    \
49     struct args<RES,                                                                                \
50                 BOOST_PP_ENUM_PARAMS(n,ARG)                                                         \
51                 BOOST_PP_COMMA_IF(n)                                                                \
52                 BOOST_PP_ENUM(BOOST_PP_SUB(BOOST_MSM_VISITOR_ARG_SIZE,n), MSM_ARGS_PRINT, no_args)     \
53                 >                                                                                   \
54     {                                                                                               \
55         typedef ::boost::function<RES(BOOST_PP_ENUM_PARAMS(n, ARG))> type;                          \
56         enum {args_number=n};                                                                       \
57         BOOST_PP_REPEAT(n, MSM_ARGS_TYPEDEF_SUB, ~ )                                                \
58     };
59 MSM_VISITOR_MAIN_ARGS(BOOST_MSM_VISITOR_ARG_SIZE)
60 BOOST_PP_REPEAT(BOOST_MSM_VISITOR_ARG_SIZE, MSM_VISITOR_ARGS, ~)
61 
62 #undef MSM_VISITOR_ARGS
63 #undef MSM_ARGS_PRINT
64 
65 }}}
66 
67 #endif //BOOST_MSM_BACK_ARGS_H
68 
69